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+The Project Gutenberg eBook of Animal intelligence, by Edward Lee
+Thorndike
+
+This eBook is for the use of anyone anywhere in the United States and
+most other parts of the world at no cost and with almost no restrictions
+whatsoever. You may copy it, give it away or re-use it under the terms
+of the Project Gutenberg License included with this eBook or online at
+www.gutenberg.org. If you are not located in the United States, you
+will have to check the laws of the country where you are located before
+using this eBook.
+
+Title: Animal intelligence
+       Experimental studies
+
+Author: Edward Lee Thorndike
+
+Release Date: January 29, 2023 [eBook #69904]
+
+Language: English
+
+Produced by: Emmanuel Ackerman, Kobus Meyer and the Online Distributed
+             Proofreading Team at https://www.pgdp.net (This file was
+             produced from images generously made available by The
+             Internet Archive)
+
+*** START OF THE PROJECT GUTENBERG EBOOK ANIMAL INTELLIGENCE ***
+
+
+
+
+
+
+ANIMAL INTELLIGENCE
+
+
+
+
+                              [Illustration]
+
+                          THE MACMILLAN COMPANY
+                       NEW YORK · BOSTON · CHICAGO
+                              SAN FRANCISCO
+
+                         MACMILLAN & CO., LIMITED
+                        LONDON · BOMBAY · CALCUTTA
+                                MELBOURNE
+
+                    THE MACMILLAN CO. OF CANADA, LTD.
+                                 TORONTO
+
+
+
+
+                           ANIMAL INTELLIGENCE
+
+                           EXPERIMENTAL STUDIES
+
+                                    BY
+                           EDWARD L. THORNDIKE
+                  TEACHERS COLLEGE, COLUMBIA UNIVERSITY
+
+                                 New York
+                          THE MACMILLAN COMPANY
+                                   1911
+
+                          _All rights reserved_
+
+                             COPYRIGHT, 1911,
+                        BY THE MACMILLAN COMPANY.
+
+              Set up and electrotyped. Published June, 1911.
+
+                              Norwood Press
+                  J. S. Cushing Co.—Berwick & Smith Co.
+                          Norwood, Mass., U.S.A.
+
+
+
+
+PREFACE
+
+
+The main purpose of this volume is to make accessible to students of
+psychology and biology the author’s experimental studies of animal
+intellect and behavior.[1] These studies have, I am informed by teachers
+of comparative psychology, a twofold interest. Since they represent the
+first deliberate and extended application of the experimental method in
+animal psychology, they are a useful introduction to the later literature
+of that subject. They mark the change from books of general argumentation
+on the basis of common experience interpreted in terms of the faculty
+psychology, to monographs reporting detailed and often highly technical
+experiments interpreted in terms of original and acquired connections
+between situation and response. Since they represent the point of view
+and the method of present animal psychology, but in the case of very
+general and simple problems, they are useful also as readings for
+students who need a general acquaintance with some sample of experimental
+work in this field.
+
+It has seemed best to leave the texts unaltered except for the correction
+of typographical errors, renumbering of tables and figures, and redrawing
+the latter. In a few places, where the original text has been found
+likely to be misunderstood, brief notes have been added. It is hard
+to resist the impulse to temper the style, especially of the ‘Animal
+Intelligence,’ with a certain sobriety and restraint. What one writes
+at the age of twenty-three is likely to irritate oneself a dozen years
+later, as it doubtless irritated others at the time. The charitable
+reader may allay his irritation by the thought that a degree of
+exuberance, even of arrogance, is proper to youth.
+
+To the reports of experimental studies are added two new essays dealing
+with the general laws of human and animal learning.
+
+    JANUARY, 1911.
+
+
+
+
+CONTENTS
+
+
+                                                                      PAGE
+
+  THE STUDY OF CONSCIOUSNESS AND THE STUDY OF BEHAVIOR                   1
+
+  ANIMAL INTELLIGENCE                                                   20
+
+      Introduction                                                      20
+
+      Description of Apparatus                                          29
+
+      Experiments with Cats                                             35
+
+      Experiments with Dogs                                             56
+
+      Experiments with Chicks                                           61
+
+      Reasoning or Inference                                            67
+
+      Imitation                                                         76
+
+          In Chicks                                                     81
+
+          In Cats                                                       85
+
+          In Dogs                                                       92
+
+      The Mental Fact in Association                                    98
+
+      Association by Similarity and the Formation of Concepts          116
+
+      Criticism of Previous Theories                                   125
+
+      Delicacy of Association                                          128
+
+      Complexity of Associations                                       132
+
+      Number of Associations                                           135
+
+      Permanence of Associations                                       138
+
+      Inhibition of Instincts by Habit                                 142
+
+      Attention                                                        144
+
+      The Social Consciousness of Animals                              146
+
+      Interaction                                                      147
+
+      Applications to Pedagogy, Anthropology, etc.                     149
+
+      Conclusion                                                       153
+
+  THE INSTINCTIVE REACTIONS OF YOUNG CHICKS                            156
+
+  A NOTE ON THE PSYCHOLOGY OF FISHES                                   169
+
+  THE MENTAL LIFE OF THE MONKEYS                                       172
+
+      Introduction                                                     173
+
+      Apparatus                                                        177
+
+      Learning without Tuition                                         182
+
+          Tests with Mechanisms                                        184
+
+          Tests with Signals                                           195
+
+      Experiments on the Influence of Tuition                          209
+
+          Introduction                                                 209
+
+          Imitation of Human Beings                                    211
+
+          Imitation of Other Monkeys                                   219
+
+          Learning apart from Motor Impulses                           222
+
+      General Mental Development of the Monkeys                        236
+
+  LAWS AND HYPOTHESES OF BEHAVIOR                                      241
+
+  THE EVOLUTION OF THE HUMAN INTELLECT                                 282
+
+
+
+
+ANIMAL INTELLIGENCE
+
+
+
+
+CHAPTER I
+
+THE STUDY OF CONSCIOUSNESS AND THE STUDY OF BEHAVIOR
+
+
+The statements about human nature made by psychologists are of two
+sorts,—statements about _consciousness_, about the inner life of
+thought and feeling, the ‘self as conscious,’ the ‘stream of thought’;
+and statements about _behavior_, about the life of man that is left
+unexplained by physics, chemistry, anatomy and physiology, and is roughly
+compassed for common sense by the terms ‘intellect’ and ‘character.’
+
+Animal psychology shows the same double content. Some statements concern
+the conscious states of the animal, what he is to himself as an inner
+life; others concern his original and acquired ways of response, his
+behavior, what he is to an outside observer.
+
+Of the psychological terms in common use, some refer only to conscious
+states, and some refer to behavior regardless of the consciousness
+accompanying it; but the majority are ambiguous, referring to the man or
+animal in question, at times in his aspect of inner life, at times in his
+aspect of reacting organism, and at times as an undefined total nature.
+Thus ‘intensity,’ ‘duration’ and ‘quality’ of sensations, ‘transitive’
+and ‘substantive’ states and ‘imagery’ almost inevitably refer to states
+of consciousness. ‘Imitation,’ ‘invention’ and ‘practice’ almost
+inevitably refer to behavior observed from the outside. ‘Perception,’
+‘attention,’ ‘memory,’ ‘abstraction,’ ‘reasoning’ and ‘will’ are samples
+of the many terms which illustrate both ways of studying human and animal
+minds. That an animal perceives an object, say, the sun, may mean either
+that his mental stream includes an awareness of that object distinguished
+from the rest of the visual field; or that he reacts to that object as a
+unit. ‘Attention’ may mean a clearness, focalness, of the mental state;
+or an exclusiveness and devotion of the total behavior. It may, that
+is, be illustrated by the sharpness of objects illumined by a shaft of
+light, or by the behavior of a cat toward the bird it stalks. ‘Memory’
+may be consciousness of certain objects, events or facts; or may be
+the permanence of certain tendencies in either thought or action. ‘To
+recognize’ may be to feel a certain familiarity and surety of being able
+to progress to certain judgments about the thing recognized; or may be to
+respond to it in certain accustomed and appropriate ways. ‘Abstraction’
+may refer to ideas of qualities apart from any consciousness of their
+concrete accompaniments, and to the power of having such ideas; or to
+responses to qualities irrespective of their concrete accompaniments,
+and to the power of making such responses. ‘Reasoning’ may be said
+to be present when certain sorts of consciousness, or when certain
+sorts of behavior, are present. An account of ‘the will’ is an account
+of consciousness as related to action or an account of the actions
+themselves.
+
+Not only in psychological judgments and psychological terms, but also
+in the work of individual psychologists, this twofold content is seen.
+Amongst writers in this country, for example, Titchener has busied
+himself almost exclusively with consciousness ‘as such’; Stanley Hall,
+with behavior; and James, with both. In England Stout, Galton and Lloyd
+Morgan have represented the same division and union of interests.
+
+On the whole, the psychological work of the last quarter of the
+nineteenth century emphasized the study of consciousness to the
+neglect of the total life of intellect and character. There was a
+tendency to an unwise, if not bigoted, attempt to make the science
+of human nature synonymous with the science of facts revealed by
+introspection. It was, for example, pretended that the only value of all
+the measurements of reaction-times was as a means to insight into the
+reaction-consciousness,—that the measurements of the amount of objective
+difference in the length, brightness or weight of two objects that men
+could judge with an assigned degree of correctness were of value only so
+far as they allowed one to infer something about the difference between
+two corresponding consciousnesses. It was affirmed that experimental
+methods were not to aid the experimenter to know what the subject did,
+but to aid the subject to know what he experienced.
+
+The restriction of studies of human intellect and character to studies
+of conscious states was not without influence on scientific studies
+of animal psychology. For one thing, it probably delayed them. So
+long as introspection was lauded as the chief method of psychology, a
+psychologist would tend to expect too little from mere studies, from the
+outside, of creatures who could not report their inner experiences to
+him in the manner to which he was accustomed. In the literature of the
+time will be found many comments on the extreme difficulty of studying
+the psychology of animals and children. But difficulty exists only in the
+case of their _consciousness_. Their _behavior_, by its simpler nature
+and causation, is often far easier to study than that of adults. Again,
+much time was spent in argumentation about the criteria of consciousness,
+that is, about what certain common facts of behavior meant in reference
+to inner experience. The problems of inference about consciousness
+from behavior distracted attention from the problems of learning more
+about behavior itself. Finally, when psychologists began to observe
+and experiment upon animal behavior, they tended to overestimate the
+resulting insight into the stream of the animal’s thought and to neglect
+the direct facts about what he did and how he did it.
+
+Such observations and experiments are, however, themselves a means of
+restoring a proper division of attention between consciousness and
+behavior. A psychologist may think of himself as chiefly a stream of
+consciousness. He may even think of other men as chiefly conscious
+selves whose histories they report by word and deed. But it is only by
+an extreme bigotry that he can think of a dog or cat as chiefly a stream
+or chain or series of consciousness or consciousnesses. One of the lower
+animals is so obviously a bundle of original and acquired connections
+between situation and response that the student is led to attend to the
+whole series,—situation, response and connection or bond,—rather than
+to just the conscious state that may or may not be one of the features
+of the bond. It is so useful, in understanding the animal, to see what
+it does in different circumstances and what helps and what hinders its
+learning, that one is led to an intrinsic interest in varieties of
+behavior as well as in the kinds of consciousness of which they give
+evidence.
+
+What each open-minded student of animal psychology at first hand comes
+thus to feel vaguely, I propose in this essay to try to make definite
+and clear. The studies reprinted in this volume produced in their
+author an increased respect for psychology as the science of behavior, a
+willingness to make psychology continuous with physiology, and a surety
+that to study consciousness for the sake of inferring what a man can or
+will do, is as proper as to study behavior for the sake of inferring what
+conscious states he can or will have. This essay will attempt to defend
+these positions and to show further that psychology may be, at least in
+part, as independent of introspection as physics is.
+
+A psychologist who wishes to broaden the content of the science to
+include all that biology includes under the term ‘behavior,’ or all that
+common sense means by the words ‘intellect’ and ‘character,’ has to meet
+certain objections. The first is the indefiniteness of this content.
+
+The indefiniteness is a fact, but is not in itself objectionable. It is
+true that by an animal’s behavior one means the facts about the animal
+that are left over after geometry, physics, chemistry, anatomy and
+physiology have taken their toll, and that are not already well looked
+after by sociology, economics, history, esthetics and other sciences
+dealing with certain complex and specialized facts of behavior. It is
+true that the boundaries of psychology, from physiology on the one hand,
+and from sociology, economics and the like on the other, become dubious
+and changeable. But this is in general a sign of a healthy condition
+in a science. The pretense that there is an impassable cleft between
+physiology and psychology should arouse suspicion that one or the other
+science is studying words rather than realities.
+
+The same holds against the objection that, if psychology is the science
+of behavior, it will be swallowed up by biology. When a body of facts
+treated subjectively, vaguely and without quantitative precision by one
+science or group of scientists comes to be treated more objectively,
+definitely and exactly by another, it is of course a gain, a symptom
+of the general advance of science. That geology may become a part of
+physics, or physiology a part of chemistry, is testimony to the advance
+of geology and physiology. Light is no less worthy of study by being
+found to be explainable by laws discovered in the study of electricity.
+Meteorology had to reach a relatively high development to provoke the wit
+to say that “All the science in meteorology is physics, the rest is wind.”
+
+These objections to be significant should frankly assert that between
+physical facts and mental facts, between bodies and minds, between any
+and all of the animal’s movements and its states of consciousness,
+there is an impassable gap, a real discontinuity, found nowhere else in
+science; and that by making psychology responsible for territory on both
+sides of the gap, one makes psychology include two totally disparate
+groups of facts, things and thoughts, requiring totally different methods
+of study. This is, of course, the traditional view of the scope of
+psychology, reiterated in the introductions to the standard books and
+often accepted in theory as axiomatic.
+
+It has, however, already been noted that in practice psychologists do
+study facts in disregard of this supposed gap, that the same term refers
+to facts belonging some on one side of it and some on the other, and
+that, in animal psychology, it seems very unprofitable to try to keep
+on one side or the other. Moreover, the practice to which the study of
+animal and child psychology leads is, if I understand their writings,
+justified as a matter of theory by Dewey and Santayana. If then, as a
+matter of scientific fact, human and animal behavior, with or without
+consciousness, seems a suitable subject for a scientific student, we may
+study it without a too uneasy sense of philosophic heresy and guilt.
+
+The writer must confess not only to the absence of any special reverence
+for the supposed axiom, but also to the presence of a conviction that it
+is false, the truth being that whatever feature of any animal, say John
+Smith, of _Homo sapiens_, is studied—its length, its color of hair, its
+body temperature, its toothache, its anxiety, or its thinking of 9 ×
+7—the attitude and methods of the student may properly be substantially
+the same.
+
+Of the six facts in the illustration just given, the last three would by
+the traditional view be all much alike for study, and all much unlike any
+of the first three. The same kind of science, physical science, would be
+potent for the first three and impotent for the last three (save to give
+facts about certain physical facts which ‘paralleled’ them). Conversely
+one kind of science, psychology, would by the traditional view deal with
+the last three, but have nothing to say about the first three.
+
+But is there in actual fact any such radical dichotomy of these six facts
+as objects of science? Take any task of science with respect to them, for
+example, identification. A score of scientific men, including John Smith
+himself, are asked to identify John’s stature at a given moment. Each
+observes it carefully, getting, let us say, as measures: 72.10 inches,
+72.11, 72.05, 72.08, 72.09, 72.11, etc.
+
+In the case of color of hair each observes as before, the reports being
+brown, light brown, brown, light brown, between light brown and brown,
+and so forth.
+
+In the case of body temperature, again, each observes as before, there
+being the same variability in the reports; but John _may also observe
+in a second way_, not by observing a thermometer with eyes, but by
+observing the temperature of his body through other sense-organs so
+situated that they lead to knowledge of only his own body’s temperature.
+It is important to note that for efficient knowledge of his own
+body-temperature, John does not use the sense approach peculiar to him,
+but that available for all observers. He identifies and measures his
+‘feverishness’ by studying himself as he would study any other animal, by
+thermometer and eye.
+
+In the case of the toothache the students proceed as before, except
+that they use John’s gestures, facial expression, cries and verbal
+reports, as well as his mere bodily structure and condition. They not
+only observe the cavities in his teeth, the signs of ulcer and the like,
+but they also ask him, tapping a tooth, “Does it hurt?” “How long has
+it hurt?” “Does it hurt very much?” and the like. John, if their equal
+in knowledge of dentistry, would use the same methods, testing himself,
+asking himself questions and using the replies made by himself to himself
+in inner speech. But, as with temperature, he would get data, for his
+identification of the toothache, from a source unavailable for the
+others, the sense-organs in his teeth.
+
+It is worth while to consider how they and he would proceed to an exact
+identification or measure of the intensity of his toothache such as was
+made of his stature or body-temperature. First, they would need a scale
+of toothaches of varying intensities. Next, they would need means of
+comparing the intensity of his toothache with those of this scale to see
+which it was most like. Given this scale and means of comparison, they
+would turn John’s attention from the original toothache to one of given
+intensity, and compare the two, both by his facial expression, gestures
+and the like, and by the verbal reports made. John would do likewise,
+reporting to himself instead of to them. The similarity of the procedure
+to that in studying a so-called physical fact is still clearer if we
+suppose a primitive condition of the scales of length and temperature.
+Suppose for example that for the length of a man we had only ‘short’ or
+‘tall as a deer,’ ‘medium’ or ‘tall as a moose,’ and ‘tall’ or ‘tall
+as a horse’; and for the intensity of the toothache of a man ‘little’
+or ‘intense as a pin-prick,’ ‘medium’ or ‘intense as a knife-cut,’
+and ‘great’ or ‘intense as a spear-thrust.’ Then obviously the only
+difference between the identification of the length of a man’s body and
+the identification of the intensity of his toothache would be that the
+latter was made by all on the basis of behavior as well as anatomy, and
+made by the individual having it on the basis of data from an additional
+sense-organ.
+
+In actual present practice, if observers were asked to identify the
+intensity of John’s toothache on a scale running from zero intensity
+up, the variability of the reports would be very great in comparison
+with those of stature or body-temperature. Supposing the most intense
+toothache to be called _K_, we might well have reports of from say .300
+_K_ to .450 _K_, some observers identifying the fact with a condition
+one and a half times as intense as that chosen by others. But such a
+variability might also occur in primitive men’s judgments of length or
+temperature.
+
+It is important to note that the accuracy of John’s own identification
+of it depends in any case on his knowledge of the scale and his power of
+comparing his toothache therewith. Well-trained outside observers might
+identify the intensity of John’s toothache more accurately than he could.
+
+In the case of John’s anxiety, the most striking fact is the low degree
+of accuracy in identification. The quality of the anxiety and its
+intensity would both be so crudely measured by present means that even if
+the observers were from the score of most competent psychologists, their
+reports would probably be not much better than, say, the descriptions
+now found in masterpieces of fiction and drama. Science could not
+tell at all closely how much John’s anxiety at this particular time
+resembled either his anxiety on some other occasion or anything else.
+This inferiority is due in part to the fact that the manifestations
+of anxiety in behavior, including verbal reports, are so complicated
+by facts other than the anxiety itself, by, for example, the animal’s
+health, temperament, concomitant ideas and emotions, knowledge of
+language, clearness in expression and the like. It is due in part to
+the very low status of our classification of kinds of anxieties and
+of our units and scales for measuring the amount of each kind. Hence
+the variation amongst observers would be even greater than in the case
+of the toothache, and the confidence of all in their judgments would
+be less, and far, far less than their confidence in their judgment of
+John’s stature. The best possible present knowledge of John’s anxiety,
+though scientific in comparison with ordinary opinion about it, would
+seem grossly unscientific in comparison with knowledge of his stature or
+weight. Knowledge of the anxiety would improve with better knowledge of
+its manifestations, including verbal reports by John, and with better
+means of classification and measurement.
+
+John’s knowledge of his own anxiety would be in part the same as that of
+the other observers. He too would judge his condition by its external
+manifestations, would name its sort and rate its amount on the basis of
+his own behavior, as he saw his own face, heard his own groans, and read
+the notes he wrote describing his condition. But he would also, as with
+the toothache, have data from internal sense-organs and perhaps from
+centrally initiated neural actions. In so far as he could report these
+data to himself for use in scientific thought more efficiently than he
+could report them to the other observers, he would have, as with the
+toothache, an advantage comparable to the advantage of a criminologist
+who happened also to be or to have been a thief, or of a literary critic
+who happened to have written what he judged. It is important to note that
+only in so far as he who has ‘immediate experience’ of or participates
+in or is ‘directly conscious’ of the anxiety, reports it to himself as
+thinker or scientific student, in common with the other nineteen, that
+this advantage accrues. To really _be_ or _have_ the anxiety is not to
+correctly _know_ it. An insane man must become sane in order to know
+his insane condition. Bigotry, stupidity and false reasoning can be
+understood only by one who never was them or has ceased to be them.
+
+In our last illustration, John’s thinking of ‘9 × 7 equals 63,’ the
+effect on John’s behavior may be so complicated by other conditions
+in John, and is so subject to the particular conditions which we name
+John’s ‘will,’ that the observers would often be at loss except for
+John’s verbal report. Not that the observer is restricted to that. If
+John does the example 217 × 69 in the usual way, it is a very safe
+inference that he thought 9 × 7 equals 63, regardless of the absence of a
+verbal report from him. But often there is little else to go by. To John
+himself, on the contrary, it is easier to be sure that he is thinking
+of 9 × 7 equals 63, than that he has a particular sort and strength of
+toothache. Consequently if we suppose John to be thinking of that fact
+while under observation, and the twenty observers to be required to
+identify the fact he is thinking of, it is sure that there might be an
+enormous variability in their guesses as to what the fact was and that
+his testimony might be worth far more than that of all the other nineteen
+without his testimony. His observation is influenced by the action of
+the neurones in his central nervous system as theirs is not, and, in the
+case of the thought ‘9 × 7 equals 63,’ the action of these neurones is of
+special importance.
+
+Our examination of the way science treats these six facts shows no
+impassable cleft between knowledge of a man’s body and knowledge of his
+mind. Scientific statements about the toothache, anxiety and numerical
+judgment are in general more variable than statements about length,
+hair-color and body-temperature, but there is here no difference save of
+degree. Some physical facts, such as hair-color, eye-color or health,
+are, in fact, judged more variably than some mental facts, such as rate
+of adding, accuracy of perception of a certain sort and the like. So
+far as the lack of agreement amongst impartial observers goes, there is
+continuity from the identification of a length to that of an ideal.
+
+Scientific judgments about the facts of John’s mind also depend, in
+general, more upon his verbal reports than do judgments about his body.
+But here also the difference is only of degree. The physician studying
+wounds, ulcers, tumors, infections and other facts of a man’s body
+may depend more upon his verbal reports than does the moralist who is
+studying the man’s character. Verbal reports too are themselves a gradual
+and continuous extension of coarser forms of behavior. They signify
+consciousness no more truly than do signs, gestures, facial expression
+and the general bodily motions of pursuit, retreat, avoidance or seizure.
+
+Nor is it true that physical facts are known to many observers and mental
+facts to but one, who _is_ or _has_ or _directly experiences_ them. If it
+were true, sociology, economics, history, anthropology and the like would
+either be physical sciences or represent no knowledge at all. The kind of
+knowledge of which these sciences and the common judgments of our fellow
+men are made up is knowledge possessed by many observers in common, the
+individual of whom the facts is known, knowing the fact in part in just
+the same way that the others know it.
+
+The real difference between a man’s scientific judgments about himself
+and the judgment of others about him is that he has _added sources of
+knowledge_. Much of what goes on in him influences him in ways other
+than those in which it influences other men. But this difference is not
+coterminous with that between judgments about his ‘mind’ and about his
+‘body.’ As was pointed out in the case of body-temperature, a man knows
+certain facts about his own body in such additional ways.
+
+Furthermore, there is no more truth in the statement that a man’s
+pain or anxiety or opinions are matters of direct consciousness, pure
+experience, than in the statement that his length, weight and temperature
+are, or that the sun, moon and stars are. If by the pain we must mean
+the pain as felt by some one, then by the sun we can mean only the sun
+as seen by some one. Pain and sun are equally subjects for a science of
+‘consciousness as such.’ But if by the sun is meant the sun of common
+sense, physics and astronomy, the sun as known by any one, then by the
+pain we can mean the pain of medicine, economics and sociology, the pain
+as known by any one, and by the sufferer long after he _was_ or _had_ it.
+
+All facts emerge from the matrix of pure experience; but they become
+facts for science only after they have emerged therefrom. A man’s anxiety
+may be the anxiety as directly felt by the man, or as thought of by him,
+or as thought of by the general consensus of scientific observers. But
+so also may be his body-temperature or weight or the composition of the
+blood in his veins. There can be no valid reason other than a pragmatic
+one for studying a man’s anxiety solely as _felt_ by him while studying
+his body-temperature as _thought of_ by him and others. And the practical
+reasons are all in favor of studying all facts as they exist for any
+impartial observer. A man’s mind as it is to thinking men is all that
+thinking men can deal with and all that they have any interest in dealing
+with.
+
+Finally, the subject-matter of psychology is not sharply marked off from
+the subject-matter of physiology by being absolutely non-spatial. On the
+contrary, the toothache, anxiety and judgment are referred unequivocally,
+by every sane man who thinks of them, to the space occupied by the body
+of the individual in question. That is the surest fact about them.
+It is true that we do not measure the length, height, thickness and
+weight of an animal’s pain or anxiety, but neither do we those of his
+pulse, temperature, health, digestion, metabolism, patellar reflex or
+heliotropism.
+
+Two noteworthy advantages are secured by the study of behavior. First,
+the evidence about intellect and character offered by action and the
+influence of intellect and character upon action are given due attention.
+Second, the connections of conscious states are studied as well as their
+composition.
+
+The mind or soul of the older psychology was the cause not only of
+consciousness, but also of modifiability in thought and action. It was
+the substance or force in man whereby he was sensitive to certain
+events, was able to make certain movements, and not only had ideas but
+connected them one with another and with various impressions and acts.
+It was supposed to account for actual bodily action as well as for the
+action-consciousness. It explained the connections between ideas as well
+as their internal composition. If a modern psychologist defines mind
+as the sum total of consciousness, and lives up to that definition, he
+omits the larger portion of the task of his predecessors. To define our
+subject-matter as the nature and behavior of men, beginning where anatomy
+and physiology leave off, is, on the contrary, to deliberately assume
+responsibility for the entire heritage. Behavior includes consciousness
+_and_ action, states of mind _and_ their connections.
+
+Even students devoted to ‘consciousness as such’ must admit that the
+movements of an animal and their connections with other features of
+his life deserve study, by even their kind of psychologist. For the
+fundamental means of knowing that an animal has a certain conscious
+state are knowledge that it makes certain movements and knowledge of
+what conscious states are connected with those movements. Knowledge of
+the action-system of an animal and its connections is a prerequisite to
+knowledge of its stream of consciousness.
+
+There are better reasons for including the action-system of an animal in
+the psychologist’s subject-matter. An animal’s conscious stream is of
+no account to the rest of the world except in so far as it prophesies
+or modifies his action.[2] There can be no moral warrant for studying
+man’s nature unless the study will enable us to control his acts. If
+a psychologist is to study man’s consciousness without relation to
+movement, he might as well fabricate imaginary consciousnesses to
+describe and analyze. The lovers of consciousness for its own sake often
+do this unwittingly, but would scarcely take pride therein!
+
+The truth of the matter is, of course, that an animal’s mind is, by any
+definition, something intimately associated with his connection-system
+or means of binding various physical activities to various physical
+impressions. The whole series—external situations and motor responses as
+well as their bonds—must be studied to some extent in order to understand
+whatever we define as mind. The student of behavior, by frankly accepting
+the task of supplying any needed information not furnished by physiology,
+and of studying the animal in action as well as in thought, is surer of
+getting an adequate knowledge of whatever features of an animal’s life
+may be finally awarded the title of mind.
+
+The second advantage in studying total behavior rather than consciousness
+as such is that thereby the connections of mental facts one with another
+and with non-mental facts receive due attention.
+
+The original tendencies to connect certain thoughts, feelings and acts
+with certain situations—tendencies which we call reflexes, instincts
+and capacities—are not themselves states of consciousness; nor are
+the acquired connections which we call habits, associations of ideas,
+tendencies to attend, select and the like. No state of consciousness
+bears within itself an account of when and how it will appear, or of
+what bodily act will be its sequel. What any given person will think in
+any given situation is unpredictable by mere descriptions and analyses
+of his previous thoughts each by itself. To understand the _when_, _how_
+and _why_ of states of consciousness one must study other facts than
+states of consciousness. These non-conscious relations or connections,
+knowledge of which informs us of the result to come from the action of a
+given situation on a given animal, may be expected to be fully half of
+the subject-matter of mental science.
+
+As was noted in the early pages of this chapter, the psychologist
+commonly does adopt the attitude of treating mind as a system of
+connections long enough to give some account of the facts of instinct,
+habit, memory, and the like. But the dogma that psychology deals
+exclusively with the inner stream of mind-stuff has made these accounts
+needlessly scanty and vague.
+
+One may appreciate fully the importance of finding out whether the
+attention-consciousness is clearness or is something else, and whether
+it exists in two or three discrete degrees or in a continuous series of
+gradations, and still insist upon the equal importance of finding out
+to what facts and for what reasons human beings do attend. There would
+appear, for example, to be an unfortunate limitation to the study of
+human nature by the examination of its consciousnesses, when two eminent
+psychologists, writing elaborate accounts of attention from that point of
+view, tell us almost nothing whereby we can predict what any given animal
+will attend to in any given situation, or can cause in any given animal a
+state of attention to any given fact.
+
+One may enjoy the effort to define the kind of mind-stuff in which one
+thinks of classes of facts, relations between facts and judgments about
+facts, and still protest that a proper balance in the study of intellect
+demands equal or greater attention to the problems of why any given
+animal thinks of any given fact, class or relation in any given situation
+and why he makes this or that judgment about it.
+
+In the case of the so-called action-consciousness the neglect of
+the connections becomes preposterous. The adventitious scraps of
+consciousness called ‘willing’ which may intervene between a situation
+productive of a given act and the act itself are hopelessly uninstructive
+in comparison with the bonds of instinct and habit which cause the
+situation to produce the act. In conduct, at least, that kind of
+psychology which Santayana calls ‘the perception of character’ seems an
+inevitable part of a well-balanced science of human nature. I quote from
+his fine description of the contrast between the external observation
+of a mind’s connections and the introspective recapitulation of its
+conscious content, though it is perhaps too pronounced and too severe.
+
+“_Perception of Character._—There is, however, a wholly different and
+far more positive method of reading the mind, or what in a metaphorical
+sense is called by that name. This method is to read character. Any
+object with which we are familiar teaches us to divine its habits; slight
+indications, which we should be at a loss to enumerate separately,
+betray what changes are going on and what promptings are simmering in
+the organism.... The gift of reading character ... is directed not upon
+consciousness but upon past or eventual action. Habits and passions,
+however, have metaphorical psychic names, names indicating dispositions
+rather than particular acts (a disposition being mythically represented
+as a sort of wakeful and haunting genius waiting to whisper suggestions
+in a man’s ear). We may accordingly delude ourselves into imagining that
+a pose or a manner which really indicates habit indicates feeling instead.
+
+“_Conduct Divined, Consciousness Ignored._... As the weather prophet
+reads the heavens, so the man of experience reads other men. Nothing
+concerns him less than their consciousness; he can allow that to run
+itself off when he is sure of their temper and habits. A great master of
+affairs is usually unsympathetic. His observation is not in the least
+dramatic or dreamful, he does not yield himself to animal contagion
+or reënact other people’s inward experience. He is too busy for that,
+and too intent on his own purposes. His observation, on the contrary,
+is straight calculation and inference, and it sometimes reaches truths
+about people’s character and destiny which they themselves are very far
+from divining. Such apprehension is masterful and odious to weaklings,
+who think they know themselves because they indulge in copious soliloquy
+(which is the discourse of brutes and madmen), but who really know
+nothing of their own capacity, situation, or fate.”[3]
+
+Mr. Santayana elsewhere hints that both psychology and history will
+become studies of human behavior considered from without,—a part, that
+is, of what he calls physics,—if they are to amount to much.
+
+Such a prediction may come true. But for the present there is no need
+to decide which is better—to study an animal’s self as conscious, its
+stream of direct experience, or to study the intellectual and moral
+nature that causes its behavior in thought and action and is known to
+many observers. Since worthy men have studied both, both are probably
+worthy of study. All that I wish to claim is the right of a man of
+science to study an animal’s intellectual and moral behavior, following
+wherever the facts lead—to “the sum total of human experience considered
+as dependent upon the experiencing person,” to the self as conscious, or
+to a connection-system known to many observers and born and bred in the
+animal’s body.
+
+
+
+
+CHAPTER II
+
+ANIMAL INTELLIGENCE; AN EXPERIMENTAL STUDY OF THE ASSOCIATIVE PROCESSES
+IN ANIMALS[4]
+
+
+This monograph is an attempt at an explanation of the nature of the
+process of association in the animal mind. Inasmuch as there have been no
+extended researches of a character similar to the present one either in
+subject-matter or experimental method, it is necessary to explain briefly
+its standpoint.
+
+Our knowledge of the mental life of animals equals in the main our
+knowledge of their sense-powers, of their instincts or reactions
+performed without experience, and of their reactions which are built up
+by experience. Confining our attention to the latter, we find it the
+opinion of the better observers and analysts that these reactions can
+all be explained by the ordinary associative processes without aid from
+abstract, conceptual, inferential thinking. These associative processes
+then, as present in animals’ minds and as displayed in their acts, are
+my subject-matter. Any one familiar in even a general way with the
+literature of comparative psychology will recall that this part of the
+field has received faulty and unsuccessful treatment. The careful, minute
+and solid knowledge of the sense-organs of animals finds no counterpart
+in the realm of associations and habits. We do not know how delicate
+or how complex or how permanent are the possible associations of any
+given group of animals. And although one would be rash who said that our
+present equipment of facts about instincts was sufficient or that our
+theories about it were surely sound, yet our notion of what occurs when a
+chick grabs a worm are luminous and infallible compared to our notion of
+what happens when a kitten runs into the house at the familiar call. The
+reason that they have satisfied us as well as they have is just that they
+are so vague. We say that the kitten associates the sound ‘kitty kitty’
+with the experience of nice milk to drink, which does very well for a
+common-sense answer. It also suffices as a rebuke to those who would
+have the kitten ratiocinate about the matter, but it fails to tell what
+real mental content is present. Does the kitten feel “_sound of call,
+memory-image of milk in a saucer in the kitchen, thought of running into
+the house, a feeling, finally, of ‘I will run in’_”? Does he perhaps feel
+only the sound of the bell and an impulse to run in, similar in quality
+to the impulses which make a tennis player run to and fro when playing?
+The word ‘association’ may cover a multitude of essentially different
+processes, and when a writer attributes anything that an animal may do
+to association, his statement has only the negative value of eliminating
+reasoning on the one hand and instinct on the other. His position is like
+that of a zoölogist who should to-day class an animal among the ‘worms.’
+To give to the word a positive value and several definite possibilities
+of meaning is one aim of this investigation.
+
+The importance to comparative psychology in general of a more scientific
+account of the association-process in animals is evident. Apart from the
+desirability of knowing all the facts we can, of whatever sort, there
+is the especial consideration that these associations and consequent
+habits have an immediate import for biological science. In the higher
+animals the bodily life and preservative acts are largely directed by
+these associations. They, and not instinct, make the animal use the
+best feeding grounds, sleep in the same lair, avoid new dangers and
+profit by new changes in nature. Their higher development in mammals
+is a chief factor in the supremacy of that group. This, however, is a
+minor consideration. The main purpose of the study of the animal mind
+is to learn the development of mental life down through the phylum,
+to trace in particular the origin of human faculty. In relation to
+this chief purpose of comparative psychology the associative processes
+assume a rôle predominant over that of sense-powers or instinct, for in
+a study of the associative processes lies the solution of the problem.
+Sense-powers and instincts have changed by addition and supersedence,
+but the cognitive side of consciousness has changed not only in quantity
+but also in quality. Somehow out of these associative processes have
+arisen human consciousnesses with their sciences and arts and religions.
+The association of ideas proper, imagination, memory, abstraction,
+generalization, judgment, inference, have here their source. And in the
+metamorphosis the instincts, impulses, emotions and sense-impressions
+have been transformed out of their old natures. For the origin and
+development of human faculty we must look to these processes of
+association in lower animals. Not only then does this department need
+treatment more, but promises to repay the worker better.
+
+Although no work done in this field is enough like the present
+investigation to require an account of its results, the _method_
+hitherto in use invites comparison by its contrast and, as I believe,
+by its faults. In the first place, most of the books do not give us a
+psychology, but rather a _eulogy_, of animals. They have all been about
+animal _intelligence_, never about animal _stupidity_. Though a writer
+derides the notion that animals have reason, he hastens to add that
+they have marvelous capacity of forming associations, and is likely to
+refer to the fact that human beings only rarely reason anything out,
+that their trains of ideas are ruled mostly by association, as if, in
+this latter, animals were on a par with them. The history of books on
+animals’ minds thus furnishes an illustration of the well-nigh universal
+tendency in human nature to find the marvelous wherever it can. We wonder
+that the stars are so big and so far apart, that the microbes are so
+small and so thick together, and for much the same reason wonder at the
+things animals do. They used to be wonderful because of the mysterious,
+God-given faculty of instinct, which could almost remove mountains. More
+lately they have been wondered at because of their marvelous mental
+powers in profiting by experience. Now imagine an astronomer tremendously
+eager to prove the stars as big as possible, or a bacteriologist whose
+great scientific desire is to demonstrate the microbes to be very, very
+little! Yet there has been a similar eagerness on the part of many
+recent writers on animal psychology to praise the abilities of animals.
+It cannot help leading to partiality in deductions from facts and more
+especially in the choice of facts for investigation. How can scientists
+who write like lawyers, defending animals against the charge of having no
+power of rationality, be at the same time impartial judges on the bench?
+Unfortunately the real work in this field has been done in this spirit.
+The level-headed thinkers who might have won valuable results have
+contented themselves with arguing against the theories of the eulogists.
+They have not made investigations of their own.
+
+In the second place, the facts have generally been derived from
+anecdotes. Now quite apart from such pedantry as insists that a man’s
+word about a scientific fact is worthless unless he is a trained
+scientist, there are really in this field special objections to the
+acceptance of the testimony about animals’ intelligent acts which
+one gets from anecdotes. Such testimony is by no means on a par with
+testimony about the size of a fish or the migration of birds, etc. For
+here one has to deal not merely with ignorant or inaccurate testimony,
+but also with prejudiced testimony. Human folk are as a matter of fact
+eager to find intelligence in animals. They like to. And when the animal
+observed is a pet belonging to them or their friends, or when the story
+is one that has been told as a story to entertain, further complications
+are introduced. Nor is this all. Besides commonly misstating what
+facts they report, they report only such facts as show the animal at
+his best. Dogs get lost hundreds of times and no one ever notices it
+or sends an account of it to a scientific magazine. But let one find
+his way from Brooklyn to Yonkers and the fact immediately becomes a
+circulating anecdote. Thousands of cats on thousands of occasions sit
+helplessly yowling, and no one takes thought of it or writes to his
+friend, the professor; but let one cat claw at the knob of a door
+supposedly as a signal to be let out, and straightway this cat becomes
+the representative of the cat-mind in all the books. The unconscious
+distortion of the facts is almost harmless compared to the unconscious
+neglect of an animal’s mental life until it verges on the unusual and
+marvelous. It is as if some denizen of a planet where communication
+was by thought-transference, who was surveying humankind and reporting
+their psychology, should be oblivious to all our intercommunication
+save such as the psychical-research society has noted. If he should
+further misinterpret the cases of mere coincidence of thoughts as facts
+comparable to telepathic communication, he would not be more wrong than
+some of the animal psychologists. In short, the anecdotes give really the
+_abnormal_ or _supernormal_ psychology of animals.
+
+Further, it must be confessed that these vices have been only
+ameliorated, not obliterated, when the observation is first-hand, is
+made by the psychologist himself. For as men of the utmost scientific
+skill have failed to prove good observers in the field of spiritualistic
+phenomena,[5] so biologists and psychologists before the pet terrier or
+hunted fox often become like Samson shorn. They, too, have looked for the
+intelligent and unusual and neglected the stupid and normal.
+
+Finally, in all cases, whether of direct observation or report by good
+observers or bad, there have been three other defects. Only a single
+case is studied, and so the results are not necessarily true of the
+type; the observation is not repeated, nor are the conditions perfectly
+regulated; the previous history of the animal in question is not known.
+Such observations may tell us, if the observer is perfectly reliable,
+that a certain thing takes place; but they cannot assure us that it will
+take place universally among the animals of that species, or universally
+with the same animal. Nor can the influence of previous experience be
+estimated. All this refers to means of getting knowledge about what
+animals _do_. The next question is, “What do they _feel_?” Previous work
+has not furnished an answer or the material for an answer to this more
+important question. Nothing but carefully designed, crucial experiments
+can. In abandoning the old method one ought to seek above all to replace
+it by one which will not only tell more accurately _what they do_, and
+give the much-needed information _how they do it_, but also inform us
+_what they feel_ while they act.
+
+To remedy these defects, experiment must be substituted for observation
+and the collection of anecdotes. Thus you immediately get rid of several
+of them. You can repeat the conditions at will, so as to see whether
+or not the animal’s behavior is due to mere coincidence. A number of
+animals can be subjected to the same test, so as to attain typical
+results. The animal may be put in situations where its conduct is
+especially instructive. After considerable preliminary observation of
+animals’ behavior under various conditions, I chose for my general method
+one which, simple as it is, possesses several other marked advantages
+besides those which accompany experiment of any sort. It was merely to
+put animals when hungry in inclosures from which they could escape by
+some simple act, such as pulling at a loop of cord, pressing a lever,
+or stepping on a platform. (A detailed description of these boxes and
+pens will be given later.) The animal was put in the inclosure, food was
+left outside in sight, and his actions observed. Besides recording his
+general behavior, special notice was taken of how he succeeded in doing
+the necessary act (in case he did succeed), and a record was kept of the
+time that he was in the box before performing the successful pull, or
+clawing, or bite. This was repeated until the animal had formed a perfect
+association between the sense-impression of the interior of that box and
+the impulse leading to the successful movement. When the association
+was thus perfect, the time taken to escape was, of course, practically
+constant and very short.
+
+If, on the other hand, after a certain time the animal did not succeed,
+he was taken out, but _not fed_. If, after a sufficient number of
+trials, he failed to get out, the case was recorded as one of complete
+failure. Enough different sorts of methods of escape were tried to
+make it fairly sure that association in general, not association of a
+particular sort of impulse, was being studied. Enough animals were taken
+with each box or pen to make it sure that the results were not due to
+individual peculiarities. None of the animals used had any previous
+acquaintance with any of the mechanical contrivances by which the doors
+were opened. So far as possible the animals were kept in a uniform state
+of hunger, which was practically utter hunger.[6] That is, no cat or dog
+was experimented on, when the experiment involved any important question
+of fact or theory, unless I was sure that his motive was of the standard
+strength. With chicks this is not practicable, on account of their
+delicacy. But with them dislike of loneliness acts as a uniform motive to
+get back to the other chicks. Cats (or rather kittens), dogs and chicks
+were the subjects of the experiments. All were apparently in excellent
+health, save an occasional chick.
+
+By this method of experimentation the animals are put in situations which
+call into activity their mental functions and permit them to be carefully
+observed. One may, by following it, observe personally more intelligent
+acts than are included in any anecdotal collection. And this actual
+vision of animals in the act of using their minds is far more fruitful
+than any amount of history of what animals have done without the history
+of how they did it. But besides affording this opportunity for purposeful
+and systematic observation, our method is valuable because it frees the
+animal from any influence of the observer. The animal’s behavior is
+quite independent of any factors save its own hunger, the mechanism of
+the box it is in, the food outside, and such general matters as fatigue,
+indisposition, etc. Therefore the work done by one investigator may be
+repeated and verified or modified by another. No personal factor is
+present save in the observation and interpretation. Again, our method
+gives some very important results which are quite uninfluenced by
+_any_ personal factor in any way. The curves showing the progress of
+the formation of associations, which are obtained from the records of
+the times taken by the animal in successive trials, are facts which
+may be obtained by any observer who can tell time. They are absolute,
+and whatever can be deduced from them is sure. So also the question of
+whether an animal does or does not form a certain association requires
+for an answer no higher qualification in the observer than a pair of
+eyes. The literature of animal psychology shows so uniformly and often so
+sadly the influence of the personal equation that any method which can
+partially eliminate it deserves a trial.
+
+Furthermore, although the associations formed are such as could not
+have been previously experienced or provided for by heredity, they are
+still not too remote from the animal’s ordinary course of life. They
+mean simply the connection of a certain act with a certain situation
+and resultant pleasure, and this general type of association is found
+throughout the animal’s life normally. The muscular movements required
+are all such as might often be required of the animal. And yet it will
+be noted that the acts required are nearly enough like the acts of the
+anecdotes to enable one to compare the results of experiment by this
+method with the work of the anecdote school. Finally, it may be noticed
+that the method lends itself readily to experiments on imitation.
+
+We may now start in with the description of the apparatus and of the
+behavior of the animals.[7]
+
+
+DESCRIPTION OF APPARATUS
+
+[Illustration: FIG. 1.]
+
+The shape and general apparatus of the boxes which were used for the cats
+is shown by the accompanying drawing of box K. Unless special figures
+are given, it should be understood that each box is approximately 20
+inches long, by 15 broad, by 12 high. Except where mention is made to
+the contrary, the door was pulled open by a weight attached to a string
+which ran over a pulley and was fastened to the door, just as soon as
+the animal loosened the bolt or bar which held it. Especial care was
+taken not to have the widest openings between the bars at all near the
+lever, or wire loop, or what not, which governed the bolt on the door.
+For the animal instinctively attacks the large openings first, and if
+the mechanism which governs the opening of the door is situated near one
+of them, the animal’s task is rendered easier. You do not then get the
+association-process so free from the helping hand of instinct as you do
+if you make the box without reference to the position of the mechanism to
+be set up within it. These various mechanisms are so simple that a verbal
+description will suffice in most cases. The facts which the reader should
+note are the nature of the movement which the cat had to make, the nature
+of the object at which the movement was directed, and the position of the
+object in the box. In some special cases attention will also be called
+to the force required. In general, however, that was very slight (20 to
+100 grams if applied directly). The various boxes will be designated by
+capital letters.
+
+A. A string attached to the bolt which held the door ran up over a pulley
+on the front edge of the box, and was tied to a wire loop (2½ inches
+in diameter) hanging 6 inches above the floor in front center of box.
+Clawing or biting it, or rubbing against it even, if in a certain way,
+opened the door. We may call this box A ‘_O at front_.’
+
+B. A string attached to the bolt ran up over a pulley on the front edge
+of the door, then across the box to another pulley screwed into the
+inside of the back of the box 1¼ inches below the top, and passing over
+it ended in a wire loop (3 inches in diameter) 6 inches above the floor
+in back center of box. Force applied to the loop or _to the string_ as it
+ran across the top of the box between two bars would open the door. We
+may call B ‘_O at back_.’
+
+B1. In B1 the string ran outside the box, coming down through a hole at
+the back, and was therefore inaccessible and invisible from within. Only
+by pulling the loop could the door be opened. B1 may be called ‘_O at
+back 2d_.’
+
+C. A door of the usual position and size (as in Fig. 1) was kept closed
+by a wooden button 3½ inches long, ⅞ inch wide, ½ inch thick. This turned
+on a nail driven into the box ½ inch above the middle of the top edge of
+the door. The door would fall inward as soon as the button was turned
+from its vertical to a horizontal position. A pull of 125 grams would
+do this if applied sideways at the lowest point of the button 2¼ inches
+below its pivot. The cats usually clawed the button round by downward
+pressure on its top edge, which was 1¼ inches above the nail. Then, of
+course, more force was necessary. C may be called ‘_Button_.’
+
+D. The door was in the extreme right of the front. A string fastened to
+the bolt which held it ran up over a pulley on the top edge and back to
+the top edge of the back side of the box (3 inches in from the right
+side) and was there firmly fastened. The top of the box was of wire
+screening and arched over the string ¾ inch above it along its entire
+length. A slight pull on the string anywhere opened the door. This box
+was 20 × 16, but a space 7 × 16 was partitioned off at the left by a wire
+screen. D may be called ‘_String_.’
+
+D1 was the same box as B, but had the string fastened firmly at the back
+instead of running over a pulley and ending in a wire loop. We may call
+it ‘_String 2d_.’
+
+E. A string ran from the bolt holding the door up over a pulley and down
+to the floor outside the box, where it was fastened 2 inches in front of
+the box and 1½ inches to the left of the door (looking from the inside).
+By poking a paw out between the bars and pulling this string inward the
+door would be opened. We may call E ‘_String outside_.’
+
+In F the string was not fastened to the floor but ended in a loop 2½
+inches in diameter which could be clawed down so as to open the door.
+Unless the pull was in just the right direction, the string was likely
+to catch on the pulley. This loop hung 3 inches above the floor, and 1¾
+inches in front of the box. We may call F ‘_String outside unfastened_.’
+
+G was a box 29 × 20½ × 22½, with a door 29 × 12 hinged on the left side
+of the box (looking from within), and kept closed by an ordinary thumb
+latch placed 15 inches from the floor. The remainder of the front of the
+box was closed in by wooden bars. The door was a wooden frame covered
+with screening. It was _not_ arranged so as to open as soon as the latch
+was lifted, but required a force of 400 grams, even when applied to the
+best advantage. The bar of the thumb latch, moreover, would fall back
+into place again unless the door were pushed out at least a little. The
+top of this box was not of bars or screening, but solid. We may call G
+‘_Thumb latch_.’
+
+H was, except for the opening where the door was situated, a perfectly
+solid and dark box. In the front was cut an opening about 9 × 7 inches.
+A wooden frame covered with wire netting hung in front of this. It was
+fastened to the box only by a screw through the middle of the frame’s
+top piece, and could therefore be pushed to either side so as to permit
+escape from the box if it were prevented from swinging back into place.
+
+I was a box 12 × 14 × 23. The door was 8 inches wide, 4 high, and hinged
+at the left side. It was held closed by a wooden bar which moved easily
+on a pivot and which could be pushed up by another bar which projected
+5 inches into the box. This second bar was pivoted so that downward
+pressure on it pushed the first bar up and let the door swing open. The
+second bar entered the box at a point 4 inches above the floor and 2½
+inches in from the right side of the box. In its normal position its
+inner end was 5½ inches above the floor. A depression of 2 inches at that
+end was necessary to open the door. Of course, nearer the pivot a shorter
+depression would do. The front of the box was closed by bars, but the
+rest by solid boards. We may call I ‘_Lever_.’
+
+J was the same as B except that the door was not opened by a weight as
+soon as the bolt was pulled up. On the contrary, the door was held closed
+by a small piece of board (4 × 3½ × ¾ thick) placed against it outside.
+After pulling the loop at the back the cat had to knock down this support
+and push the door open. We may call J ‘_Double_.’
+
+K was a box arranged so that three separate acts were required to open
+the door, which was held by two bolts at the top and two bars outside.
+One of the bolts was connected with a platform in the back center of the
+box so that depressing the platform raised the bolt. The other was raised
+by a string which ran up over a pulley in the front, across the box 1
+inch above the bars, over a pulley near the corner of the box, and down
+to the floor, where it was fastened. Pulling on this string, either by
+clawing at it where it was running vertically from the last pulley to the
+floor, or by putting the paw out between the bars which covered the top
+of the box, and clawing the string downward, would raise the bolt. If
+both bolts were raised and _either_ bar was pushed up or down far enough
+to be out of the way, the cat could escape. K, or ‘_Triple_,’ as it may
+be called, is the box reproduced in Figure 1.
+
+L was a box that also required three acts to open the door. It was a
+combination of A (O at front), D (string), I (lever). The lever or bar
+to be depressed was 2 inches to the right of the door, which was in the
+front center. The string to be clawed or bitten ran from front center to
+back center 1 inch below the top of the box.
+
+Z was a box with back and sides entirely closed, with front and top
+closed by bars and screening, with a small opening in the left-hand
+corner. A box was held in front of this and drawn away when the cats
+happened to lick themselves. Thus escape and food followed always upon
+the impulse to lick themselves, and they soon would immediately start
+doing so as soon as pushed into the box. The same box was used with the
+impulse changed to that for scratching themselves. The size of this box
+was 15 × 10 × 16.
+
+
+EXPERIMENTS WITH CATS
+
+In these various boxes were put cats from among the following. I give
+approximately their ages while under experiment.
+
+  No. 1. 8-10 months.
+  No. 2. 5-7 months.
+  No. 3. 5-11 months.
+  No. 4. 5-8 months.
+  No. 5. 5-7 months.
+  No. 6. 3-5 months.
+  No. 7. 3-5 months.
+  No. 8. 6-6½ months.
+  No. 10. 4-8 months.
+  No. 11. 7-8 months.
+  No. 12. 4-6 months.
+  No. 13. 18-19 months.
+
+The behavior of all but 11 and 13 was practically the same. When put into
+the box the cat would show evident signs of discomfort and of an impulse
+to escape from confinement. It tries to squeeze through any opening; it
+claws and bites at the bars or wire; it thrusts its paws out through any
+opening and claws at everything it reaches; it continues its efforts
+when it strikes anything loose and shaky; it may claw at things within
+the box. It does not pay very much attention to the food outside, but
+seems simply to strive instinctively to escape from confinement. The
+vigor with which it struggles is extraordinary. For eight or ten minutes
+it will claw and bite and squeeze incessantly. With 13, an old cat, and
+11, an uncommonly sluggish cat, the behavior was different. They did not
+struggle vigorously or continually. On some occasions they did not even
+struggle at all. It was therefore necessary to let them out of some box
+a few times, feeding them each time. After they thus associate climbing
+out of the box with getting food, they will try to get out whenever put
+in. They do not, even then, struggle so vigorously or get so excited
+as the rest. In either case, whether the impulse to struggle be due
+to an instinctive reaction to confinement or to an association, it is
+likely to succeed in letting the cat out of the box. The cat that is
+clawing all over the box in her impulsive struggle will probably claw
+the string or loop or button so as to open the door. And gradually all
+the other non-successful impulses will be stamped out and the particular
+impulse leading to the successful act will be stamped in by the resulting
+pleasure, until, after many trials, the cat will, when put in the box,
+immediately claw the button or loop in a definite way.
+
+The starting point for the formation of any association in these cases,
+then, is the set of instinctive activities which are aroused when a cat
+feels discomfort in the box either because of confinement or a desire
+for food. This discomfort, plus the sense-impression of a surrounding,
+confining wall, expresses itself, prior to any experience, in squeezings,
+clawings, bitings, etc. From among these movements one is selected by
+success. But this is the starting point only in the case of the first
+box experienced. After that the cat has associated with the feeling of
+confinement certain impulses which have led to success more than others
+and are thereby strengthened. A cat that has learned to escape from A by
+clawing has, when put into C or G, a greater tendency to claw at things
+than it instinctively had at the start, and a less tendency to squeeze
+through holes. A very pleasant form of this decrease in instinctive
+impulses was noticed in the gradual cessation of howling and mewing.
+However, the useless instinctive impulses die out slowly, and often play
+an important part even after the cat has had experience with six or eight
+boxes. And what is important in our previous statement, namely, that
+the activity of an animal when first put into a new box is not directed
+by any appreciation of _that_ box’s character, but by certain general
+impulses to act, is not affected by this modification. Most of this
+activity is determined by heredity; some of it, by previous experience.
+
+My use of the words _instinctive_ and _impulse_ may cause some
+misunderstanding unless explained here. Let us, throughout this
+book, understand by instinct any reaction which an animal makes to a
+situation _without experience_. It thus includes unconscious as well as
+conscious acts. Any reaction, then, to totally new phenomena, when first
+experienced, will be called instinctive. Any impulse then felt will be
+called an instinctive impulse. Instincts include whatever the nervous
+system of an animal, as far as inherited, is capable of. My use of the
+word will, I hope, everywhere make clear what fact I mean. If the reader
+gets the fact meant in mind it does not in the least matter whether he
+would himself call such a fact instinct or not. Any one who objects to
+the word may substitute ‘hocus-pocus’ for it wherever it occurs. The
+definition here made will not be used to prove or disprove any theory,
+but simply as a signal for the reader to imagine a certain sort of fact.
+
+The word _impulse_ is used against the writer’s will, but there is no
+better. Its meaning will probably become clear as the reader finds it in
+actual use, but to avoid misconception at any time I will state now that
+_impulse_ means the consciousness accompanying a muscular innervation
+_apart from that feeling of the act which comes from seeing oneself
+move, from feeling one’s body in a different position, etc._ It is the
+_direct feeling of the doing_ as distinguished from the _idea of the
+act done_ gained through eye, etc. For this reason I say ‘impulse _and_
+act’ instead of simply ‘act.’ Above all, it must be borne in mind that
+by impulse I never mean the _motive_ to the act. In popular speech you
+may say that hunger is the impulse which makes the cat claw. That will
+never be the use here. The word _motive_ will always denote that sort
+of consciousness. Any one who thinks that the act ought not to be thus
+subdivided into impulse and deed may feel free to use the word _act_ for
+_impulse_ or _impulse and act_ throughout, if he will remember that the
+act in this aspect of being felt as to be done or as doing is in animals
+the important thing, is the thing which gets associated, while the act as
+done, as viewed from outside, is a secondary affair. I prefer to have a
+separate word, _impulse_, for the former, and keep the word _act_ for the
+latter, which it commonly means.
+
+Starting, then, with its store of instinctive impulses, the cat hits
+upon the successful movement, and gradually associates it with the
+sense-impression of the interior of the box until the connection is
+perfect, so that it performs the act as soon as confronted with the
+sense-impression. The formation of each association may be represented
+graphically by a time-curve. In these curves lengths of one millimeter
+along the abscissa represent successive experiences in the box, and
+heights of one millimeter above it each represent ten seconds of time.
+The curve is formed by joining the tops of perpendiculars erected along
+the abscissa 1 mm. apart (the first perpendicular coinciding with the
+_y_ line), each perpendicular representing the time the cat was in the
+box before escaping. Thus, in Fig. 2 on page 39 the curve marked _12 in
+A_ shows that, in 24 experiences or trials in box A, cat 12 took the
+following times to perform the act, 160 sec., 30 sec., 90 sec., 60, 15,
+28, 20, 30, 22, 11, 15, 20, 12, 10, 14, 10, 8, 8, 5, 10, 8, 6, 6, 7.
+A short vertical line below the abscissa denotes that an interval of
+approximately 24 hours elapsed before the next trial. Where the interval
+was longer it is designated by a figure 2 for two days, 3 for three days,
+etc. If the interval was shorter, the number of hours is specified by
+1 hr., 2 hrs., etc. In many cases the animal failed in some trial to
+perform the act in ten or fifteen minutes and was then taken out by me.
+Such failures are denoted by a break in the curve either at its start or
+along its course. In some cases there are short curves after the main
+ones. These, as shown by the figures beneath, represent the animal’s
+mastery of the association after a very long interval of time, and may be
+called memory-curves. A discussion of them will come in the last part of
+the chapter.
+
+[Illustration: FIG. 2.]
+
+The time-curve is obviously a fair representation of the progress of
+the formation of the association, for the two essential factors in the
+latter are the disappearance of all activity save the particular sort
+which brings success with it, and perfection of that particular sort of
+act so that it is done precisely and at will. Of these the second is, on
+deeper analysis, found to be a part of the first; any clawing at a loop
+except the particular claw which depresses it is theoretically a useless
+activity. If we stick to the looser phraseology, however, no harm will
+be done. The combination of these two factors is inversely proportional
+to the time taken, provided the animal surely wants to get out at once.
+This was rendered almost certain by the degree of hunger. Theoretically
+a perfect association is formed when both factors are perfect,—when the
+animal, for example, does nothing but claw at the loop, and claws at it
+in the most useful way for the purpose. In some cases (_e.g._ 2 in K on
+page 53) neither factor ever gets perfected in a great many trials. In
+some cases the first factor does but the second does not, and the cat
+goes at the thing not always in the desirable way. In all cases there is
+a fraction of the time which represents getting oneself together after
+being dropped in the box, and realizing where one is. But for our purpose
+all these matters count little, and we may take the general slope of the
+curve as representing very fairly the progress of the association. The
+slope of any particular part of it may be due to accident. Thus, very
+often the second experience may have a higher time-point than the first,
+because the first few successes may all be entirely due to accidentally
+hitting the loop, or whatever it is, and whether the accident will
+happen sooner in one trial than another is then a matter of chance.
+Considering the general slope, it is, of course, apparent that a gradual
+descent—say, from initial times of 300 sec. to a constant time of 6 or 8
+sec. in the course of 20 to 30 trials—represents a difficult association;
+while an abrupt descent, say in 5 trials, from a similar initial height,
+represents a very easy association. Thus, 2 in Z, on page 57, is a hard,
+and 1 in I, on page 49, an easy association.
+
+[Illustration: FIG. 3.]
+
+In boxes A, C, D, E, I, 100 per cent of the cats given a chance to do so,
+hit upon the movement and formed the association. The following table
+shows the results where some cats failed:—
+
+
+TABLE 1
+
+        NO. CATS TRIED  NO. CATS FAILED
+       +---------------+---------------+
+  F    |       5       |       4       |
+  G    |       8       |       5       |
+  H    |       9       |       2       |
+  J    |       5       |       2       |
+  K    |       5       |       2       |
+       +---------------+---------------+
+
+The time-curves follow. By referring to the description of apparatus they
+will be easily understood. Each mm. along the abscissa represents one
+trial. Each mm. above it represents 10 seconds.
+
+[Illustration: FIG. 4.]
+
+[Illustration: FIG. 5.]
+
+These time-curves show, in the first place, what associations are easy
+for an animal to form, and what are hard. The act must be one which the
+animal will perform in the course of the activity which its inherited
+equipment incites or its previous experience has connected with the
+sense-impression of a box’s interior. The oftener the act naturally
+occurs in the course of such activity, the sooner it will be performed
+in the first trial or so, and this is one condition, sometimes, of the
+ease of forming the association. For if the first few successes are five
+minutes apart, the influence of one may nearly wear off before the next,
+while if they are forty seconds apart the influences may get summated.
+But this is not the only or the main condition of the celerity with which
+an association may be formed. It depends also on the amount of attention
+given to the act. An act of the sort likely to be well attended to will
+be learned more quickly. Here, too, accident may play a part, for a cat
+may merely happen to be attending to its paw when it claws. The kind of
+acts which insure attention are those where the movement which works the
+mechanism is one which the cat makes definitely to get out. Thus A (O
+at front) is easier to learn than C (button), because the cat does A in
+trying to claw down the front of the box and so is attending to what it
+does; whereas it does C generally in a vague scramble along the front
+or while trying to claw outside with the other paw, and so does not
+attend to the little unimportant part of its act which turns the button
+round. Above all, _simplicity_ and _definiteness_ in the act make the
+association easy. G (thumb latch), J (double) and K and L (triples) are
+hard, because complex. E is easy, because directly in the line of the
+instinctive impulse to try to pull oneself out of the box by clawing at
+anything outside. It is thus very closely attended to. The extreme of
+ease is reached when a single experience stamps the association in so
+completely that ever after the act is done at once. This is approached in
+I and E.
+
+[Illustration: FIG. 6.]
+
+In these experiments the sense-impressions offered no difficulty one more
+than the other.
+
+Vigor, abundance of movements, was observed to make differences between
+individuals in the same association. It works by shortening the first
+times, the times when the cat still does the act largely by accident.
+Nos. 3 and 4 show this throughout. Attention, often correlated with lack
+of vigor, makes a cat form an association more quickly after he gets
+started. No. 13 shows this somewhat. The absence of a fury of activity
+let him be more conscious of what he did do.
+
+[Illustration: FIG. 7.]
+
+The curves on pages 57 and 58, showing the history of cats 1, 5, 13 and
+3, which were let out of the box Z when they licked themselves, and of
+cats 6, 2 and 4, which were let out when they scratched themselves, are
+interesting because they show associations where there is no congruity
+(no more to a cat than to a man) between the act and the result. One
+chick, too, was thus freed whenever he pecked at his feathers to dress
+them. He formed the association, and would whirl his head round and poke
+it into his feathers as soon as dropped in the box. There is in all these
+cases a noticeable tendency, of the cause of which I am ignorant, to
+diminish the act until it becomes a mere vestige of a lick or scratch.
+After the cat gets so that it performs the act soon after being put in,
+it begins to do it less and less vigorously. The licking degenerates into
+a mere quick turn of the head with one or two motions up and down with
+tongue extended. Instead of a hearty scratch, the cat waves its paw up
+and down rapidly for an instant. Moreover, if sometimes you do not let
+the cat out after this feeble reaction, it does not at once repeat the
+movement, as it would do if it depressed a thumb piece, for instance,
+without success in getting the door open. Of the reason for this
+difference I am again ignorant.
+
+Previous experience makes a difference in the quickness with which the
+cat forms the associations. After getting out of six or eight boxes by
+different sorts of acts the cat’s general tendency to claw at loose
+objects within the box is strengthened and its tendency to squeeze
+through holes and bite bars is weakened; accordingly it will learn
+associations along the general line of the old more quickly. Further,
+its tendency to pay attention to what it is doing gets strengthened,
+and this is something which may properly be called a change in degree
+of intelligence. A test was made of the influence of experience in this
+latter way by putting two groups of cats through I (lever), one group (1,
+2, 3, 4, 5) after considerable experience, the other (10, 11, 12) after
+experience with only one box. As the act in I was not along the line
+of the acts in previous boxes, and as a decrease in the squeezings and
+bitings would be of little use in the box as arranged, the influence of
+experience in the former way was of little account. The curves of all are
+shown on page 49.
+
+[Illustration: FIG. 8.]
+
+If the whole set of curves are examined in connection with the following
+table, which gives the general order in which each animal took up the
+different associations which he eventually formed, many suggestions
+of the influence of experience will be met with. The results are not
+exhaustive enough to justify more than the general conclusion that there
+is such an influence. By taking more individuals and thus eliminating all
+other factors besides experience, one can easily show just how and how
+far experience facilitates association.
+
+When, in this table, the letters designating the boxes are in italics it
+means that, though the cat formed the association, it was in connection
+with other experiments and so is not recorded in the curves.
+
+
+TABLE 2
+
+  +------+-------------------------------+
+  |Cat 1 | _A_ _B_  _C_ _D₁_ _D_ Z I     |
+  |Cat 2 | _C_ _D₁_ _D_  E    Z  H J I K |
+  |Cat 3 |  A   C    E   G    H  J Z I K |
+  |Cat 4 |  C   F    G   D    Z  H J I K |
+  |Cat 5 |  C   E    Z   H    I          |
+  |Cat 6 | _A_ _C_   E   Z               |
+  |Cat 7 | _A_ _C_                       |
+  |Cat 10|  C   I    A   H    D  L       |
+  |Cat 11|  C   I    A   H    D  L       |
+  |Cat 12|  C   I    A   H    D  L       |
+  |Cat 13|  A   C    D   G    Z          |
+  +------+-------------------------------+
+
+[Illustration: FIG. 9.]
+
+The advantage due to experience in our experiments is not, however,
+the same as ordinarily in the case of trained animals. With them the
+associations are with the acts or voice of man or with sense-impressions
+to which they naturally do not attend (_e.g._ figures on a blackboard,
+ringing of a bell, some act of another animal). Here the advantage of
+experience is mainly due to the fact that by such experience the animals
+gain the habit of attending to the master’s face and voice and acts and
+to sense-impressions in general.
+
+I made no attempt to find the differences in ability to acquire
+associations due to age or sex or fatigue or circumstances of any
+sort. By simply finding the average slope in the different cases to be
+compared, one can easily demonstrate any such differences that exist. So
+far as this discovery is profitable, investigation along this line ought
+now to go on without delay, the method being made clear. Of differences
+due to differences in the species, genus, etc., of the animals I will
+speak after reviewing the time-curves of dogs and chicks.
+
+In the present state of animal psychology there is another value to
+these results which was especially aimed at by the investigator from the
+start. They furnish a quantitative estimate of what the average cat can
+do, so that if any one has an animal which he thinks has shown superior
+intelligence or perhaps reasoning power, he may test his observations and
+opinion by taking the time-curves of the animal in such boxes as I have
+described.
+
+[Illustration: FIG. 10.]
+
+If his animal in a number of cases forms the associations very much more
+quickly, or deals with the situation in a more intelligent fashion than
+my cats did, then he may have ground for claiming in his individual a
+variation toward greater intelligence and, possibly, intelligence of a
+different order. On the other hand, if the animal fails to rise above the
+type in his dealings with the boxes, the observer should confess that his
+opinion of the animal’s intelligence may have been at fault and should
+look for a correction of it.
+
+We have in these time-curves a fairly adequate measure of what the
+ordinary cat can do, and how it does it, and in similar curves soon to
+be presented a less adequate measure of what a dog may do. If other
+investigators, especially all amateurs who are interested in animal
+intelligence, will take other cats and dogs, especially those supposed
+by owners to be extraordinarily intelligent, and experiment with them in
+this way, we shall soon get a notion of how much variation there is among
+animals in the direction of more or superior intelligence. The beginning
+here made is meager but solid. The knowledge it gives needs to be much
+extended. The variations found in individuals should be correlated, not
+merely with supposed superiority in intelligence, a factor too vague to
+be very serviceable, but with observed differences in vigor, attention,
+memory and muscular skill. No phenomena are more capable of exact and
+thorough investigation by experiment than the associations of animal
+consciousness. Never will you get a better psychological subject than a
+hungry cat. When the crude beginnings of this research have been improved
+and replaced by more ingenious and adroit experimenters, the results
+ought to be very valuable.
+
+Surely every one must agree that no man now has a right to advance
+theories about what is in animals’ minds or to deny previous theories
+unless he supports his thesis by systematic and extended experiments. My
+own theories, soon to be proclaimed, will doubtless be opposed by many.
+I sincerely hope they will, provided the denial is accompanied by actual
+experimental work. In fact, I shall be tempted again and again in the
+course of this book to defend some theory, dubious enough to my own mind,
+in the hope of thereby inducing some one to oppose me and in opposing me
+to make the experiments I have myself had no opportunity to make yet.
+Probably there will be enough opposition if I confine myself to the
+theories I feel sure of.
+
+[Illustration: FIG. 11.]
+
+
+EXPERIMENTS WITH DOGS
+
+The boxes used were as follows:
+
+AA was similar to A (O at front), except that the loop was of stiff cord
+⅜ inch in diameter and was larger (3½ inches diameter); also it was hung
+a foot from the floor and 8 inches to the right of the door. The box
+itself was 41 × 20 × 23.
+
+BB was similar to B, the loop being the same as in AA, and being hung a
+foot from the floor. The box was of the same size and shape as AA.
+
+BB1 was like BB, but the loop was hung 18 inches from the floor.
+
+CC was similar to C (button), but the button was 6 inches long, and the
+box was 36½ × 22 × 23.
+
+II was similar to I, but the box was 30 × 20 × 25 inches; the door (11
+inches wide, 6 high) was in the left front corner, and the lever was 6
+inches long and entered the box at a point 2 inches to the right of the
+door and 4 inches above the floor.
+
+[Illustration: FIG. 12.]
+
+In M the same box as in II was used, but instead of a lever projecting
+inside the box, a lever running outside parallel to the plane of the
+front of the box and 18 inches long was used. This lay close against the
+bars composing the front of the box, and could be pawed down by sticking
+the paw out an inch or so between two bars, at a point about 15 inches
+high and 6 inches in from the right edge of the front. We may call M
+‘_Lever outside_.’
+
+[Illustration: FIG. 13.]
+
+N was a pen 5 × 3 feet made of wire netting 46 inches high. The door, 31
+× 20, was in the right half of the front. A string from the bolt passed
+up over a pulley and back to the back center, where it was fastened 33
+inches above the floor. Biting or pawing this string opened the door.
+
+O was like K, except that there was only one bar, that the string ran
+inside the box, so that it was easily accessible, and that the bolt
+raised in K by depression of the platform could be raised in O (and was
+by the dog experimented on) by sticking the muzzle out between two bars
+just above the bolt and by biting the string, at the same time jerking it
+upward. O was 30 × 20 × 25 in size.
+
+The box G was used for both dogs and cats, without any variation save
+that for dogs the resistance of the door to pressure outwards was doubled.
+
+In these boxes were put in the course of the experiments dog 1 (about 8
+months old), and dogs 2 and 3, adults, all of small size.
+
+A dog who, when hungry, is shut up in one of these boxes is not nearly
+so vigorous in his struggles to get out as is the young cat. And even
+after he has experienced the pleasure of eating on escape many times he
+does not try to get out so hard as a cat, young or old. He does try to
+a certain extent. He paws or bites the bars or screening, and tries to
+squeeze out in a tame sort of way. He gives up his attempts sooner than
+the cat, if they prove unsuccessful. Furthermore his attention is taken
+by the food, not the confinement. He wants to get _to_ the food, not _out
+of_ the box. So, unlike the cat, he confines his efforts to the front
+of the box. It was also a practical necessity that the dogs should be
+kept from howling in the evening, and for this reason I could not use
+as motive the utter hunger which the cats were made to suffer. In the
+morning, when the experiments were made, the dogs were surely hungry,
+and no experiment is recorded in which the dog was not in a state to be
+willing to make a great effort for a bit of meat, but the motive may not
+have been even and equal throughout, as it was with the cats.
+
+[Illustration: FIG. 14.]
+
+The curves on page 60 are to be interpreted in the same way as those for
+the cats, and are on the same scale. The order in which No. 1 took up the
+various associations was AA, BB, BB1, G, N, CC, II, O.
+
+The percentage of dogs succeeding in the various boxes is given below,
+but is of no consequence, because so few were tried, and because the
+motive, hunger, was not perhaps strong enough, or equal in all cases.
+
+In AA 3 out of 3.
+
+In BB 0 out of 2 (that is, without previous experience of AA).
+
+In CC 1 out of 2.
+
+In II 3 out of 3.
+
+In M 1 out of 2.
+
+In N 1 out of 3.
+
+In G 1 out of 3.
+
+
+EXPERIMENTS WITH CHICKS
+
+The apparatus was as follows:
+
+[Illustration: FIG. 15. FIG. 16. FIG. 17.]
+
+P was simply a small pen arranged with two exits, one leading to the
+inclosure where were the other chicks and food, one leading to another
+pen with no exit. The drawing (Fig. 15 on this page) explains itself. A
+chick was placed at A and left to find its way out. The walls were made
+of books stuck up on end.
+
+Q was a similar pen arranged so that the real exit was harder to find.
+(See Fig. 16.)
+
+R was still another pen similarly constructed, with four possible avenues
+to be taken. (See Fig. 17.)
+
+S was a pen with walls 11 inches high. On the right side an inclined
+plane of wire screening led from the floor of the pen to the top of its
+front wall. Thence the chick could jump down to where its fellows and the
+food and drink were. S was 17 × 14 in size.
+
+T was a pen of the same size as S, with a block of wood 3 inches by 3
+and 2 inches high in the right back corner. From this an inclined plane
+led to the top of the front wall (on the right side of the box). But a
+partition was placed along the left edge of this plane, so that a chick
+could reach it only _via_ the wooden block, not by a direct jump.
+
+U was a pen 16 × 14 × 10 inches. Along the back toward the right corner
+were placed a series of steps 1½ inches wide, the first 1, the second
+2, and the third 3 inches high. In the corner was a platform 4 × 4, and
+4 high, from which access to the top of the front wall of the pen could
+be gained by scrambling up inside a stovepipe 11 inches long, inclined
+upward at an angle of about 30°. From the edge of the wall the chick
+could, of course, jump down to food and society. The top of the pen was
+covered so that the chick could not from the platform jump onto the edge
+of the stovepipe or the top of the pen wall. The only means of exit was
+to go up the steps to the platform, up through the stovepipe to the front
+wall, and then jump down.
+
+The time-curves for chicks 90, 91, 92, 93, 94 and 95, all 2-8 days old
+when experimented on, follow on page 65. The scale is the same as that
+in the curves of the cats and dogs. Besides these simple acts, which any
+average chick will accidentally hit upon and associate, there are, in
+the records of my preliminary study of animal intelligence, a multitude
+of all sorts of associations which some chicks have happened to form.
+Chicks have escaped from confinement by stepping on a little platform in
+the back of the box, by jumping up and pulling a string like that in D,
+by pecking at a door, by climbing up a spiral staircase and out through
+a hole in the wall, by doing this and then in addition walking across a
+ladder for a foot to another wall from which they jump down, etc. Not
+every chick will happen upon the right way in these cases, but the chicks
+who did happen upon it all formed the associations perfectly after enough
+trials.
+
+The behavior of the chicks shows the same general character as that
+of the cats, conditioned, of course, by the different nature of the
+instinctive impulses. Take a chick put in T (inclined plane) for an
+example. When taken from the food and other chicks and dropped into the
+pen he shows evident signs of discomfort; he runs back and forth, peeping
+loudly, trying to squeeze through any openings there may be, jumping up
+to get over the wall, and pecking at the bars or screen, if such separate
+him from the other chicks. Finally, in his general running around he goes
+up the inclined plane a way. He may come down again, or he may go on up
+far enough to see over the top of the wall. If he does, he will probably
+go running up the rest of the way and jump down. With further trials he
+gains more and more of an impulse to walk up an inclined plane when he
+sees it, while the vain running and pecking, etc., are stamped out by the
+absence of any sequent pleasure. Finally, the chick goes up the plane as
+soon as put in. In scientific terms this history means that the chick,
+when confronted by loneliness and confining walls, responds by those acts
+which in similar conditions in nature would be likely to free him. Some
+one of these acts leads him to the successful act, and the resulting
+pleasure stamps it in. Absence of pleasure stamps all others out. The
+case is just the same as with dogs and cats. The time-curves are shown in
+Fig. 18.
+
+Coming now to the question of differences in intelligence between
+the different animals, it is clear that such differences are hard to
+estimate accurately. The chicks are surely very much slower in forming
+associations and less able to tackle hard ones, but the biggest part of
+the difference between what they do and what the dogs and cats do is not
+referable so much to any difference in intelligence as to a difference
+in their bodily organs and instinctive impulses. As between dogs and
+cats, the influence of the difference in quantity of activity, in the
+direction of the instinctive impulses, in the versatility of the fore
+limb, is hard to separate from the influence of intelligence proper.
+The best practical tests to judge such differences in general would be
+differences in memory, which are very easily got at, differences in the
+delicacy and complexity attainable, and, of course, differences in the
+slope of the curves for the same association. If all these tests agreed,
+we should have a right to rank one animal above the other in a scale
+of intelligence. But this whole question of grading is, after all, not
+so important for comparative psychology as its popularity could lead
+one to think. Comparative psychology wants first of all to trace human
+intellection back through the phylum to its origin, and in this aim is
+helped little by knowing that dogs are brighter than cats, or whales than
+seals, or horses than cows. Further, the whole question of ‘intelligence’
+should be resolved into particular inquiries into the development of
+attention, activity, memory, etc.
+
+[Illustration: FIG. 18.]
+
+So far as concerns dogs and cats, I should decide that the former were
+more generally intelligent. The main reason, however, why dogs seem to us
+so intelligent is not a good reason for the belief. It is because, more
+than any other domestic animal, they direct their attention to _us_, to
+what we do, and so form associations connected with acts of ours.
+
+Having finished our attempt to give a true description of the facts of
+association, so far as observed from the outside, we may now progress to
+discuss its inner nature. A little preface about certain verbal usages is
+necessary before doing so. Throughout I shall use the word ‘animal’ or
+‘animals,’ and the reader might fancy that I took it for granted that the
+associative processes were the same in all animals as in these cats and
+dogs of mine. Really, I claim for my animal psychology only that it is
+the psychology of just these particular animals. What this warrants about
+animals in general may be left largely to the discretion of the reader.
+As I shall later say, it is probable that in regard to imitation and the
+power of forming associations from a lot of free ideas, the anthropoid
+primates are essentially different from the cats and dogs.
+
+The reasons why I say ‘animals’ instead of ‘dogs and cats of certain
+ages’ are two. I do think that the probability that the other mammals,
+barring the primates, offer no objections to the theories here advanced
+about dogs and cats is a very strong probability, strong enough to force
+the burden of proof upon any one who should, for instance, say that
+horse-goat psychology was not like cat-dog psychology in these general
+matters. I should claim that, till the contrary was shown in any case,
+my statements should stand for the mammalian mind in general, barring
+the primates. My second reason is that I hate to burden the reader
+with the disgusting rhetoric which would result if I had to insert
+particularizations and reservations at every step. The word ‘animal’ is
+too useful, rhetorically, to be sacrificed. Finally, inasmuch as most
+of my theorizing will be in the line of denying certain relatively high
+functions to animals, the evidence from cats and dogs is sufficient, for
+they are from among the most intelligent animals, and functions of the
+kind to be discussed, if absent in their case, are probably absent from
+the others.
+
+
+REASONING OR INFERENCE
+
+The first great question is whether or not animals are ever led to do
+any of their acts by reasoning. Do they ever conclude from inference
+that a certain act will produce a certain desired result, and so do it?
+The best opinion has been that they do not. The best interpretation of
+even the most extraordinary performances of animals has been that they
+were the result of accident and association or imitation. But it has
+after all been only opinion and interpretation, and the opposite theory
+persistently reappears in the literature of the subject. So, although
+it is in a way superfluous to give the _coup de grâce_ to the despised
+theory that animals reason, I think it is worth while to settle this
+question once for all.
+
+The great support of those who do claim for animals the ability to infer
+has been their wonderful performances which resemble our own. These could
+not, they claim, have happened by accident. No animal could learn to open
+a latched gate by accident. The whole substance of the argument vanishes
+if, as a matter of fact, animals do learn those things by accident.
+_They certainly do._ In this investigation choice was made of the
+intelligent performances described by Romanes in the following passages.
+I shall quote at some length because these passages give an admirable
+illustration of an attitude of investigation which this research will, I
+hope, render impossible for any scientist in the future. Speaking of the
+general intelligence of cats, Romanes says:
+
+    “Thus, for instance, while I have only heard of one solitary
+    case ... of a dog which, without tuition, divined the use of
+    a thumb latch so as to open a closed door by jumping on the
+    handle and depressing the thumb-piece, I have received some
+    half-dozen instances of this display of intelligence on the
+    part of cats. These instances are all such precise repetitions
+    of one another that I conclude the fact to be one of tolerably
+    ordinary occurrence among cats, while it is certainly rare
+    among dogs. I may add that my own coachman once had a cat
+    which, certainly without tuition, learnt thus to open a door
+    that led into the stables from a yard into which looked some
+    of the windows of the house. Standing at these windows when
+    the cat did not see me, I have many times witnessed her _modus
+    operandi_. Walking up to the door with a most matter-of-course
+    kind of air, she used to spring at the half hoop handle just
+    below the thumb latch. Holding on to the bottom of this
+    half-hoop with one fore paw, she then raised the other to the
+    thumb piece, and while depressing the latter finally with her
+    hind legs scratched and pushed the door posts so as to open the
+    door....
+
+    “Of course in all such cases the cats must have previously
+    observed that the doors are opened by persons placing their
+    hands upon the handles and, having observed this, the animals
+    act by what may be strictly termed rational imitation. But it
+    should be observed that the process as a whole is something
+    more than imitative. For not only would observation alone be
+    scarcely enough (within any limits of thoughtful reflection
+    that it would be reasonable to ascribe to an animal) to enable
+    a cat upon the ground to distinguish that the essential part
+    of the process consists not in grasping the handle, but in
+    depressing the latch; but the cat certainly never saw any one,
+    after having depressed the latch, pushing the door posts with
+    his legs; and that this pushing action is due to an originally
+    deliberate intention of opening the door, and not to having
+    accidentally found this action to assist the process, is shown
+    by one of the cases communicated to me; for in this case, my
+    correspondent says, ‘the door was not a loose-fitting one, by
+    any means, and I was surprised that by the force of one hind
+    leg she should have been able to push it open after unlatching
+    it.’ Hence we can only conclude that the cats in such cases
+    have a very definite idea as to the mechanical properties of
+    a door: they know that to make it open, even when unlatched,
+    it requires to be _pushed_—a very different thing from trying
+    to imitate any particular action which they may see to be
+    performed for the same purpose by man. The whole psychological
+    process, therefore, implied by the fact of a cat opening a
+    door in this way is really most complex. First the animal must
+    have observed that the door is opened by the hand grasping
+    the handle and moving the latch. Next she must reason, by
+    ‘the logic of feelings’—‘If a hand can do it, why not a paw?’
+    Then strongly moved by this idea she makes the first trial.
+    The steps which follow have not been observed, so we cannot
+    certainly say whether she learns by a succession of trials that
+    depression of the thumb piece constitutes the essential part
+    of the process, or, perhaps more probably, that her initial
+    observations supplied her with the idea of clicking the thumb
+    piece. But, however this may be, it is certain that the pushing
+    with the hind feet after depressing the latch must be due to
+    adaptive reasoning unassisted by observation; and only by the
+    concerted action of all her limbs in the performance of a
+    highly complex and most unnatural movement is her final purpose
+    attained.” (Animal Intelligence, pp. 420-422.)
+
+A page or two later we find a less ponderous account of a cat’s success
+in turning aside a button and so opening a window:—
+
+    “At Parara, the residence of Parker Bowman, Esq., a full-grown
+    cat was one day accidentally locked up in a room without any
+    other outlet than a small window, moving on hinges, and kept
+    shut by means of a swivel. Not long afterwards the window was
+    found open and the cat gone. This having happened several
+    times, it was at last found that the cat jumped upon the window
+    sill, placed her fore paws as high as she could reach against
+    the side, deliberately reached with one over to the swivel,
+    moved it from its horizontal to a vertical position, and then,
+    leaning with her whole weight against the window, swung it open
+    and escaped.” (Animal Intelligence, p. 425.)
+
+A description has already been given on page 31 of the small box (C),
+whose door fell open when the button was turned, and also of a large
+box (CC) for the dogs, with a similar door. The thumb-latch experiment
+was carried on with the same box (G) for both cats and dogs, but the
+door was arranged so that a greater force (1.3 kilograms) was required
+in the case of the dogs. It will be remembered that the latch was so
+fixed that if the thumb piece were pressed down, without contemporaneous
+outward pressure of the door, the latch bar would merely drop back into
+its catch as soon as the paw was taken off the door. If, however, the
+door were pushed outward, the latch bar, being pressed closely against
+the outer edge of its catch, would, if lifted, be likely to fall outside
+it and so permit the door to open if then or later sufficient pressure
+were exerted. Eight cats (Nos. 1, 2, 3, 4, 5, 6, 7 and 13) were, one
+at a time, left in this thumb-latch box. All exhibited the customary
+instinctive clawings and squeezings and bitings. Out of the eight all
+succeeded in the course of their vigorous struggles in pressing down
+the thumb piece, so that if the door had been free to swing open, they
+could have escaped. Six succeeded in pushing both thumb-piece down and
+door out, so that the bar did not fall back into its place. Of these five
+succeeded in also later pushing the door open, so that they escaped and
+got the fish outside. Of these, three, after repeated trials, associated
+the complicated movements required with the sight of the interior of the
+box so firmly that they attacked the thumb latch the moment they were put
+in. The history of the formation of the association in the case of 3 and
+of 4 is shown in the curves in Figs. 6 and 7. In the case of 13 the exact
+times were not taken. The combination of accidents required was enough to
+make No. 1 and No. 6 take a long time to get out. Consequently, weariness
+and failure inhibited their impulses to claw, climb, etc., more than the
+rare pleasure from getting out strengthened them, and they failed to
+form the association. Like the cats who utterly failed to get out, they
+finally ceased to try when put in. The history of their efforts is as in
+Table 3: the figures in the columns represent the time (in minutes and
+seconds) the animal was in the box before escaping or before being taken
+out if he failed to escape. Cases of failure are designated by an F after
+the figures. Double lines represent an interval of twenty-four hours.
+
+
+TABLE 3
+
+  +----------+---------+
+  |  No. 1.  |  No. 6. |
+  +==========+=========+
+  | 13.00 F  | 17.50   |
+  |  9.30    |  3.30   |
+  |  1.40    |  9.00   |
+  |   .50    |  2.10   |
+  | 15.00    |  1.45   |
+  |  6.00 F  |  1.55   |
+  +==========+         |
+  | 14.00    | 13.00   |
+  |          +=========+
+  | 20.00 F  |  5.00   |
+  |  4.30    |  2.30   |
+  | 20.00 F  | 15.00   |
+  | 20.00 F  | 10.00 F |
+  |          +=========+
+  | 15.00 F  |  5.00   |
+  +==========+         |
+  | 60.00 F  | 15.00 F |
+  |          +=========+
+  |          | 10.00 F |
+  |          +=========+
+  |          | 10.00 F |
+  +----------+---------+
+
+It should be noted that, although cats 3 and 4 had had some experience
+in getting out of boxes by clawing at loops and turning buttons, they
+had never had anything at all like a thumb latch to claw at, nor had
+they ever seen the door opened by its use, nor did they even have any
+experience of the fact that the part of the box where the thumb piece
+was was the door. And we may insert here, what will be stated more fully
+later, that there was displayed no observation of the surroundings or
+deliberation upon them. It was just a mad scramble to get out.
+
+Three dogs (1, 2 and 3) were given a chance to liberate themselves from
+this same box. 2 and 3, who were rather inactive, failed to even push the
+thumb piece down. No. 1, who was very active, did push it down at the
+same time that she happened to be pushing against the door. She repeated
+this and formed the association as shown in the curve on page 60. She had
+had experience only of escaping by pulling a loop of string.
+
+Out of 6 cats who were put in the box whose door opened by a button,
+not one failed, in the course of its impulsive activity, to push the
+button around. Sometimes it was clawed to one side from below; sometimes
+vigorous pressure on the top turned it around; sometimes it was pushed
+up by the nose. No cat who was given repeated trials failed to form a
+perfect association between the sight of the interior of that box and
+the proper movements. Some of these cats had been in other boxes where
+pulling a loop of string liberated them, 3 and 4 had had considerable
+experience with the boxes and probably had acquired a general tendency to
+claw at loose objects. 10, 11 and 12 had never been in _any box_ before.
+The curves are on pages 41 and 43.
+
+Of two dogs, one, when placed in a similar but larger box, succeeded in
+hitting the button in such a way as to let the door open, and formed
+a permanent association, as shown by the curves on page 41. No one who
+had seen the behavior of these animals when trying to escape could doubt
+that their actions were directed by instinctive impulses, not by rational
+observation. It is then absolutely sure that a dog or cat _can_ open a
+door closed by a thumb latch or button, merely by the accidental success
+of its natural impulses. If _all_ cats, when hungry and in a _small_ box,
+will accidentally push the button that holds the door, an _occasional_
+cat in a _large_ room may very well do the same. If three cats out of
+eight will accidentally press down a thumb piece and push open a small
+door, three cats out of a thousand may very well open doors or gates in
+the same way.
+
+But besides thus depriving of their value the facts which these
+theorizers offer as evidence, we may, by a careful examination of
+the method of formation of these associations as it is shown in the
+time-curves, gain positive evidence that no power of inference was
+present in the subjects of the experiments. Surely if 1 and 6 had
+possessed any power of inference, they would not have failed to get
+out after having done so several times. Yet they did. (See p. 71.) If
+they had once even, much less if they had six or eight times, inferred
+what was to be done, they should have made the inference the seventh or
+ninth time. And if there were in these animals any power of inference,
+however rudimentary, however sporadic, however dim, there should have
+appeared among the multitude some cases where an animal, seeing through
+the situation, knows the proper act, does it, and from then on does
+it immediately upon being confronted with the situation. There ought,
+that is, to be a sudden vertical descent in the time-curve. Of course,
+where the act resulting from the impulse is very simple, very obvious,
+and very clearly defined, a single experience may make the association
+perfect, and we may have an abrupt descent in the time-curve without
+needing to suppose inference. But if in a complex act, a series of
+acts or an ill-defined act, one found such a sudden consummation in
+the associative process, one might very well claim that reason was at
+work. Now, the scores of cases recorded show no such phenomena. The
+cat does not look over the situation, much less _think_ it over, and
+then decide what to do. It bursts out at once into the activities which
+instinct and experience have settled on as suitable reactions to the
+situation ‘_confinement when hungry with food outside_.’ It does not
+ever in the course of its successes realize that such an act brings
+food and therefore decide to do it and thenceforth do it immediately
+from _decision_ instead of from impulse. The one impulse, out of
+many accidental ones, which leads to pleasure, becomes strengthened
+and stamped in thereby, and more and more firmly associated with the
+sense-impression of that box’s interior. Accordingly it is sooner and
+sooner fulfilled. Futile impulses are gradually stamped out. The gradual
+slope of the time-curve, then, shows the absence of reasoning. They
+represent the wearing smooth of a path in the brain, not the decisions of
+a rational consciousness.
+
+In a later discussion of imitation further evidence that animals do not
+reason will appear. For the present, suffice it to say, that a dog, or
+cat, or chick, who does not in his own impulsive activity learn to escape
+from a box by pulling the proper loop, or stepping on a platform, or
+pecking at a door, will not learn it from seeing his fellows do so. They
+are incapable of even the inference (if the process may be dignified by
+that name) that what gives another food will give it to them also. So,
+also, it will be later seen that an animal cannot learn an act by being
+put through it. For instance, a cat who fails to push down a thumb piece
+and push out the door cannot be taught by having one take its paw and
+press the thumb piece down with it. This _could_ be learned by a certain
+type of associative process without inference. _Were there inference, it
+surely would be learned._
+
+Finally, attention may be called to the curves which show the way that
+the animal mind deals with a series of acts (_e.g._ curves for G, J, K,
+L and O, found on pages 45 to 55 and 60). Were there any reasoning the
+animals ought early to master the method of escape in these cases (see
+descriptions on pages 31 to 34) so as to do the several acts in order,
+and not to repeat one after doing it once, or else ought utterly to fail
+to master the thing. But, in all these experiments, where there was every
+motive for the use of any reasoning faculty, if such existed, where the
+animals literally lived by their intellectual powers, one finds no sign
+of abstraction, or inference, or judgment.
+
+So far I have only given facts which are quite uninfluenced by any
+possible incompetence or prejudice of the observer. These alone seem
+to disprove the existence of any rational faculty in the subjects
+experimented on. I may add that my observations of all the conduct of all
+these animals during the months spent with them, failed to find any act
+that even _seemed_ due to reasoning. I should claim that this quarrel
+ought now to be dropped for good and all,—that investigation ought to
+be directed along more sensible and profitable lines. I should claim
+that the psychologist who studies dogs and cats in order to defend this
+‘reason’ theory is on a level with a zoölogist who should study fishes
+with a view to supporting the thesis that they possessed clawed digits.
+The rest of this account will deal with more promising problems, of
+which the first, and not the least important, concerns the facts and
+theories of _imitation_.
+
+
+IMITATION
+
+To the question, ‘Do animals imitate?’ science has uniformly answered,
+‘Yes.’ But so long as the question is left in this general form, no
+correct answer to it is possible. It will be seen, from the results
+of numerous experiments soon to be described, that imitation of a
+certain sort is not possible for animals, and before entering upon that
+description it will be helpful to differentiate this matter of imitation
+into several varieties or aspects. The presence of some sorts of
+imitation does not imply that of other sorts.
+
+There are, to begin with, the well-known phenomena presented by the
+imitative birds. The power is extended widely, ranging from the parrot
+who knows a hundred or more articulate sounds to the sparrow whom a
+patient shoemaker taught to get through a tune. Now, if a bird really
+gets a sound in his mind from hearing it and sets out forthwith to
+imitate it, as mocking birds are said at times to do, it is a mystery and
+deserves closest study. If a bird, out of a lot of random noises that it
+makes, chooses those for repetition which are like sounds that he has
+heard, it is again a mystery _why_, though not as in the previous case a
+mystery _how_, he does it. The important fact for our purpose is that,
+though the imitation of sounds is so habitual, there does not appear to
+be any marked general imitative tendency in these birds. There is no
+proof that parrots do muscular acts from having seen other parrots do
+them. But this should be studied. At any rate, until we know what sort of
+sounds birds imitate, what circumstances or emotional attitudes these
+are connected with, how they learn them and, above all, whether there is
+in birds which repeat sounds any tendency to imitate in other lines, we
+cannot, it seems to me, connect these phenomena with anything found in
+the mammals or use them to advantage in a discussion of animal imitation
+as the forerunner of human. In what follows they will be left out of
+account, will be regarded as a specialization removed from the general
+course of mental development, just as the feathers or right aortic
+arch of birds are particular specializations of no consequence for the
+physical development of mammals. For us, henceforth, imitation will mean
+imitation minus the phenomena of imitative birds.
+
+There are also certain pseudo-imitative or semi-imitative phenomena which
+ought to be considered by themselves. For example, the rapid loss of
+the fear of railroad trains or telegraph wires among birds, the rapid
+acquisition of arboreal habits among Australian rodents, the use of
+proper feeding grounds, etc., may be held to be due to imitation. The
+young animal stays with or follows its mother from a specific instinct to
+keep near that particular object, to wit, its mother. It may thus learn
+to stay near trains, or scramble up trees, or feed at certain places and
+on certain plants. Actions due to following pure and simple may thus
+simulate imitation. Other groups of acts which now seem truly imitative
+may be indirect fruits of some one instinct. This must be kept in mind
+when one estimates the supposed imitation of parents by young. Further,
+it is certain that in the case of the chick, where early animal life has
+been carefully observed, instinct and individual experience between them
+rob imitation of practically all its supposed influence. Chicks get along
+without a mother very well. Yet no mother takes more care of her children
+than the hen. Care in other cases, then, need not mean instruction
+through imitation.
+
+These considerations may prevent an unreserved acceptance of the common
+view that young animals get a great number of their useful habits from
+imitation, but I do not expect or desire them to lead to its summary
+rejection. I should not now myself reject it, though I think it quite
+possible that more investigation and experiment may finally reduce all
+the phenomena of so-called imitation of parents by young to the level of
+indirect results of instinctive acts.
+
+Another special department of imitation may be at least vaguely marked
+off: namely, apparent imitation of certain limited sorts of acts which
+are somewhat frequent in the animal’s life. An example will do better
+than further definition.
+
+Some sheep were being driven on board ship one at a time. In the course
+of their progress they had to jump over a hurdle. On this being removed
+before all had passed it, the next sheep was seen to jump as if to get
+over a hurdle, and so on for five or six, apparently sure evidence that
+they imitated the action, each of the one in front. Now, it is again
+possible that among gregarious animals there may be elaborate connections
+in the nervous system which allow the sight of certain particular acts in
+another animal to arouse the innervation leading to those acts, but that
+these connections are _limited_. The reactions on this view are specific
+responses to definite signals, comparable to any other instinctive or
+associational reaction. The sheep jumps when he sees the other sheep
+jump, not because of a general ability to do what he sees done, but
+because he is furnished with the instinct to jump at such a sight, or
+because his experience of following the flock over boulders and brooks
+and walls has got him into the habit of jumping at the spot where he
+sees one ahead of him jump; and so he jumps even though no obstacle be
+in his way. If due to instinct, the only peculiarity of such a reaction
+would be that the sense-impression calling forth the act would be the
+same act as done by another. If due to experience, there would be an
+exact correspondence to the frequent acts called forth _originally_ by
+several elements in a sense-impression, one of which is essential, and
+done _afterwards_ when only the _non-essentials_ are present. These two
+possibilities have not been sufficiently realized, yet they may contain
+the truth. On the other hand, these limited acts may be the primitive,
+sporadic beginnings of the general imitative faculty which we find in
+man. To this general faculty we may now turn, having cleared away some of
+the more doubtful phenomena which have shared its name.
+
+It should be kept in mind that an imitative act may be performed quite
+unthinkingly, as when a man in the mob shouts what the others shout or
+claps when the others clap; may be done from an inference that since A
+by doing X makes pleasure for himself, I by doing X may get pleasure
+for myself; may, lastly, be done from what may be called a transferred
+association. This process is the one of interest in connection with our
+general topic, and most of my experiments on imitation were directed to
+the investigation of it. Its nature is simple. One sees the following
+sequence: ‘A turning a faucet, A getting a drink.’ If one can free this
+association from its narrow confinement to A, so as to get from it the
+association, ‘impulse to turn faucet, _me_ getting a drink,’ one will
+surely, if thirsty, turn the faucet, though he had never done so before.
+If one can from an act witnessed learn to do the act, he in some way
+makes use of the sequence seen, transfers the process to himself; in the
+common human sense of the word, he _imitates_. This kind of imitation
+is surely common in human life. It may be apparent in ontogeny before
+any power of inference is shown. After that power does appear, it still
+retains a wide scope, and teaches us a majority, perhaps, of the ordinary
+accomplishments of our practical life.
+
+Now, as the writers of books about animal intelligence have not
+differentiated this meaning from the other possible ones, it is
+impossible to say surely that they have uniformly credited it to animals,
+and it is profitless to catalogue here their vague statements. Many
+opposers of the ‘reason’ theory have presupposed such a process and used
+it to replace reason as the cause of some intelligent performances. The
+upholders of the reason theory have customarily recognized such a process
+and claimed to have discounted it in their explanations of the various
+anecdotes. So we found Mr. Romanes, in the passage quoted, discussing the
+possibility that such an imitative process, without reason, could account
+for the facts. In his chapter on Imitation in ‘Habit and Instinct,’
+Principal C. Lloyd Morgan, the sanest writer on comparative psychology,
+seems to accept imitation of this sort as a fact, though he could, if
+attacked, explain most of his illustrations by the simple forms. The fact
+is, as was said before, that no one has analyzed or systematized the
+phenomena, and so one cannot find clear, decisive statements to quote.
+
+At any rate, whether previous authorities have agreed that such a process
+is present or not, it is worth while to tackle the question; and the
+formation of associations by imitation, if it occurs, is an important
+division of the formation of associations in general. The experiments and
+their results may now be described.
+
+
+IMITATION IN CHICKS
+
+No. 64 learned to get out of a certain pen (16 × 10 inches) by crawling
+under the wire screening at a certain spot. There was also a chance to
+get out by walking up an inclined plane and then jumping down. No. 66 was
+put in with 64. After 9 minutes 20 seconds, 66 went out by the inclined
+plane, although 64 had in the meantime crawled out under the screen 9
+times. (As soon as he got out and ate a little he was put back.) It was
+impossible to judge how many of these times 66 really saw 64 do this.
+He was looking in that direction 5 of the times. So also, in three more
+trials, 66 used the inclined plane, though 64 crawled under each time. 67
+was then tried. In 4 minutes 10 seconds, he crawled under, 64 having done
+so twice. Being then put in _alone_, he, without the chance to imitate,
+still crawled under. So probably he went under _when with 64_ not by
+imitation but by accident, just as 64 had learned the thing himself.
+
+[Illustration: Fig. 19. Fig. 20.]
+
+The accompanying figure (19) shows the apparatus used in the next
+experiment. A represents the top of a box (5 × 4 inches), 13 inches above
+the level of the floor C. On the floor C were the chicks and food. B is
+the top of a box 10 inches high. Around the edges of A except the one
+next B a wire screen was placed, and 65 was repeatedly put upon A until
+he learned to go quickly back to C _via_ B. Then the screen was bent
+outward at X so that a chick could barely squeeze through and down (A to
+C). Eleven chicks were then one at a time placed on A with 65. In every
+case but one they went A-C. In the case of the chick (75) who went A-B-C,
+there could have been no imitation, for he went down _before_ 65 did. One
+other went through the hole before 65 went to B. The remaining nine all
+had a chance to imitate 65 and to save the uncomfortable struggle to get
+through the hole, 65 going A-B-C 8 times before 68 went A-C, 2 times when
+with 66 and 76, once in the case of each of the others.
+
+In still another experiment the apparatus was (as shown in Fig. 20) a
+pen 14 inches square, 10 inches high, with a wire screen in front and a
+hole 3½ inches square in the back. This hole opened into a passageway (B)
+leading around to C, where were the other chicks and food. Chicks who had
+failed, when put in alone, to find the way out, were put in with other
+chicks who had learned the way, to see if by seeing them go out they
+would learn the way. Chick 70 was given 4 trials alone, being left in the
+box 76 minutes all told. He was then given 9 trials (165 minutes) with
+another chick who went out _via_ B 36 times. 70 failed to follow him on
+any occasion. The trials were all given in the course of two days. Chick
+73 failed in 1 trial (12 minutes) to get out of himself, and was then
+given 4 trials (94 minutes) with another chick who went out _via_ B 33
+times. In this experiment, as in all others reported, sure evidence that
+the animals wanted to get out, was afforded by their persistent peckings
+and jumpings at the screen or bars that stood between them and C. Chick
+72, after 8 unsuccessful trials alone (41 minutes), was given 8 trials
+with a chance to imitate. After the other chick had gone out 44 times,
+72 _did go out_. He did not follow the other but went 20 seconds later.
+It depends upon one’s general opinion whether one shall attribute this
+one case out of three to accident or imitation.
+
+I also took two chicks, one of whom learned to escape from A (in Fig. 19)
+by going to B and jumping down the side to the _right_ of A, the other
+of whom learned to jump down the side to the _left_, and placed them
+together upon A. Each took his own course uninfluenced by the other in 10
+trials.
+
+Chicks were also tried in several pens where there was only one possible
+way of escape to see if they would learn it _more quickly_ when another
+chick did the thing several times before their eyes. The method was
+to give some chicks their first trial with an imitation possibility
+and their second without, while others were given their first trial
+without and their second with. If the ratio of the average time of the
+first trial to the average time of the second is smaller in the first
+class than it is in the second class, we may find evidence of this
+sort of influence by imitation. Though imitation may not be able to
+make an animal _do_ what he would otherwise _not do_, it may make him
+do _quicker_ a thing he would have done sooner or later any way. As a
+fact the ratio is _much larger_. This is due to the fact that a chick,
+when in a pen with another chick, is not afflicted by the discomfort
+of loneliness, and so does not try so hard to get out. So the other
+chick, who is continually being put in with him to teach him the way
+out, really prolongs his stay in. This factor destroys the value of
+these quantitative experiments, and I do not insist upon them as
+evidence against imitation, though they certainly offer none for it. I
+do not give descriptions of the apparatus used in these experiments or
+a detailed enumeration of the results, because in this discussion we
+are not dealing primarily with imitation as a slight general factor
+in forming experience, but as a definite associational process in the
+mind. The utter absence of imitation in this limited sense is apparently
+demonstrated by the results of the following experiments.
+
+V was a box 16 × 12 × 8½, with the front made of wire screening and at
+the left end a little door held by a bolt but in such a way that a sharp
+peck at the top of the door would force it open.
+
+W was a box of similar size, with a door in the same place fixed so that
+it was opened by raising a bolt. To this bolt was tied a string which
+went up over the top of the edge of the box and back across the box, as
+in D. By jumping up and coming down with the head over this thread, the
+bolt would be pulled up. The thread was 8½ inches above the floor.
+
+X was a box of similar size, with door, bolt and string likewise. But
+here the string continued round a pulley at the back down to a platform
+in the corner of the box. By stepping on the platform the door was opened.
+
+Y was a box 12 × 8 × 8½, with a door in the middle of the front, which I
+myself opened when a chick pecked at a tack which hung against the front
+of the box 1½ inches above the top of the door.
+
+These different acts, pecking at a door, jumping up and with the neck
+pulling down a string, stepping on a platform, and pecking at a tack,
+were the ones which various chicks were given a chance to imitate. The
+chicks used were from 16 to 30 days old. The method of experiment was
+to put a chick in, leave him 60 to 80 seconds, then put in another who
+knew the act, and on his performing it, to let both escape. No cases were
+counted unless the imitator apparently saw the other do the thing. After
+about ten such chances to learn the act, the imitator was left in alone
+for ten minutes. The following table gives the results. The imitators,
+of course, had previously failed to form the association of themselves. F
+denotes failure to perform the act:
+
+
+TABLE 4
+
+  ======+=====+=========+============+==============
+        |     |NO. TIMES|  TIME IN   |
+  CHICK | ACT |   SAW   |WHICH FAILED| FINAL TIME
+  ------+-----+---------+------------+--------------
+    84  |  V  |   38    |  45.00 F   |  15.00 F
+    85  |  V  |   30    |  30.00 F   |  10.00 F
+    86  |  V  |   44    |  55.00 F   |  15.00 F
+    87  |  V  |   26    |  35.00 F   |  15.00 F
+    80  |  W  |   54    |  60.00 F   |  15.00 F
+    81  |  W  |   40    |  45.00 F   |  15.00 F
+    87  |  W  |   27    |  30.00 F   |  10.00 F
+    81  |  X  |   18    |  20.00 F   |  10.00 F
+    82  |  X  |   21    |  20.00 F   |   8.40 _Did_
+    83  |  X  |   33    |  35.00 F   |  15.00 F
+    84  |  X  |   46    |  55.00 F   |  15.00 F
+    84  |  Y  |   45    |  55.00 F   |  15.00 F
+    83  |  Y  |   29    |  35.00 F   |  15.00 F
+  ======+=====+=========+============+==============
+
+Thus out of all these cases only one did the act in spite of the ample
+chance for imitation. I have no hesitation in declaring 82’s act in
+stepping on the platform the result of mere accident, and am sure that
+any one who had watched the experiments would agree.
+
+
+IMITATION IN CATS
+
+By reference to the previous descriptions of apparatus, it will be seen
+that box D was arranged with two compartments, separated by a wire
+screen. The larger of these had a front of wooden bars with a door which
+fell open when a string stretched across the top was bitten or clawed
+down. The smaller was closed by boards on three sides and by the wire
+screen on the fourth. Through the screen a cat within could see the one
+to be imitated pull the string, go out through the door thus opened and
+eat the fish outside. When put in this compartment, the top being covered
+by a large box, a cat soon gave up efforts to claw through the screen,
+quieted down and watched more or less the proceedings going on in the
+other compartment. Thus this apparatus could be used to test the power of
+imitation. A cat who had no experience with the means of escape from the
+large compartment was put in the closed one; another cat, who would do it
+readily, was allowed to go through the performance of pulling the string,
+going out, and eating the fish. Record was made of the number of times he
+did so and of the number of times the imitator had his eyes clearly fixed
+on him. These were called ‘times seen.’ Cases where the imitator was
+looking in the general direction of the ‘imitatee’ and might very well
+have seen him and probably did, were marked ‘doubtful.’ In the remaining
+cases the cat did not see what was done by his instructor. After the
+imitatee had done the thing a number of times, the other was put in the
+big compartment alone, and the time it took him before pulling the string
+was noted and his general behavior closely observed. If he failed in 5
+or 10 or 15 minutes to do so, he was released and not fed. This entire
+experiment was repeated a number of times. From the times taken by the
+imitator to escape and from observation of the way that he did it, we can
+decide whether imitation played any part. The history of several cases
+are given in the following tables. In the first column are given the
+lengths of time that the imitator was shut up in the box watching the
+imitatee. In the second column is the number of times that the latter did
+the trick. In the third and fourth are the times that the imitator surely
+and possibly saw it done, while in the last is given the time that, when
+tried alone, the imitator took to pull the string, or if he failed,
+the time he was in the box trying to get out. Times are in minutes and
+seconds, failures denoted by F:
+
+
+TABLE 5 (a)
+
+  =======================+=====================================+===========
+                         |      NO. 7 IMITATING NO. 2          |
+  --------------+--------+------------+-----------+------------+-----------
+                |  Time  |No. of times|   No. of  |No. of times| Time of 7
+                |Watching|   2 did    |times 7 saw|  Doubtful  |when alone
+  --------------+--------+------------+-----------+------------+-----------
+                |  10.00 |     11     |     3     |       5    |
+  After 48 Hours|  11.00 |     10     |     4     |       2    |
+                |  12.00 |     20     |     4     |      13    |  10.00 F
+                |        |            |           |            |   1.00[8]
+  After 24 Hours|   8.00 |     20     |     6     |      11    |   3.30
+                |        |            |           |            |  10.00 F
+                |  13.00 |     25     |     8     |      12    |  20.00 F
+  After 24 Hours|   9.00 |     20     |     4     |      11    |  10.00 F
+  After 24 Hours|  12.00 |     35     |     5     |      21    |  30.00 F
+  After 2 Hours |  10.00 |     25     |     3     |       8    |  25.00 F
+  After 24 Hours|  15.00 |     35     |     6     |      21    |  20.00 F
+  After 24 Hours|   6.00 |     20     |     0     |       7    |  10.00 F
+    Total times surely and possibly seen,— 43           111    |
+  =============================================================+===========
+
+
+TABLE 5 (b)
+
+  =======================+=====================================+===========
+                         |        NO. 5 IMITATING NO. 2        |
+  --------------+--------+------------+-----------+------------+-----------
+                |  Time  |No. of times|   No. of  |No. of times| Time of 5
+                |Watching|   2 did    |times 5 saw|  Doubtful  |when alone
+  --------------+--------+------------+-----------+------------+-----------
+                |  12.00 |     15     |     3     |      8     |   5.00 F
+  After  2 Hours|  10.00 |      8     |     4     |      4     |
+  After 24 Hours|   5.00 |      5     |     0     |      3     |
+  After 1 Hour  |  14.00 |     10     |     5     |      3     |  10.00 F
+  After 1 Hour  |  13.00 |     22     |     7     |     11     |  10.00 F
+  After 24 Hours|   7.00 |     15     |     3     |      8     |   5.00 F
+  After 48 Hours|  18.00 |     20     |     2     |      9     |  20.00 F
+  After 24 Hours|  14.00 |     20     |     2     |     10     |  30.00 F
+  After 24 Hours|  10.00 |     20     |     7     |     12     |  20.00 F
+    Total times surely and possibly seen,— 33           68     |
+  =============================================================+===========
+
+
+TABLE 5 (c)
+
+  =======================+=====================================+===========
+                         |        NO. 6 IMITATING NO. 2        |
+  --------------+--------+------------+-----------+------------+-----------
+                |  Time  |No. of times|   No. of  |No. of times| Time of 6
+                |Watching|   2 did    |times 6 saw|  Doubtful  |when alone
+  --------------+--------+------------+-----------+------------+-----------
+                |  12.00 |     30     |     0     |     19     |   1.10[9]
+  After 48 Hours|  11.00 |     30     |     0     |     11     |   9.30
+  After 72 Hours|  10.00 |     30     |     0     |     15     |   3.00
+  After 72 Hours|   6.00 |     20     |     3     |      7     |   1.50
+  After 24 Hours|   9.00 |     30     |     1     |     13     |  10.00 F
+  After 24 Hours|  10.00 |     30     |     6     |      9     |  10.00 F
+  After 24 Hours|  10.00 |     30     |     1     |      8     |   9.40
+    Total times surely and possibly seen,— 11           82     |
+  =============================================================+===========
+
+
+TABLE 5 (d)
+
+  =======================+=====================================+===========
+                         |        NO. 3 IMITATING NO. 2        |
+  --------------+--------+------------+-----------+------------+-----------
+                |  8.00  |     30     |     2     |     19     |   3.30[10]
+                |        |            |           |            |   3.30
+  After 48 Hours| 10.00  |     30     |     2     |     14     |    .20
+                |        |            |           |            |    .20
+  After 72 Hours| 10.00  |     30     |     2     |      8     |    .18
+                |        |            |           |            |    .08
+    Total times surely and possibly seen,—  6           41     |
+  =============================================================+===========
+
+Before entering upon a discussion of the facts shown by these tables,
+we must describe the behavior of the imitators, when, after seeing 2
+pull the string, they were put in alone. In the opinion of the present
+observer there was not the slightest difference between their behavior
+and that of cats 4, 10, 11, 12 and 13, who were put into the same
+position without ever having seen 2 escape from it. 6, 7, 5 and 3 paid
+no more attention to the string than they did, but struggled in just
+the same way. No one, I am sure, who had seen them, would have claimed
+that their conduct was at all influenced by what they had seen. When
+they did hit the string the act looked just like the accidental success
+of the ordinary association experiment. But, besides these personal
+observations, we have in the impersonal time-records sufficient proofs
+of the absence of imitation. If the animals pulled the string from
+having seen 2 do so, they ought to pull it in each individual case at
+an approximately regular length of time after they were put in, and
+presumably pretty soon thereafter. That is, if an association between
+the sight of that string in that total situation and a certain impulse
+and consequent freedom and food had been formed in their minds by the
+observation of the acts of 2, they ought to pull it _on seeing it_, and
+if any disturbing factor required that a certain time should elapse
+before the imitative faculty got in working order, that time ought to be
+somewhere near constant. The times were, as a fact, long and irregular
+in the extreme. Furthermore, if the successful cases were even in part
+due to imitation, the times ought to decrease the more they saw 2 do the
+thing. Except with 3, they _increase_ or give place to failures. Whereas
+6 and 7, if they had been put in again immediately after their first
+successful trial and from then on repeatedly, would have unquestionably
+formed the association, they did not, when put in after a further
+chance to increase their knowledge by imitation, do the thing as soon
+as before. The case of 3 is not here comparable to the rest because he
+_was_ given three trials in immediate succession. He was a more active
+cat and quicker to learn, as may be seen by comparing his time curves
+with those of 7, 6 and 5. That the mere speed with which he mastered
+this association is no sign that imitation was present may be seen by
+reference to the time curves of 4 and 13 (on p. 43).
+
+Some cats were also experimented with in the following manner. They were
+put into a box [No. 7 into box A (O at front), No. 5 into B (O at back)]
+and left for from 45 to 75 seconds. Then a cat who knew the way to get
+out was put in, and, of course, pulled at the loop and opened the door.
+_Both cats then went out and both were fed._ After the cat had been
+given a number of such chances to learn by imitation, he was put in and
+left until he did the thing, or until 5 or 10 minutes elapsed. As in the
+preceding experiments, no change in their behavior which might signify
+imitation was observed. No. 7 acted exactly like 3, or 10, or 11, when
+put in the box, apparently forming the association by accident in just
+the same way. Good evidence that he did not imitate is the fact that,
+whereas 1 (whom he saw) pulled the loop with his teeth, 7 pulled it with
+his paw. 5 failed to form the association, though he saw 3 do it 8 times
+and probably saw him 18 times more. He did get out twice by clawing the
+_string_ in the _front_ of the box, not the _loop_ in the _back_, as 3
+did. These successes took place early in the experiment. After that he
+failed when left alone to get out at all.
+
+Another experiment was made by a still different method. My cats were
+kept in a large box about 4 ft. high, the front of which was covered with
+poultry-yard netting. Its top was a board which could be removed. To save
+opening the door and letting them all loose, I was in the habit of taking
+them out by the top when I wanted to experiment with them. Of course the
+one who happened to climb up (perhaps attracted by the smell of fish
+on my fingers) was most likely to be taken out and experimented with
+and fed. Thus they formed the habit of climbing up the front of the box
+whenever I approached. Of three cats which I obtained at the same time,
+one did not after 8 or 10 days acquire this habit. Even though I held out
+a piece of fish through the netting, he would not climb after it. It was
+reasonable to suppose that imitation might overcome this sluggishness,
+if there were any imitation. I therefore put two cats with him and had
+them climb up 80 times before his eyes and get fish. He never followed or
+tried to follow them.
+
+4 and 3 had been subjected to the following experiment. I would make a
+certain sound and after 10 seconds would go up to the cage and hold the
+fish out to them through the netting at the top. They would then, of
+course, climb up and eat it. After a while, they began to climb up upon
+hearing the signal (4) or before the 10 seconds were up. I then took 12
+and 10, who were accustomed to going up when they saw me approach, but
+who had no knowledge of the fact that the signal meant anything, and gave
+them each a chance to imitate 3. That is, one of them would be left in
+the box with 3, the signal would be given, and after from 5 to 10 seconds
+3 would climb up. At 10 seconds I would come up with food, and then,
+of course, 12 would climb up. This was repeated again and again. The
+question was whether imitation would lead them to form the association
+more quickly than they would have done alone. It did not. That when at
+last they did climb up before 10 seconds was past, that is, before I
+approached with food, it was not due to imitation, is shown by the fact
+that on about half of such occasions they climbed up _before 3 did_. That
+is, they reacted to the _signal_ by _association_, not to his _movements_
+by _imitation_.
+
+
+IMITATION IN DOGS
+
+Here the method was not to see if imitation could arouse more quickly an
+act which accident was fairly likely to bring forth sooner or later, but
+to see if, where accident failed, imitation would succeed.
+
+3 was found to be unable of himself to escape from box BB1, and was then
+given a chance to learn from watching 1. The back of box BB1 was torn
+off and wire netting substituted for it. Another box with open front was
+placed directly behind and against box BB1. No. 3, who was put in this
+second box, could thus see whatever took place in and in front of box BB1
+(O at back, high). The record follows:—
+
+
+TABLE 6 (a)
+
+  =======================================+================================
+                                         |      DOG 3 IMITATING DOG 1
+  --------------------------------+------+------+--------------+----------
+                                  | Times| Times|Times probably|   Time
+                                  | 1 did| 3 saw|    3 saw     | in alone
+  --------------------------------+------+------+--------------+----------
+                                  |   30 |   7  |     14       |  3.00 F
+  After 1 Hour                    |   35 |   9  |     14       |  3.00 F
+  After 1 Hour                    |   10 |   3  |      3       |  5.00 F
+  After 24 Hours                  |   20 |   6  |      8       |
+                                  |   30 |   8  |     13       |  6.00 F
+  After 48 Hours                  |   25 |   8  |     11       |  8.00 F
+                                  |   25 |   6  |     12       |  6.00 F
+                                  |   25 |   9  |      7       | 10.00 F
+  After 24 Hours                  |   30 |  10  |     11       | 40.00 F
+                                  |      |      |              |
+    Total times surely and possibly seen,—  66        93       |
+  =============================================================+==========
+
+A similar failure to imitate was observed in the case of another simple
+act. No. 1, as may be seen on page 60, had learned to escape from a pen
+about 8 by 5 feet by jumping up and biting a cord which ran from one end
+of the pen to the other and at the front end was tied to the bolt which
+held the door. Dogs 2 and 3 had failed in their accidental jumping and
+pawing to hit this cord, and were then given a chance to learn by seeing
+1 do so, escape, and, of course, be fed. 1 always jumped in the same way,
+biting the cord at the same place, namely, where a loose end from a knot
+in it hung down 4 or 5 inches. 2 and 3 would either be tied up in the pen
+or left in a pen at one side. They had a perfect chance to see 1 perform
+his successful act. After every twenty or thirty performances by 1, 2 and
+3 would be put in alone. It should be remembered that here, as also in
+the previous experiment and all others, the imitators certainly _wanted_
+to get out when thus left in alone. They struggled and jumped and pawed
+and bit, but they never jumped _at the cord_. Their records follow:—
+
+
+TABLE 6 (b)
+
+  =======================================+==============================
+                                         |  DOG 2 IMITATING DOG 1
+  --------------------------------+------+------+---------+-------------
+                                  | Times| Times| Times   |  Time 2 was
+                                  | 1 did| 2 saw| Doubtful|  in alone
+  --------------------------------+------+------+---------+-------------
+                                  |  30  |  9   |    11   | 10.00 F
+  After 1 Hour                    |  30  | 10   |     9   | 10.00 F
+  After 48 Hours                  |  25  |  8   |     8   |
+  After 1 Hour                    |  10  |  3   |     4   |  9.00 F[11]
+  After 24 Hours                  |  30  |  8   |    12   | 15.00 F
+  After 1 Hour                    |  30  |  9   |    12   | 15.00 F
+  After 48 Hours                  |  20  |  7   |     6   | 10.00 F
+                                  |  20  |  8   |     7   |
+  After 48 Hours                  |  30  |  6   |     8   | 15.00 F
+  After 24 Hours                  |  15  |  2   |     4   | 10.00 F
+    Total times surely and possibly seen,— 70        81   |
+  ========================================================+=============
+
+
+TABLE 6 (c)
+
+  =======================================+==============================
+                                         |  DOG 3 IMITATING DOG 1
+  --------------------------------+------+------+---------+-------------
+                                  | Times| Times| Times   |  Time 3 was
+                                  | 1 did| 3 saw| Doubtful|  in alone
+  --------------------------------+------+------+---------+-------------
+                                  |  30  |  10  |    10   | 10.00 F
+  After  1 Hour                   |  30  |   9  |    10   | 10.00 F
+  After  1 Hour                   |  15  |   6  |     4   |
+  After 24 Hours                  |  30  |   9  |    11   | 15.00 F
+  After 24 Hours                  |  30  |  10  |    12   | 15.00 F
+  After  1 Hour                   |  30  |   8  |     9   | 10.00 F
+  After 48 Hours                  |  20  |   6  |     7   | 40.00 F
+  After  1 Hour                   |  20  |   6  |     5   |
+  After 48 Hours                  |  30  |   8  |     9   | 15.00 F
+  After 24 Hours                  |  15  |   3  |     4   | 20.00 F
+    Total times surely and possibly seen,—  75       81   |
+  ========================================================+=============
+
+Another corroborative, though not very valuable, experiment was the
+following: Dog 3 had been taught for the purpose of another experiment
+to jump up on a box and beg when I held a piece of meat above the box. I
+then caused him to do this 110 times (within two days) in the presence of
+1. Although 1 saw him at least 20 per cent of the times (3 was always fed
+each time he jumped on the box), he never tried to imitate him.
+
+It seems sure from these experiments that the animals were unable
+to form an association leading to an act from having seen the other
+animal, or animals, perform the act in a certain situation. Thus we
+have further restricted the association process. Not only do animals
+not have associations accompanied, more or less permeated and altered,
+by inference and judgment; they do not have associations of the sort
+which may be acquired from other animals by imitation. What this implies
+concerning the actual mental content accompanying their acts will be
+seen later on. It also seems sure that we should give up imitation as an
+_a priori_ explanation of any novel intelligent performance. To say that
+a dog who opens a gate, for instance, need not have reasoned it out _if
+he had seen another dog do the same thing_, is to offer, instead of one
+false explanation, another equally false. Imitation in any form is too
+doubtful a factor to be presupposed without evidence. And if a general
+imitative faculty is not sufficiently developed to succeed with such
+simple acts as those of the experiments quoted, it must be confessed that
+the faculty is in these higher mammals still rudimentary and capable
+of influencing to only the most simple and habitual acts, or else that
+for some reason its sphere of influence is limited to a certain class
+of acts, possessed of some _qualitative difference_ other than mere
+simplicity, which renders them imitable. The latter view seems a hard
+one to reconcile with a sound psychology of imitation or association at
+present, without resorting to instinct. Unless a certain class of acts
+are by the innate mental make-up especially tender to the influence of
+imitation, the theory fails to find good psychological ground to stand
+on. The former view may very well be true. But in any case the burden
+of proof would now seem to rest upon the adherents to imitation; the
+promising attitude would seem to be one which went without imitation
+as long as it could, and that is, of course, until it surely found it
+present.
+
+Returning to imitation considered in its human aspect, to imitation
+as a transferred association in particular, we find that here our
+analytical study of the animal mind promises important contributions to
+general comparative psychology. If it is true, and there has been no
+disagreement about it, that the primates do imitate acts of such novelty
+and complexity that only this out-and-out kind of imitation can explain
+the fact, we have located one great advance in mental development. Till
+the primates we get practically nothing but instincts and individual
+acquirement through impulsive trial and error. Among the primates we
+get also acquisition by imitation, one form of the increase of mental
+equipment by tradition. The child may learn from the parent quickly
+without the tiresome process of seeing for himself. The less active and
+less curious may share the progress of their superiors. The brain whose
+impulses hitherto could only be dislodged by specific sense-impressions
+may now have any impulse set agoing by the sight of the movement to which
+it corresponds.
+
+All this on the common supposition that the primates _do_ imitate, that
+a monkey in the place of these cats and dogs _would_ have pulled the
+string. My apology for leaving the matter in this way without experiments
+of my own is that the monkey which I procured for just this purpose
+failed in two months to become tame enough to be thus experimented on.
+Accurate information about the nature and extent of imitation among
+the primates should be the first aim of further work in comparative
+psychology, and will be sought by the present writer as soon as he can
+get subjects fit for experiments.
+
+    In a questionnaire which was sent to fifteen animal trainers,
+    the following questions were asked:—
+
+    1. “If one dog was in the habit of ‘begging’ to get food and
+    another dog saw him do it ten or twenty times, would the second
+    dog then beg himself?”
+
+    2. “In general is it easier for you to teach a cat or dog a
+    trick if he has seen another do it?”
+
+    3. “In general do cats imitate each other? Do dogs? Do
+    monkeys?”
+
+    4. “Give reasons for your opinion, and please write all the
+    reasons you have.”
+
+Five gentlemen (Messrs. R. C. Carlisle, C. L. Edwards, V. P. Wormwood, H.
+S. Maguire and W. E. Burke) courteously responded to my questionnaire.
+All are trainers of acknowledged reputation. To these questions on
+imitation four replied.
+
+To the first question we find the following answers: (_a_) “Most dogs
+would.” (_b_) “Yes; he will very likely do it. He will try and imitate
+the other dog _generally_.” (_c_) “If a young dog with the mother, it
+would be very apt to.... With older dogs, it would depend very much upon
+circumstances.” (_d_) “He would not.”
+
+To 2 the answers were: (_a_) “Very much easier.” (_b_) “It is always
+easier if they see another one do it often.” (_c_) “This would also
+depend on certain conditions. In teaching to jump out of a box and
+in again, seeing another might help, but in teaching something very
+difficult, I do not think it would be the case.” (_d_) “It is not.”
+
+To 3 the answers were: (_a_) “Yes. Some. More than either dogs or cats.”
+(_b_) “Yes. Yes. Yes.” (_c_) “In certain things, yes; mostly in those
+things which are in compliance to the laws of their own nature.” (_d_)
+“No. No. Yes, they are born imitators.”
+
+The only definite answer to question 4 was: “Take a dog or cat and close
+them up in a room and go in and out several times, and you will find that
+they will go to the door and stand up on their hind legs with front paws
+on the door knob and try to open the door to get out. I could also give
+you a hundred more such reasons.” This was given by (_b_).
+
+The replies to a test question, however, go to show that these opinions
+regarding imitation may be mistaken. Question 8 was: “If you wanted to
+teach a cat to get out of a cage by opening an ordinary thumb latch and
+then pushing the door, would you take the cat’s paw and push down the
+thumb piece with it and then push the door open with the paw, or would
+you just leave the cat inside until it learned the trick itself?” The
+second is certainly the better way, as will be seen in a later part of
+this paper, and pushing the latch with the cat’s paw has absolutely no
+beneficial influence on the formation of the association, yet (_a_) and
+(_b_) both chose the first way, and (_c_) answered ambiguously. Further,
+the only reason given is, of course, no reason at all. It proves too
+much, for if there were such imitation as that, my cats and dogs would
+surely have done the far simpler things required of them. I cannot find
+that trainers make any practical use of imitation in teaching animals
+tricks, and on the whole I think these replies leave the matter just
+where it was before. They are mere opinions—not records of observed
+facts. It seems arrogant and may seem to some unjustifiable thus to
+discard testimony, to stick to a theory based on one’s own experiments in
+the face of these opinions. If I had wished to gain applause and avoid
+adverse criticism, I would have abstained from upholding the radical
+view of the preceding pages. At times it seems incredible to me that the
+results of my experiments should embody the truth of the matter, that
+there should be no imitation. The theory based on them seems, even to me,
+too radical, too novel. It seems highly improbable that I should be right
+and all the others wrong. But I cannot avoid the responsibility of giving
+what seems to my judgment the most probable explanation of the results of
+the experiments; and that is the radical explanation already given.
+
+
+THE MENTAL FACT IN ASSOCIATION
+
+It is now time to put the question as to just what is in an animal’s
+mind when, having profited by numerous experiences, he has formed the
+association and does the proper act when put in a certain box. The
+commonly accepted view of the mental fact then present is that the sight
+of the inside of the box reminds the animal of his _previous pleasant
+experience after escape_ and _of the movements_ which he made which were
+immediately followed by and so associated with that escape. It has been
+taken for granted that _if the animal remembered the pleasant experience
+and remembered the movement, he would make the movement_. It has been
+assumed that the association was _an association of ideas_; that when
+one of the ideas was of a movement the animal was capable of making
+the movement. So, for example, Morgan says, in the ‘Introduction to
+Comparative Psychology’: “If a chick takes a ladybird in its beak forty
+times and each time finds it nasty, this is of no practical value to the
+bird unless the sight of the insect suggests _the nasty taste_” (p. 90).
+
+Again, on page 92, Morgan says, “_A race after the ball_ had been
+suggested through the channel of olfactory sensations.” Also, on page
+86 “... the visual impression suggested the idea or representation of
+unpleasant gustatory experience.” The attitude is brought out more
+completely in a longer passage on page 118: “On one of our first ascents
+one of them put up a young coney, and they both gave chase. Subsequently
+they always hurried on to this spot, and, though they never saw another
+coney there, reiterated disappointment did not efface _the memory of
+that first chase_, or so it seemed.” That is, according to Morgan, the
+dogs thought of the chase and its pleasure, on nearing the spot where it
+had occurred, and so hurried on. On page 148 of ‘Habit and Instinct,’ we
+read, “Ducklings so thoroughly associated water with the sight of their
+tin that they tried to drink from it and wash in it when it was empty,
+nor did they desist for some minutes,” and this with other similar
+phenomena is attributed to the ‘association by contiguity’ of human
+psychology.
+
+From these quotations it seems fairly sure that if we should ask Mr.
+Morgan, who is our best comparative psychologist, what took place in the
+mind of one of these cats of our experiments during the performance of
+one of the ‘tricks’ he would reply: “The cat performs the act because
+of the association of ideas. He is reminded by the sight of the box and
+loop of his experience of pulling that loop and of eating fish outside.
+So he goes and pulls it again.” This view has stood unchallenged, but its
+implication is false. It implies that an animal, whenever it thinks of
+an act, can supply an _impulse to do_ the act. It takes for granted that
+the performance of a cat who gets out of a box is mentally like that of
+a man who thinks of going down street or of writing a letter and then
+does it. The mental process is not alike in the two cases, for animals
+can _not_ provide the impulse to _do_ whatever act they think of. _No cat
+can form an association leading to an act unless there is included in
+the association an impulse of its own which leads to the act._ There is
+no general storehouse from which the impulse may be supplied after the
+association is formed.
+
+Before describing the experiments which justify these statements, it will
+be worth while to recall the somewhat obvious facts about the composition
+of one of these associations. There might be in an association, such as
+is formed after experience with one of our boxes, the following elements:—
+
+1. Sense-impression of the interior of the box, etc.
+
+2. (_a_) Discomfort and (_b_) desire to get out.
+
+3. Representation of oneself pulling the loop.
+
+4. Fiat comparable to the human “I’ll do it.”
+
+5. The impulse which actually does it.
+
+6. Sense-impression of oneself pulling the loop, seeing one’s paw in a
+certain place, feeling one’s body in a certain way, etc.
+
+7. Sense-impression of going outside.
+
+8. Sense-impression of eating, and the included pleasure.
+
+Also between 1 and 4 we may have 9, representations of one’s experience
+in going out, 10, of the taste of the food, etc. 6, 7 and 8 come after
+the act and do not influence it, of course, except in so far as they
+are the basis of the future 3’s, 9’s and 10’s. About 2 we are not at
+present disputing. Our question is as to whether 3 or 5 is the essential
+thing. In human associations 3 certainly often is, and the animals
+have been credited with the same kind. Whatever he _thinks_, Professor
+Morgan surely _talks_ as if 1 aroused 9 and 10 and 3 and leaves 5 to be
+supplied at will. We have affirmed that 5 is the essential thing, that no
+association without a specific 5 belonging to it and acquired by it can
+lead to an act. Let us look at the reasons.
+
+A cat has been made to go into a box through the door, which is then
+closed. She pulls a loop and comes out and gets fish. She is made to go
+in by the door again, and again lets herself out. After this has happened
+enough times, the cat will of her own accord go into the box after eating
+the fish. It will be hard to keep her out. The old explanation of this
+would be that the cat associated the memory of being in the box with the
+subsequent pleasure, and therefore performed the equivalent of saying
+to herself, “Go to! I will go in.” The thought of _being in_, they say,
+makes her _go in_. _The thought of being in will not make her go in._
+For if, instead of pushing the cat toward the doorway or holding it
+there, and thus allowing it to itself give the impulse, to innervate the
+muscles, to walk in, you shut the door first and drop the cat in through
+a hole in the top of the box, she will, after escaping as many times
+as in the previous case, _not_ go into the box of her own accord. She
+has had exactly the same opportunity of connecting the idea of being in
+the box with the subsequent pleasure. Either a cat cannot connect ideas,
+representations, at all, or she has not the power of progressing from the
+thought of being in to the act of going in. The only difference between
+the first cat and the second cat is that the first cat, in the course of
+the experience, has the impulse to crawl through that door, while the
+second has not the impulse to crawl through the door or to drop through
+that hole. So, though you put the second cat on the box beside the hole,
+she doesn’t try to get into the box through it. The impulse is the _sine
+qua non_ of the association. The second cat has everything else, but
+cannot supply that. These phenomena were observed in six cats, three of
+which were tried by the first method, three by the second. Of the first
+three, one went in himself on the 26th time and frequently thereafter,
+one on the 18th and the other on the 37th; the two last as well as the
+first did that frequently in later trials. The other three all failed to
+go in themselves after 50, 60 and 75 trials, respectively.
+
+The case of No. 7 was especially instructive, though not among these six.
+No. 7 had had some trials in which it was put in through the door, but
+ordinarily in this particular experiment was dropped in. After about 80
+trials it would frequently exhibit the following phenomena: It would,
+after eating the fish, go up to the doorway and, rushing from it, search
+for fish. The kitten was very small and would go up into the doorway,
+whirl round and dash out, all in one quick movement. The best description
+of its behavior is the paradoxical one that it went out without going
+in. The association evidently concerned what it had _done_, what it had
+an impulse for, namely, _coming out through that door_ to get fish, not
+what it remembered, had a representation of.
+
+Still more noteworthy evidence is found in the behavior of cats and
+dogs who were put in these boxes, left one or two minutes, and then
+put through the proper movement. For example, a cat would be put in B
+(O at back) and left two minutes. I would then put my hand in through
+the top of the box, take the cat’s paw and with it pull down the loop.
+The cat would then go out and eat the fish. This would be done over and
+over again, and after every ten or fifteen such trials the cat would be
+left in alone. If in ten or twenty minutes he did not escape, he would
+be taken out through the top and not fed. In one series of experiments
+animals were taken and thus treated in boxes from which their own
+impulsive activity had failed to liberate them. The results, given in
+the table below, show that no animal who fails to perform an act in the
+course of his own impulsive activity will learn it by being put through
+it.
+
+In these experiments some of the cats and all of the dogs but No. 1
+showed no agitation or displeasure at my handling from the very start.
+Nor was there any in Dog 1 or the other cats after a few trials. It may
+also be remarked that in the trials alone which took place during and
+at the end of the experiment the animals without exception showed that
+they did not fail to perform the act from lack of a desire to get out.
+They all tried hard enough to get out and would surely have used the
+association if they had formed it.
+
+
+TABLE 7
+
+  ===========+===============================+==============+============+
+  Individual | Apparatus                     |Time in which |Number of   |
+             |                               |impulsive     |times the   |
+             |                               |activity      |animal was  |
+             |                               |failed to lead|put through |
+             |                               |to the act    |the movement|
+  -----------+-------------------------------+--------------+------------+
+  Cat 1      | F (String outside unfastened) |     55.00    |     77     |
+  Cat 5      | G (Thumb latch)               |     57.00    |     59     |
+  Cat 7      | G (Thumb latch)               |     50.00    |     30     |
+  Cat 2      | G (Thumb latch)               |     54.00    |    141     |
+  Dog 2      | BB1 (O at back, high)         |     48.00    |     30     |
+  Dog 3      | BB1 (O at back, high)         |     20.00    |     85     |
+  Dog 2      | M (Lever outside)             |     15.00    |     95     |
+  Dog 1      | FF[12]                        |     30.00    |    110     |
+  Chick 89   | X (see page 53)               |     20.00    |     30     |
+  Cat 13     | KKK,[13][14]                  |     40.00    |     65     |
+  ===========+===============================+==============+============+
+
+  ===========+===============================+===============+========
+  Individual | Apparatus                     |Time in which  |Time of
+             |                               |this experience|final
+             |                               |failed to lead |trial
+             |                               |to the act     |
+  -----------+-------------------------------+---------------+--------
+  Cat 1      | F (String outside unfastened) |    120.00     | 20.00
+  Cat 5      | G (Thumb latch)               |     55.00     | 10.00
+  Cat 7      | G (Thumb latch)               |     35.00     | 10.00
+  Cat 2      | G (Thumb latch)               |    110.00     | 20.00
+  Dog 2      | BB1 (O at back, high)         |     80.00     | 60.00
+  Dog 3      | BB1 (O at back, high)         |     55.00     | 10.00
+  Dog 2      | M (Lever outside)             |    140.00     | 30.00
+  Dog 1      | FF[12]                        |    135.00     | 60.00
+  Chick 89   | X (see page 53)               |     60.00     | 30.00
+  Cat 13     | KKK,[13][14]                  |     60.00     | 10.00
+ ============+===============================+===============+========
+
+Now, the only difference between the experiences of the animals in these
+experiments and their experiences in those where they let themselves
+out, is that here they only saw and felt themselves making the movement,
+whereas in the other case they also felt the impulse, gave the
+innervation. That, then, is the essential. It may be objected that the
+animals failed because they did not _attend_ to the process of being put
+through the movement, that, had they attended to it, they would later
+themselves have made the movement. It is, however, improbable that out
+of fifty times an animal should not have attended to what was going on
+at least two or three times. But if seeing himself do it was on a par
+with feeling an impulse to and so doing it, even two or three times
+would suffice to start the habit. And it is even more improbable that an
+experience should be followed by keen pleasure fifty times and not be
+attended to with might and main, unless animals attend _only_ to their
+own impulses and the excitements thereof. But if the latter be true, it
+simply affirms our view from a more fundamental standpoint.
+
+In another set of experiments animals were put in boxes with whose
+mechanisms they had had no experience, and from which they might or
+might not be able to escape by their own impulsive acts. The object was
+to see whether the time taken to form the association could be altered
+by my instruction. The results turned out to give a better proof of the
+inability to form an association by being put through the act than any
+failure to change the time-curve. For it happened in all but one of
+the cases that the movement which the animal made to open the door was
+different from the movement which I had put him through. Thus, several
+cats were put through (in Box C [button]) the following movement: I took
+the right paw and, putting it against the lower right-hand side of the
+button, pushed it round to a horizontal position. The cats’ ways were
+as follows: No. 1 turned it by clawing vigorously at its top; No. 6, by
+pushing it round with his nose; No. 7, in the course of an indiscriminate
+scramble at first, in later trials either by pushing with his nose or
+clawing at the top, settling down finally to the last method. Nos. 2 and
+5 did it as No. 1 did. Cat 2 was tried in B (O at back). I took his paw
+and pressed the loop with it, but he formed the habit of clawing and
+biting the string at the top of the box near the front. No. 1 was tried
+in A. I pressed the loop with his paw, but he formed the habit of biting
+at it.
+
+In every case I kept on putting the animal through the act every time,
+if at the end of two minutes (one in several cases) it had not done it,
+even after it had shown, by using a different way, that my instruction
+had no influence. I never succeeded in getting the animal to change its
+way for mine. Moreover, if any one should fancy that the animal really
+profited by my instruction so as to learn what result to attain, namely,
+the turning of a certain button, but chose a way of his own to turn
+it, he would be deluding himself. The time taken to learn the act with
+instruction was no shorter than without.
+
+If, then, an animal happens to learn an act by being put through it, it
+is just happening, nothing more. Of course, you may _direct_ the animal’s
+efforts so that he will perform the act himself the sooner. For instance,
+you may hold him so that his accidental pawing will be sure to hit the
+vital point of the contrivance. But the animal cannot form an association
+leading to an act unless the particular impulse to that act is present as
+an element of the association; he cannot supply it from a general stock.
+The groundwork of animal associations is not the association of _ideas_,
+but the association of idea or sense-impression with _impulse_.
+
+In the questionnaire mentioned elsewhere, some questions were asked with
+a view to obtaining corroboration or refutation of this theory that an
+impulse or innervation is a necessary element in every association formed
+if that association leads to an act. The questions and answers were:—
+
+_Question 1_: “If you wanted to teach a horse to tap seven times with his
+hoof when you asked him, ‘How many days are there in a week?,’ would you
+teach him by taking his leg and making him go through the motions?”
+
+_A_ answered, “Yes! at first.”
+
+_B_ answered, “No! I would not.”
+
+_C_ answered, “At first, yes!”
+
+_D_ answered, “No!”
+
+_Question 2_: “Do you think you _could_ teach him that way, even if
+naturally you would take some other way?”
+
+_A_ answered, “In time, yes!”
+
+_B_ answered, “I think it would be a very hard way.”
+
+_C_ answered, “Certainly I do.”
+
+_D_ answered, “I do not think I could.”
+
+_E_ answered, “Yes.”
+
+_Question 3_: “How would you teach him?”
+
+_A_ answered, “I should tap his foot with a whip, so that he would raise
+it, and reward him each time.”
+
+_B_ answered, “I should teach him by the motion of the whip.”
+
+_C_ answered, “First teach him by pricking his leg the number of times
+you wanted his foot lifted.”
+
+_D_ answered, “You put figure 2 on blackboard and touch him on leg twice
+with cane, and so on.”
+
+_E_ answered ambiguously.
+
+It is noteworthy that even those who think they _could_ teach an animal
+by putting him through the trick do not use that method, except at first.
+And what they really do then is probably to stimulate the animal to the
+reflex act of raising his hoof. The hand simply replaces the cane or
+whip as the means of stimulus. The answers are especially instructive,
+because the numerous counting tricks done by trained horses seem, at
+first, to be incomprehensible, unless the trainer can teach the horse by
+putting it through the movement the proper number of times. The counting
+tricks performed by Mascot, Professor Maguire’s horse, were quoted to me
+by a friend as incomprehensible on my theory. The answers given above
+show how simple the thing really is. All the counting-tricks of all the
+intelligent horses depend on the fact that a horse raises his hoof when
+a certain stimulus is given. One simple reaction gives the basis for a
+multitude of tricks. In the same way other tricks, which at first sight
+seem to require that the animal should learn by being put through the
+movement, may depend on some simple reflex or natural impulse.
+
+Another question was, “How would you teach a cat to get out of a box, the
+door of which was closed with a thumb latch?”
+
+_A_ answered, “I should use a puffball as a plaything for the cat to claw
+at.” This means, I suppose, that he would get the cat to claw at the
+puffball and thus direct its clawings to the vicinity of the thumb piece.
+
+_B_ answered, “I would put the cat in and get it good and hungry and then
+open the door by lifting the latch with my finger. Then put some food
+that the cat likes outside, and she will soon try to imitate you and so
+learn the trick.”
+
+_C_ answered, “I would first adjust all things in connection with the
+surroundings of the cat so they would be applicable to the laws of its
+nature, and then proceed to teach the trick.”
+
+I suppose this last means that he would fix the box so that some of the
+cat’s instinctive acts would lead it to perform the trick. The answer
+given by _B_ means apparently that he would simply leave the thing to
+accident, for any such imitation as he supposes is out of the question.
+At all events, none of these would naturally start to teach the trick by
+putting the animal through the motions, which, were it a possible way,
+would probably be a traditional one among trainers. On the whole, I see
+in these data no reason for modifying our dogma that animals cannot learn
+acts without the impulse.
+
+Presumably the reader has already seen budding out of this dogma a new
+possibility, a further simplification of our theories about animal
+consciousness. The possibility is that animals may have _no images or
+memories at all, no ideas to associate_. Perhaps the entire fact of
+association in animals is the presence of sense-impressions with which
+are associated, by resultant pleasure, certain impulses, and that,
+therefore, and therefore only, a certain situation brings forth a certain
+act. Returning to our analysis of the association, this theory would say
+that there was no (9) or (10) or (3) or (4), that the sense-impression
+gave rise, when accompanied by the feeling of discomfort, to the impulse
+(5) directly, without the intervention of any representations of the
+taste of the food, or the experience of being outside, or the sight of
+oneself doing the act. This theory might be modified so as to allow
+that the representations could be there, but to deny that they were
+necessary, were inevitably present, that the impulse was connected to the
+sense-impression through them. It would then claim that the effective
+part of the association was a direct bond between the situation and the
+impulse, but would not cut off the possibility of there being an aura
+of memories along with the process. It then becomes a minor question of
+interpretation which will doubtless sooner or later demand an answer. I
+shall not try to answer it now. The more radical question, the question
+of the utter exclusion of representative trains of thought, of any
+genuine association of _ideas_ from the mental life of animals, is
+worth serious consideration. I confess that, although certain authentic
+anecdotes and certain experiments, to be described soon, lead me to
+reject this exclusion, there are many qualities in animals’ behavior
+which seem to back it up. If one takes his stand by a rigid application
+of the law of parsimony, he will find justification for this view which
+no experiments of mine can overthrow.
+
+Of one thing I am sure, and that is that it is worth while to state the
+question and how to solve it, for although the point of view involved is
+far removed from that of our leading psychologists to-day, it cannot long
+remain so. I am sorry that I cannot pretend to give a final decision.
+
+The view seems preposterous because, if an animal has sense-impressions
+when his brain is excited by currents starting in the end-organs,
+it seems incredible that he should not be conscious in imagination
+and memory by having similar excitations caused from within. We are
+accustomed to think of memory as the companion of sensation. But,
+after all, it is a question of fact whether the connections in the
+cat brain include connections between present sensation-neuroses and
+past sensation-neuroses. The only connections may be those between the
+former and impulse-neuroses, and there is no authoritative reason why
+we should suppose any others unless they are demonstrated by the cat’s
+behavior. This is just the point at issue. Such evidence as the phenomena
+of animals’ dreams does not at all prove the presence of memory or
+imagination. A dog may very well growl in his sleep without any idea of
+a hostile dog. The impulse to growl _may_ be caused by chance excitement
+of its own neurosis without any sensation-neurosis being concerned.
+_Acts_ of recognition may have no _feelings_ of recognition going with or
+causing them. A sense-impression of me gets associated in my dog’s mind
+with the impulses to jump on me, lick my hand, wag his tail, etc. If,
+after a year, the connection between the two has lasted, he will surely
+jump on me, lick my hand and wag his tail, though he has not and never
+had any representation of me.
+
+The only logical way to go at this question and settle it is, I think,
+to find some associations the formation of which requires the presence
+of images, of ideas. You have to give an animal a chance to associate
+sense-impression A with sense-impression B and then to associate B
+with some act C so that the presence of B in the mind will lead to the
+performance of C. Presumably the representation of B, if present,
+will lead to C just as the sense-impression B did. Now, if the chance
+to associate B with A has been improved, you ought, when the animal is
+confronted with the sense-impression A, to get a revival of B and so
+the act C. Such a result would, if all chance to associate C with A had
+been eliminated, demonstrate the presence of representations and their
+associations. I performed such an experiment in a form modified so as to
+make it practicable with my animals and resources. Unfortunately, this
+modification spoils the crucial nature of the experiment and robs it of
+much of its authority. The experiment was as follows:—
+
+A cat was in the big box where they were kept (see p. 90) very hungry.
+As I had been for a long time the source of all food, the cats had grown
+to watch me very carefully. I sat, during the experiment, about eight
+feet from the box, and would at intervals of two minutes clap my hands
+four times and say, “I must feed those cats.” Of course the cat would at
+first feel no impulse except perhaps to watch me more closely when this
+signal was given. After ten seconds had elapsed I would take a piece of
+fish, go up to the cage and hold it through the wire netting, three feet
+from the floor. The cat would then, of course, feel the impulse to climb
+up the front of the cage. In fact, experience had previously established
+the habit of climbing up whenever I moved toward the cage, so that in the
+experiment the cat did not ordinarily wait until I arrived there with the
+fish. In this experiment
+
+A = The sense-impression of my movements and voice when giving the signal.
+
+B = The sense-impression of my movements in taking fish, rising, walking
+to box, etc.
+
+C = The act of climbing up, with the impulse leading thereunto.
+
+The question was whether after a while A would remind the cat of B, and
+cause him to do C before he got the _sense-impression_ of B, that is,
+before the ten seconds were up. If A leads to C through a memory of B,
+animals surely _can_ have association of ideas proper, and probably often
+_do_. Now, as a fact, after from thirty to sixty trials, the cat does
+perform C immediately on being confronted by A or some seconds later,
+at all events before B is presented. And it is my present opinion that
+their action is to be explained by the presence, through association, of
+the idea B. But it is not impossible that A was associated _directly_
+with the impulse to C, although that impulse was removed from it by
+ten seconds of time. Such an association is, it seems to me, highly
+improbable, unless the neurosis of A, and with it the psychosis,
+continues until the impulse to C appears. But if it does so continue
+during the ten seconds, and thus get directly linked to C, we have
+exactly a representation, an image, a memory, in the mind for eight of
+those ten seconds. It does not help the deniers of images to substitute
+an image of A for an image of B. Yet, unless they do this, they have
+to suppose that A comes and goes, and that after ten seconds C comes,
+and, passing over the intervening blank, willfully chooses out A and
+associates itself with it. There are some other considerations regarding
+the behavior of the cats from the time the signal was given till they
+climbed up, which may be omitted in the hope that it will soon be
+possible to perform a decisive experiment. If an observer can make sure
+of the animal’s attention to a sequence A-B, where B does not arouse any
+impulse to an act, and then later get the animal to associate B with C,
+leaving A out this time, he may then, if A, when presented anew, arouses
+C, bid the deniers of representations to forever hold their peace.
+
+Another reason for allowing animals representations and images is found
+in the longer time taken to form the association between the act of
+licking or scratching and the consequent escape. If the associations in
+general were simply between situation and impulse and act, one would
+suppose that the situation would be associated with the impulse to lick
+or scratch as readily as with the impulse to turn a button or claw a
+string. Such is not the case. By comparing the curves for Z on pages
+57-58 with the others, one sees that for so simple an act it takes a
+long time to form the association. This is not a final reason, for lack
+of attention, a slight increase in the time taken to open the door after
+the act was done, or an absence of preparation in the nervous system for
+connections between these particular acts and definite sense-impressions,
+may very well have been the cause of the difficulty in forming the
+associations. Nor is it certain that _ideas_ of clawing loops would be
+easier to form than ideas of scratching or licking oneself. The matter
+is still open to question. But, as said before, my opinion would be that
+animals _do_ have representations and that such are the beginning of the
+rich life of ideas in man. For the most part, however, such are confined
+to specific and narrow practical lines. There was no evidence that my
+animals habitually _did_ form associations of ideas from their experience
+throughout, or that such were constantly revived without the spur of
+immediate practical advantage.[15]
+
+Before leaving the topic an account may be given of experiments similar
+to the one described above as performed on Cats 3 and 4, which were
+undertaken with Cat 13 and Dogs 1, 2 and 3.
+
+Cat 13 was fed with pieces of fish at the top of the wire netting 45
+times, to accustom it to climbing up when it saw me come with fish. I
+then went through the same process as with 3 and 4, but at intervals of
+60 to 90 seconds instead of 120. After 90 such trials it occasionally
+climbed up a little way, but though 135 trials in all were given, it
+never made the uniform and definite reaction which 3 and 4 did. It
+reacted, when it reacted at all, at from 5 to 9 seconds after the
+signal. Whether age, weight, lack of previous habitual climbing when I
+approached, or a slowness in forming the association made the difference,
+is uncertain.
+
+Dog 1 was experimented on in the following manner: I would put him in a
+big pen, 20×10 feet, and sit outside facing it, he watching me as was
+his habit. I would pound with a stick and say, “Go over to the corner.”
+After an interval (10 seconds for 35 trials, 5 seconds for 60 trials)
+I would go over to the corner (12 feet off) and drop a piece of meat
+there. He, of course, followed and secured it. On the 6th, 7th, 16th,
+17th, 18th and 19th trials he did perform the act before the 10 seconds
+were up, then for several times went during the two-minute intervals
+without regarding the signal, and finally abandoned the habit altogether,
+although he showed by his behavior when the signal was given that he was
+not indifferent to it.
+
+Dogs 1, 2 and 3 were also given 95, 135 and 95 trials, respectively,
+the acts done being (1) standing up against the wire netting inclosing
+the pen, (2) placing the paws on top of a keg, and (3) jumping up onto
+a box. The time intervals were 5 seconds in each case. No dog of these
+ever performed the act before I started to take the meat to feed them,
+but they did show, by getting up if they were lying down when the signal
+was given, or by coming to me if they were in some other part of the
+pen, that something was suggested to them by it. Why these cases differ
+from the cases of Cats 3 and 4 (10 and 12 also presented phenomena like
+those reported in the cases of 3 and 4) is an interesting though not
+very important question. The dogs were not kept so hungry as were the
+cats, and experience had certainly not rendered the particular impulses
+involved so sensitive, so ready to discharge. Dogs 2 and 3 were older.
+There is no reason to invoke any qualitative difference in the mental
+make-up of the animals until more illuminating experiments are made.
+
+
+ASSOCIATION BY SIMILARITY AND THE FORMATION OF CONCEPTS
+
+What there is to say on this subject from the standpoint of my
+experiments will be best introduced by an account of the experiments
+themselves.
+
+Dog 1 had escaped from AA (O at front) 26 times. He was then put in
+BB (O at back). Now, whereas 2 and 3, who were put in without previous
+experience with AA, failed to paw the loop in BB, No. 1 succeeded. His
+times were 7.00, .35, 2.05, .40, .32, .10, 1.10, .38, .10, .05, and from
+then on he pawed the loop as soon as put in the box. After a day or so he
+was put in BB1 (O at back high). Although the loop was in a new position,
+his times were only .20, .10, .10, etc. After nine days he was put in a
+box arranged with a little wooden platform 2½ inches square, hung where
+the loop was in BB1. Although the platform resembled the loop not the
+least save in position, his times were only .10, .07, .05, etc.
+
+[Illustration: FIG. 21.]
+
+From the curves given in Figure 21, which tell the history of 10, 11 and
+12 in B1 (O at back) after each had previously been familiarized with A
+(O at front), we see this same influence of practice in reacting to one
+mechanism upon the time taken to react to a mechanism at all similar. It
+naturally takes a cat a longer time to accidentally claw a loop in the
+back than in the front, yet a comparison of these curves with those on
+page 39, Figure 2, shows the opposite to have been the case with 10, 11
+and 12. The same remarkable quickness was noted in Cats 1 and 3 when put
+into B (O at back) after learning A (O at front). Moreover, the loops
+were not alike. The loop in A was of smaller wire, covered with a bluish
+thread, while the loop in B was covered with a black rubber compound, the
+diameter of the loop being three times that of A’s loop.
+
+If any advocate of reason in animals has read so far, I doubt not that
+his heart has leaped with joy at these two preceding paragraphs. “How,”
+he will say, “can you explain these facts without that prime factor in
+human reason, association by similarity? Surely they show the animal
+perceiving likenesses and acting from general ideas.” _This is the very
+last thing that they show._ Let us see why they do not show this and what
+they do show. He who thinks that these animals had a general notion of a
+loop-like thing as the thing to be clawed, that they felt the loop in B,
+different as it was in size, color and position, to be still a loop, to
+have the essential quality of the other, must needs presuppose that the
+cat has a clear, accurate sensation and representation of both. Only if
+the cat discriminates can it later associate by noticing similarities.
+This is what such thinkers do presuppose. A bird, for instance, dives
+in the same manner into a river of yellow water, a pond or an ocean.
+It has a general notion, they say, of water. It knows that river water
+is one thing and pond water another thing, but it knows that both are
+water, _ergo_, fit to dive into. The cat who reacts to a loop of small
+wire of a blue color knows just what that loop is, and when it sees a
+different loop, knows its differences, but knows also its likeness, and
+reacts to the essential. Thus crediting the cat with our differentiation
+and perception of individuality, they credit it with our conceptions and
+perceptions of similarity. Unless the animal has the first, there is no
+reason to suppose the last. Now, _the animal does not have either_.
+It does not in the first place react to that particular loop in A,
+with recognition of its qualities. It reacts to a vague, ill-defined
+sense-impression, undiscriminated and even unperceived in the technical
+sense of the word. Morgan’s phrase, “a bit of pure experience,” is
+perhaps as good as any. The loop is to the cat what the ocean is to a
+man, when thrown into it when half-asleep. Thus the cat who climbed up
+the front of the cage whenever I said, “I must feed those cats,” would
+climb up just as inevitably when I said, “My name is Thorndike,” or
+“To-day is Tuesday.” So cats would claw at the loop or button when the
+door was open. So cats would paw at the place where a loop had been,
+though none was there. The reaction is not to a well-discriminated
+object, but to a vague situation, and any element of the situation may
+arouse the reaction. The whole situation in the case of man is speedily
+resolved into elements; the particular elements are held in focus, and
+the non-essential is systematically kept out of mind. In the animal the
+whole situation sets loose the impulse; all of its elements, including
+the non-essentials, get yoked with the impulse, and the situation may
+be added to or subtracted from without destroying the association,
+provided you leave something which will set off the impulse. The animal
+does not think one is like the other, nor does it, as is so often said,
+mistake one for the other. It does not think _about_ it at all; it just
+thinks _it_, and the _it_ is the kind of “pure experience” we have
+been describing. In human mental life we have accurate, discriminated
+sensations and perceptions, realized as such, and general notions, also
+realized as such. Now, what the phenomena in animals which we have been
+considering show is that they have neither. Far from showing an advanced
+stage of mentality, they show a very primitive and unspecialized stage.
+They are to be explained not by the presence of _general_ notions, but by
+the absence of notions of _particulars_. The idea that animals react to
+a particular and absolutely defined and realized sense-impression, and
+that a similar reaction to a sense-impression which varies from the first
+proves an association by similarity, is a myth. We shall see later how an
+animal does come in certain cases to discriminate, in one sense of the
+word, with a great degree of delicacy, but we shall also see then what
+must be emphasized now, that naturally the animal’s brain reacts very
+coarsely to sense-impressions, and that the animal does not think about
+his thoughts at all.
+
+This puts a new face upon the question of the origin and development of
+human abstractions and consequent general ideas. It has been commonly
+supposed that animals had ‘recepts’ or such semi-abstractions as Morgan’s
+‘predominants,’ and that by associating with these, arbitrary and
+permanent signs, such as articulate sounds, one turned them into genuine
+ideas of qualities. Professor James has made the simple but brilliant
+criticism that all a recept really means is _a tendency to react in a
+certain way_. But I have tried to show that the fact that an animal
+reacts alike to a lot of things gives no reason to believe that it is
+conscious of their common quality and reacts to that consciousness,
+because the things it reacts to in the first place are not the
+hard-and-fast, well-defined ‘things’ of human life. What a ‘recept’ or
+‘predominant’ really stands for is no thing which can be transformed into
+a notion of a quality by being labelled with a name. This easy solution
+of the problem of abstraction is impossible. A true idea of the problem
+itself is better than such a solution.
+
+My statement of what has been the course of development along this line
+is derived from observations of animals’ behavior and Professor James’
+theory of the nature of and presumable brain processes going with the
+abstractions and conceptions of human consciousness, but it is justified
+chiefly by its harmony with the view that conception, the faculty of
+having general notions, has been naturally selected by reason of its
+utility. The first thing is for an animal to learn to react alike only
+to things which resemble each other in the _essential_ qualities. On an
+artificial, analytic basis, feelings of abstract qualities might grow out
+of reacting alike to objects similar in such a respect that the reaction
+would be useless or harmful. But in the actual struggle for existence,
+starting with the mammalian mind as we have found it, you will tend to
+get reactions to the _beneficial_ similarities by selection from among
+these so-called mistakes, _before you get any general faculty of noticing
+similarities_. In order that this faculty of indifferent reaction to
+different things shall grow into the useful faculty of indifferent
+reaction to different things _which have all some quality that makes the
+reaction a fit one_, there must be a tremendous range of associations.
+For a lot of the similarities which are non-essential have to be stamped
+out, not by a power of feeling likeness, but by their failure to lead to
+pleasure. With such a wide range of associations we may get reactions
+on the one hand where impulses have been connected with one particular
+sense-impression because when connected with all others they had failed
+to give pleasure, and on the other hand, reactions where an impulse has
+been connected with numerous different impressions possessing one common
+quality, and disconnected with all impressions, otherwise like these,
+which fail to have that one quality.
+
+Combined with this multiplication of associations, there is, I think, an
+equally important factor, the loosening of the elements of an association
+from one another and from it as a whole. Probably the idea of the look
+of the loop or lever or thumb latch never entered the mind of any one of
+my cats during the months that they were with me, except when the front
+end of the association containing it was excited by putting the cat
+into the box. In general, the unit of their consciousness, apart from
+impulses and emotions, is a whole association-series. Such soil cannot
+grow general ideas, for the ideas, so long as they never show themselves
+except for a particular practical business, will not be thought about
+or realized in their nature or connections. If enough associations are
+provided by a general curiosity, such as is seen among the monkeys,
+if the mental elements of the association are freed, isolated, felt
+by themselves, _then_ a realization of the ideas, feelings of their
+similarity by transition from one to the other, feelings of qualities
+and of meanings, may gradually emerge. Language will be a factor in the
+isolation of the ideas and a help to their realization. But when any
+one says that language has been the cause of the change from brute to
+man, when one talks as if _nothing but it_ were needed to turn animal
+consciousness into human, he is speaking as foolishly as one who should
+say that a proboscis added to a cow would make it an elephant.
+
+This is all I have to say, in this connection, about association by
+similarity and conception, and with it is concluded our analysis of the
+nature of the association-process in animals. Before proceeding to treat
+of the delicacy, complexity, number and permanence of these associations,
+it seems worth while to attempt to describe graphically, not by analysis,
+the mental fact we have been studying, and also to connect our results
+with the previous theories of association.
+
+One who has seen the phenomena so far described, who has watched the
+life of a cat or dog for a month or more under test conditions, gets,
+or fancies he gets, a fairly definite idea of what the intellectual
+life of a cat or dog feels like. It is most like what we feel when
+consciousness contains little thought about anything, when we feel the
+sense-impressions in their first intention, so to speak, when we feel our
+own body, and the impulses we give to it. Sometimes one gets this animal
+consciousness while in swimming, for example. One feels the water, the
+sky, the birds above, but with no thoughts _about_ them or memories of
+how they looked at other times, or æsthetic judgments about their beauty;
+one feels no _ideas_ about what movements he will make, but feels himself
+make them, feels his body throughout. Self-consciousness dies away.
+Social consciousness dies away. The meanings, and values, and connections
+of things die away. One feels sense-impressions, has impulses, feels the
+movements he makes; that is all.
+
+This pictorial description may be supplemented by an account of some
+associations in human life which are learned in the same way as are
+animal associations; associations, therefore, where the process of
+formation is possibly homologous with that in animals. When a man
+learns to swim, to play tennis or billiards, or to juggle, the process
+is something like what happens when the cat learns to pull the string
+to get out of the box, provided, of course, we remove, in the man’s
+case, all the accompanying mentality which is not directly concerned in
+learning the feat.[16] Like the latter, the former contains desire,
+sense-impression, impulse, act and possible representations. Like it, the
+former is learned gradually. Moreover, the associations concerned cannot
+be formed by imitation. One does not know how to dive just by seeing
+another man dive. You cannot form them from being put through them,
+though, of course, this helps indirectly, in a way that it does not with
+animals. One makes use of no feelings of a common element, no perceptions
+of similarity. The tennis player does not feel, “This ball coming at
+this angle and with this speed is similar in angle, though not in speed,
+to that other ball of an hour ago, therefore I will hit it in a similar
+way.” He simply feels an impulse from the sense-impression. Finally,
+the elements of the associations are not isolated. No tennis player’s
+stream of thought is filled with free-floating representations of any of
+the tens of thousands of sense-impressions or movements he has seen and
+made on the tennis court. Yet there is consciousness enough at the time,
+keen consciousness of the sense-impressions, impulses, feelings of one’s
+bodily acts. So with the animals. There is consciousness enough, but of
+this kind.
+
+Thus, the associations in human life, which compare with the simple
+connections learned by animals, are associations involving connections
+between novel, complex and often inconstant sense-impressions and
+impulses to acts similarly novel, complex and often inconstant. Man has
+the elements of most of his associations in isolated form, attended
+to separately, possessed as a permanent fund, recallable at will, and
+multifariously connected among themselves, but with these associations
+which we have mentioned, and with others like them, he deals as the
+animals deal with theirs. The process, in the man’s mind, leaving out
+extraneous mental stuff, may be homologous to the association-process
+in animals. Of course, by assiduous attention to the elements of these
+associations, a man may isolate them, may thus get these associations
+to the same plane as the rest. But they pass through the stage we have
+described, even then, and with most men, stay there. The abstraction, the
+naming, etc., generally come from observers of the game or action, and
+concern things as felt by them, not by the participant.
+
+
+CRITICISM OF PREVIOUS THEORIES
+
+We may now look for a moment at what previous writers have said about the
+nature of association in animals. The complaint was made early in this
+book that all the statements had been exceedingly vague and of no value,
+except as retorts to the ‘reason’ school. In the course of the discussion
+I have tried to extricate from this vagueness definite statements about
+imitation, association of ideas, association by ideas. There is one more
+theory, more or less hidden in the vagueness,—the theory that association
+in animals is the same as association in man, that the animal mind
+differs from the human mind only by the absence of reason and what it
+implies. Presumably, silence about what association is, means that it is
+the association which human psychology discusses. When the silence is
+broken, we get such utterances of this theory as the following:—
+
+“I think we may say then that the higher animals are able to proceed a
+long way in the formation and definition of highly complex constructs,
+analogous to but probably differing somewhat from those which we form
+ourselves. These constructs, moreover, through association with
+reconstructs, or representations, link themselves in trains so that a
+sensation, or group of sensations, may suggest a series of reconstructs,
+or a series of remembered phenomena.” (C. L. Morgan, Animal Life and
+Intelligence, p. 341.)
+
+“Lastly, before taking leave of the subject of the chapter, I am
+most anxious that it should not be thought that, in contending that
+intelligence is not reason, I wish in any way to disparage intelligence.
+Nine tenths at least of the actions of average men are intelligent and
+not rational. Do we not all of us know hundreds of practical men who are
+in the highest degree intelligent, but in whom the rational, analytic
+faculty is but little developed? Is it any injustice to the brutes to
+contend that their inferences are of the same order as those of these
+excellent practical folk? In any case, no such injustice is intended;
+and if I deny them self-consciousness and reason, I grant to the higher
+animals perceptions of marvelous acuteness and intelligent inferences of
+wonderful accuracy and precision—intelligent inferences in some cases,
+no doubt, more perfect even than those of man, who is often disturbed by
+many thoughts” (_ibid._, pp. 376-377).
+
+“Language and the analytic faculty it renders possible differentiate man
+from the brute” (_ibid._, p. 376).
+
+Here, as elsewhere, it should be remembered that Lloyd Morgan is not
+quoted because he is the worst offender or because he represents the
+opposite in general of what the present writer takes to be the truth. On
+the contrary, Morgan is quoted because he is the least offender, because
+he has taken the most advanced stand along the line of the present
+investigation, because my differences from him are in the line of his
+differences from other writers. With the theory of the passages just
+quoted, however, which attribute extensive association of ideas and
+general powers comparable to those of men minus reason, to the brutes,
+and which repeat the time-honored distinction by language, I do not, in
+the least, agree. Association in animals does not equal association in
+man. The latter is built over and permeated and transformed by inference
+and judgment and comparison; it includes imitation in our narrow sense
+of transferred association; it obtains where no impulse is included; it
+thus takes frequently the form of long trains of thought ending in no
+pleasure-giving act; its elements are often loose, existing independently
+of the particular association; the association is not only thought,
+but at the same time thought _about_. None of these statements may
+be truthfully made of animal association. Only a small part of human
+association is at all comparable to it. My opinion of what that small
+part is has already been given. Moreover, further differences will be
+found as we consider the data relating to the delicacy, complexity,
+number, and permanence of associations in animals. I said a while ago
+that man was no more an animal with language than an elephant was a cow
+with a proboscis. We may safely broaden the statement and say that _man
+is not an animal plus reason_. It has been one great purpose of this
+investigation to show that even after leaving reason out of account,
+there are tremendous differences between man and the higher animals.
+The problem of comparative psychology is not only to get human reason
+from some lower faculties, but to get human _association_ from animal
+association.
+
+Our analysis, necessarily imperfect because the first attempted, of the
+nature of the association-process in animals is finished, and we have now
+to speak of its limitations in respect to delicacy, complexity, number
+and permanence.
+
+
+DELICACY OF ASSOCIATIONS
+
+It goes without saying that the possible delicacy of associations is
+conditioned by the delicacy of sense-powers. If an animal doesn’t feel
+differently at seeing two objects, it cannot associate one with one
+reaction, the other with another. An equally obvious factor is attention;
+what is not attended to will not be associated. Beyond this there is no
+_a priori_ reason why an animal should not react differently to things
+varying only by the most delicate difference, and I am inclined to think
+an animal could; that any two objects with a difference appreciable
+by sensation which are also able to win attention may be reacted to
+differently. Experiments to show this are very tedious, and the practical
+question is, “What will the animal naturally attend to?” The difficulty,
+as all trainers say, is to get the animal’s attention to your signal
+somehow. Then he will in time surely react differently, if you give him
+the chance, to a figure 7 on the blackboard from the way he does to a
+figure 8, to your question, “How many days are there in a week?” and to
+your question, “How many legs have you?” The chimpanzee in London that
+handed out 3, 4, 5, 6, or 7 straws at command was not thereby proved of
+remarkable intelligence or of remarkably delicate associative power. Any
+reputable animal trainer would be ashamed to exhibit a horse who could
+not do as much ‘counting’ as that. The maximum of delicacy in associating
+exhibited by any animal, to my knowledge, is displayed in the performance
+of the dog ‘Dodgerfield,’ exhibited by a Mr. Davis, who brings from four
+cards, numbered 1, 2, 3 and 4, whichever one his master shall _think of_.
+That is, you write out an arbitrary list, e.g. 4, 2, 1, 3, 3, 2, 2, 1,
+4, 2, etc., and hand it to Mr. Davis, who looks at the list, thinks of
+the first number, says “Attention! Dodger!” and then, “Bring it.” This
+the dog does and so on through the list. Mr. Davis makes no signals which
+anyone sitting even right beside or in front of him can detect. Thus the
+dog exceeds the human observers in delicacy and associates each with
+a separate act four attitudes of his master, which to human observers
+seem all alike. Mr. Davis says he thinks the dog is a mind reader. I
+think it quite possible that whatever signs the dog goes by are given
+unconsciously and consist only of some very delicate general differences
+in facial expression or the manner of saying the words, “Bring it,” or
+slight sounds made by Mr. Davis in thinking to himself the words one or
+two or three or four. Mr. Davis keeps his eyes shut and his hands behind
+a newspaper. The dog looks directly at his face.
+
+To such a height possible delicacy may attain, but possible delicacy is
+quite another thing from actual untrained and unstimulated delicacy.
+The difference in reaction has to be brought about by associating with
+pleasure the reaction to the different sense-impression when it itself
+differs and associating with pain tendencies to confuse the reactions.
+The animal does not naturally as a function of sense-powers discriminate
+at all delicately. Thus the cat who climbed up the wire netting when
+I said, “I must feed those cats!” did not have a delicate association
+of just that act with just those words. For after I had dropped the
+clapping part of the signal and simply used those words, it would react
+just as vigorously to the words, “To-morrow is Tuesday” or “My name is
+Thorndike.” The reaction naturally was to a very vague stimulus. Taking
+cat 10 when just beginning to learn to climb up at the signal, “I must
+feed those cats!” I started in to improve the delicacy, by opposing to
+this formula the formula, “I will not feed them,” after saying which, I
+kept my word. That is, I gave sometimes the former signal and fed the
+cats, sometimes the latter and did not. The object was to see how long
+the cat would be in learning always to go up when I gave the first, never
+to do so when I gave the second signal. I said the words in both cases
+as I naturally would do, so that there was a difference in emphasis and
+tone as well as in the mere nature of the syllables. The two signals were
+given in all sorts of combinations so that there was no regularity in the
+recurrence of either which might aid the animal. The cat at first did not
+always climb up at the first signal and often _did_ climb up at the wrong
+one. The change from this condition to one of perfect discrimination is
+shown in the accompanying curves (Fig. 22), one showing the decrease in
+_failures_ to respond to the wrong signal. The first curve is formed by
+a line joining the tops of perpendiculars erected at intervals of 1 mm.
+along the abscissa. The height of a perpendicular represents the number
+of times the cat failed to respond to the food-signal in 20 trials, a
+height of 1 mm. being the representative of one failure. Thus, the entire
+curve stands for 280 trials, there being no failures after 60 trials, and
+only 1 after the 40th.
+
+[Illustration: FIG. 22.]
+
+In the other curve, also, each 1 mm. along the abscissa stands for 20
+trials, and the perpendiculars whose tops the curve unites represent the
+number of times the cat in each 20 _did_ climb up at the signal which
+meant no food. It will be seen that 380 experiences were necessary before
+the animal learned that the second signal was different from the first.
+The experiment shows beautifully the animal method of acquisition. If
+at any stage the animal could have isolated the two ideas of the two
+sense-impressions, and felt them together in comparison, this long and
+tedious process would have been unnecessary.
+
+It might be stated here that the animals also acquired associations of
+moderate delicacy in discriminating between the different boxes. No cat
+tried to get out of A or B by licking herself, for instance.
+
+The question may naturally be raised that if naturally associations
+are thus vague, the common phenomenon of a dog obeying his master’s
+commands, and no one else’s, is inexplicable. The difference between
+one man and another, one voice and another, it may be said, is not
+much of a difference, yet is here uniformly discriminated, although we
+cannot suppose any such systematic training to reject the other slightly
+differing commands. My cats did not so discriminate. If any one else sat
+in my chair and called out, “I must feed the cats,” they reacted, and
+probably very many animals would, if untroubled by emotions of curiosity
+or fear at the new individual, go through their tricks as well at
+another’s voice as at that of their master. The other cases exemplify the
+influence of attention. Repeated attention to these sense-impressions has
+rendered them clear-cut and detailed, and the new impression consequently
+does not equal them in calling forth the reaction.
+
+The main thing to carry away from this discussion is the assurance that
+the delicacy of the animal in associating acts with impressions is
+nothing like the delicacy of the man who feels that a certain tone is
+higher, or weight is heavier, than another, but _is_ like the delicacy
+of the man who runs to a certain spot to hit one tennis ball and to a
+different spot to hit one coming with a slightly different speed.
+
+
+COMPLEXITY OF ASSOCIATIONS
+
+An important question, especially if one wishes to rate an animal on a
+scale of intelligence, is the question of how complex an association it
+can form. A man can learn that to open a door he has to put the key in
+its hole, turn it, turn the knob, and pull the door. Here, then, is a
+complex act connected with the simple sense-impression. Or, conversely,
+a man knows that when the ringing of a bell is followed by a whistle and
+that by a red light he is to do a certain thing, while if any of the
+three happens alone, he is not to. How far, then, we ask, can animals go
+along the line of increased complexity in the associations?
+
+We must not mistake for a complex association a series of associations,
+where one sense-impression leads to an act such as to present a new
+sense-impression which leads to another act which in its turn leads to
+a new sense-impression. Of the formation of such _series_ animals are
+capable to a very high degree. Chicks from 10 to 25 days old learned to
+go directly through a sort of big labyrinth requiring a series of 23
+distinct and in some cases fairly difficult associations, of which 11
+involved choices between two paths. By this power of acquiring a long
+series animals find their way to distant feeding grounds and back again.
+But all such cases are examples of the _number_, not of the complexity,
+of animal associations.
+
+Some of my boxes were such as did give a chance for a complex association
+to be formed. Such were G (thumb latch), J (double), K and L (triples)
+for the cats, and O (triple) for the dogs. It would be possible for a
+cat, after stepping on the platform in K, to notice that the platform was
+in a different position, and so feel then a different sense-impression
+from before, and thus turn the thing into a serial association. The
+cat would then be like a man who on seeing a door should feel only the
+impulse to stick the key in the hole, but then, seeing the door plus
+a key in the hole, should feel the impulse to turn the key and so on
+through. My cats did not give any signs of this, so that with them it
+was either a complex association or an irregular happening of the proper
+impulses. Probably the same was the case with Dog 1. Cats 10, 11, 12 in L
+knew all the movements separately before being experimented on with the
+combination. Cats 2, 3, 4 had had some experience of D, which worked by a
+string something like the string part of K. The string in K was, however,
+quite differently situated and required an altogether different movement
+to pull it. Since further No. 2, who had had ten times as much experience
+in D as 3 or 4, succeeded no better with the string element of K than
+they, it is probable that the experience did not help very much. All else
+in all these compound associations was new. At the same time the history
+of these animals’ dealings with these boxes would not fairly represent
+that of animals without general experience of clawing at all sorts of
+loose or shaky things in the inside of a box. These cats had learned
+to claw at all sorts of things. The time-curves were taken as in the
+formation of the other associations, and, in addition, the order in which
+the animal did the several things required was recorded in every trial.
+
+In the case of all the curves, except the latter part of 3 in G, one
+notices a very gradual slope and an excessive irregularity in the curve
+throughout. Within the limits of the trials given the animals are unable
+to form a perfect association and what advancement they make is very
+slow. The case of 3 in G is not an exception to this, but a proof of it.
+For 3 succeeded in making a perfect association, by accidentally hitting
+on a way to turn the compound association into a simple one. He happened
+one time to paw down the thumb piece at the same time that his other fore
+limb, with which he was holding on between the door and the top of the
+box, was pressing against the door. This giving him success he repeated
+it in later trials and in a short time had it fixed as an element in a
+perfect association. The marked change in his curve, from an irregular
+and gradual slope at such a height as displayed a very imperfect
+association, to a constant and very slight height, shows precisely the
+change from a compound to a simple association.
+
+Compound associations are formed slowly and not at all well. Further
+observation shows that they were really not formed at all. For the
+animals did not, except 3 in K for a certain period, do the several
+things in a constant order, nor did they do them only once apiece. On the
+contrary, an animal would pull the string several times after the bolt
+had gone up with its customary click, and would do sometimes one thing
+first, sometimes another. It may also be noted here, in advance of its
+proper place, that these compound associations are far below the simple
+in point of permanence. The conduct of the animals is clearly not that
+of minds having associated with a certain box’s interior the idea of a
+succession of three movements. The animal does not feel, “I did this and
+that and that and got out,” or, more simply still, “this and that and
+that means getting out.” If it did, we should soon see it doing what was
+necessary without repetition and in a fairly constant time.
+
+I imagine, however, that an animal could learn to associate with one
+sense-impression a compound act so as to perform its elements in a
+regular order. By arranging the box so that the second and third elements
+of the act could be performed _only after the first had been_, and the
+third _only after the first and second_, I am inclined to think you
+could get a very vigorous cat to learn the elements in order and form
+the association perfectly. The case is comparable to that of delicacy.
+The cat does not _tend_ to know what he is doing or to depart from the
+hit-or-miss method of learning, but by associating the other combinations
+of elements with failure to get pleasure, as in delicacy experiments we
+associated the reactions to all but the one signal, you could probably
+stamp out all but the 1, 2, 3 order.
+
+The fact that you have to thus maneuver to get the animals to have the
+three impulses in a regular order shows that even when they are so,
+there is no idea of the three as in an order, no thinking about them.
+Representations do not get beyond their first intention. They are not
+carried up into a free life which works them over anew. A complex _act_
+does not imply a complex _thought_, or, more exactly, a performance of a
+series does not imply the thought of a series. Consequently, since the
+complexity of the act depends on the power which failure has to stamp out
+all other combinations, it is far more limited than in man.
+
+
+NUMBER OF ASSOCIATIONS
+
+The patent and important fact is that there are so few in animals
+compared to the human stock. Even after taking into account the various
+acts associated with various smells, and exaggerating the possibility
+of getting an equipment of associations in this field which man lacks,
+one must recognize how far below man any animal is in respect to mere
+quantity of associations. The associations with words alone of an
+average American child of ten years far outnumber those of any dog. A
+good billiard player probably has more associations in connection with
+this single pastime than a dog with his whole life’s business. In the
+associations which are homologous with those of animals man outdoes them
+and adds an infinity of associations of a different sort. The primates
+would seem, by virtue of their incessant curiosity and addition to
+experience not for any practical purpose but merely for love of mental
+life, to represent an advanced stage toward this tremendous quantity
+of associations. In man not only this activity and curiosity, but also
+education, increases the number of associations. Associations are
+formed more quickly, and the absence of need for self-support during
+a long infancy gives time. Associations thus formed work back upon
+practical life, and by showing better ways decrease the need of work,
+and so again increase the chance to form associations. The result in
+the case of a human mind to-day is the possession of a thesaurus of
+valuable associations, if the time has been wisely spent. The free life
+of ideas, imitation, all the methods of communication, and the original
+accomplishments which we may include under the head of invention, make
+the process of acquisition in many cases quite a different one from the
+trial and error method of the animals, and in general much shorten it.
+
+Small as it is, however, the number of associations which an animal may
+acquire is probably much larger than popularly supposed.
+
+My cats and dogs did not mix up their acts with the wrong
+sense-impressions. The chicks that learned the series of twenty-three
+associations did not find it a task beyond their powers to retain
+them. Several three-day-old chicks, which I caused to learn ten simple
+associations in the same day, kept the things apart and on the next
+morning went through each act at the proper stimulus. In the hands
+of animal trainers some animals get a large number of associations
+perfectly in hand. The horse Mascot is claimed to know the meaning of
+fifteen hundred signals! He certainly knows a great many, and such as
+are naturally difficult of acquisition. It would be an enlightening
+investigation if some one could find out just how many associations a
+cat or dog could form, if he were carefully and constantly given an
+opportunity. The result would probably show that the number was limited
+only by the amount of motive available and the time taken to acquire
+each. For there is probably nothing in their brain structure which
+limits the number of connections that can be formed, or would cause such
+connections, as they grew numerous, to become confused.
+
+In their anxiety to credit animals with human powers, the psychologists
+have disregarded or belittled, perhaps, the possibilities of the strictly
+animal sort of association. They would think it more wonderful that a
+horse should respond differently to a lot of different numbers on the
+blackboard than that he should infer a consequence from premises. But
+if it be made a direct question of pleasure or pain to an animal, he
+can associate any number of acts with different stimuli. Only he does
+not form any associations until he has to, until the direct benefit is
+apparent, and, for his ordinary life, comparatively few are needed.
+
+On the whole our judgment from a comparison of man’s associations with
+the brutes’ must be that a man’s are naturally far more delicate,
+complex and numerous, and that in as far as the animals attain delicacy,
+complexity, or a great number of associations, they do it by methods
+which man uses only in a very limited part of the field.
+
+
+PERMANENCE OF ASSOCIATIONS
+
+Once formed, the connections by which, when an animal feels a certain
+sense-impression, he does a certain thing, persist over considerable
+intervals of time. With the curves on pages 39 to 58 and 60 to 65 are
+given in many instances[17] additional curves showing the animal’s
+proficiency after an interval without experience. To these data may be
+added the following:—
+
+The three chicks that had learned to escape through the long labyrinth
+(involving twenty-three associations) succeeded in repeating the
+performance after ten days’ interval. Similarly the chicks used as
+imitators in V, W, X and Y did not fail to perform the proper act
+after an interval of twenty days. Cat 6, who had had about a hundred
+experiences in C (button), had the association as perfect after twenty
+days as when it left off. Cat 2, who had had 36 experiences with C and
+had attained a constant time of 8 seconds, escaped fourteen days later
+in 3, 9 and 8 seconds, respectively, in three trials. Cat 1, after an
+interval of twenty days, failed in 10 minutes to escape from C. The
+signal for climbing up the front of the cage was reacted to by No.
+3 after an interval of twenty-four days. No. 10, who had learned to
+discriminate between ‘I must feed those cats’ and ‘I will not feed them,’
+was tried after _eighty_ days. It was given 50 trials with the second
+signal mingled indiscriminately with 25 trials with the first. I give
+the full record of these, ‘yes’ equalling a trial in which she ‘forgot’
+and climbed up, ‘no’ equalling a trial in which she wisely stayed down.
+Dashes represent intervening trials with the first signal, _to which
+she always reacted_. It will be observed that 50 trials put the cat in
+the same position that 350 had done in her first experience, although in
+that first experience she had had only about a hundred trials after the
+association had been perfected. The association between the first signal
+and climbing up was perfect after the eighty days.
+
+
+TABLE 8
+
+  =======+========+========+========+========+========
+  TRIALS | TRIALS | TRIALS | TRIALS | TRIALS | TRIALS
+   1-7   |  8-17  | 18-27  | 28-35  | 36-42  | 43-50
+  -------+--------+--------+--------+--------+--------
+    —    |   yes  |   no   |   —    |   —    |   —
+    —    |   yes  |   yes  |   —    |   no   |   —
+    yes  |   yes  |   no   |   —    |   no   |   —
+    yes  |   —    |   no   |   no   |   —    |   —
+    no   |   yes  |   —    |   no   |   no   |   —
+    —    |   yes  |   —    |   yes  |   no   |   no
+    yes  |   no   |   yes  |   no   |   no   |   no
+    yes  |   yes  |   yes  |   —    |   —    |   yes
+    no   |   no   |   yes  |   no   |   —    |   no
+    no   |   —    |   yes  |   yes  |   no   |   no
+    —    |   —    |   no   |   no   |   no   |   no
+    —    |   yes  |   no   |   no   |        |   no
+    —    |   yes  |        |        |        |   no
+         |   —    |        |        |        |
+  =======+========+========+========+========+========
+
+All these data show that traces of the connections once formed are very
+slow in being lost. If we allow that part of the time in the first trial
+in all these cases is due to the time taken to realize the situation
+(time not needed in the trials when the association is forming and the
+animal is constantly being dropped into boxes), we may say that the
+association is as firm as ever for a considerable time after practice
+at it is stopped. How long a time would be required to annul the
+influence of any given quantity of experience, say of an association
+which had been gone through with ten times, I cannot say. It could, if
+profitable, easily be determined in any case. The only case of total
+loss of the association (No. 1 in C) is so exceptional that I fancy
+something other than lapse of time was its cause. The main interest of
+these data, considered as quantitative estimates, is not psychological,
+but biological. They show what a tremendous advantage the well-developed
+association-process is to an animal. The ways to different feeding
+grounds, the actions of enemies, the appearance of noxious foods, are
+all connected permanently with the proper reaction by a few experiences
+which need be reënforced only very rarely. Of course, associations
+without any permanence would be useless, but the usefulness increases
+immensely with such a degree of permanence as these results witness. An
+interesting experiment from the biological point of view would be to see
+how infrequently an experience could occur and yet lead eventually to a
+perfect association. An experiment approximating this is recorded in the
+time-curves for Box H in Figure 7, on page 47. Three trials at a time
+were given, the trials being two or three days apart. As may be seen from
+the curves, the association was readily formed.
+
+The chief psychological interest of these data is that they show that
+permanence of associations _is not memory_. The fact that a cat, when
+after an interval she is put into box G, proceeds to immediately press
+the thumb piece and push the door, does not at all mean that the cat
+feels the box to be the same from which she weeks ago freed herself by
+pushing down that thumb piece, or thinks about ever having felt or done
+anything in that box. She does not refer the present situation to a
+situation of the past and realize that it is the same, but simply feels
+on being confronted with that situation the same impulse which she felt
+before. She does the thing now for just the same reason that she did it
+before, namely, because pleasure has connected that act above all others
+with that sense-impression, so that it is the one she feels like doing.
+Her condition is that of the swimmer who starts his summer season after
+a winter’s deprivation. When he jumps off the pier and hits the water,
+he swims, not because he remembers that this is the way he dealt with
+water last summer and so applies his remembrance to present use, but just
+because experience has taught him to feel like swimming when he hits the
+water. All talk about recognition and memory in animals, if it asserts
+the presence of anything more than this, is a gross mistake. For real
+memory is an absolute thing, including everything but forgetfulness. If
+the cat had real memory, it would, when after an interval dropped into
+a box, remember that from this box it escaped by doing this or that and
+consequently, either immediately or after a time of recollection, go
+do it, or else it would not remember and would fail utterly to do it.
+On the contrary, we have all grades of _partial_ ‘forgetfulness,’ just
+like the grades of swimming one might find if he dropped a dozen college
+professors into the mill ponds of their boyhood, just like the grades of
+forgetfulness of the associations once acquired on the ball field which
+are manifested when on the Fourth of July the ‘solid men’ of a town get
+out to amuse their fellow citizens. The animal makes attacks on a spot
+around the vital one, or claws at the thing—but not so precisely as
+before, or goes at it a while and then resorts to instinctive methods of
+getting out. Its actions are exactly what would be expected of an animal
+in whom the sense-impression aroused the impulse imperfectly, or weakly,
+or intermittently, but are not at all like the actions of one who felt,
+“I used to get out of this box by pulling that loop down.” In fact, the
+record of No. 10 given on page 139 seems to be final on this point. If
+at any time in the course of the 50 trials it had _remembered_ that ‘I
+will not feed them’ meant ‘no fish,’ it would thenceforth have failed
+to react. It would have stopped short in the ‘yes’ reactions, instead
+of gradually decreasing their percentage. ‘Memory’ in animals, if one
+still chooses to use the word, is _permanence of associations_, not the
+presence of an idea of an experience attributed to the past.
+
+To this proposition two corollaries may be added. First, these phenomena
+of incomplete forgetfulness extend the evidence that animals do not have
+a stock of independent ideas, the return of which, plus past associates,
+equals memory. Second, there is, properly speaking, no continuity in
+their mental streams. The present thought does not clutch the past to
+its bosom or hold the future in its womb. The animal’s self is not a
+being ‘looking before and after,’ but a direct practical association of
+feelings and impulses. So far as experiences come continuously, they may
+be said to form a continuous mental life, but there is no continuity
+imposed from within. The feelings of its own body are always present, and
+impressions from outside may come as they come to us. When the habit of
+attending to the elements of its associations and raising them up into
+the life of free ideas is acquired, these permanent bodily associations
+may become the basis of a feeling of self-hood and the trains of ideas
+may be felt as a continuous life.
+
+
+INHIBITION OF INSTINCTS BY HABIT
+
+One very important result of association remains to be considered, its
+inhibition of instincts and previous associations. An animal who has
+become habituated to getting out of a box by pulling a loop and opening
+the door will do so even though the hole in the top of the box be
+uncovered, whereas, if, in early trials, you had left any such hole, he
+would have taken the instinctive way and crawled through it. Instances of
+this sort of thing are well-nigh ubiquitous. It is a tremendous factor
+in animal life, and the strongest instincts may thus be annulled. The
+phenomenon has been already recognized in the literature of the subject,
+a convenient account being found in James’ ‘Psychology,’ Vol. II, pages
+394-397. In addition to such accounts, one may note that the influence
+of association is exerted in two ways. The instinct may wane by not
+being used, because the animal forms the habit of meeting the situation
+in a different way, or it may be actually inhibited. An instance of the
+former sort is found in the history of a cat which learns to pull a loop
+and so escape from a box whose top is covered by a board nailed over it.
+If, after enough trials, you remove a piece of the board covering the
+box, the cat, when put in, will still pull the loop instead of crawling
+out through the opening thus made. But, at any time, if she happens to
+notice the hole, she _may_ make use of it. An instance of the second
+sort is that of a chick which has been put on a box with a wire screen
+at its edge, preventing her from jumping directly down, as she would
+instinctively do, and forcing her to jump to another box on one side
+of it and thence down. In the experiments which I made, the chick was
+prevented by a second screen from jumping directly from the second box
+also. That is, if in the accompanying figure, A is a box 34 inches high,
+B a box 25 inches high, C a box 16 inches high, and D the pen with the
+food and other chicks, the subject had to go A-B-C-D. The chick tried at
+first to get through the screen, pecked at it and ran up and down along
+it, looking at the chicks below and seeking for a hole to get through.
+Finally it jumped to B and, after a similar process, to C. After enough
+trials it forms the habit and when put on A goes immediately to B, then
+to C and down. Now if, after 75 or 80 trials, you take away the screens,
+giving the chick a free chance to go to D from either A or B, and then
+put it on A, the following phenomenon appears. The chick goes up to the
+edge, looks over, walks up and down it for a while, still looking down
+at the chicks below, and then goes and jumps to B as habit has taught it
+to do. The same actions take place on B. No matter how clearly the chick
+sees the chance to jump to D, it does not do so. The impulse has been
+truly inhibited. It is not the mere habit of going the other way, but the
+impossibility of going _that_ way. In one case I observed a chick in whom
+the instinct was all but, yet not quite, inhibited. When tried without
+the screen, it went up to the edge to look over _nine times_, and at
+last, after seven minutes, did jump straight down.
+
+[Illustration: FIG. 23.]
+
+
+ATTENTION
+
+I have presupposed throughout one function which it will be well to now
+recognize explicitly, attention. As usual, attention emphasizes and
+facilitates the process which it accompanies. Unless the sense-impression
+is focussed by attention, it will not be associated with the act which
+comes later. Unless two differing boxes are attended to, there will be
+no difference in the reactions to them. The really effective part of
+animal consciousness, then, as of human, is the part which is attended
+to; attention is the ruler of animal as well as human mind.
+
+But in giving attention its deserts we need not forget that it is not
+here comparable to the whole of human attention. Our attention to the
+other player and the ball in a game of tennis _is_ like the animal’s
+attention, but our attention to a passage in Hegel, or the memory which
+flits through our mind, or the song we hear, or the player we idly watch,
+is _not_. There ought, I think, to be a separate name for attention
+when working for immediate practical associations. It is a different
+species from that which holds objects so that we may define them, think
+about them, remember them, etc., and the difference is, as our previous
+sentence shows, not that between voluntary and involuntary attention. The
+cat watching me for signs of my walking to the cage with fish is not in
+the condition of the man watching a ball game, but in that of the player
+watching the ball speeding toward him. There is a notable difference in
+the permanence of the impression. The man watching the game can remember
+just how that fly was hit and how the fielder ran for it, though he
+bestowed only a slight quantity of attention on the matter, while the
+fielder may attend to the utmost to the ball and yet not remember at all
+how it came or how he ran for it. The one sort of attention leads you to
+_think_ about a thing, the other to _act_ with reference to it. We must
+be careful to remember that when we say that the cat attended to what was
+said, we do not mean that he thereby established an idea of it. Animals
+are not proved to form separate ideas of sense-impressions because they
+attend to them, for the kind of attention they give is the kind which,
+when given by men, results in practical associations, not in establishing
+ideas of objects. If attention rendered clear the idea, we should not
+have the phenomena of incomplete forgetfulness lately mentioned. The
+animal would get a definite idea of just the exact thing done and would
+do it or nothing. The human development of attention is in closest
+connection with the acquisition of a stock of free ideas.
+
+
+SOCIAL CONSCIOUSNESS
+
+Besides attention there is another topic somewhat apart from our general
+one, which yet deserves a few words. It concerns animals’ social
+consciousness, their consciousness of the feelings of their fellows.
+Do animals, for example, when they see others feeding, feel that the
+others are feeling pleasure? Do they, when they fight, feel that the
+other feels pain? So level-headed a thinker as Lloyd Morgan has said that
+they do, but the conduct of my animals would seem to show that they did
+not. For it has given us good reason to suppose that they do not possess
+_any_ stock of isolated ideas, much less any abstracted, inferred, or
+transferred ideas. These ideas of others’ feelings imply a power to
+transfer states felt in oneself to another and realize them as there. Now
+it seems that any ability to thus transfer and realize an idea ought to
+carry with it an ability to form a transferred association, to imitate.
+If the animal realizes the mental states of the other animal who before
+his eyes pulls the string, goes out through the door, and eats fish,
+he ought to form the association, ‘impulse to pull string, pleasure of
+eating fish.’ This we saw the animal could not do.
+
+In fact, pleasure in another, pain in another, is not a
+sense-presentation or a representation or feeling of an object of any
+sort, but rather a ‘meaning,’ a feeling ‘_of the fact that_.’ It can
+exist only as something thought _about_. It is never ‘a bit of direct
+experience,’ but an abstraction from our own life referred to that of
+another.
+
+I fancy that these feelings of others’ feelings may be connected pretty
+closely with imitation, and for that reason may begin to appear in the
+monkeys. There we have some fair evidence for their presence in the
+tricks which monkeys play on each other. Such feelings seem the natural
+explanation of the apparently useless tail-pullings and such like which
+make up the attractions of the monkey cage. These may, however, be
+instinctive forms of play-activity or merely examples of the general
+tendency of the monkeys to fool with everything.
+
+
+INTERACTION
+
+I hope it will not be thought impertinent if from the standpoint of this
+research I add a word about a general psychological problem, the problem
+of interaction. I have spoken all along of the connection between the
+situation and a certain impulse and act being stamped in when pleasure
+results from the act and stamped out when it doesn’t. In this fact,
+which is undeniable, lies a problem which Lloyd Morgan has frequently
+emphasized. _How are pleasurable results able to burn in and render
+predominant the association which led to them?_ This is perhaps the
+greatest problem of both human and animal psychology. Unfortunately in
+human psychology it has been all tangled up with the problems of free
+will, mental activity, voluntary attention, the creation of novel acts,
+and almost everything else. In our experiments we get the data which give
+rise to the problem, in a very elementary form.
+
+It should first be noted about the _fact_ that the pleasure does not
+burn in an impulse and act themselves, but an impulse and act _as
+connected with that particular situation_. No cat ever goes around
+clawing, clawing, clawing all the time, because clawing in these boxes
+has resulted in pleasure. Secondly, the connection thus stamped in
+is _not contemporaneous, but prior to_ the pleasure. So much for the
+fact; now for the explanation. I do not wish to rehearse or add to the
+arguments with which so many pages have been already filled by scientists
+and philosophers both. What we need most is not argument, but accurate
+accounts of the mental fact and of the brain-process. But I do wish to
+say to the parallelist, what has not to my knowledge been said, that if
+he presupposes, to account for this fact, a ‘physical analogue of the
+hedonic consciousness,’ it is his bounden duty to first show how any
+motion in any neurone or group of neurones in the nervous system can
+possess this power of stamping in any current which causes it. For no one
+would, from our present knowledge of the brain, judge _a priori_ that any
+motion in any part of it could be conceived which should be thus regnant
+over all the others. And next he must show the possibility of the current
+which represents the association being the excitant of the regnant motion
+in a manner direct enough for the purpose.
+
+I wish also to say that whoever thinks that, going along with the current
+which parallels the association, there is an accompanying minor current,
+which parallels the pleasure and which stamps in the first current when
+present with it, flies directly in the face of the facts. _There is no
+pleasure along with the association. The pleasure does not come until
+after the association is done and gone._ It is caused by no such minor
+current, but by the excitation of peripheral sense-organs when freedom
+from confinement is realized or food is secured. Of course, the notion of
+such a secondary subcurrent is mythology, anyway.
+
+To the interactionist I would say: “Do not any more repeat in tiresome
+fashion that consciousness _does_ alter movement, but get to work and
+show when, where, in what forms and to what degrees it does so. Then,
+even if it turns out to have been a physical parallel that did the work,
+you will, at least, have the credit of attaining the best knowledge about
+the results and their conditions, even though you misnamed the factor.”
+
+Besides this contribution to general psychology, I think we may safely
+offer one to pedagogical science. At least some of our results possess
+considerable pedagogical interest. The fundamental form of intellection,
+the association-process in animals, is one, we decided, which requires
+the personal experience of the animal in all its elements. The
+association cannot be taught by putting the animal through it or giving
+it a chance to imitate. Now every observant teacher realizes how often
+the cleverest explanation and the best models for imitation fail. Yet
+often, in such cases, a pupil, if somehow enticed to do the thing, even
+without comprehension of what it means, even without any real knowledge
+of what he is doing, will finally get hold of it. So, also, in very
+many kinds of knowledge, the pupil who does anything from imitation, or
+who does anything from being put through it, fails to get a real and
+permanent mastery of the thing. I am sure that with a certain type of
+mind the only way to teach fractions in algebra, for example, is to get
+the pupil to do, do, do. I am inclined to think that in many individuals
+certain things cannot be learned save by actual performance. And I think
+it is often a fair question, when explanation, imitation and actual
+performance are all possible methods, which is the best. We are here
+alongside the foundations of mental life, and this hitherto unsuspected
+law of animal mind may prevail in human mind to an extent hitherto
+unknown. The best way with children may often be, in the pompous words of
+an animal trainer, ‘to arrange everything in connection with the trick
+so that the animal will be compelled by the laws of his own nature to
+perform it.’
+
+This does not at all imply that I think, as a present school of
+scientists seem to, that because a certain thing _has been_ in phylogeny
+we ought to repeat it in ontogeny. Heaven knows that Dame Nature
+herself in ontogeny abbreviates and skips and distorts the order of the
+appearance of organs and functions, and for the best of reasons. We ought
+to make an effort, as she does, to omit the useless and antiquated and
+get to the best and most useful as soon as possible; we ought to change
+what _is_ to what _ought to be_, as far as we can. And I would not
+advocate this animal-like method of learning in place of the later ones
+unless it does the same work better. I simply suggest that in many cases
+where at present its use is never dreamed of, it may be a good method.
+As the fundamental form of intellection, every student of _theoretical_
+pedagogy ought to take it into account.
+
+There is one more contribution, this time to anthropology. If the method
+of trial and error, with accidental success, be the method of acquiring
+associations among the animals, the slow progress of primitive man,
+the long time between stone age and iron age, for instance, becomes
+suggestive. Primitive man probably acquired knowledge by just this
+process, aided possibly by imitation. At any rate, progress was not
+by seeing through things, but by accidentally hitting upon them. Very
+possibly an investigation of the history of primitive man and of the
+present life of savages in the light of the results of this research
+might bring out old facts in a new and profitable way.
+
+Comparative psychology has, in the light of this research, two tasks
+of prime importance. One is to study the passage of the child mind from
+a life of immediately practical associations to the life of free ideas;
+the other is to find out how far the anthropoid primates advance toward
+a similar passage, and to ascertain accurately what faint beginnings
+or preparations for such an advance the early mammalian stock may be
+supposed to have had. In this latter connection I think it will be
+of the utmost importance to bear in mind the possibility that _the
+present anthropoid primates may be mentally degenerate_. Their present
+aimless activity and incessant, but largely useless, curiosity may be
+the degenerated vestiges of such a well-directed activity and useful
+curiosity as led _homo sapiens_ to important practical discoveries,
+such as the use of tools, the art of making fire, etc. It is even a
+remote possibility that their chattering is a _relic_ of something like
+language, not a _beginning_ of such. Comparative psychology should use
+the phenomena of the monkey mind of to-day to find out what the primitive
+mind from which man’s sprung off was like. That is the important thing
+to get at, and the question whether the present monkey mind has not gone
+back instead of ahead is an all-important question. A natural and perhaps
+sufficient cause of degeneracy would be arboreal habits. The animal that
+found a means of survival in his muscles might well lose the means before
+furnished by his brain.
+
+To these disconnected remarks still another must be added, addressed
+this time to the anecdote school. Some member of it who has chanced to
+read this may feel like saying: “This experimental work is all very
+well. Your cats and dogs represent, it is true, specimens from the top
+stratum of animal intelligence, and your negations, based on their
+conduct, may be authoritative so far as concerns the average, typical
+mammalian mind. But our anecdotes do not claim to be stories of the
+conduct of the average or type, but of those exceptional individuals
+who have begun to attain higher powers. And, if even a few dogs and
+cats have these higher powers, our contention is, in a modified form,
+upheld.” To all this I agree, provided the anecdote school now realize
+just what sort of a position they hold. They are clearly in pretty much
+the same position as spiritualists. Their anecdotes are on pretty much
+the same level as the anecdotes of thought-transference, materializations
+of spirits, supernormal knowledge, etc. Not in quite the same position,
+for far greater care has been given by the Psychical Research Society to
+establishing the criteria of authenticity, to insuring good observation,
+to explaining by normal psychology all that can be so explained, in the
+case of the latter than the anecdote school has done in the case of
+the former. The off-hand explanation of certain anecdotes by invoking
+reason, or imitation, or recognition, or feelings of qualities, is on a
+par with the explanation of trance-phenomena and such like by invoking
+the spirits of dead people. I do not deny that we may get lawfully a
+supernormal psychology, or that the supernormal acts it finds may turn
+out to be explained by these functions which I have denied to the normal
+animal mind. But I must soberly declare that I think there is less
+likelihood that such functions are the explanation of animal acts than
+that the existence of the spirits of dead people is the true explanation
+of the automatisms of spiritualistic phenomena. So much for the anecdote
+school, if it calls itself by its right name and pretends only to give an
+_abnormal_ animal psychology. The sad fact has been that it has always
+pushed forward these exceptions as the essential phenomena of animal
+mind. It has built up a general psychology from abnormal data. It is like
+an anatomy written from observations on dime-museum freaks.
+
+
+CONCLUSION
+
+I do not think it is advisable here, at the close of this paper, to give
+a summary of its results. The paper itself is really only such a summary
+with the most important evidence, for the extent of territory covered
+and the need of brevity have prevented completeness in explanation or
+illustration. If the reader cares here, at the end, to have the broadest
+possible statement of our conclusions and will take the pains to supply
+the right meaning, we might say that our work has described a method,
+crude but promising, and has made the beginning of an exact estimate of
+just what associations, simple and compound, an animal can form, how
+quickly he forms them, and how long he retains them. It has described
+the method of formation, and, on the condition that our subjects were
+representative, has rejected reason, comparison or inference, perception
+of similarity, and imitation. It has denied the existence in animal
+consciousness of any important stock of free ideas or impulses, and so
+has denied that animal association is homologous with the association of
+human psychology. It has homologized it with a certain limited form of
+human association. It has proposed, as necessary steps in the evolution
+of human faculty, a vast increase in the number of associations, signs of
+which appear in the primates, and a freeing of the elements thereof into
+independent existence. It has given us an increased insight into various
+mental processes. It has convinced the writer, if not the reader, that
+the old speculations about what an animal could do, what it thought, and
+how what it thought grew into what human beings think, were a long way
+from the truth, and _not on the road to it_.
+
+Finally, I wish to say that, although the changes proposed in
+the conception of mental development have been suggested somewhat
+fragmentarily and in various connections, that has not been done because
+I think them unimportant. On the contrary, I think them of the utmost
+importance. I believe that our best service has been to show that
+animal intellection is made up of a lot of specific connections, whose
+elements are restricted to them, and which subserve practical ends
+_directly_, and to homologize it with the intellection involved in such
+human associations as regulate the conduct of a man playing tennis. The
+fundamental phenomenon which I find presented in animal consciousness is
+one which can harden into inherited connections and reflexes, on the one
+hand, and thus connect naturally with a host of the phenomena of animal
+life; on the other hand, it emphasizes the fact that our mental life has
+grown up as a mediation between stimulus and reaction. The old view of
+human consciousness is that it is built up out of elementary sensations,
+that very minute bits of consciousness come first and gradually get built
+up into the complex web. It looks for the beginnings of consciousness to
+_little_ feelings. This our view abolishes and declares that the progress
+is not from little and simple to big and complicated, but from direct
+connections to indirect connections in which a stock of isolated elements
+plays a part, is from ‘pure experience’ or undifferentiated feelings, to
+discrimination, on the one hand, to generalizations, abstractions, on
+the other. If, as seems probable, the primates display a vast increase
+of associations, and a stock of free-swimming ideas, our view gives to
+the line of descent a meaning which it never could have so long as the
+question was the vague one of more or less ‘intelligence.’ It will,
+I hope, when supported by an investigation of the mental life of the
+primates and of the period in child life when these directly practical
+associations become overgrown by a rapid luxuriance of free ideas,
+show us the real history of the origin of human faculty. It turns out
+apparently that a modest study of the facts of association in animals has
+given us a working hypothesis for a comparative psychology.
+
+
+
+
+CHAPTER III
+
+THE INSTINCTIVE REACTIONS OF YOUNG CHICKS[18]
+
+
+The data to be presented in this article were obtained in the course of
+a series of experiments conducted in connection with the psychological
+laboratory of Harvard University during the year 1896-1897. About sixty
+chicks were used as subjects. In general their experiences were entirely
+under my control from birth. Where this was not true, the conditions of
+their life previous to the experiments were known, and were such as would
+have had no influence in determining the quality of their reactions in
+the particular experiments to which they were subjected. It is not worth
+while to recount the means taken so to regulate the chick’s environment
+that his experience along certain lines should be in its entirety known
+to the observer and that consequently his inherited abilities could be
+surely differentiated. The nature of the experiments will, in most cases,
+be such that little suspicion of the influence of education by experience
+will be possible. In the other cases I will mention the particular means
+then taken to prevent such influence.
+
+Some of my first experiments were on color vision in chicks from 18 to
+30 hours old, just old enough to move about readily and to be hungry. On
+backgrounds of white and black cardboard were pasted pieces of colored
+paper about 2 mm. square. On each background there were six of these
+pieces,—one each of yellow, red, orange, green, blue and black (on the
+white ground) or white (on the black). They were in a row about half an
+inch apart. The chicks had been in darkness for all but three or four
+hours of their life so far. During those few hours the incubator had been
+illuminated and the chicks had that much chance to learn color.
+
+The eight chicks were put, one at a time, on the sheet of cardboard
+facing the colored spots. Count was kept of the number of times that they
+pecked at each spot and, of course, they were watched to see whether they
+would peck at all at random. In the experiments with the white background
+all the colors were reacted to (_i.e._ pecked at) except black (but the
+letters on a newspaper were pecked at by the same chicks the same day).
+One of the chicks pecked at all five, one at four, three at three, one
+at two and one at yellow only. These differences are due probably to
+accidental position or movements. Taking the sums of the reactions to
+each color-spot we get the following table:—
+
+
+I
+
+  =======+================+=========================
+         |TIMES REACTED TO|TOTAL NUMBER OF PECKS[19]
+  -------+----------------+-------------------------
+  Red    |       12       |           31
+  Yellow |        9       |           21
+  Orange |        6       |           34
+  Green  |        5       |           11
+  Blue   |        1       |            3
+  =======+================+=========================
+
+I should attach no importance whatever to the quantitative estimate given
+in the table. The only fact of value so far is the evidence that from
+the first the chick reacts to all colors. In no case was there any random
+pecking at the white surface of the cardboard.
+
+On a black background the same chicks reacted to all the colors.
+
+II is a table of the results.
+
+
+II
+
+  =======+================+=====================
+         |TIMES REACTED TO|TOTAL NUMBER OF PECKS
+  -------+----------------+---------------------
+  White  |        6       |         19
+  Blue   |        4       |         11
+  Red    |        4       |          8
+  Green  |        4       |          4
+  Orange |        2       |          7
+  Yellow |        2       |          4
+  -------+----------------+---------------------
+
+In other experiments chicks were tried with green spots on a red ground,
+red spots on a green ground, yellow spots on an orange ground, green
+spots on a blue ground, and black spots on a white ground. All were
+reacted to. Thus, what is apparently a long and arduous task to the
+child is heredity’s gift to the chick. It is conceivable, though to me
+incredible, that what the chick reacts to is not the color, but the very
+minute elevation of the spot. My spots were made so that they were only
+the thickness of thin paper above pasteboard. Any one who cares to resort
+to the theory that this elevation caused the reaction can settle the case
+by using color-spots absolutely level with the surface.[20]
+
+
+INSTINCTIVE REACTIONS TO DISTANCE, DIRECTION, SIZE, ETC.
+
+I have purposely chosen this awkward heading rather than the simple
+one, Space-Perception, because I do not wish to imply that there is in
+the young chick such consciousness of space-facts as there is in human
+beings. All that will be shown here is that he reacts appropriately in
+the presence of space-facts, reacts in a fashion which would in the case
+of a man go with genuine perception of space.
+
+If one puts a chick on top of a box in sight of his fellows below, the
+chick will regulate his conduct by the height of the box. To be definite,
+we may take the average chick of about 95 hours. If the height is less
+than 10 inches, he will jump down as soon as you put him up. At 16 inches
+he will jump in from 5 seconds to 3 or 4 minutes. At 22 inches he will
+still jump down, but after more hesitation. At 27½ inches 6 chicks out
+of eight at this age jumped within 5 minutes. At 39 inches the chick
+_will NOT jump down_. The numerical values given here would, of course,
+vary with the health, development, hunger and degree of lonesomeness of
+the chick. All that they are supposed to show is that at any given age
+the chick without experience of heights regulates his conduct rather
+accurately in accord with the space-fact of distance which confronts
+him. The chick does not peck at objects remote from him, does not, for
+instance, confuse a bird a score of feet away with a fly near by, or try
+to get the moon inside his bill. Moreover, he reacts in pecking with
+considerable accuracy at the very start. Lloyd Morgan has noted that in
+his very first efforts the chick often fails to seize the object, though
+he hits it, and on this ground has denied the perfection of the instinct.
+But, as a matter of fact, the pecking reaction may be as perfect at birth
+as it is after 10 or 12 days’ experience. It certainly is not perfect
+then. I took nine chicks from 10 to 14 days old and placed them one at
+a time on a clear surface over which were scattered grains of cracked
+wheat (the food they had been eating in this same way for a week) and
+watched the accuracy of their pecking. Out of 214 objects pecked at, 159
+were seized, 55 _were not_. Out of the 159 that were seized, _only_ 116
+were seized on the first peck, 25 on the second, 16 on the third, and the
+remaining two on the fourth. Of the 55 that were not successfully seized,
+31 were pecked at only once, 10 twice, 10 three times, 3 four times and
+1 five times. I fancy one would find that adult fowls would show by no
+means a perfect record. So long as chicks with ten days’ experience fail
+to seize on the first trial 45 per cent of the time, it is hardly fair to
+argue against the perfection of the instinct on the ground of failures to
+seize during the first day.
+
+The chick’s practical appreciation of space-facts is seen further in his
+attempts to escape when confined. Put chicks only twenty or thirty hours
+old in a box with walls three or four inches high and they will react to
+the perpendicularity of the confining walls by trying to jump over them.
+In fact, in the ways he moves, the directions he takes and the objects he
+reacts to, the chicken has prior to experience the power of appropriate
+reaction to colors and facts of all three dimensions.
+
+
+INSTINCTIVE MUSCULAR COÖRDINATIONS
+
+In the acts already described we see fitting coördinations at work in
+the chick’s reactions to space-facts. A few more samples may be given.
+In jumping down from heights the chick does not walk off or fall off
+(save rarely), but jumps off. He meets the situation “loneliness on a
+small eminence” by walking around the edge and peering down; he meets
+the situation “sight of fellow chicks below” by (after an amount of
+hesitation varying roughly with the height) jumping off, holding his
+stubby wings out and keeping right side up. He lands on his feet almost
+every time and generally very cleverly. A four days’ chick will jump down
+a distance eight times his own height without hurting himself a bit. If
+one takes a chick two or three weeks old who has never had a chance to
+jump up or down, and puts him in a box with walls three times the height
+of the chick’s back, he will find that the chick will jump, or rather
+fly, nearly, if not quite, over the wall, flapping his wings lustily
+and holding on to the edge with his neck while he clambers over. Chicks
+one day old will, in about 57 per cent of the cases, balance themselves
+for five or six seconds when placed on a stiff perch. If eight or nine
+days old, they will, though never before on any perch or anything like
+one, balance perfectly for a minute or more. The muscular coördination
+required is invoked immediately when the chick feels the situation “feet
+on a perch.” The _strength_ is lacking in the first few days. From the
+fifth or sixth day on chicks are also able (their ability increases with
+age) to balance themselves on a slowly swinging perch.
+
+Another complex coördination is seen in the somewhat remarkable instinct
+of swimming. Chicks only a day or two old will, if tossed into a pond,
+head straight for the shore and swim rapidly to it. It is impossible to
+compare their movements in so doing with those of ducklings, for the
+chick is agitated, paddles his feet very fast and swims to get out, not
+for swimming’s sake. Dr. Bashford Dean, of Columbia University, has
+suggested to me that the movements may not be those of swimming, but only
+of running. At all events, they are utterly different from those of an
+adult fowl. In the case of the adult there is no vigorous instinct to
+strike out toward the shore. The hen may try to fly back into the boat
+if it is dropped overboard, and whether dropped in or slung in from the
+shore, will float about aimlessly for a while and only very slowly reach
+the shore. The movements the chick makes do look to be such as trying to
+run in water might lead to, but it is hard to see why a hen shouldn’t run
+to get out of cold water as well as a chick. If, on the other hand, the
+actions of the chick are due to a real swimming instinct, it is easy to
+see that, being unused, the instinct might wane as the animal grew up.
+
+Such instinctive coördinations as these, together with the walking,
+running, preening of feathers, stretching out of leg backward, scratching
+the head, etc., noted by other observers, make the infant chick a very
+interesting contrast to the infant man. That the helplessness of the
+child is a sacrifice to plasticity, instability and consequent power to
+develop we all know; but one begins to realize how much of a sacrifice
+when one sees what twenty-one days of embryonic life do for the chick
+brain. And one cannot help wondering whether some of the space-perception
+we trace to experience, some of the coördinations which we attribute to
+a gradual development from random, accidentally caused movements may not
+be more or less definitely provided for by the child’s inherited brain
+structure. Walking has been found to be instinctive; why not other things?
+
+
+INSTINCTIVE EMOTIONAL REACTIONS
+
+The only experiments to which I wish to refer at length under this
+heading are some concerning the chick’s instinctive fears. Before
+describing them, it may be well to mention their general bearing on
+the results obtained by Spalding and Morgan. They corroborate Morgan’s
+decision that no well-defined specific fears are present; that the fears
+of young chicks are of strange moving objects in general, shock in
+general, strange sounds in general. On the other hand, no such general
+disturbances of the chick’s environment led to such well-marked reactions
+as Spalding described. And so when Morgan thinks that such behavior as
+Spalding witnessed on the part of the chick that heard the hawk’s cry
+demands for its explanation nothing more than a general fear of strange
+sounds, my experiments do not allow me to agree with him. If Spalding
+really saw the conduct which he says the chick exhibited on the third
+day of its life in the presence of man, and later at the stimulus of
+the sight or sound of the hawk, there are specific reactions. For the
+running, crouching, silence, quivering, etc., that one gets by yelling,
+banging doors, tormenting a violin, throwing hats, bottles, or brushes
+at the chick is never anything like so pronounced and never lasts one
+tenth as long as it did with Spalding’s chicks. But, as to the fear of
+man, Spalding must have been deluded. In the second, third and fourth
+days there is no such reaction to the sight of man as he thought he saw.
+Miss Hattie E. Hunt, in the _American Journal of Psychology_, Vol. IX.,
+No. 1, asserts that there is no instinctive fear of a cat. Morgan did
+not find such. I myself put chicks of 2, 5, 9 and 17 days (different
+individuals each time, 11 in all) in the presence of a cat. They showed
+no fear, but went on eating as if there was nothing about. The cat was
+still, or only slowly moving. I further put a young kitten (eight inches
+long) in the pen with chicks. He felt of them with his paw, and walked
+around among them for five or ten minutes, yet they showed no fear (nor
+did he instinctively attack them). If, however, you let a cat jump at
+chicks in real earnest, they will not stay to be eaten, but will manifest
+fear—at least chicks three to four weeks old will. I did not try this
+experiment with chicks at different ages, because it seemed rather cruel
+and degrading to the experimenter. When in the case of the older chicks
+nature happened to make the experiment, it was hard to decide whether
+there was more violent fear of the jumping cat than there was when one
+threw a basket or football into the pen. There was not very much more.
+
+We may now proceed to a brief recital of the facts shown by the
+experiments in so far as they are novel. It should be remembered
+throughout that in every case chicks of different ages were tested so as
+to demonstrate transitory instincts if such existed, _e.g._, the presence
+of a fear of flame was tested with chicks 59 and 60, one day old, 30 and
+32, two days old, 21 and 22, three days old, 23 and 24, seven days old,
+27 and 29, nine days old, 16 and 19, eleven days old, and so on up to
+twenty-days-old chicks. By thus using different subjects at each trial
+one, of course, eliminates any influence of experience.
+
+The first notable fact is that there develops in the first month a
+general fear of novel objects in motion. For four or five days there
+seems to be no such. You may throw a hat or slipper or shaving mug at a
+chick of that age, and he will do no more than get out of the way of it.
+But a twenty-five-days-old chick will generally chirr, run and crouch for
+five or ten seconds. My records show this sort of thing beginning about
+the tenth day, but it is about ten days more before it is very marked.
+In general, also, the reaction is more pronounced if many chicks are
+together, and is then displayed earlier (only two at a time were taken
+in the experiments the results of which have just been quoted). Thus the
+reaction is to some degree a social performance, the presence of other
+chicks combining with the strange object to increase the vigor of the
+reaction. Chicks ordinarily scatter apart when they thus run from an
+object.
+
+One witnesses a similar gradual growth of the fear of man (not as such
+probably, but merely as a large moving object). For four or five days
+you can jump at the chick, grab at it with your hands, etc., without
+disturbing it in the least. A chick twenty days old, however, although he
+has never been touched or approached by a man, and in some cases never
+seen one except as the daily bringer of food, and has never been in any
+way injured by any large moving object of any sort, will run from you if
+you try to catch him or even get very near him. There is, however, even
+then, nothing like the utter fear described by Spalding.
+
+Up to thirty days there was no fear of a mocking bird into whose cage
+the chicks were put, no fear of a stuffed hawk or a stuffed owl (kept
+stationary). Chicks try to escape from water (even though warmed to the
+temperature of their bodies) from the very first. Up to forty days there
+appears no marked waning of the instinct. They did not show any emotional
+reaction to the flame produced by six candles stuck closely together.
+From the start they react instinctively to confinement, to loneliness,
+to bodily restraint, but their feeling in these cases would better be
+called discomfort than fear. From the 10th or 12th to the 20th day, and
+probably later and very possibly earlier, one notices in chicks a general
+avoidance of open places. Turn them out in your study and they will not
+go out into the middle of the room, but will cling to the edges, go under
+chairs, around table legs and along the walls. One sees nothing of the
+sort up through the fourth day. Some experiments with feeding hive bees
+to the chicks are interesting in connection with the following statement
+by Lloyd Morgan: “One of my chicks, three or four days old, snapped up
+a hive bee and ran off with it. Then he dropped it, shook his head much
+and often, and wiped his bill repeatedly. I do not think he had been
+stung: _probably he tasted the poison_” (‘Introduction to Comparative
+Psychology,’ p. 86). I fed seven bees apiece to three chicks from ten to
+twenty days old. _They ate them all greedily_, first smashing them down
+on the ground violently in a rather dexterous manner. Apparently this
+method of treatment is peculiar to the object. Chicks _three_ days old
+did not eat the bees. Some pecked at them, but none would snap them up,
+and when the bee approached, they sometimes sounded the danger note.
+
+Finally an account may be given of the reaction of chicks at different
+ages, up to twenty-six days, to loud sounds. These were the sounds made
+by clapping the hands, slamming a door, whistling sharply, banging a tin
+pan on the floor, mewing like a cat, playing a violin, thumping a coal
+scuttle with a shovel, etc. Two chicks were together in each experiment.
+Three fourths of the times no effect was produced. On the other occasions
+there was some running or crouching or, at least, starting to run or
+crouch; but, as was said, nothing like what Spalding reports as the
+reaction to the ‘cheep’ of the hawk. It is interesting to notice that
+the two most emphatic reactions were to the imitation mew. One time a
+chick ran wildly, chirring, and then crouched and stayed still until I
+had counted 105. The other time a chick crouched and stayed still until I
+counted 40. But the other chick with them did not; and in a dozen other
+cases the ‘meaw’ had no effect.
+
+I think that the main interest of most of these experiments is the proof
+they afford that instinctive reactions are not necessarily definite,
+perfectly appropriate and unvarying responses to accurately sensed and,
+so to speak, estimated stimuli. The old notion that instinct was a
+God-given substitute for reason left us an unhappy legacy in the shape of
+the tendency to think of all inherited powers of reaction as definite
+particular acts invariably done in the presence of certain equally
+definite situations. Such an act as the spider’s web-spinning might be
+a stock example. Of course, there are many such instinctive reactions
+in which a well-defined act follows a well-defined stimulus with the
+regularity and precision with which the needle approaches the magnet.
+But our experiments show that there are acts just as truly instinctive,
+depending in just the same way on inherited brain-structure, but
+characterized by being vague, irregular, and to some extent dissimilar,
+reactions to vague, complex situations.
+
+The same stimulus doesn’t always produce just the same effect, doesn’t
+produce precisely the same effect in all individuals. The chick’s
+brain is evidently prepared in a general way to react more or less
+appropriately to certain stimuli, and these reactions are among the most
+important of its instincts or inherited functions. But yet one cannot
+take these and find them always and everywhere. This helps us further to
+realize the danger of supposing that in observation of animals you can
+depend on a rigid uniformity. One would never suppose because one boy
+twirled his thumb when asked a question that all boys of that age did.
+But naturalists have been ready to believe that because one young animal
+made a certain response to a certain stimulus, the thing was an instinct
+common to all in precisely that same form. But a loud sound may make one
+chick run, another crouch, another give the danger call, and another do
+nothing whatever.
+
+In closing this article I may speak of one instinct which shows itself
+clearly from at least as early as the sixth day, which is preparatory
+to the duties of adult life and of no other use whatsoever. It is
+interesting in connection with the general matter of animal play. The
+phenomenon is as follows: The chicks are feeding quietly when suddenly
+two chicks rush at each other, face each other a moment and then go about
+their business. This thing keeps up and grows into the ordinary combat of
+roosters. It is rather a puzzle on any theory that an instinct needed so
+late should begin to develop so early.
+
+
+
+
+CHAPTER IV
+
+A NOTE ON THE PSYCHOLOGY OF FISHES[21]
+
+
+Numerous facts witness in a vague way to the ability of fishes to profit
+by experience and fit their behavior to situations unprovided for by
+their innate nervous equipment. All the phenomena shown by fishes as a
+result of taming are, of course, of this sort. But such facts have not
+been exact enough to make clear the mental or nervous processes involved
+in such behavior, or simple enough to be available as demonstrations
+of such processes. It seemed desirable to obtain evidence which should
+demonstrate both the fact and the process of learning or intelligent
+activity in the case of fishes and demonstrate them so readily that any
+student could possess the evidence first hand.
+
+Through the kindness of the officials of the United States Fish
+Commission at Woods Holl, especially of the director, Dr. Bumpus, I was
+able to test the efficiency of some simple experiments directed toward
+this end. The common Fundulus was chosen as a convenient subject, and
+also because of the neurological interest attaching to the formation of
+intelligent habits by a vertebrate whose forebrain lacks a cortex.
+
+The fishes studied were kept in an aquarium (about 4 feet long by 2 feet
+wide, with a water depth of about 9 inches) represented by Fig. 24. The
+space at one end, as represented by the lines in the figure, was shaded
+from the sun by a cover, and all food was dropped in at this end. Along
+each side of the aquarium were fastened simple pairs of cleats, allowing
+the experimenter to put across it partitions of wood, glass or wire
+screening. One of these in position is shown in the figure by the dotted
+line. These partitions were made each with an opening, as shown in Fig.
+25. If now we cause the fish to leave his shady corner and swim up to
+the sunny end by putting a slide (without any opening) in behind him at
+_D_ and moving it gently from _D_ to _A_ and then place, say slide _I_,
+across the aquarium at 1, we shall have a chance to observe the animal’s
+behavior to good purpose.
+
+[Illustration: FIG. 24.]
+
+[Illustration: FIG. 25.]
+
+This fish dislikes the sunlight and tries to get back to _D_. He reacts
+to the situation in which he finds himself by swimming against the
+screen, bumping against it here and there along the bottom. He may stop
+and remain still for a while. He will occasionally rise up toward the
+top of the water, especially while swimming up and down the length of
+the screen. When he happens to rise up to the top at the right-hand end,
+he has a clear path in front of him and swims to _D_ and feels more
+comfortable.
+
+If, after he has enjoyed the shade fifteen minutes or more, you again
+confine him in _A_, and keep on doing so six or eight times a day for a
+day or so, you will find that he swims against the screen less and less,
+swims up and down along it fewer and fewer times, stays still less and
+less, until finally his only act is to go to the right-hand side, rise
+up, and swim out. In correspondence with this change in behavior you will
+find a very marked decrease in the time he takes to escape. The fish
+has clearly profited by his experience and modified his conduct to suit
+a situation for which his innate nervous equipment did not definitely
+provide. He has, in common language, _learned_ to get out.
+
+This particular experiment was repeated with a number of individuals.
+Another experiment was made, using three slides, _II_, _III_, and
+another, requiring the fish to find his way from _A_ to _B_, _B_ to _C_,
+and from _C_ to _D_. The results of these and still others show exactly
+the same general mental process as does the one described—a process which
+I have discussed at length elsewhere.
+
+Whatever interest there is in the demonstration in the case of the
+bony fishes of the same process which accounts for so much of the
+behavior of the higher vertebrates may be left to the neurologists.
+The value of the experiment, if any, to most students will perhaps
+be the extreme simplicity of the method, the ease of administering
+it, and its possibilities. By using long aquaria, one can study the
+formation of very complex series of acts and see to what extent any
+fish can carry the formation of such series. By proper arrangements the
+delicacy of discrimination of the fish in any respect may be tested.
+The artificiality of the surroundings may, of course, be avoided when
+desirable.
+
+
+
+
+CHAPTER V
+
+THE MENTAL LIFE OF THE MONKEYS; AN EXPERIMENTAL STUDY[22]
+
+
+The literary form of this monograph is not at all satisfactory to its
+author. Compelled by practical considerations to present the facts
+in a limited space, he has found it necessary to omit explanation,
+illustration and many rhetorical aids to clearness and emphasis. For the
+same reason detailed accounts of the administration of the experiments
+have not always been given. In many places theoretical matters are
+discussed with a curtness that savors of dogmatism. In general when a
+theoretical point has appeared justified by the evidence given, I have,
+to economize space, withheld further evidence.
+
+There is, however, to some extent a real fitness in the lack of
+clearness, completeness and finish in the monograph. For the behavior of
+the monkeys, by virtue of their inconstant attention, decided variability
+of performance, and generally aimless, unforetellable conduct would be
+falsely represented in any clean-cut, unambiguous, emphatic exposition.
+The most striking testimony to the mental advance of the monkeys over
+the dogs and cats is given by the difficulty of making clear emphatic
+statements about them.
+
+
+INTRODUCTION
+
+The work to be described in this paper is a direct continuation of
+the work done by the author in 1897-1898 and described in Monograph
+Supplement No. 8 of the _Psychological Review_ under the heading, ‘Animal
+Intelligence; an Experimental Study of the Associative Processes in
+Animals.’[23] This monograph affords by far the best introduction to the
+present discussion, and I shall therefore assume an acquaintance with it
+on the part of my readers.
+
+It will be remembered that evidence was there given that ordinary
+mammals, barring the primates, did not infer or compare, did not imitate
+in the sense of ‘learning to do an act from seeing it done,’ did not
+learn various simple acts from being put through them, showed no signs
+of having in connection with the bulk of their performances any mental
+images. Their method of learning seemed to be the gradual selection of
+certain acts in certain situations by reason of the satisfaction they
+brought. Quantitative estimates of this gradualness were given for a
+number of dogs and cats. Nothing has appeared since the ‘Experimental
+Study’ to negate any of these conclusions in the author’s mind. The
+work of Kline and Small[24] on rodents shows the same general aspect of
+mammalian mentality.
+
+Adult human beings who are not notably deficient in mental functions,
+at least all such as psychologists have observed, possess a large stock
+of images and memories. The sight of a chair, for example, may call up
+in their minds a picture of the person who usually sits in it, or the
+sound of his name. The sound of a bell may call up the idea of dinner.
+The outside world also is to them in large part a multitude of definite
+percepts. They feel the environment as trees, sticks, stones, chairs,
+tables, letters, words, etc. I have called such definite presentations
+‘free ideas’ to distinguish them from the vague presentations such as
+atmospheric pressure, the feeling of malaise, of the position of one’s
+body when falling, etc. It is such ‘free ideas’ which compose the
+substance of thought and which lead us to perhaps the majority of the
+different acts we perform, though we do, of course, react to the vaguer
+sort as well. I saw definitely in writing the last sentence the words
+‘majority of the different acts’ and thought ‘we perform’ and so wrote
+it. I see a bill and so take check book and pen and write. I think of the
+cold outside and so put on an overcoat. This mental function ‘having free
+ideas,’ gives the possibility of learning to meet situations properly
+by thinking about them, by being reminded of some property of the fact
+before us or some element therein.
+
+We can divide all learning into (1) _learning by trial and accidental
+success_, by the strengthening of the connections between the
+sense-impressions representing the situation and the acts—or impulses and
+acts—representing our successful response to it and by the inhibition
+of similar connections with unsuccessful responses; (2) _learning by
+imitation_, where the mere performance by another of a certain act in a
+certain situation leads us to do the same; and (3) _learning by ideas_,
+where the situation calls up some idea (or ideas) which then arouses the
+act or in some way modifies it.
+
+The last method of learning has obviously been the means of practically
+all the advances in civilization. The evidence quoted a paragraph or so
+back from the Experimental Study shows the typical mammalian mind to be
+one which rarely or never learns in this fashion. The present study of
+the primates has been a comparative study with two main questions in
+view: (1) How do the monkeys vary from the other mammals in the general
+mental functions revealed by their methods of learning? (2) How do they,
+on the other hand, vary from adult civilized human beings?
+
+The experiments to be described seem, however, to be of value apart from
+the possibility of settling crucial questions by means of the evidence
+they give. To obtain exact accounts of what animals can learn by their
+own unaided efforts, by the example of their fellows or by the tuition of
+a trainer, and of how and how fast they learn in each case, seems highly
+desirable. I shall present the results in the manner which fits their
+consideration as arguments for or against some general hypotheses, but
+the naturalist or psychologist lacking the genetic interest may find an
+interest in them at their face value. I shall confine myself mainly to
+questions concerning the method of learning of the primates, and will
+discuss their sense-powers and unlearned reactions or instincts only in
+so far as is necessary to its comprehension.
+
+It has been impossible for the author to make helpful use of the
+anecdotes and observations of naturalists and miscellaneous writers
+concerning monkey intelligence. The objections to such data pointed out
+in Chapter II, pp. 22-26, hold here. Moreover it is not practicable to
+sift out the true from the false or to interpret these random instances
+of animal behavior even if assuredly true. In the study of animal life
+the part is only clear in the light of the whole, and it is wiser to
+limit conclusions to such as are drawn from the constant and systematic
+study of a number of animals during a fairly long time. After a large
+enough body of such evidence has been accumulated we may be able to
+interpret random observations.
+
+The subjects of the experiments were three South American monkeys of the
+genus _Cebus_. At the time of beginning the experiment No. 1 was about
+half grown, No. 2 was about one fourth full size and No. 3 was about half
+grown. No. 1 was under observation from November, 1899, to February,
+1900; No. 2 and No. 3 from October, 1900, to February, 1901. No. 1 was
+during the period of experimentation decidedly tame, showing no fear
+whatever of my presence and little fear at being handled. He would handle
+and climb over me with no hesitation. No. 2 was timid, did not allow
+handling, but showed no fear of my presence and no phenomena that would
+differentiate his behavior in the experiments discussed from that of No.
+1, save much greater caution in all respects. No. 3 also showed no fear
+at my presence. Any special individual traits that are of importance in
+connection with any of the observations will be mentioned in their proper
+places. No. 1 was kept until June, 1900, in my study in a cage 3 by 6 by
+6 feet, and was left in the country till October, 1900. From October,
+1900, all three were kept in a room 8 by 9 feet, in cages 6 feet tall by
+3 long by 2.6 wide for Nos. 1 and 2, 3 feet by 3 feet by 20 inches for
+No. 3. I studied their behavior in learning to get into boxes, the doors
+to which could be opened by operating some mechanical contrivance, in
+learning to obtain food by other simple acts, in learning to discriminate
+between two signals, that is, to respond to each by a different act, and
+in their general life.
+
+Following the order of the ‘Animal Intelligence,’ I shall first recount
+the observations of the way the monkeys learned, solely by their own
+unaided efforts, to operate simple mechanical contrivances.
+
+Besides a number of boxes such as were used with the dogs and cats (see
+illustration on p. 30), I tried a variety of arrangements which could
+be set up beside a cage, and which would, when some simple mechanism was
+set in action, throw a bit of food into the cage. Figure 26 shows one of
+these. See description of QQ (ff) on page 182.
+
+[Illustration: FIG. 26. _A_, loop; _BB_, lever, pivoted at _M_. A bit of
+food put in front of _C_ would be thrown down the chute _DDD_ when _A_
+was released.]
+
+
+APPARATUS
+
+The different mechanisms which I used were the following:—
+
+Box BB (O at back) was about 20 by 14 by 12 inches with a door in the
+front which was held by a bolt to which was tied a string. This string
+ran up the front of the box outside, over a pulley, across the top, and
+over another pulley down into the box, where it ended in a loop of wire.
+
+Box MM (bolt) was the same as BB but with no string and loop attachment
+to the bolt.
+
+Box CC (single bar) was a box of the same size as BB. The door was held
+by a bar about 3 by 1 by 5 inches which swung on a nail at the left side.
+
+Box CCC (double bar) was CC with a second similar bar on the right side
+of the door.
+
+Box NN (hook) was a box about the size of BB with its door held by an
+ordinary hook on the left side which hooked through an eyelet screwed
+into the door.
+
+Box NNN was NN with the hook on the right instead of the left side.
+
+Box NNNN was box NN with two hooks, one on each side.
+
+Apparatus OO (string box) consisted of a square box tied to a string,
+which formed a loop running over a pulley by the cage and a pulley
+outside, so that pulling on the under string would bring the box to the
+cage. In each experiment the box was first pulled back to a distance of 2
+feet 3 inches from the cage, and a piece of banana put in it. The monkey
+could, of course, secure the banana by pulling the box near enough.
+
+Apparatus OOO was the same as OO, with the box tied to the upper string,
+so that the upper string had to be pulled instead of the lower.
+
+Box PP was about the size of BB. Its door was held by a large string
+securely fastened at the right, passing across the front of the door and
+ending in a loop which was put over a nail on the box at the left of the
+door. By pulling the string off the nail the door could be opened.
+
+Box RR (wood plug) was a box about the size of BB. The door was held by
+a string at its top, which passed up over the front and top to the rear,
+where it was fastened to a wooden plug which was inserted in a hole in
+the top of the box. When the plug was pulled out of the hole, the door
+would fall open.
+
+Box SS (triple; wood-plug, hook and bar) was a box about the size of BB.
+To open the door, a bar had to be pushed around, a hook unhooked and a
+plug removed from a hole in the top of the box.
+
+Box TT (nail plug) was 14 by 10 by 10 inches with a door 5.5 by 10 on
+the right side of the front, the rest of the front being barred up. The
+door was hinged at the bottom and fastened at its top to a wire which
+was fastened to a nail 2.5 inches long, which, when inserted in a hole
+0.25 inches in diameter at the back of the top of the box, held the door
+closed. By drawing out this nail and pulling the door the animal could
+open the door.
+
+Box VV (plug at side) was a box about 18 by 10 by 10, the door held by
+a plug passing through a hole in the side of the box. When the plug was
+pulled out, the door could be pushed inward.
+
+Box W (loop) was 17 by 10 by 10 inches with a door 5 by 9 at the left
+side of its front hinged at the bottom. The door was prevented from
+falling inward by a wire stretched behind it. It was prevented from
+falling outward by a wire firmly fastened at the right side and held by a
+loop over a nail at the left. By pulling the loop outward and to the left
+it could be freed from the nail. The door could then be pulled open.
+
+Box WW (bar inside) was 16 by 14 by 10 inches with a door 4 by 11 at the
+left of its front hinged at the bottom. The door could be pushed in or
+pulled out when a bar on its inside was lifted out of a latch. The bar
+was accessible from the outside through an opening in the front of the
+box. It had to be lifted to a height of 1.5 inches (an angle of about
+30°).
+
+Box XX (bar outside) was about 13 by 11 by 10 inches with a door 7 by
+8 on the left side of the front. The door was held in place by a bar
+swinging on a nail at the top, with its other end resting in a latch at
+the left side of the box. By pushing this up through an angle of 45° the
+door could be opened.
+
+Box YY (push bar) was a box 16 by 8 by 12 inches with a door at the left
+of its front. The door was held by a brass bar which swung down in front
+of an L-shaped piece of steel fastened to the inside of the door. This
+brass bar was hung on a pivot at its center and the other end attached
+to a bar of wood; the other end of this bar projected through a hole at
+the right side of the box. By pushing this bar in about an inch the door
+could be opened.
+
+Box LL (triple; nail plug, hook and bar) was a box 10 by 10 by 13 with a
+door 3 by 8.5 at the left side. The door could be opened only after (1) a
+nail plug had been removed from a hole in the back of the top of the box
+as in TT, (2) a hook in the door had been unhooked, and (3) a bar on the
+left side had been turned from a horizontal to a vertical position.
+
+Box Alpha (catch at back) was 11 by 10 by 15 with the door (4 by 4) in
+the left side of its front. The door was held by a bolt, which, when let
+down, held in a catch on the inside of the door. A string fastened to the
+bolt ran across to the back of the box and through a hole to the outside.
+There it ended in a piece of wood 2.5 by 1 by .25 inches. When this piece
+of wood was pulled, the bolt went up and the door fell open.
+
+Box Beta was the same as NN except in size. It was 10 by 10 by 13 inches.
+
+Box KK (triple; bolt, side plug, and knob) was a box 16 by 9 by 11 with
+a door at the left side of the front. The door was held by a bolt on the
+right side, a wooden plug stuck through a hole in the box on its left
+side and a nail which held in a catch at its top. This nail was fastened
+to a wooden knob (1 by 5 by .375) which lay in a depression at the top of
+the box. Only when the bolt had been drawn and the plug and knob pulled,
+could the door be opened.
+
+Box Gamma (wind) was 10 by 10 by 13 inches with its door held by a wire
+fastened at the top and wound three times about a screw eye in the top of
+the box. By unwinding the wire the door could be opened.
+
+Box Delta (push back) was 12 by 11 by 10 inches. Its door was held by
+a wooden bar projecting from the right two inches in front of it. This
+bar was so arranged that it could be pushed or pulled toward the right,
+allowing the door to fall open. It could not be swung up or down.
+
+Box Epsilon (lever or push down) was 12 by 9 by 5 inches. At the right
+side of its front was a hole ½ inch broad by 1½ inches up and down.
+Across this hole on the inside of the box was a strip of brass, the end
+of one bar of a lever. If this strip was depressed ⅛ of an inch, the door
+at the extreme left would be opened by a spring.
+
+Box Zeta (side plug) was 12 by 11 by 10 inches. Its door was held by a
+round bar of wood put through a hoop of steel at the left side of the
+box. This bar was loose and could easily be pulled out, allowing the door
+to be opened.
+
+Box Theta was the same as KK except that the door could be opened as soon
+as the bolt alone was pulled or pushed up.
+
+Box Eta was like Alpha save that the object at the back of the box to be
+pulled was a brass ring.
+
+Apparatus QQ (chute) consisted of a lever mechanism so arranged that
+by pushing in a bar of wood ¼ to ½ an inch, a piece of banana would be
+thrown down a chute into the cage. The apparatus was placed outside the
+cage in such a way that it could be easily reached by the monkey’s arm
+through the wire netting.
+
+QQ (a) was of the same general plan. By turning a handle through 270°
+food could be obtained.
+
+QQ (b) was like QQ (a) except that 2½ full revolutions of the handle in
+one direction were necessary to cause the food to drop down.
+
+QQ (c) was a chute apparatus so arranged as to work when a nail was
+pulled out of a hole.
+
+QQ (d) was arranged to work at a sharp pull upon a brass ring hanging to
+it.
+
+QQ (e) was arranged to work when a hook was unhooked.
+
+QQ (f) was arranged to work when a loop at the end of a string was pulled
+off from a nail.
+
+QQ (ff) was QQ (f) with a stiff wire loop instead of a loop of string.
+
+
+EXPERIMENTS ON THE ABILITIES OF THE MONKEYS TO LEARN WITHOUT TUITION
+
+I will describe a few of the experiments with No. 1 as samples and then
+present the rest in the form of a table. No. 1 was tried first in BB (O
+at back) on January 17, 1900, being _put inside_. He opened the box by
+pulling up the string just above the bolt. His times were .05, 1.38,
+6.00, 1.00, .10, .05, .05. He was not easily handled at this time, so I
+changed the experiment to the form adopted in future experiments. I put
+the food inside and left the animal to open the door from the outside. He
+pulled the string up within 10 seconds each time out of 10 trials.
+
+I then tried him in MM (bolt). He failed in 15. I then (January 18th)
+tried him in CC (single bar outside). He got in in 36.00 minutes; he did
+not succeed a second time that night, but in the morning the box was
+open. His times thenceforth were 20, 10, 16, 25 and on January 19th, 40,
+5, 12, 8, 5, 5, 5 seconds.
+
+I then tried him (January 21, 1900) in CCC (double bar). He did it at
+first by pushing the old bar and then pulling at the door until he worked
+the second bar gradually around. Later he at times pushed the second
+bar. The times taken are shown in the time-curve. I then (January 25th)
+tried him in NN (hook). See time-curves on page 185. I then (January
+27th) tried him in NNN (hook on other side). He opened it in 6, 12 and 4
+seconds in the first three trials. I then (20 minutes later) tried him
+with NNNN (double hook). He opened the door in 12, 10, 6 and 6 seconds. I
+then (January 27th) tried him with PP (string across). He failed in 10.
+I then (February 21st) tried him with apparatus OO (string box). For his
+progress as shown by the times taken see the time-curve. His progress is
+also shown in the decrease of the useless pullings at the wrong string.
+There were none in the 9th trial, 14th, 15th, 16th, 18th, 24th, and
+following trials.
+
+No. 1 was then (February 24th) tried with OOO (string box with box on
+upper string). No. 1 succeeded in 2.20, then failed in 10.00. The rest of
+the experiment will be described under imitation.
+
+He was next tried (March 24th) with apparatus QQ (chute). He failed
+in 10.00, though he played with the apparatus much of the time. Other
+experiments were with box RR (wood-plug) (April 5th). He failed in 10.00.
+After he had, in a manner to be described later, come to succeed with RR,
+he was tried in box SS (triple; wood-plug, hook and bar) (April 18th);
+see time-curve. No more experiments of this nature were tried until
+October, 1900.
+
+The rest of the experiments with No. 1 and all those with No. 2 and No.
+3 may best be enumerated in the form of a table. (See Table 9 on page
+187.) It will show briefly the range of performances which the unaided
+efforts of the animals can cope with. It will also give the order in
+which each animal experienced them. F means that the animal failed to
+succeed. The figures are minutes and seconds, and represent the time
+taken in the first trial or the total time taken without success where
+there is an F. In cases where the animal failed in say 10 minutes, but in
+a later trial succeeded, say in 2.40, the record will be 2.40 after 10 F.
+There are separate columns for all three animals, headed No. 1, No. 2 and
+No. 3. Im. stands for a practically immediate success.
+
+The curves on pages 185 and 186 (Figs. 27 and 28) show the progress of
+the formation of the associations in those cases where the animal was
+given repeated trials, with, however, nothing to guide him but his own
+unaided efforts. Each millimeter on the abscissa represents one trial
+and each millimeter on the ordinate represents 10 seconds, the ordinates
+representing the time taken by the animal to open the box. A break in
+the curve, or an absence of the curve at the beginning of the base-line
+represents cases where the animal failed in 10 minutes or took a very
+long time to get out.
+
+[Illustration: FIG. 27.]
+
+[Illustration: FIG. 28.]
+
+In discussing these facts we may first of all clear our way of one
+popular explanation, that this learning was due to ‘reasoning.’ If
+we use the word reasoning in its technical psychological meaning as
+the function of reaching conclusions by the perception of relations,
+comparison and inference, if we think of the mental content involved as
+feelings of relation, perceptions of similarity, general and abstract
+notions and judgments, we find no evidence of reasoning in the behavior
+of the monkeys toward the mechanisms used. And this fact nullifies the
+arguments for reasoning in their case as it did in the case of the
+dogs and cats. The argument that successful dealings with mechanical
+contrivances imply that the animals reasoned out the properties of the
+mechanisms, is destroyed when we find mere selection from their general
+instinctive activities sufficient to cause success with bars, hooks,
+loops, etc. There is also in the case of the monkeys, as in that of the
+other mammals, positive evidence of the absence of any general function
+of reasoning. We shall find that at least very many simple acts were not
+learned by the monkeys in spite of their having seen me perform them
+again and again; that the same holds true of many simple acts which they
+saw other monkeys do, or were put through by me. We shall find that after
+having abundant opportunity to realize that one signal meant food at the
+bottom of the cage and another none, a monkey would not act from the
+obvious inference and consistently stay up or go down as the case might
+be, but would make errors such as would be natural if he acted under
+the growing influence of an association between sense-impression and
+impulse or sense-impression and idea, but quite incomprehensible if he
+had compared the two signals and made a definite inference. We shall find
+that, after experience with several pairs of signals, the monkeys yet
+failed, when a new pair was used, to do the obvious thing to a rational
+mind; viz., to compare the two, think which meant food, and act on the
+knowledge directly.
+
+
+TABLE 9
+
+  -------------------------------+---------------------------------+
+                                 |              No. 1.             |
+                                 +-------------+---------+---------+
+                                 |             |Min. Sec.|         |
+  -------------------------------+-------------+---------+---------+
+  Box TT (nail plug)             |Oct. 19, 1900|  0.40   |         |
+  Box UU (old plug at side)      |Oct. 19, 1900|         |  F 60.00|
+  Box VV (wire loop)             |Oct. 20, 1900|         |{ F 10.00|
+                                 |             |         |{ F 10.00|
+                                 |             |         |{ F 10.00|
+  Box WW (bar inside)            |Oct. 20, 1900|         |  F 10.00|
+                                 |             |         |         |
+                                 |             |         |         |
+                                 |             |         |         |
+  Box XX (bar outside)           |Oct. 23, 1900|   im.   |  after  |
+                                 |             |         |   [25]  |
+                                 |             |         |  F 10.00|
+  Box YY (push bar)              |Oct. 30, 1900| 2.00[26]|         |
+  Box Beta (single hook)         |             |         |         |
+                                 |             |         |         |
+                                 |             |         |         |
+  Box LL (triple; nail plug,     |Nov. 4, 1900 |16.00[27]|         |
+    hook and bar outside)        |             |         |         |
+  Box Alpha (catch at back)      |Nov. 5, 1900 |   .35   |         |
+  Box KK (triple; bolt, side-plug|Nov. 7, 1900 |         |  F 10.00|
+    and knob)                    |             |         |  F 10.00|
+  Box Theta (bolt at top)        |Nov. 19, 1900|         |  F 10.00|
+  Box Eta (ring at back)         |Dec. 17, 1900|   im.   |         |
+  App. QQ (push chute)           |             |         |         |
+  Box Gamma (wind)               |Jan. 3, 1901 |   .20   |         |
+                                 |             |         |         |
+  Box Delta (push back)          |Jan. 4, 1901 |         |  F  5.00|
+                                 |             |         |  F  5.00|
+  App. QQ (a) (bar chute)        |Jan. 6, 1901 |  8.00   |         |
+  Box Zeta (new side plug)       |Jan. 7, 1901 |  1.10   |   after |
+                                 |             |         |  F  5.00|
+  App. QQ (b) (2½ revolution     |             |         |         |
+    chute)                       |Jan. 9, 1901 |  3.00   |         |
+  App. QQ (c) (nail-plug         |             |         |         |
+    chute)                       |Jan. 11, 1901|         |  F  5.00|
+                                 |             |         |  F  5.00|
+  Box Epsilon (push down)        |Jan. 12, 1901|         |  F  5.00|
+                                 |             |         |  F 10.00|
+  App. QQ (d) (ring chute)       |Jan. 16, 1901|         |  F  5.00|
+                                 |             |         |  F  5.00|
+  App. QQ (e) (hook chute)       |             |         |         |
+  App. QQ (f) (string chute)     |Jan. 17, 1901|         |  F  5.00|
+  App. QQ (ff) (string-wire      |Jan. 17, 1901|   .20   |         |
+    chute)                       |             |         |         |
+  -------------------------------+-------------+---------+---------+
+
+  -------------------------------+---------------------------------+
+                                 |             No. 2.              |
+                                 +-------------+---------+---------+
+                                 |             |Min. Sec.|         |
+  -------------------------------+-------------+---------+---------+
+  Box TT (nail plug)             |Oct. 21, 1900|  14.10  |         |
+  Box UU (old plug at side)      |             |         |         |
+  Box VV (wire loop)             |Oct. 24, 1900|         |  F 10.00|
+                                 |Oct. 25, 1900|         |  F 10.00|
+                                 |             |         |         |
+  Box WW (bar inside)            |Oct. 21, 1900|  5.00   |    after|
+                                 |             |         |  F 30.00|
+                                 |             |         |         |
+                                 |             |         |         |
+  Box XX (bar outside)           |Oct. 24, 1900|  3.40   |         |
+                                 |             |         |         |
+                                 |             |         |         |
+  Box YY (push bar)              |             |         |         |
+  Box Beta (single hook)         |Oct. 30, 1900|  9.00   |    after|
+                                 |             |         |  F 10.00|
+                                 |             |         |and 10.00|
+  Box LL (triple; nail plug,     |Oct. 3, 1900 |  2.00   |         |
+    hook and bar outside)        |             |         |         |
+  Box Alpha (catch at back)      |Oct. 5, 1900 |  6.00   |         |
+  Box KK (triple; bolt, side-plug|Oct. 7, 1900 |         |  F 60.00|
+    and knob)                    |             |         |         |
+  Box Theta (bolt at top)        |             |         |         |
+  Box Eta (ring at back)         |             |         |         |
+  App. QQ (push chute)           |             |         |         |
+  Box Gamma (wind)               |             |         |         |
+                                 |             |         |         |
+  Box Delta (push back)          |             |         |         |
+                                 |             |         |         |
+  App. QQ (a) (bar chute)        |             |         |         |
+  Box Zeta (new side plug)       |             |         |         |
+                                 |             |         |         |
+  App. QQ (b) (2½ revolution     |             |         |         |
+    chute)                       |             |         |         |
+  App. QQ (c) (nail-plug         |             |         |         |
+    chute)                       |             |         |         |
+                                 |             |         |         |
+  Box Epsilon (push down)        |             |         |         |
+                                 |             |         |         |
+  App. QQ (d) (ring chute)       |             |         |         |
+                                 |             |         |         |
+  App. QQ (e) (hook chute)       |             |         |         |
+  App. QQ (f) (string chute)     |             |         |         |
+  App. QQ (ff) (string-wire      |             |         |         |
+    chute)                       |             |         |         |
+  -------------------------------+-------------+---------+---------+
+
+  -------------------------------+----------------------------------
+                                 |               No. 3.
+                                 +-------------+---------+----------
+                                 |             |Min. Sec.|
+  -------------------------------+-------------+---------+----------
+  Box TT (nail plug)             |Oct. 21, 1900|  36.00  |
+  Box UU (old plug at side)      |             |         |
+  Box VV (wire loop)             |Oct. 22, 1900|         |{ F 10.00
+                                 |             |         |{ F 10.00
+                                 |             |         |{ F 10.00
+  Box WW (bar inside)            |Oct. 22, 1900|         |{ F 10.00
+                                 |Oct. 24, 1900|         |{ F  5.00
+                                 |             |         |{ F 10.00
+                                 |             |         |{ F 15.00
+  Box XX (bar outside)           |Oct. 23, 1900|   .30   |
+                                 |             |         |
+                                 |             |         |
+  Box YY (push bar)              |             |         |
+  Box Beta (single hook)         |Oct. 24, 1900|   im.   |
+                                 |             |         |
+                                 |             |         |
+  Box LL (triple; nail plug,     |Nov. 3, 1900 |  1.45   |
+    hook and bar outside)        |             |         |
+  Box Alpha (catch at back)      |Nov. 5, 1900 |         |
+  Box KK (triple; bolt, side-plug|Nov. 7, 1900 |         | F 10.00
+    and knob)                    |             |         |
+  Box Theta (bolt at top)        |Jan. 8, 1901 |         | F 10.00
+  Box Eta (ring at back)         |Dec. 17, 1900|  4.20   |
+  App. QQ (push chute)           |Dec. 17, 1900|         | F 60.00
+  Box Gamma (wind)               |Jan. 4, 1901 |         | F 10.00
+                                 |             |         | F 10.00
+  Box Delta (push back)          |Jan. 4, 1901 |  2.10   |after[28]
+                                 |             |         | F 10.00
+  App. QQ (a) (bar chute)        |Jan. 7, 1901 |         | F 10.00
+  Box Zeta (new side plug)       |Jan. 8, 1901 |   .50   |
+                                 |             |         |
+  App. QQ (b) (2½ revolution     |             |         |
+    chute)                       |Jan. 8, 1901 |         | F 10.00
+  App. QQ (c) (nail-plug         |             |         |
+    chute)                       |Jan. 11, 1901|         | F  5.00
+                                 |             |         | F  5.00
+  Box Epsilon (push down)        |Jan. 12, 1901|         | F 10.00
+                                 |             |         |
+  App. QQ (d) (ring chute)       |Jan. 16, 1901|   im.   |
+                                 |             |         |
+  App. QQ (e) (hook chute)       |Jan. 16, 1901|         | F  5.00
+  App. QQ (f) (string chute)     |             |         |
+  App. QQ (ff) (string-wire      |Jan. 19, 1901|         | F  5.00
+    chute)                       |             |         | F  5.00
+  -------------------------------+-------------+---------+----------
+
+The methods one has to take to get them to do anything, their general
+conduct in becoming tame and in the experiments throughout, confirm
+these conclusions. The following particular phenomena are samples of the
+many which are inconsistent with the presence of reasoning as a general
+function. No. 1 had learned to open a door by pushing a bar around from
+a horizontal to a vertical position. The same box was then fitted with
+two bars. He turned the first bar round thirteen times before attempting
+to push the other bar around. In box LL all three monkeys would in the
+early trials do one or two of the acts over and over after they had once
+done them. No. 1, who had learned to pull a loop of wire off from a nail,
+failed thereafter to pull off a similar loop made of string. No. 1 and
+No. 3 had learned to poke their left hands through the cage for me to
+take and operate a chute with. It was extremely difficult to get either
+of them to put his right hand through or even to let me take it and pull
+it through.
+
+A negative answer to the question “Do the monkeys reason?” thus
+seems inevitable, but I do not attach to the question an importance
+commensurate with the part it has played historically in animal
+psychology. For I think it can be shown, and I hope in a later monograph
+to show, that reasoning is probably but one secondary result of the
+general function of having free ideas in great numbers, one product of a
+type of brain which works in great detail, not in gross associations. The
+denial of reasoning need not mean, and does not to my mind, any denial
+of continuity between animal and human mentality or any denial that the
+monkeys are mentally nearer relatives to man than are the other mammals.
+
+So much for supererogatory explanation. Let us now turn to a more
+definite and fruitful treatment of these records.
+
+The difference between these records and those of the chicks, cats and
+dogs given on pages 39-65 _passim_ is undeniable. Whereas the latter
+were practically unanimous, save in the cases of the very easiest
+performances, in showing a process of gradual learning by a gradual
+elimination of unsuccessful movements, and a gradual reënforcement of
+the successful one, these are unanimous, save in the very hardest, in
+showing a process of sudden acquisition by a rapid, often apparently
+instantaneous, abandonment of the unsuccessful movements and a selection
+of the appropriate one which rivals in suddenness the selections made by
+human beings in similar performances. It is natural to infer that the
+monkeys who suddenly replace much general pulling and clawing by a single
+definite pull at a hook or bar have an idea of the hook or bar and of the
+movement they make. The rate of their progress is so different from that
+of the cats and dogs that we cannot help imagining as the cause of it a
+totally different mental function, namely, free ideas instead of vague
+sense-impressions and impulses. But our interpretation of these results
+should not be too hasty. We must first consider several other possible
+explanations of the rapidity of learning by the monkeys before jumping to
+the conclusion that the forces which bring about the sudden formation of
+associations in human beings are present.
+
+First of all it might be that the difference was due to the superiority
+of the monkeys in clear detailed vision. It might be that in given
+situations where associations were to be formed on the basis of smells,
+the cats and dogs would show similar rapid learning. There might be,
+that is, no general difference in type of mental functioning, but only
+a special difference in the field in which the function worked. This
+question can be answered by an investigation of the process of forming
+associations in connection with smells by dogs and cats. Such an
+investigation will, I hope, soon be carried on in the Columbia Laboratory
+by Mr. Davis.[29]
+
+Secondly, it might be that the superior mobility and more detailed
+and definite movements of the monkeys’ hands might have caused the
+difference. The slowness in the case of the dogs and cats might be at
+least in part the result of difficulty in executing movements, not in
+intending them. This difficulty in execution is a matter that cannot be
+readily estimated, but the movements made by the cats and dogs would
+not on their face value seem to be hard. They were mostly common to the
+animals’ ordinary life. At the same time there were certain movements
+(_e.g._ depressing the lever) which were much more quickly associated
+with their respective situations by the cats than others were, and if
+we could suppose that all the movements learned by the monkeys were
+comparable to these few, it would detract from the necessity of seeking
+some general mental difference as the explanation of the difference in
+the results.
+
+In the third place it may be said by some that no comparison of the
+monkeys with dogs and cats is valid, since the former animals got out of
+boxes while the latter got in. It may be supposed that the instinctive
+response to confinement includes an agitation which precludes anything
+save vague unregulated behavior. Professor Wesley Mills has made
+such a suggestion in referring to the ‘Animal Intelligence’ in the
+_Psychological Review_, May, 1899. In the July number of the same journal
+I tried to show that there was no solid evidence of such a harmful
+agitation. Nor can we be at all sure that agitation when present does not
+rather quicken the wits of animals. It often seems to. However I should,
+of course, allow that for purposes of comparison it would be better to
+have the circumstances identical. And I should welcome any antagonist who
+should, by making experiments with kittens after the fashion of these
+with the monkeys, show that they did learn as suddenly as the latter.
+
+Again we know that, whereas the times taken by a cat in a box to get
+out are inversely proportional to the strength of the association,
+inasmuch as they represent fairly the amount of its efforts, on the
+other hand, the times taken by a monkey to get in represent the amounts
+of his efforts _plus the amount of time in which he is not trying to
+get in_. It may be said therefore that the time records of the monkeys
+prove nothing,—that a record of four minutes may mean thirty seconds of
+effort and three minutes thirty seconds of sleep,—that one minute may
+really represent twice as much effort. As a matter of fact this objection
+would occasionally hold against some single record. The earliest times
+and the occasional long times amongst very short ones are likely to be
+too long. The first fact makes the curves have too great a drop at the
+start, making them seem cases of too sudden learning, but the second fact
+makes the learning seem indefinite when it really is not. And in the long
+run the times taken do represent fairly well the amount of effort. I
+carefully recorded the amount of actual effort in a number of cases and
+the story it tells concerning the mental processes involved is the same
+as that told by the time-curves.
+
+Still another explanation is this: The monkeys learn quickly, it is true,
+but not quickly enough for us to suppose the presence of ideas, or the
+formation of associations among them. For if there were such ideas, they
+should in the complex acts do even better than they did. The explanation
+then is a high degree of facility in the formation of associations of
+just the same kind as we found in the chicks, dogs and cats.
+
+Such an explanation we could hardly disapprove in any case. No one can
+from objective evidence set up a standard of speed of learning below
+which all shall be learning without ideas and above which all shall be
+learning by ideas. We should not expect any hard and fast demarcation.
+
+This whole matter of the rate of learning should be studied in the light
+of other facts of behavior. My own judgment, if I had nothing but these
+time-curves to rely on, would be that there was in them an appearance of
+learning by ideas which, while possibly explicable by the finer vision
+and freer movements of the monkey in connection with ordinary mammalian
+mentality, made it worth while to look farther into their behavior. This
+we may now do.
+
+What leads the lay mind to attribute superior mental gifts to an animal
+is not so much the rate of learning as the amount learned. The monkeys
+obviously form more associations and associations in a greater variety
+than do the other mammals. The improved rate assists, but another cause
+of this greater number of associations is the general physical activity
+of the monkeys, their constant movements of the hands, their instinctive
+curiosity or tendency to fool with all sorts of objects, to enjoy having
+sense-impressions, to form associations because of the resulting sound or
+sight. These mental characteristics are of a high degree of importance
+from the comparative point of view, but they cannot be used to prove that
+the monkeys have free ideas, for a large number of associations may be
+acquired after the purely animal fashion.
+
+What is of more importance is the actual behavior of the animals in
+connection with the boxes. First of all, as has been stated, all the
+monkey’s movements are more definite, he seems not merely to pull, but
+to pull at, not merely to poke, but to push at. He seems, even in his
+general random play, to go here and there, pick up this, examine the
+other, etc., more from having the idea strike him than from feeling like
+doing it. He seems more like a man at the breakfast table than like a man
+in a fight. Still this appearance may be quite specious, and I think it
+is likely to lead us to read ideational life into his behavior if we are
+not cautious. It may be simply general activity of the same sort as the
+narrower activities of the cat or dog.
+
+In the second place the monkeys often make special movements with a
+directness which reminds one unavoidably of human actions guided by
+ideas. For instance, No. 1 escaped from his cage one day and went
+directly across the room to a table where lay a half of a banana which
+was in a very inconspicuous place. It seemed as if he had observed the
+banana and acted with the idea of its position fully in mind. Again, on
+failing to pull a hook out, No. 1 immediately applied his teeth, though
+he had before always pulled it out with his hand. So again with a plug.
+It may be that there is a special inborn tendency to bite at objects
+pulled unsuccessfully. If not, the act would seem to show the presence of
+the idea ‘get thing out’ or ‘thing come out’ and associated with it the
+impulse to use the teeth. We shall see later, however, that in certain
+other circumstances where we should expect ideas to be present and result
+in acts they do not.
+
+The fact is that those features in the behavior of the monkeys in forming
+associations between the sight of a box and the act needed to open it
+which remind us of learning by ideas may also be possibly explained by
+general activity and curiosity, the free use of the hand, and superior
+quickness in forming associations of the animal sort. We must have
+recourse to more crucial tests or at least seek evidence from a number of
+different kinds of mental performances. The first of these will naturally
+be their behavior toward these same mechanisms after a long time-interval.
+
+
+THE PERMANENCE OF ASSOCIATIONS IN THE CASE OF MECHANISMS
+
+My records are too few and in all but one case after too short an
+interval to be decisive on the point of abrupt transition from failure
+to success such as would characterize an animal in whose mind arose the
+idea of a certain part of the mechanism as the thing to be attacked or of
+a certain movement as the fit one. The animals are all under observation
+in the Columbia Laboratory, however, and I trust that later satisfactory
+tests may be made. No. 2 was not included in the tests because he was
+either unwell or had become very shy of the boxes, entering them even
+when the door was left open only after great delay. The time-curves for
+the experiments performed will be found on page 186 among the others. The
+figures beside each pair represent the number of days without practice.
+
+The records show a decided superiority to those of the cats and dogs.
+Although the number of trials in the original tests were in general fewer
+in the case of the monkeys, the retention of the association is complete
+in 6 cases out of 8 and is practically so in one case where the interval
+was 8 months.
+
+
+EXPERIMENTS ON THE DISCRIMINATION OF SIGNALS
+
+My experiments on discrimination were of the following general type: I
+got the animal into the habit of reacting to a certain signal (a sound,
+movement, posture, visual presentation or what not) by some well-defined
+act. In the cases to be described this act was to come down from his
+customary positions about the top of the cage, to a place at the bottom.
+I then would give him a bit of food. When this habit was wholly or
+partly formed, I would begin to mix with that signal another signal
+enough like it so that the animal would respond in the same manner. In
+the cases where I gave this signal I would not feed him. I could then
+determine whether the animal did discriminate or not, and his progress
+toward perfect discrimination in case he did. If an animal responds
+indiscriminately to both signals (that is, does not learn to disregard
+the ‘no food’ signal) it is well to test him by using two somewhat
+similar signals, after one of which you feed him at one place and after
+the other of which you feed him at a different place.
+
+If the animal profits by his training by acquiring ideas of the two
+signals and associates with them ideas of ‘food’ and ‘no food,’ ‘go
+down’ and ‘stay still,’ and uses these ideas to control his conduct, he
+will, we have a right to expect, change suddenly from total failure to
+differentiate the signals to total success. He will or won’t have the
+ideas, and will behave accordingly. The same result could, of course, be
+brought about by very rapid association of the new signal with the act
+of keeping still, a very rapid inhibition of the act of going down in
+response to it by virtue of the lack of any pleasure from doing so.
+
+For convenience I shall call the signals after which food was given _yes_
+signals and those after which food was not given _no_ signals. Signals
+not described in the text are shown in Fig. 29, below. The progress of
+the monkeys in discriminating is shown by Figs. 30 and 31, on pages 199
+and 201. In Figs. 30 and 31 every millimeter along the horizontal or
+base line represents 10 trials with the signal. The heights of the black
+surface represent the percentages of _wrong_ responses, 10 mm. meaning
+100 per cent of incorrect responses. Thus the first figure of the set,
+Left hand, _a_, presents the following record: First 10 trials, all
+wrong; of next 10, 7 wrong; of next 10, 6 wrong; of next 10, 7; of the
+next, 9; of the next, 9; of the next, 4; of the next, none; of the next,
+3; of the next, 2, and then 70 trials without an error.
+
+[Illustration: FIG. 29.]
+
+I will describe some of the experiments in detail and then discuss the
+graphic presentation of them all.
+
+
+EXPERIMENTS WITH NO. 1
+
+Having developed in No. 1 the habit of coming down to the bottom of his
+cage to get a bit of food when he saw me reach out and take such a bit
+from my desk, I tested his ability to discriminate by beginning to use
+now one hand, now the other, feeding him only when I used the left.
+I also used different sets of words, namely, ‘I will give some food’
+and ‘They shall not have any.’ It will be seen later that he probably
+reacted only to the difference of the hands. The experiment is similar
+to that described on pages 129 and 130 of Chapter II. At the beginning,
+it should be remembered, No. 1 would come down whichever hand was used,
+no matter what was said, except in the occasional cases where he was so
+occupied with some other pursuit as to be evidently inattentive. He did
+come to associate the act of going down with the one signal and the act
+of staying still or continuing his ordinary movements with the other
+signal. His progress in learning to do so is best seen in the curves of
+his errors. To the ‘yes’ signal he responded correctly, except for the
+occasional lapses which I just mentioned, from the start and throughout.
+With the ‘no’ signal his errors were as shown in Fig. 30, _a_. The break
+in the curve at 110 and 120 is probably not significant of an actual
+retrograde as the trials concerned followed an eight days’ cessation of
+the experiments.
+
+I next tried No. 1 with an apparatus exposing sometimes a card with a
+diamond-shaped piece of buff-colored paper on it and sometimes a card
+with a similar black piece. The black piece was three fourths of an
+inch farther behind the opening than the other. The light color was the
+‘yes’ signal. The error curves for both signals are given, as No. 1 at
+the beginning of the experiment did not go down always (Fig. 30, _b_ and
+_b₁_).
+
+I next tried No. 1 with the same apparatus but exposing cards with YES
+and N in place of the buff and black diamonds. The record of the errors
+is given in Fig. 30, _c_ and _c₁_. At the start he came down halfway very
+often. This I arbitrarily scored as an error no matter which signal it
+was in response to. It should not be supposed that these curves represent
+two totally new associations. It seems likely that the monkey reacted to
+the _position_ of the N card in the apparatus (the same as that of the
+black diamond card) rather than to the shape of the letters. On putting
+the black diamond in front he was much confused.
+
+I next gave No. 1 the chance to form the habits of coming down when I
+rapped my pencil against the table twice and of staying where he was when
+I rapped with it once. He had 90 trials of each signal but failed to give
+evidence of any different associations in the two cases.
+
+Experiments of this sort were discontinued in the summer. In October I
+tried No. 1 with the right and left hand experiment, he being in a new
+room and cage, and I being seated in a different situation. He came down
+at both signals and failed to make any ascertainable progress with the no
+signal in 80 trials. (October 20-24.)
+
+[Illustration: FIG. 30.]
+
+I then tried him with the black and buff diamonds, the black being in
+front (October 25-29). The reaction to the ‘yes’ signal was perfect from
+the start. The progress with the ‘no’ signal is shown in Fig. 30, _d_.
+
+I then tried him with an apparatus externally of different size, shape
+and color from that so far used, showing as the ‘yes’ signal a brown
+card and as the ‘no’ signal a white and gold card one half inch farther
+back in the apparatus. The ‘yes’ signal was practically perfect from the
+start. His progress with the ‘no’ signal is shown in Fig. 30, _e_.
+
+I then tried a still different arrangement for exposure, to which,
+however, he did not give uniform attention.
+
+I then tried cards 1 and 101, 101 being in front and 1 in back. 1 was
+the ‘yes’ signal. ‘Yes’ responses were perfect from the start. For ‘no’
+responses see Fig. 30, _f_. I then put the ‘yes’ signal in front and the
+‘no’ signal behind. ‘Yes’ responses perfect; for ‘no’ responses see Fig.
+30, _f_, _a_.
+
+From now on I arranged the exposures in such a way that there was no
+difference between the ‘yes’ and ‘no’ signals in distance or surroundings.
+
+The following list shows the dates, signals used, and the figures on
+page 199 presenting the results. Where there is only one figure drawn,
+it refers to progress with the ‘no’ signal, the ‘yes’ signal being
+practically perfect from the start.
+
+
+TABLE 10
+
+  ==================+==============+=============+========
+                    | ‘YES’ SIGNAL | ‘NO’ SIGNAL | FIGURE
+  ------------------+--------------+-------------+--------
+  Nov. 13-15, 1900. |       2      |     102     | _g g₁_
+  Nov. 14-16, 1900. |       3      |     103     | _i i₁_
+  Nov. 16-19, 1900. |       4      |     104     |  _h_
+  Nov. 19, 1900.    |       5      |     105     |  _j_
+  Nov. 20, 1900.    |       6      |     106     |  _k_
+  Nov. 21, 1900.    |       7      |     107     |  _l_
+  Nov. 23(?), 1900. |       8      |     108     |  _m_
+  Nov. 27-29, 1900. |       9      |     109     |  _n_
+  Nov. 30, 1900.    |      10      |     110     |  _o_
+  ==================+==============+=============+========
+
+Fig. 29 gives facsimiles of the different signals reduced to one sixth
+their actual size. The drawing of 101 is not accurate, the outer ring
+being too thick.
+
+
+EXPERIMENTS WITH NO. 2
+
+[Illustration: FIG. 31.]
+
+I first secured the partial formation of the habit of coming down when
+I took a bit of food in my hand. I then used the apparatus for exposing
+cards, YES in front being the ‘yes’ signal and a circle at the back being
+the ‘no’ signal. I gave No. 2 25 trials with the ‘yes’ signal and then
+began a regular experiment similar to those described. After about 90
+trials (November 9-12, 1900) there was no progress toward differentiation
+of response, and it was evident from No. 2’s behavior that he was
+reacting solely to the movements of my hand. So I abandoned the exposing
+apparatus and used (November 11-13, 1900) as the ‘yes’ signal the act of
+taking the food with my left hand from a pile on the front of the box and
+for the ‘no’ signal the act of taking food with my right hand from a pile
+4 inches behind that just mentioned. No. 2 did come to differentiate
+these two signals. The record of his progress is given in Fig. 31 by _A_
+and _A₁_.
+
+I then made a second attempt with the exposing apparatus, using cards 2
+and 102 (November 6, 14-21). No. 2 did react to my movements in pulling
+the string but in over 100 trials made no progress in the direction of
+a differential reaction to the ‘no’ signal. I then tried feeding him at
+each signal, feeding him at the bottom of the cage as usual when I gave
+the ‘yes’ signal and at the top when I gave the ‘no’ signal. After a
+hundred trials with the ‘no’ signal there was no progress.
+
+I then abandoned again the exposing apparatus and used as signals the
+ordinary act of taking food with my left hand (yes) and the act of moving
+my left arm from my right side round diagonally (swinging it on my elbow
+as a center) and holding the hand, after taking the food, _palm up_ (no)
+(November 26, 27, 1900). No. 2 did come to differentiate these signals.
+His progress is given in the diagram in Fig. 31 entitled ‘Palm up’ (_B_).
+
+I next used (November 27, 1900) as the ‘yes’ signal the same act as
+before and for the ‘no’ signal the act of holding the food just in front
+of the box about four inches below the edge. No. 2’s progress is shown in
+Fig. 31 in the diagram entitled ‘low front’ (_C_ and _C₁_).
+
+I next used (November 27-30) the same movement for both ‘yes’ and ‘no’
+signals save that as the ‘yes’ signal I took the food from a brown
+pasteboard box 3 by 3 by 0.5, and as the ‘no’ signal I took it from a
+white crockery cover two inches in diameter and three eighths of an
+inch high which was beside the box but three inches nearer me. No. 2’s
+progress is shown in Fig. 31 in the diagram entitled ‘Box near’ (_D_).
+
+I next used for the ‘yes’ signal the familiar act and for the ‘no’
+signal the act of holding the food six inches above the box instead of
+a quarter or a half an inch. The progress is shown in Fig. 31, _E_ and
+_E₁_. I then tried taking the food from a saucer off the front of the
+box for the ‘yes’ signal and from a small box at the back for the ‘no’
+signal. ‘Yes’ was perfect from the start (10 trials given). ‘No’ was
+right once, then wrong once, then right for the remaining eight.
+
+
+EXPERIMENTS WITH NO. 3
+
+No. 3 was kept in a cage not half so big as those of 1 and 2. Perhaps
+because of the hindrance this fact offered to forming the habit of
+reacting in some definite way to ‘yes’ signals, perhaps because of
+the fact that I did not try hand movements as signals, there was no
+successful discrimination by No. 3 of the yellow from the black diamond
+or of a card with YES from a card with a circle on it. I tried climbing
+up to a particular spot as the response to the ‘yes’ signal and staying
+still as the response to the ‘no’ signal. I also tried instead of the
+latter a different act, in which case the animal was fed after both
+signals but in different places. In the latter case No. 3 made some
+progress, but for practical reasons I postponed experiments with him.
+Circumstances have made it necessary to postpone such experiments
+indefinitely.
+
+
+PERMANENCE OF THE ABILITY TO DISCRIMINATE
+
+No. 1 and No. 2 were tried again after intervals of 33 to 48 days. The
+results of these trials are shown in Fig. 32. Here every millimeter
+along the base line represents _one_ trial with the ‘no’ signal (the
+‘yes’ signals were practically perfect), and failure is represented by a
+column 10 mm. high while success is represented by the absence of any
+column. Thus the first record reads, “No. 1 with signal 104 after 40
+days made 5 failures, then 2 successes, then 1 failure, then 1 success,
+then 3 failures, then 1 success, then 1 failure, then 3 successes, then
+1 failure, then 10 successes.” The third record (106; 40 days) reads,
+“perfect success in ten trials.”
+
+[Illustration: FIG. 32.]
+
+
+DISCUSSION OF RESULTS
+
+The results of all these discrimination experiments emphasize the
+rapidity of formation of associations amongst the monkeys, which appeared
+in their behavior toward the mechanisms. The suddenness of the change in
+many cases is immediately suggestive of human performances. If all the
+records were like c, f, h, i, j, k, l, m, B, E, and memory trials 103,
+A, B, and C, one would have to credit the animals with either marvelous
+rapidity in forming associations of the purely animal sort or concede
+that from all the objective evidence at hand they were shown to learn as
+human beings would. One would have to suppose that they had clear ideas
+of the signals and clean-cut associations with those ideas. The other
+records check such a conclusion.
+
+In studying the figures we should remember that occasional mistakes, say
+1 in 10 trials, are probably not significant of incomplete learning but
+of inattention or of precipitate action before the shutter had fairly
+exposed the card. We must not expect that a monkey who totally fails to
+discriminate will _always_ respond wrongly to the ‘no’ signal, or that
+a monkey who has come to discriminate perfectly will _always_ respond
+rightly. A sudden drop from an average high level of error to an average
+low level will signify sudden learning. Where the failure was on the
+first trial of a series a few hours or a day removed from the last
+series, I have generally represented the fact not by a column 1 mm. high
+and 1 mm. broad, but by a single 10 mm. perpendicular. See i and A. Such
+cases represent probably the failure of the animal to keep his learning
+permanent rather than any general inability to discriminate.
+
+K was to some extent a memory trial of d (after over half a year).
+
+The experiment with 10 and 110 is noteworthy. Although, as can be seen
+from the figures, the difference is obvious to one looking at the white
+part of the figure, it is not so to one looking at the black part. No.
+1 failed to improve appreciably in fifty trials, probably because his
+previous experience had gotten him into the habit of attending to the
+black lines.
+
+Before arguing from the suddenness of the change from failure to success
+we have to consider one possibility that I have not mentioned, and in
+fact for the sake of clearness in presentation have rather concealed. It
+is that the sudden change in the records, which report only whether the
+animal did or did not go down, may represent a more gradual change in
+the animal’s mind, a gradual weakening of the impulse to go down which
+makes him feel less and less inclined to go down, though still doing so,
+until this weakening reaches a sort of saturation point and stops the
+action. There were in their behavior some phenomena which might witness
+to such a process, but their interpretation is so dependent on the
+subjective attitude and prepossessions of the observer that I prefer not
+to draw any conclusions from them. On the other hand, records c, g, n, A
+and D seem to show that gradual changes can be paralleled by changes in
+the percentage of failures.
+
+In the statement of conclusions I shall represent what would be the
+effect on our theory of the matter in both cases, (1) taking the records
+to be fairly perfect parallels of the process, and (2) taking them to be
+the records of the summation points of a process not shown with surety in
+any measurable objective facts. But I shall leave to future workers the
+task of determining which case is the true one.
+
+If we judge by the objective records themselves, we may still choose
+between two views. (1) We may say that the monkeys did come to have
+ideas of the acts of going down to the bottom of the cage and of staying
+still, and that their learning represented the association of the
+sense-impressions of the two signals, one with each of these ideas, or
+possibly their association with two other ideas (of being fed and of
+not being fed), and through them with the acts. Or (2) we may say that
+the monkeys had no such ideas, but merely by the common animal sort of
+association came to react in the profitable way to each signal.
+
+If we take the first view, we must explain the failure of the animals
+to change suddenly in some of the experiments, must explain why, for
+instance, No. 1 in g should, after he had responded correctly to the
+‘no’ signal for 27 trials out of 30, fail in one trial out of four for
+a hundred or more trials. If the 27 successes were due to ideas, why
+was there regression? If the animal came to respond by staying still on
+seeing the K (card 104), because that sight was associated with the idea
+of no food or the idea of staying still, why did he, in his memory trial,
+act sometimes rightly, sometimes wrongly, for eleven trials after his
+acting rightly twice. If he stayed still because the idea was aroused,
+why did he not stay still as soon as he had a few trials to remind him of
+the idea? It is easy, one may say, to see why, with a capacity to select
+movements and associate them with sense-presentations very quickly, in
+cases where habit provides only two movements for selection and where the
+sense-presentation is very clear and simple, an animal should practically
+at once be confirmed in the one act on an occasion when he does it with
+the sense-impression in the focus of attention. It is easy, therefore, to
+explain the sudden change in i, l, m, B, C and E. But our critic may add,
+“It is very hard to suppose that an animal that learned by connecting
+the sight of a card with the idea ‘stay still’ or the idea ‘no food,’
+should be so long in making the connection as was the case in some of
+these experiments, should take 10, 20 or 40 trials to change from a high
+percentage of wrong to a high percentage of right reactions.”
+
+If we take the second view, we have to face the fact that many of the
+records are nothing like the single one we have for comparison, that of
+the kitten shown in Fig. 30, and that the appeal to a capacity to form
+animal associations very quickly seems like a far-fetched refuge from the
+other view rather than a natural interpretation. If we take the records
+to be summation points in a more gradual process, this difficulty is
+relieved.
+
+If further investigation upheld the first view, we should still not have
+a demonstration that the monkeys habitually did learn by getting percepts
+and images associated with sense-impressions, by having free ideas of the
+acts they performed; we should only have proved that they could under
+certain circumstances.
+
+The circumstances in these experiments on discrimination were such as to
+form a most favorable case. The act of going down had been performed in
+all sorts of different connections and was likely to gain representation
+in ideational life; the experience ‘bit of banana’ had again been
+attended to as a part of very many different associations and so would be
+likely to develop into a definite idea.
+
+These results then do not settle the choice between three theories: (1
+_a_) that they were due to a general capacity for having ideas, (1 _b_)
+that they were due to ideas acquired by specially favoring circumstances,
+(2) that they were due to the common form of association, the association
+of an impulse to an act with a sense-impression rather roughly felt.
+
+It would be of the utmost interest to duplicate these experiments with
+dogs, cats and other mammals and compare the records. Moreover, since
+we shall find (1 _a_) barred out by other experiments, it will be of
+great interest to test the monkeys with some other type of act than
+discrimination to see if, by giving the animal experience of the act and
+result involved in many different connections, we can get a rate of speed
+in the formation of a new association comparable to the rates in some of
+these cases.
+
+Of course here, as in our previous section, the differences in the
+sense-powers of the monkeys from those of the kitten which I have tested
+with a similar experiment may have caused the difference in behavior.
+Focalized vision lends itself to delicate associations. Perhaps if one
+used the sense of smell, or if the dogs and cats could, preserving their
+same mental faculties in general, add the capacity for focalized vision,
+they would do as well as the monkeys.
+
+
+EXPERIMENTS ON THE INFLUENCE OF TUITION
+
+The general aim of these experiments was to ascertain whether the
+monkeys’ actions were at all determined by the presence of free ideas
+and if so, to what extent. The question is, “Are the associations which
+experience leads them to form, associations between (1) the idea of an
+object and (2) the idea of an act or result and (3) the impulses and act
+itself, or are they merely associations between the sense-impression
+of the object and the impulse and act?” Can a monkey learn and does he
+commonly learn to do things, not by the mere selection of the act from
+amongst the acts done by him, but by getting some idea and then himself
+providing the act because it is associated in his mind with that idea. If
+a monkey feels an impulse to get into a box, sees his arm push a bar and
+sees a door fall open immediately thereafter and goes into the box enough
+times, he has every chance to form the association between the impulse to
+get into the box and the idea ‘arm push bar,’ provided he can have such
+an idea. If his general behavior is due to having ideas connected with
+and so causing his acts, he has had chance enough to form the association
+between the idea ‘push at’ and the act of pushing. If then a monkey forms
+an association leading to an act by being put through the act, we may
+expect that he has free ideas. And if he has free ideas in general in
+connection with his actions, we may expect him to so form associations.
+So also if a monkey shows a general capability to learn from seeing
+another monkey or a human being do a thing. A few isolated cases of
+imitation, however, might witness not to any general mental quality, but
+only to certain instincts or habits differing from others only in that
+the situation calling forth the act was the same act performed by another.
+
+If the monkeys do not learn in these ways, we must, until other evidence
+appears, suppose them to be in general destitute of a life of free ideas,
+must regard their somewhat ambiguous behavior in learning by their
+own unaided efforts as of the same type as that of the dogs and cats,
+differing only in the respects mentioned on pages 190 and 191.
+
+The general method of experimentation was to give monkeys who had failed
+of their own efforts to operate some simple mechanism, a chance to see
+me do it or see another monkey do it or to see and feel themselves do
+it, and then note any change in their behavior. The chief question is
+whether they succeed after such tuition when they have failed before
+it, but the presence of ideas would also be indicated if they attacked,
+though without success, the vital point in the mechanism when they had
+not done so before. On the other hand, mere success would not prove that
+the tuition had influenced them, for if they made a different movement
+or attacked a different spot, we could not attribute their behavior to
+getting ideas of the necessary act.
+
+The results of the experiments as a whole are on their face value a
+trifle ambiguous, but they surely show that the monkeys in question had
+no considerable stock of ideas of the objects they dealt with or of the
+movements they made and were not in general capable of acquiring, from
+seeing me or one of their comrades attack a certain part of a mechanism
+and make a certain movement, any ideas that were at all efficacious in
+guiding their conduct. They do not acquire or use ideas in anything that
+approaches the way human adults do. Whether the monkeys may not have some
+few ideas corresponding to habitual classes of objects and acts is a
+different question. Such may be present and function as the excitants of
+acts.
+
+It is likely that this question could have been definitely solved if it
+had been possible for me to work with a larger number of animals. With
+enough subjects one could use the method mentioned on page 105 of Chapter
+II, of giving the animals tuition in acts which they would eventually do
+themselves without it, and then leaving them to their efforts, noting any
+differences in the way they learned from that in which other subjects who
+had no tuition learned the same acts. The chief of such differences to
+note would be differences in the time of their first trial, in the slope
+of the time-curve and in the number of useless acts.
+
+It would also be possible to extend experiments of the type of the
+(on chair) experiment, where a subject is given first a certain time
+(calculated by the experimenter to be somewhat less than would be needed
+for the animal to hit upon the act) and if he does fail is then given
+certain tuition and then a second trial. The influence of the tuition is
+estimated by the presence or absence of cases where after tuition the act
+is done within the time.
+
+There is nothing necessarily insoluble in the problem. Given ten or
+twenty monkeys that can be handled without any difficulty and it could be
+settled in a month.
+
+With this general preface we may turn to the more special questions
+connected with the experiments on imitation of human acts and of the acts
+of other monkeys and on the formation of associations apart from the
+selection of impulses.
+
+
+IMITATION OF HUMAN BEINGS
+
+It has been a common opinion that monkeys learned to do things from
+seeing them done by human beings. We find anecdotes to that effect in
+fairly reputable authors.
+
+Of course, such anecdotes might be true and still not prove that the
+animals learned to do things because they saw them done. The animal
+may have been taught in other ways to respond to the particular sights
+in question by the particular acts. Or it may have been in each case a
+coincidence.
+
+If a monkey did actually form an association between a given situation
+and act by seeing some one respond to that situation by that act, it
+would be evidence of considerable importance concerning his general
+mental status, for it would go to show that he could and often did form
+associations between sense-impressions and ideas and between ideas and
+acts. Seeing some one turn a key in a lock might thus give him the
+idea of turning or moving the key, and this idea might arouse the act.
+However, the mere fact that a monkey does something which you have just
+done in his presence need not demonstrate or even render a bit more
+probable such a general mental condition. For he perhaps would have acted
+in just the same manner if you had offered him no model. If you put
+two toothpicks on a dish, take one and put it in your mouth, a monkey
+will do the same, not because he profits by your example, but because
+he instinctively puts nearly all small objects in his mouth. Because of
+their general activity, their instinctive impulses to grab, drop, bite,
+rub, carry, move about, turn over, etc., any novel object within their
+reach, their constant movement and assumption of all sorts of postures,
+the monkeys perform many acts like our own and simulate imitation to a
+far greater extent than other mammals.
+
+Even if a monkey which has failed of itself to do a certain thing does it
+after you have shown him the act, there need be no reason to suppose that
+he is learning by imitation, forming an association between the sight of
+the object and the act towards it through an idea gained from watching
+you. You may have caused his act simply by attracting his attention to
+the object. Perhaps if you had pointed at it or held it passively in your
+hand, you would have brought to pass just the same action on his part.
+There are several cases among my records where an act which an animal
+failed totally to do of himself was done after I had so attracted his
+attention to the object concerned.
+
+Throughout all the time that I had my monkeys under observation I never
+noticed in their general behavior any act which seemed due to genuine
+imitation of me or the other persons about. I also gave them special
+opportunities to show such by means of a number of experiments of the
+following type: where an animal failed by himself to get into some box or
+operate some mechanism, I would operate it in his presence a number of
+times and then give him a chance to profit by the tuition. His failure
+might be due to (1) the absence of instinctive impulses to make the
+movement in that situation, (2) to lack of precision in the movement, (3)
+to lack of force, or (4) to failure to notice and attack some special
+part of the mechanism. An instance of (1) was the failure to push away
+from them a bar which held a door; an instance of (2) was the failure to
+pull a wire loop off a nail; an instance of (2) or (3) was the failure to
+pull up a bolt; an instance of (4) was the failure to pull up an inside
+bar. Failures due to (3) occur rarely in the case of such mechanisms as
+were used in my investigations.
+
+The general method of experiment was to make sure that the animal would
+not of itself perform a certain act in a certain situation, then to make
+sure that his failure could not be remedied by attracting his attention
+to the object, then to perform the act for him a number of times, letting
+him get each time the food which resulted, and finally to see whether,
+having failed before the tuition, he would succeed after it. This sounds
+very simple, but such experiments are hard to carry out satisfactorily.
+If you try the animal enough times by himself to make quite sure that
+he will not of himself hit upon the act, you are likely to form in him
+the habit of meeting the particular situation in question with total
+disregard. His efforts having failed so often may be so inhibited that
+you could hardly expect any tuition to give them new life. The matter is
+worse if you add further enough trials to assure you that your attracting
+his attention to it has been unavailing. On the other hand, if you take
+failure in five or ten minutes to mean inability, and from subsequent
+success after imitation argue that imitation was efficient, you have to
+face the numerous cases where animals which have failed in ten minutes
+have succeeded in later unaided trials. With dogs and cats this does
+not much matter, because they are steady performers, and their conduct
+in one short trial tells you what to expect with some probability. But
+the monkeys are much more variable and are so frequently distracted that
+one feels much less confidence in his predictions. Moreover, you cannot
+be at all sure of having attracted a monkey’s attention to an object
+unless he does touch it. Suppose, for example, a monkey has failed to
+even touch a bar though you have put a bit of food on it repeatedly. It
+is quite possible that he may look at and take the food and not notice
+the bar, and the fact that after such tuition he still fails to push or
+pull the bar may mean simply that it has not caught his notice. I have,
+therefore, preferred in most cases to give the animals only a brief
+period of trial to test their ability by their own unaided efforts and
+to omit the attempts to test the efficacy of attracting their attention
+to the vital point in the mechanism. This makes the results appear less
+elegant and definitive but really increases their value for purposes of
+interpretation.
+
+The thoughtful reader will not expect from my experiments any perfectly
+rigorous demonstration of either the presence or the absence of imitation
+of human acts as a means of learning. The general trend of the evidence,
+it seems to me, is decidedly towards justifying the hypothesis that the
+monkeys did not learn acts from seeing me do them.
+
+I will first describe a sample experiment and then present a summary of
+all those made.
+
+On January 12th I put box Epsilon (push down) in No. 3’s cage, the door
+of the box being open. I put a bit of food in the box. No. 3 reached
+in and took it. This was repeated three times. I then put in a bit of
+food and closed the door. No. 3 pulled and bit the box, turned it over,
+fingered and bit at the hole where the lever was, but did not succeed
+in getting the door open. After ten minutes I took the box out. Later I
+took No. 3 out and let him sit on my knees (I sitting on the floor with
+the box in front of us). I would then put my hand out toward the box and
+when he was looking at it would insert my finger and depress the lever
+with as evident a movement as I could. The door, of course, opened, and
+No. 3 put his arm in and took the bit of food. I then put in another,
+closed the door and depressed the lever as before. No. 3 watched my hand
+pretty constantly, as all his experiences with me had made such watching
+profitable. After ten such trials he was put back in the cage and the
+box put in with a large piece of food in it and its door closed. No. 3
+failed in five minutes and the box was taken out. He was shown fifteen
+times more and then left to try himself. I tried him for a couple of
+minutes under just the same circumstances as existed during the tuition,
+_i.e._ he on the floor by me, the box in front. In this trial and in a
+five-minute trial inside his cage he failed to open the door or to differ
+in any essential respect from his behavior before tuition.
+
+No. 1 saw me do 9 different acts and No. 3, 7, which they had failed
+of themselves to do.[30] After from 1 to 40 chances to imitate me they
+still failed to operate at all 11 of these mechanisms. In the case of
+3 out of 5 that were worked the act was not the same as that taught.
+No. 1, who saw me pull a nail out by taking the end of it and pulling
+the nail away from the box, himself put his hand round the nail and
+wriggled it out by pulling his hand back and forth. No. 3, who saw me
+pull a bolt up with my fingers, succeeded by jerking and yanking the door
+until he shook the bolt up. He saw me pull a hook out of an eye, but he
+succeeded by pulling at a bar to which it was attached. In the case of
+one of the two remaining acts (No. 3 with _nail chute_) the act was done
+once and never again, though ample opportunity was given and tuition
+continued. It could, therefore, hardly have been due to an idea instilled
+by the tuition. The remaining case, No. 1, with loop, must, I think,
+be attributed to accident, especially since No. 3 failed to profit by
+precisely the same sort of tuition with precisely the same act.
+
+Nor is there any evidence to show that although tuition failed to cause
+successes where unaided effort failed, it yet caused attempts which would
+not otherwise have occurred. Out of fifteen cases where such might have
+appeared, there were only three where it is possible to claim that they
+did. No one of these three is a sure case. With RR (wood plug) No. 1 did
+seem to pull the plug more definitely after seeing me than before. With
+QQ (c) (nail chute) and MM (bolt at top) he may possibly have done so.
+
+In 5 cases I tried the influence of seeing me make the movement on
+animals who had done the act of themselves, the aim being to see whether
+there would be a marked shortening of the time, a change in their way of
+operating the mechanism or an attempt at such change. I will give the
+essential facts from the general table on pages 226-229.
+
+(_a_) No. 1 had succeeded in pulling in the box by the upper string in
+OOO (upper string box) in 2.20 and then failed in 3.00. I showed him 4
+times. He failed in 10. I showed him 4 more times. He failed in 10. I
+showed him 4 more times. He succeeded in .20. No change in manner of act
+or objects attacked, though my manner was different from his.
+
+(_b_) No. 1 had succeeded in QQ (a) (chute bar) in 8.00. I showed him 20
+times. He failed in 10. I showed him 10 more times. He succeeded in 2.00.
+I showed him 10 more times. He succeeded in 50 seconds. No change in his
+manner of performance or in the object attacked, though my manner was
+different from his.
+
+(_c_) No. 1 had succeeded in 3.00, .25, .07, .25, .20, .06 and .09 with
+QQ (b) (chute bar double) and then failed in 5.00. I showed him 10 times.
+He then failed in 5 twice, succeeded in 3.00, and failed in 5 again. No
+change in manner of performance or in the object attacked, though my
+manner was different from his.
+
+(_d_) No. 3 had the following record in box Delta:—
+
+  2.00 (pushed with head)
+  3.20 (pushed with head)
+    30 F
+    10 F
+    10 F
+  2.10 (pulled wire and door).
+
+I showed him 20 times by pushing the bar to the right with my finger. He
+succeeded in 8.00 and 8.00 by pulling the wire and the door. No change in
+object attacked.
+
+(_e_) No. 2 had failed twice in 5 with chute QQ (ff) (chute string wire)
+and succeeded once in 2.00 by a strong pull on the wire itself, not the
+loop. I showed him 5 times, pulling the loop off the nail. He then failed
+in 5. There was no change in the objects attacked.
+
+These records show no signs of any influence of the tuition that are
+not more probably signs of something else. We cannot attribute the
+rapid decrease in time taken in (_b_) to the tuition until we know the
+time-curve for the same process without tuition.
+
+The systematic experiments designed to detect the presence of ability to
+learn from human beings are thus practically unanimous against it. So,
+too, was the general behavior of the monkeys, though I do not consider
+the failure of the animals to imitate common human acts as of much
+importance save as a rebuke to the story-tellers and casual observers.
+The following facts are samples: The door of No. 1’s cage was closed by
+an iron hoop with a slit in it through which a staple passed, the door
+being held by a stick of wood thrust through the staple. No. 1 saw me
+open the door of his and other cages by taking out sticks hundreds of
+times, but though he escaped from his cage a dozen times in other ways,
+he never took the stick out and to my knowledge never tried to. I myself
+and visitors smoked a good deal in the monkeys’ presence, but a cigar or
+cigarette given to them was always treated like anything else.
+
+
+IMITATION OF OTHER MONKEYS
+
+It would theoretically seem far more likely that the monkeys should
+learn from watching each other than from watching human beings, and
+experimental determinations of such ability are more important than those
+described in the last section as contributions both to genetic psychology
+and to natural history. I regret that the work I have been able to do in
+the study of this phase of the mental life of the monkeys has been very
+limited and in many ways unsatisfactory.
+
+We should expect to find the tendency to imitation more obvious in the
+case of young and parents than elsewhere. I have had no chance to observe
+such cases. We should expect closely associated animals, such as members
+of a common troop or animals on friendly terms, to manifest it more
+than others. Unfortunately, two of my monkeys, by the time I was ready
+to make definite experiments, were on terms of war. The other had then
+become so shy that I could not confidently infer inability to do a thing
+from actual failure to do it. He showed no evidence of learning from his
+mates. I have, therefore, little evidence of a quantitative objective
+nature to present and shall have in the end to ask the reader to take
+some opinions without verifiable proofs.
+
+My reliable experiments, five in number, were of the following nature. A
+monkey who had failed of himself (and often also after a chance to learn
+from me or from being put through the act) would be put where he could
+see another do the act and get a reward (food) for it. He would then be
+given a chance to do it himself, and note would be taken of his success
+or failure, and of whether his act was the same as that of his model in
+case he succeeded, and of whether he tried that act more than before the
+tuition in case he tried it and failed. The results are given in Table 11.
+
+In the fourth experiment No. 1 showed further that the tuition did not
+cause his successes in that after some successes further tuition did not
+improve him.
+
+There is clearly no evidence here of any imitation of No. 1 by No. 3.
+There was also apparently nothing like purposive watching on the part
+of No. 3. He seemed often to see No. 1 open the box or work the chute
+mechanism, but without special interest.
+
+This lack of any special curiosity about the doings of their own species
+characterized the general behavior of all three of my monkeys and in
+itself lessens the probability that they learn much from one another. Nor
+did there appear, in the course of the three months and more the animals
+were together, any signs of imitation. There were indeed certain notable
+instances of the lack of it in circumstances which one would suppose
+would be favorable cases for it.
+
+For instance: No. 2 was very timid. No. 1 was perfectly tame from the
+first day No. 2 was with me, and No. 3 became tame shortly after. No.
+2 saw Nos. 1 and 3 come to me, be played with, fed and put through
+experiments, yet he never did the same nor did he abate a jot or tittle
+from his timidity save in so far as I sedulously rewarded any chance
+advances of his. Conversely No. 1 and No. 3 seemed uninfluenced by the
+fear and shyness of No. 2. No. 2’s cage was between No. 1’s and No. 3’s,
+and they were for three weeks incessantly making hostile demonstrations
+toward each other, jumping, chattering, scowling, etc. No. 2 never did
+anything of the sort. Again, seeing No. 3 eat meat did not lead No. 1 to
+take it; nor did seeing No. 1 retreat in fright from a bit of absorbent
+cotton lead No. 3 to avoid it.
+
+
+TABLE 11
+
+  Table headings:
+  Column A: SUBJECT, DATE, ACT
+  Column B: TIME TRIED ALONE, WITH RESULT
+  Column C: NO. OF TIMES IMITATEE DID
+  Column D: RESULT AFTER CHANCE FOR IMITATION
+  Column E: SIMILARITY OR DISSIMILARITY OF ACT
+  Column F: SIMILAR ACT ATTEMPTED, THOUGH UNSUCCESSFULLY IN CASES WHERE
+            IT HAD NOT BEEN BEFORE TRAINING
+  Column G: GENERAL JUDGMENT AS TO INFLUENCE OF TRAINING
+
+  ======================+========+====+======+=============+=====+=======
+            A           |   B    | C  |  D   |      E      |  F  |   G
+  ----------------------+--------+----+------+-------------+-----+-------
+  No. 3. Dec. 17, 1900. |  50 F  | 43 | 55 F |             | No. | None.
+    VV (wire loop)      |        |    |      |             |     |
+  No. 3. Jan. 15, 1901. |  91 F  | 75 | 35 F |             | No. | None.
+    QQ (c) (nail chute) | 1.30   |    |      |             |     |
+  No. 3. Jan. 21, 1901. |  63 F  | 43 |  5 F | Dissimilar. | No. | None.
+    Gamma (wind)        |        |    | 9.00 |             |     |
+                        |        |    | 6.00 |             |     |
+  No. 3. Jan. 21, 1901. |  20 F  | 30 | 1.30 | Dissimilar. | No. | None.
+    QQ (ff) (string     | 2.00   |    |  .40 |             |     |
+    chute with wire)    |        |    |  .35 |             |     |
+                        |        |    |  5 F |             |     |
+  No. 3. Jan. 23, 1901. | 1.15 F | 40 | 10 F |             | No. | None.
+     QQ (chute)         |        |    |      |             |     |
+  ======================+========+====+======+=============+=====+=======
+
+Nothing in my experience with these animals, then, favors the hypothesis
+that they have any general ability to learn to do things from seeing
+others do them. The question is still an open one, however, and a much
+more extensive study of it should be made, especially of the possible
+influence of imitation in the case of acts already familiar either as
+wholes or in their elements.
+
+
+LEARNING APART FROM MOTOR IMPULSES
+
+The reader of my monograph, ‘Animal Intelligence,’ will recall that the
+experiments there reported seemed to show that the chicks, cats and
+dogs had only slight and sporadic, if any, ability to form associations
+except such as contained some actual motor impulse. They failed to form
+such associations between the sense-impressions and ideas of movements
+as would lead them to make the movements without having themselves
+previously in those situations given the motor impulses to the movements.
+They could not, for instance, learn to do a thing from having been put
+through it by me.
+
+The monkeys Nos. 1 and 3 were tested in a similar way with a number of
+different acts. The general conclusion from the experiments, the details
+of which will be given presently, is that the monkeys are not proved to
+have the power of forming associations of ideas to any greater extent
+than the other mammals, that they do not demonstrably learn to do things
+from seeing or feeling themselves make the movement. An adult human
+being whose hand was taken and made to push in a bar or pull back a bolt
+would thereby learn to do it for himself. Cats and dogs would not, and
+the monkeys are not proved to do so. On the other hand, it is impossible
+for me to say, as of the dogs and cats, that the monkeys are proved not
+to do so. In a few cases the animals did perform acts after having been
+put through them which they had failed to perform when left to their own
+trial and success method. In the majority of cases they did not. And
+in some of these latter cases failure seemed so improbable in case the
+animal really had the power of getting an idea of the act and proceeding
+from idea to execution, that one is inevitably led to some explanation
+for the few successes other than the presence of ‘ideas.’
+
+The general manner of making these experiments was like that in the case
+of the cats and dogs, save that the monkey’s paw was used to open the
+box from the outside instead of from the inside, and that the monkeys
+were also put through the acts necessary to operate some of the chute
+mechanisms. Tests parallel to that of comparing the behavior of kittens
+who had themselves gone into boxes with those who were dropped in by me
+were made in the following manner. I would carry a monkey from his cage
+and put him in some conspicuous place (_e.g._ on the top of a chair)
+and then give him a bit of food. This I would repeat a number of times.
+Then I would turn him loose in the room to see whether he had acquired
+an idea of being on the chair which would lead him to himself go to the
+chair. I would, in order to tell whether his act, in case he did so, was
+the result of random activities or was really due to his tuition, leave
+him alone for 5 or 10 minutes before the tuition. If he got on the chair
+afterwards when he had not before, or got on it much sooner, it would
+tend to show that the idea of getting food on that chair was present and
+effective. We may call these last the ‘on chair’ type of experiments.
+
+A sample experiment with a box is the following:—
+
+On January 4, 1901, box Delta (push back) was put in No. 1’s cage. He
+failed in 5, though he was active in trying to get in for about 4 minutes
+of the time and pulled and pushed the bar a great deal, though up and
+down and out instead of back. In his aimless pushings and pullings he
+nearly succeeded. He failed in 5 in a second trial also. I then opened
+the door of the cage, sat down beside it, held out my hand, and when he
+came to me took his right paw and with it (he being held in front of the
+box) pushed the bar back (and pulled the door open in those cases when it
+did not fall open of itself). He reached in and took the food and went
+back to the top of his cage and ate it. (No. 1 generally did this, while
+No. 3 generally stayed by me.) I then tried him alone; result 10 F; no
+activity at all. On January 5th I put the box in; result 10 F. He was
+fairly active. He pulled at the bar but mostly from a position on the top
+of the box and with his left hand; no attempts like the one I had tried
+to teach him. Being left alone he failed in 5. Being tried again with
+the door of the cage open and me sitting as I had done while putting him
+through the act, he succeeded in 7.00 by pushing the bar with his head
+in the course of efforts to poke his head in at the door. I then put him
+through the act 10 times and left him to himself. He failed in 5.00; no
+activity. I then sat down by the cage as when teaching him. He failed in
+5; little activity. Later in the day I put him through the act 10 times
+and then left him to himself. He failed in 5; little activity. I sat
+down as before. He failed in five; little activity. On January 6th I put
+him through the act 10 times and then left him. He failed in 10. This
+was repeated later in the day with the same result. Record:—By himself,
+10 F. Put through 80 times. F 65 (a) [the (a) refers to a note of his
+unrepeated chance success with his head]. No similar act unsuccessfully
+attempted. Influence of tuition, none.
+
+With the chute mechanisms the record would be of the same nature. With
+them I put the animal through generally by taking his paw, held out
+through the wire netting of the cage, and making the movement with it.
+In one experiment (No. 3 with QQ chute) the first 58 trials were made by
+taking the monkey outside the cage and holding him instead of having him
+put his paw through the netting for me to take.
+
+Many of the experiments were with mechanisms which had previously
+been used in experiments concerning the ability to learn from seeing
+me operate them. And the following Table (12) includes the results of
+experiments of both sorts. The results of experiments of the ‘on chair’
+type are in Table 13. In cases where the same apparatus was used for both
+purposes, the sort of training which was given first is that where an A
+is placed.
+
+In the first four experiments with No. 1 there was some struggling and
+agitation on his part while being held and put through the act. After
+that there was none in his case except occasional playfulness, and there
+was never any with No. 3 after the first third of the first experiment.
+The monkeys soon formed the habit of keeping still, because it was only
+when still that I put them through the act and that food resulted. After
+you once get them so that they can be held and their arms taken without
+their clinging to you, they quickly learn to adapt themselves to the
+experiments.
+
+With No. 1, out of 8 cases where he had of himself failed (in five of the
+cases he had also failed after being shown by me), he succeeded after
+being put through (13, 21, 51, 10, 7, 80, and 10 times) in two cases (QQ
+(chute) and RR (wood plug). The act was unlike the one taught him in the
+former case.
+
+
+TABLE 12
+
+  Table headings:
+  Column A: SUBJECT. DATE. ACT
+  Column B: TIMES TRIED ALONE, WITH RESULT
+  Column C: NUMBER OF TIMES ATTENTION ATTRACTED
+  Column D: RESULT
+  Column E: NUMBER OF TIMES SHOWN BY ME
+  Column F: RESULT IN TRIALS AFTER BEING SHOWN BY ME
+  Column G: NUMBER OF TIMES PUT THROUGH THE ACT
+  Column H: RESULT IN TRIALS AFTER BEING PUT THROUGH THE ACT
+  Column I: COMPARISON OF ACT USED WITH ACT TAUGHT
+  Column J: SIMILAR ACT ATTEMPTED THOUGH UNSUCCESSFULLY
+  Column K: ACT DONE ONCE OR MORE, BUT NOT REPEATED IN SPITE OF
+            REPEATED TUITION
+
+  ========================+==========+====+========+========+========+
+             A            |    B     | C  |    D   |    E   |   F    |
+  ------------------------+----------+----+--------+--------+--------+
+  No. 1, Jan. 7, 1900,    |   10 F   |    |        |        |        |
+    PP (string across)    |   10 F   |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 17, 1900,   |   15 F   |    |        | 21 A   |150 F   |
+    MM (bolt at top)      |          |    |        |        | 10 F   |
+                          |          |    |        |        |        |
+  No. 1, Feb. 24, 1900,   |  2.20    |    |        |  4}    | 10 F   |
+    OOO (upper string)    |   3 F    |    |        |  4} 12 | .20    |
+                          |          |    |        |  4}    |        |
+                          |          |    |        |  4     | .22    |
+                          |          |    |        |        |        |
+  No. 1, Mar. 24, 1900,   | 120 F    |    |        | 10 A   | 60 F   |
+    QQ (chute)            |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Apr. 5, 1900,    |  10 F    |  2 |  5 F   |  1 A   |  2 F   |
+    RR (wood plug)        |          |    |        |  1     |  2 F   |
+                          |          |    |        |  1     |  2 F   |
+                          |          |    |        |  1     |  5 F   |
+                          |          |    |        |        |        |
+  No. 1, Oct. 20, 1900,   |  10 F    |    |        |  4     | .22    |
+    VV (loop)             |  10 F    |    |        |        |        |
+                          |  10 F    |    |        |        |        |
+                          |  10 F    |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Nov. 19, 1900,   |  10 F    |    |        |  5     | 10 F   |
+    Theta (new bolt)      |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 4, 1901,    |  10 F    |    |        | 15     | 10 F   |
+    Delta (push back)     |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 6, 1901,    |  8.00    |    |        | 40     | 10 F   |
+    QQ (a) (single        |          |    |        |        |2.00    |
+    wind chute)           |          |    |        |        | .50    |
+                          |          |    |        |        |        |
+  No. 1, Jan. 7, 1901,    |   5 F    |    |        |        |        |
+    Zeta (side plug new)  |          |    |        |        |        |
+                          |  1.10    |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 9, 1901,    |  3.00    |    |        | 10     |  5 F   |
+    QQ (b) (2½            | to .06   |    |        |        |  5 F   |
+    wind chute)           |   5 F    |    |        |        |3.00    |
+                          |          |    |        |        |  5 F   |
+                          |          |    |        |        |        |
+  No. 1, Jan. 11, 1901,   |   5 F    |  5 |  5 F   |  1[32] |2.20    |
+    QQ (c) (nail chute)   |   5 F    |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 12, 1901,   |   5 F    |    |        | 25 A   | 10 F   |
+    Epsilon (push down)   |  10 F    |    |        |        | 10 F   |
+                          |          |    |        | 15     | 10 F   |
+                          |          |    |        |        |        |
+  No. 1, Jan. 16, 1901,   |   5 F    |  5 |  3.30  |        |        |
+    QQ (d) (pull chute)   |   5 F    |    |   .10  |        |        |
+                          |          |    |        |        |        |
+  No. 1, Jan. 17, 1901,   |   5 F    |  5 |  5 F   | 15 A   |  5 F   |
+    QQ (f) (string chute) |          |    |        |        |  5 F   |
+                          |          |    |        |        |        |
+  No. 1, Jan. 18, 1901,   |   5 F    |  3 |   im.  |        |        |
+    QQ (e) (hook chute)   |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Dec. 17, 1900,   |  60 F    |  3 | 60 F   | 10 A   |  5 F   |
+    QQ (chute)            |          |    |        | 30     | 30 F   |
+                          |          |    |        |        |        |
+  No. 3, Dec. 17, 1900,   |  10 F    |    |        |        |        |
+    VV (loop)             |  20 F    |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 4, 1901,    |  10 F    |    |        | 20     |8.00[34]|
+    Delta (push back)     |  2.10    |    |        |        |8.00[34]|
+                          |  (by     |    |        |        |        |
+                          | pulling  |    |        |        |        |
+                          | string)  |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 4, 1901,    |  10 F    |    |        | 30     | 10 F   |
+    Gamma (wind)          |  10 F    |    |        |        | 10 F   |
+                          |          |    |        |        |        |
+  No. 3, Jan. 8, 1901,    |  10 F[36]|    |        | 25     |  6 F   |
+    Theta (bolt at top)   |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 9, 1901,    |  10 F    |    |        |        |3.00[37]|
+    QQ (a) (chute bar)    |          |    |        |        |        |
+                          |          |    |        |        |        |
+                          |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 9, 1901,    |          |    |        |        |        |
+    QQ (b) (2½ wind chute)|  10 F    |    |        | 20     | 8 F    |
+                          |          |    |        |        | 8 F    |
+                          |          |    |        |        |        |
+  No. 3, Jan. 11, 1901,   |    5 F   | 10 |  5 F   | 25 A   | 5 F    |
+    QQ (c) (nail chute)   |    5 F   |    |12 F[38]|        | 5 F    |
+                          |          |    |        |        |1.30    |
+                          |          |    |        |        | 5 F    |
+                          |          |    |        |        |10 F    |
+                          |          |    |        |        |        |
+  No. 3, Jan. 15, 1901,   |    10 F  |    |        | 25 A   | 5 F    |
+    Epsilon (push down)   |          |    |        |        | 5 F    |
+                          |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 16, 1901,   |          |    |        |        |        |
+    QQ (e) (hook chute)   |    5 F   |  5 |  5 F   |  5 A   |2.00    |
+                          |          |    |        |        |1.25    |
+                          |          |    |        |        |1.20    |
+                          |          |    |        |        |        |
+  No. 3, Jan. 19, 1901,   |    5 F   |    |   5    |  5 A   | 5 F    |
+    QQ (ff) (string chute |    5 F   |    |        |        |        |
+    with wire)            | 2.00[39] |    |        |        |        |
+                          |          |    |        |        |        |
+                          |          |    |        |        |        |
+  No. 3, Jan. 22, 1901,   |    5 F   |    |        |        |        |
+    WW (bar inside)       |previously|    |        |        |        |
+                          |   some   |    |        |        |        |
+                          |  40.00 F |    |        |        |        |
+  ========================+==========+====+========+========+========+
+
+  ========================+======+========+===========+========+======
+             A            |  G   |   H    |     I     |   J    |  K
+  ------------------------+------+--------+-----------+--------+------
+  No. 1, Jan. 7, 1900,    | 13   |  10 F  |           |   No.  |
+    PP (string across)    |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 17, 1900,   | 21   |  10 F  |           |   (?)  |
+    MM (bolt at top)      |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Feb. 24, 1900,   |      |        | Partly    |        |
+    OOO (upper string)    |      |        | similar.  |   No.  |
+                          |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Mar. 24, 1900,   | 10   | 30.00  |Dissimilar.|   No.  |
+    QQ (chute)            |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Apr. 5, 1900,    |  7   |  2.20  | Similar.  | Yes(?) |
+    RR (wood plug)        |  2   |  2.00  |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Oct. 20, 1900,   |      |        | Similar.  |        |
+    VV (loop)             |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Nov. 19, 1900,   | 51 A | 132 F  |           |   No.  |
+    Theta (new bolt)      |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 4, 1901,    | 80 A |65 F[31]|           |   No.  |
+    Delta (push back)     |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 6, 1901,    |      |        |Dissimilar.|        |
+    QQ (a) (single        |      |        |           |        |
+    wind chute)           |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 7, 1901,    |      |        |           |        |
+    Zeta (side plug new)  | 20   |   im.  |     ?     |        |
+                          |      |   im.  |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 9, 1901,    |      |        |Dissimilar.|   No.  |Yes.
+    QQ (b) (2½            |      |        |           |        |
+    wind chute)           |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 11, 1901,   |      |        |Dissimilar.|        |Yes.[33]
+    QQ (c) (nail chute)   |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 12, 1901,   | 10   |   5 F  |           |   No.  |
+    Epsilon (push down)   | 10   |  10 F  |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 16, 1901,   |      |        |           |        |
+    QQ (d) (pull chute)   |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 17, 1901,   | 10   |   5 F  |           |        |
+    QQ (f) (string chute) |      |        |           |        |
+                          |      |        |           |        |
+  No. 1, Jan. 18, 1901,   |      |        |           |        |
+    QQ (e) (hook chute)   |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Dec. 17, 1900,   |113   |  90 F  |           |   (?)  |
+    QQ (chute)            |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Dec. 17, 1900,   | 23   |  20 F  |           |   No.  |
+    VV (loop)             |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 4, 1901,    | 5 A  |2.00[35]|Dissimilar.|   No.  |
+    Delta (push back)     |  5   |  3.20  |           |        |
+                          | 15   |  30 F  |           |        |
+                          |  5   |  10 F  |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 4, 1901,    | 20 A |   5 F  |           |   No.  |
+    Gamma (wind)          |      |   8 F  |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 8, 1901,    |      |        |Dissimilar.|        |
+    Theta (bolt at top)   |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 9, 1901,    | 10   |        |           |   No   |
+    QQ (a) (chute bar)    | 10   |   .40  |    ?      |complete|
+                          | 10   |  1.00  |           | circle.|
+                          | 10   |  1.00  |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 9, 1901,    |      |        |           |        |
+    QQ (b) (2½ wind chute)|      |   5 F  |Dissimilar.|        |Yes.
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 11, 1901,   | 45   |  38 F  |           |   No.  |Yes.
+    QQ (c) (nail chute)   |      |        |           |        |
+                          | 10   |  10 F  |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 15, 1901,   | 20   | 11.00  |           |   No.  |Yes.
+    Epsilon (push down)   |      |  30 F  |     ?     |        |
+                          | 15   |  10 F  |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 16, 1901,   |      |        |           |        |
+    QQ (e) (hook chute)   | 10   |   .10  |Dissimilar.|   No.  |
+                          |      |   .10  |           |        |
+                          |      |        |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 19, 1901,   |  7   |   5 F  |           |        |
+    QQ (ff) (string chute |  8   |   5 F  |           |        |
+    with wire)            | 12   |  3.00  |Dissimilar.|   No.  |
+                          |      |   5 F  |           |        |
+                          |      |        |           |        |
+  No. 3, Jan. 22, 1901,   | 10   |   5 F  |           |        |
+    WW (bar inside)       |      |6.00[40]|           |        |
+                          |      |        |           |        |
+                          |      |7.00[40]|Dissimilar.|   No.  |
+  ========================+======+========+===========+========+======
+
+In only one case (bolt at top) out of eight was there possibly any
+attempt at the act after he had been put through which had not been made
+before. The ‘yes or?’ in the table with RR was a case occurring after the
+imitation of me but before the putting No. 1 through.
+
+Out of 6 cases where he had himself failed, No. 3 succeeded (after being
+put through 113, 23, 20, 10, 10, 20 and 10 times) in 3 cases (chute bar,
+push down and bar inside). The act was dissimilar in all three cases,
+bearing absolutely no resemblance in one case. There was no unsuccessful
+attempt at the act taught him in any of the cases. With the chute he
+did finger the bar after tuition where he had not done so before, but
+it was probably an accidental result of his holding his hand out toward
+it for me to take as he had formed the habit of doing. In the case of
+box Epsilon (push down), with which he succeeded by pushing his hand in
+above the lever (an act which though unlike that taught him might be by
+some considered to be due to an idea gained from the tuition), he failed
+entirely after further tuition (15 times).
+
+Like the dogs and cats, then, the monkeys seemed unable to learn to do
+things from being put through them. We may now examine those which they
+did do of themselves before tuition and ask whether they learned the more
+rapidly thereby or modified their behavior in ways which might be due to
+the tuition. There are too few cases and no chance for comparison on the
+first point; on the second the records are unanimous in showing no change
+in the method of operating the mechanisms due to the tuition.
+
+As in Table 9, figures followed by F mean that in that length of time
+the animal failed. Figures without an F denote the time taken by the
+animal to operate the mechanism.
+
+As a supplement to Table 12 I have made a summary of the cases where the
+animals did succeed after tuition, that shows the nature of the act shown
+them as compared with the act they made use of.
+
+
+SUPPLEMENT TO TABLE 12
+
+  ==========+=====================+===================+====================
+  APPARATUS | MODEL GIVEN OR ACT  |   ACT OF NO. 1    |   ACT OF NO. 3
+            |     PUT THROUGH     |                   |
+  ----------+---------------------+-------------------+--------------------
+  OOO       |To pull upper        |Pulled both strings|
+            |  string.            |  alternately, but |
+            |                     |  upper enough     |
+            |                     |  more to succeed. |
+            |                     |                   |
+  QQ        |To push bar in.      |Inserted fingers   |
+            |                     |   between bar and |
+            |                     |   its slot and    |
+            |                     |   pulled and      |
+            |                     |   pushed vaguely. |
+            |                     |                   |
+  RR        |To pull plug out     |Pulled and bit.    |
+            |  with right hand.   |                   |
+            |                     |                   |
+  VV        |To pull loop off nail|_Similar._         |
+            |  with right hand.   |                   |
+            |                     |                   |
+  QQ (a)    |To pull bar around   |Pulled back        |Pulled back
+            |  toward him.        |  and forth        |  and forth
+            |                     |  indiscriminately.|  indiscriminately.
+            |                     |                   |
+  QQ (b)    |To pull bar around   |Pulled back        |
+            |  toward him in      |  and forth        |
+            |  2½ continuous      |  indiscriminately.|
+            |  revolutions.       |                   |
+            |                     |                   |
+  QQ (c)    |To take nail and pull|Pulled back and    |_Similar_ or
+            |  directly outward.  |  forth.           |  nearly so.
+            |                     |                   |
+  Delta     |To push bar to right |                   |Did before tuition
+            |  with right hand.   |                   |  by pulling wire;
+            |                     |                   |  after tuition by
+            |                     |                   |  chance movement
+            |                     |                   |  of head.
+            |                     |                   |
+  Theta     |To pull bolt up with |                   |Pulled door and
+            |  right hand.        |                   |  worked bolt loose.
+            |                     |                   |
+  Epsilon   |To stand in front,   |                   |Inserted arm in
+            |  insert fingers of  |                   |  general activity
+            |  right hand and     |                   |  while on top of
+            |  press lever down.  |                   |  the box.
+            |                     |                   |
+  QQ (e)    |To pull hook down.   |                   |Pulled at the lever
+            |                     |                   |  and hook in a
+            |                     |                   |  general attack on
+            |                     |                   |  the apparatus.
+            |                     |                   |
+  QQ (ff)   |To pull wire loop    |                   |Pulled outward on
+            |  off nail with      |                   |  the lever which
+            |  right hand.        |                   |  pushed the banana
+            |                     |                   |  down the
+            |                     |                   |  chute so hard as
+            |                     |                   |  to pull it off its
+            |                     |                   |  pivot.
+            |                     |                   |
+  WW        |To stand on top of   |                   |Pulled at door until
+            |  box, reach right   |                   |  bar worked out
+            |  hand down and      |                   |  of its catch.
+            |  pull bar up.       |                   |
+  ==========+=====================+===================+====================
+
+I have kept the results of the tests of the ‘on chair’ type separate from
+the others because they may be tests of a different thing and surely are
+subject to different conditions.
+
+They were tests of the animals’ ability to form the habit of going to a
+certain place by reason of having been _carried_ there and securing food
+thereby. I would leave the animal loose in the room, and if he failed
+in 5 or 10 minutes to go to the place of his own accord, would put him
+back in his cage; if he did go of his own accord, I would note the time.
+Then I would take him, carry him to the place, and feed him. After doing
+this 10 times I would turn him loose again and see whether the idea of
+being fed in such and such a place was present and active in making him
+go to the place. In such tests we are absolutely sure that the animal can
+without any difficulty perform the necessary movements and would in case
+the proper stimulus to set them off appeared, if, for instance, a bit of
+food on one of the places to which he was to go caught his eye. In so far
+forth the tests were favorable cases for learning. On the other hand, the
+situation associated with getting food may have been in these cases not
+the mere ‘being on box’ but the whole previous experience ‘being carried
+while clinging and being put or let jump on a box.’ In this respect the
+tests may have been less favorable than the acts where getting food was
+always the direct sequent of the act of going into the box.
+
+The experiments were:—
+
+A. Carrying the animal and putting him on a chair.
+
+B. Carrying the animal and putting him on a pile of boxes.
+
+C. Carrying the animal and putting him on the top of a sewing machine.
+
+D. Carrying the animal and putting him on the middle of a board 6 feet
+long, stretched horizontally across the room, 3 feet from the floor.
+
+E. Carrying the animal and putting him on the side of the cage, head down.
+
+The results are given in Table 13.
+
+The size of the room in which I worked and other practical difficulties
+prevented me from extending these experiments. As they stand, no stable
+judgments can be inferred from them. It should be noted that in the
+successful cases there were no other signs of the presence of the idea
+‘food when there’ than the mere going to a certain place. The animal did
+not wait at the place more than a second or two, did not look at me or
+show any signs of expecting anything.
+
+
+TABLE 13
+
+  ================+==========+==============+===============+===========
+     EXPERIMENT   |          |RESULTS BEFORE|NUMBER OF TIMES|  RESULTS
+      AND DATE    |  ANIMAL  |   TRAINING   |  PUT THROUGH  |   AFTER
+                  |          |              |               |  TRAINING
+  ----------------+----------+--------------+---------------+-----------
+  A. Jan. 22, 1901|  No. 1.  |      5 F     |      10       |    1.00
+                  |          |              |               |    3.00
+     Jan. 22, 1901|  No. 1.  |      5 F     |      10       |     im.
+                  |          |              |               |    3.30
+     Jan. 23, 1901|  No. 3.  |      5 F     |      10       |    3.30
+                  |          |      5 F     |               |
+  B. Jan. 26, 1901|  No. 1.  |     10 F     |      10 and 5 |   10 F 5 F
+                  |  No. 3.  |      5 F     |      10       |    5 F
+                  |          |              |      10       |    5 F
+  C. Jan. 27, 1901|  No. 1.  |      5 F     |      10       |    3.00
+  D. Jan. 27, 1901|  No. 1.  |     3.20     |      10       |    5 F
+  E. Jan. 26, 1901|  No. 3.  |      5 F     |       5       |    5 F
+  ================+==========+==============+===============+===========
+
+Although, as I noted in the early part of this monograph, there were
+occasionally phenomena in the general behavior of the monkeys which of
+themselves impressed one as being suggestive of an ideational life,
+the general run of their learning apart from the specific experiments
+described was certainly confined to the association of impulses of their
+own with certain situations. The following examples will suffice:—
+
+In getting them so that they would let themselves be handled it was of
+almost no service to _take_ them and feed them while holding them or
+otherwise make that state pleasant for them. By far the best way is to
+wait patiently till they do come near, then feed them; wait patiently
+till they do take hold of your arm, then feed them. If you do take them
+and hold them partly by force, you must feed them only when they are
+comparatively still. In short, in taming them one comes unconsciously
+to adopt the method of rewarding certain of their impulses rather than
+certain _conditions_ which might be associated in their minds with ideas,
+had they such.
+
+After No. 1 and No. 3 had both reached a point where both could hardly
+be gotten to leave me and go back into their cages or down to the floor
+of the room, where they evidently enjoyed being held by me, they still
+did not climb upon me. The idea of clinging to me was either absent or
+impotent to cause them to act. What they did do was, in the case of
+No. 1, to jump about, pawing around in the air, until I caught an arm
+or leg, to which stimulus he had by dint of the typical sort of animal
+association learned to react by jumping to my arm and clinging there; in
+the case of No. 3, to stand still until I held my arm right in front of
+him (if he were in his cage) or to come and stand on his hind legs in
+front of me (if he were out on the floor). In both cases No. 3’s act was
+one which had been learned by my rewarding his impulses. I often tried,
+at this period of their intimacy with me, this instructive experiment.
+The monkey would be clinging to me so that I could hardly tear him away.
+I would do so, and he would, if dropped loose from me, make no efforts to
+get back.
+
+I have already mentioned my failure to get the animals to put out their
+right hands through the netting after they had long done so with their
+left hands. With No. 3 I tried putting my fingers through and poking the
+arm out and then making the movement with it. He profited little if any
+by this tuition. Had I somehow induced him to do it himself, a few trials
+would have been sufficient to get the habit well under way.
+
+Monkey No. 1 apparently enjoyed scratching himself. Among the stimuli
+which served to set off this act of scratching was the irritation from
+tobacco smoke. If any one would blow smoke in No. 1’s face, he would
+blink his eyes and scratch himself, principally in the back. After a
+time he got in the habit of coming to the front of his cage when any one
+was smoking and making such movements and sounds as in his experience
+had attracted attention and caused the smoker to blow in his face. He
+was often given a lighted cigar or cigarette to test him for imitation.
+He formed the habit of rubbing it on his back. After doing so he would
+scratch himself with great vigor and zest. He came to do this always
+when the proper object was given him. I have recounted all this to show
+that the monkey enjoyed scratching himself. _Yet he apparently never
+scratched himself except in response to some sensory stimulus._ He was
+apparently incapable of thinking ‘scratch’ and so doing. Yet the act was
+quite capable of association with circumstances with which as a matter
+of hereditary organization it had no connection. For by taking a certain
+well-defined position in front of his cage and feeding him whenever he
+did scratch himself I got him to always scratch within a few seconds
+after I took that position.
+
+
+GENERAL MENTAL DEVELOPMENT OF THE MONKEYS
+
+It is to be hoped that the growing recognition of the worth of
+comparative and genetic studies will lead to investigations of the mental
+make-up of other species of monkeys, and to the careful overhauling of
+the work done so far, including these rather fragmentary studies of mine.
+Work with three monkeys of one species, especially when no general body
+of phenomena, such as one has at hand in the case of domestic animals,
+can be used as a means of comparison, must necessarily be of limited
+application in all its details and of insecure application even in its
+general features. What I shall say concerning the advance in the mental
+development of the monkeys over that of other mammals may then be in
+strictness true of only my three subjects, and it may be left to the
+judgment of individuals to extend my conclusions as far as seems to them
+likely. To me it seems fairly likely that the very general mental traits
+which the research has demonstrated hold true with little variation in
+the monkeys in general.
+
+The monkeys represent progress in mental development from the generalized
+mammalian type toward man:—
+
+1. In their sensory equipment, in the presence of focalized vision.
+
+2. In their motor equipment, in the coördinated movements of the hand and
+the eye.
+
+3. In their instincts or inherited nervous connections, in their general
+physical and mental activity.
+
+4. In their method of learning or associative processes; in—
+
+  _a._ Quicker formation of associations,
+  _b._ Greater number of associations,
+  _c._ Greater delicacy of associations,
+  _d._ Greater complexity of associations,
+  _e._ Greater permanence of associations.
+
+The fact of (1) is well known to comparative anatomists. Its importance
+in mental development is perhaps not realized, but appears constantly to
+a systematic student.
+
+(2) is what accounts for much of the specious appearance of human ways
+of thinking in the monkeys and becomes in its human extension the handy
+tool for much of our intellectual life. It is in great measure the
+prerequisite of 4 _c_.
+
+(3) accounts for the rest of such specious appearances, is at the basis
+of much of 4 _b_, presages the similar though extended instincts of the
+human being, which I believe are the leading efficient causes of human
+mental capacity, and is thus the great mental bond which would justify
+the inclusion of monkeys and man in a common group if we were to classify
+animals on the basis of mental characteristics.
+
+Even the casual observer, if he has any psychological insight, will be
+struck by the general, aimless, intrinsically valuable (to the animal’s
+feelings) physical activities of a monkey compared with the specialized,
+definitely aroused, utilitarian activities of a dog or cat. Watch the
+latter and he does but few things, does them in response to obvious
+sense presentations, does them with practical consequences of food,
+sex-indulgence, preparation for adult battles, etc. If nothing that
+appeals to his special organization comes up, he does nothing. Watch a
+monkey and you cannot enumerate the things he does, cannot discover the
+stimuli to which he reacts, cannot conceive the _raison d’être_ of his
+pursuits. Everything appeals to him. He likes to be active for the sake
+of activity.
+
+The observer who has proper opportunities and takes proper pains will
+find this intrinsic interest to hold of mental activity as well. No. 1
+happened to hit a projecting wire so as to make it vibrate. He repeated
+this act hundreds of times in the few days following. He did not, could
+not, eat, make love to, or get preliminary practice for the serious
+battles of life out of, that sound. But it did give him mental food,
+mental exercise. Monkeys seem to enjoy strange places; they revel, if I
+may be permitted an anthropomorphism, in novel objects. They like to have
+feelings as they do to make movements. The fact of mental life is to them
+its own reward.
+
+It is beyond question rash for any one to venture hypotheses concerning
+the brain parallel of mental conditions, most of all for the ignoramus
+in the comparative histology of the nervous system, but one cannot help
+thinking that the behavior of the monkeys points to a cerebrum that is
+no longer a conservative machine for making a few well-defined sorts of
+connections between sense-impressions and acts, that is not only fitted
+to do more delicate work in parts, but is also alive, tender all over,
+functioning throughout, set off in action by anything and everything. And
+if one adds coördinations allowing a freedom and a differentiation of
+action of the muscles used in speech comparable to that already present
+in connection with the monkey’s hand, he may well ask, “What more of a
+nervous mechanism do you need to parallel the behavior of the year-old
+child?” However, this is not the place to speculate upon the importance
+to human development of our instinctive aimless activity, physical and
+mental, or to describe further its similarity and evident phylogenetic
+relationship to the instinctive behavior of the monkeys. Elsewhere I
+shall undertake that task.
+
+4. In their method of learning, the monkeys do not advance far beyond the
+generalized mammalian type, but in their proficiency in that method they
+do. They seem at least to form associations very much faster, and they
+form very many more. They also seem superior in the delicacy and in the
+complexity of the associations formed and the connections seem to be more
+permanent.
+
+This progress may seem, and doubtless will to the thinker who looks upon
+the human intellect as a collection of functions of which ideation,
+judgment and reasoning are chief, to be slight. To my mind it is not
+so in reality. For it seems to me highly probable that the so-called
+‘higher’ intellectual processes of human beings are but secondary results
+of the general function of having free ideas and that this general
+function is the result of the formation after the fashion of the animals
+of a very great number of associations. I should therefore say, “Let
+us not wonder at the comparative absence of free ideas in the monkeys,
+much less at the absence of inferences or concepts. Let us not wonder
+that the only demonstrable intellectual advance of the monkeys over the
+mammals in general is the change from a few, narrowly confined, practical
+associations to a multitude of all sorts, for that may turn out to be at
+the bottom the only _demonstrable advance of man_, an advance which in
+connection with a brain acting with increased delicacy and irritability,
+brings in its train the functions which mark off human mental faculty
+from that of all other animals.”
+
+The typical process of association described in Chapter II has since been
+found to exist among reptiles (by Mr. R. M. Yerkes) and among fishes (by
+myself). It seems fairly likely that not much more characterizes the
+primates. If such work as that of Lubbock and the Peckhams holds its own
+against the critical studies of Bethe, this same process exists in the
+insects. Yerkes and Bosworth think they have demonstrated its presence
+in the crayfish. Even if we regard the learning of the invertebrates as
+problematic, still this process is the most comprehensive and important
+thing in mental life. I have already hinted that we ought to turn our
+views of human psychology upside down and study what is now casually
+referred to in a chapter on habit or on the development of the will, as
+the general psychological law, of which the commonly named processes are
+derivatives. When this is done, we shall not only relieve human mentality
+from its isolation and see its real relationships with other forms; we
+may also come to know more about it, may even elevate our psychologies
+to the explanatory level and connect mental processes with nervous
+activities without arousing a sneer from the logician or a grin from the
+neurologist.
+
+
+
+
+CHAPTER VI
+
+LAWS AND HYPOTHESES FOR BEHAVIOR
+
+
+LAWS OF BEHAVIOR IN GENERAL
+
+_Behavior is predictable._ The first law of behavior, one fraction of
+the general law of the uniformity of nature, is that with life and
+mind, as with mass and motion, the same cause will produce the same
+effect,—that _the same situation will, in the same animal, produce the
+same response_,—and that _if the same situation produces on two occasions
+two different responses, the animal must have changed_.
+
+Scientific students of behavior will, with few exceptions, accept this
+law in theory, but in practice we have not fully used it. We have too
+often been content to say that a man may respond in any one of several
+ways to the same situation, or may attend to one rather than another
+feature of the same object, without insisting that the man must in each
+case be different, and without searching for the differences in him which
+cause the different reactions.
+
+The changes in an organism which make it respond differently on different
+occasions to the same situation range from temporary to permanent
+changes. Hunger, fatigue, sleep, and certain diseases on the one hand,
+and learning, immunity, growth and senility on the other, illustrate this
+range.
+
+Behavior is predictable _without recourse to magical agencies_. It is,
+of course, the case that any given difference between the responses
+of an animal to the same situation depends upon some _particular_
+difference in the animal. Each immunity, for example, has its detailed
+representation in an altered condition of the blood or other bodily
+tissue. In general the changes in an animal which cause changes in its
+behavior to the same situation are fully enumerated in a list of the
+bodily changes concerned. That is, whatever changes may be supposed to
+have taken place in the animal’s vital force, spiritual essence, or
+other magical bases for life and thought, are useless for scientific
+explanation and control of behavior.
+
+No competent thinker probably doubts this in the case of such changes
+as are referred to by hunger, sleep, fatigue, so-called ‘functional’
+diseases and immunity, and those who do doubt it in the case of mental
+growth and learning seem to represent an incomplete evolution from
+supernatural, or rather infrascientific, thinking. There may be in
+behavior a surplus beyond what would be predictable if the entire history
+of every atom in the body was known—a surplus necessarily attributable to
+changes in the animal’s incorporeal structure. But scientific thinkers
+properly refuse to deliberately count upon such a surplus.
+
+_Every response or change in response of an animal is then the result of
+the interaction of its original knowable nature and the environment._
+This may seem too self-evident a corollary for mention. It should be
+so, but, unfortunately, it is not. Two popular psychological doctrines
+exist in defiance of it. One is the doctrine that the movements of early
+infancy are random, the original nature of the animal being entirely
+indifferent as to what movement shall be made upon a given stimulus. But
+no animal can have an original nature that does not absolutely prescribe
+just what the response shall be to every stimulus. If the movements are
+really random, they occur by virtue of some force that works at random.
+If the movements are really the result of the action of the environment
+on the animal’s nature, they are never random. A baby twiddles his thumbs
+or waves his legs for exactly the same sort of reason that a chick pecks
+at a worm or preens its wing.
+
+The other doctrine which witnesses to neglect of the axiom that behavior
+is the creation of the environment, acting on the animal’s nature, is the
+doctrine that the need for a certain behavior helps to create it, that
+being in a difficulty tends in and of itself to make an animal respond so
+as to end the difficulty.
+
+The truth is that to a difficulty the animal responds by whatever its
+inherited and acquired nature has connected with the special form of
+difficulty and that in many animals the one response of those thus
+provided which relieves the difficulty is selected and connected more
+firmly with that difficulty’s next appearance. The difficulty acts only
+as a stimulus to the animal’s nature and its relief acts only as a
+premium to the connection whereby it was relieved. The law of original
+behavior, or the law of instinct, is then that _to any situation an
+animal will, apart from learning, respond by virtue of the inherited
+nature of its reception-, connection- and action-systems_.
+
+The inquiry into the laws of learning to be made in this essay is limited
+to those aspects of behavior which the term has come historically to
+signify, that is, to intellect, skill, morals and the like.
+
+For the purposes of this essay it is not necessary to decide just what
+features of an animal’s behavior to include under intellect, skill,
+morals and the like. The statements to be made will fit any reasonable
+dividing line between behavior on the one side and mere circulation,
+digestion, excretion and the like on the other. There should in fact
+be no clear dividing line, since there is no clear gap between those
+activities which naturalists have come to call behavior and the others.
+
+The discussion will include: First, a description of two laws of
+learning; second, an argument to prove that no additional forces
+are needed—that these two laws explain all learning; and third, an
+investigation of whether these two laws are reducible to more fundamental
+laws. I shall also note briefly the consequences of the acceptance of
+these laws in one sample case, that of the study of mental evolution.
+
+
+PROVISIONAL LAWS OF ACQUIRED BEHAVIOR OR LEARNING
+
+The Law of Effect is that: _Of several responses made to the same
+situation, those which are accompanied or closely followed by
+satisfaction to the animal will, other things being equal, be more firmly
+connected with the situation, so that, when it recurs, they will be
+more likely to recur; those which are accompanied or closely followed
+by discomfort to the animal will, other things being equal, have their
+connections with that situation weakened, so that, when it recurs, they
+will be less likely to occur. The greater the satisfaction or discomfort,
+the greater the strengthening or weakening of the bond._
+
+The Law of Exercise is that: _Any response to a situation will, other
+things being equal, be more strongly connected with the situation in
+proportion to the number of times it has been connected with that
+situation and to the average vigor and duration of the connections._
+
+These two laws stand out clearly in every series of experiments on animal
+learning and in the entire history of the management of human affairs.
+They give an account of learning that is satisfactory over a wide range
+of experience, so long as all that is demanded is a rough and general
+means of prophecy. We can, as a rule, get an animal to learn a given
+accomplishment by getting him to accomplish it, rewarding him when he
+does, and punishing him when he does not; or, if reward or punishment are
+kept indifferent, by getting him to accomplish it much oftener than he
+does any other response to the situation in question.
+
+For more detailed and perfect prophecy, the phrases ‘result in
+satisfaction’ and ‘result in discomfort’ need further definition, and the
+other things that are to be equal need comment.
+
+By a satisfying state of affairs is meant one which the animal does
+nothing to avoid, often doing such things as attain and preserve it. By a
+discomforting or annoying state of affairs is meant one which the animal
+commonly avoids and abandons.
+
+The satisfiers for any animal in any given condition cannot be determined
+with precision and surety save by observation. Food when hungry, society
+when lonesome, sleep when fatigued, relief from pain, are samples of the
+common occurrence that what favors the life of the species satisfies its
+individual members. But this does not furnish a completely valid rule.
+
+The satisfying and annoying are not synonymous with favorable and
+unfavorable to the life of either the individual or the species. Many
+animals are satisfied by deleterious conditions. Excitement, overeating,
+and alcoholic intoxication are, for instance, three very common and very
+potent satisfiers of man. Conditions useful to the life of the species
+in moderation are often satisfying far beyond their useful point: many
+conditions of great utility to the life of the species do not satisfy and
+may even annoy its members.
+
+The annoyers for any animal follow the rough rule that alterations
+of the animal’s ‘natural’ or ‘normal’ structure—as by cuts, bruises,
+blows, and the like,—and deprivations of or interference with its
+‘natural’ or ‘normal’ activities,—as by capture, starvation, solitude,
+or indigestion,—are intolerable. But interference with the structure
+and functions by which the species is perpetuated is not a sufficient
+criterion for discomfort. Nature’s adaptations are too crude.
+
+Upon examination it appears that the pernicious states of affairs which
+an animal welcomes are not pernicious _at the time, to the neurones_. We
+learn many bad habits, such as morphinism, because there is incomplete
+adaptation of all the interests of the body-state to the temporary
+interest of its ruling class, the neurones. So also the unsatisfying
+goods are not goods to the neurones at the time. We neglect many benefits
+because the neurones choose their immediate advantage. The neurones must
+be tricked into permitting the animal to take exercise when freezing or
+quinine when in a fever, or to free the stomach from certain poisons.
+
+Satisfaction and discomfort, welcoming and avoiding, thus seem to be
+related to the maintenance and hindrance of the life processes of the
+neurones rather than of the animal as a whole, and to temporary rather
+than permanent maintenance and hindrance.
+
+The chief life processes of a neurone concerned in learning are
+absorption of food, excretion of waste, reception and conduction of the
+nerve impulse, and modifiability or change of connections. Of these only
+the latter demands comment.
+
+The connections formed between situation and response are represented by
+connections between neurones and neurones, whereby the disturbance or
+neural current arising in the former is conducted to the latter across
+their synapses. The strength or weakness of a connection means the
+greater or less likelihood that the same current will be conducted from
+the former to the latter rather than to some other place. The strength or
+weakness of the connection is a condition of the synapse. What condition
+of the synapse it is remains a matter for hypothesis. Close connection
+might mean protoplasmic union, or proximity of the neurones in space, or
+a greater permeability of a membrane, or a lowered electrical resistance,
+or a favorable chemical condition of some other sort. Let us call
+this undefined condition which parallels the strength of a connection
+between situation and response the intimacy of the synapse. Then the
+modifiability or connection changing of a neurone equals its power to
+alter the intimacy of its synapses.
+
+As a provisional hypothesis to account for what satisfies and what annoys
+an animal, I suggest the following:—
+
+A neurone modifies the intimacy of its synapses so as to keep intimate
+those by whose intimacy its other life processes are favored and to
+weaken the intimacy of those whereby its other life processes are
+hindered. The animal’s action-system as a whole consequently does nothing
+to avoid that response whereby the life processes of the neurones other
+than connection-changing are maintained, but does cease those responses
+whereby such life processes of the neurones are hindered.
+
+This hypothesis has two important consequences. First: Learning by
+the law of effect is then more fully adaptive for the neurones in the
+changing intimacy of whose synapses learning consists, than for the
+animal as a whole. It is adaptive for the animal as a whole only in so
+far as his organization makes the neurones concerned in the learning
+welcome states of affairs that are favorable to his life and that of his
+species and reject those that are harmful.
+
+Second: A mechanism in the neurones gives results in the behavior of
+the animal as a whole that seem beyond mechanism. By their unmodifiable
+abandonment of certain specific conditions and retention of others, the
+animal as a whole can modify its behavior. Their one rule of conduct
+causes in him a countless complexity of habits. The learning of an animal
+is an instinct of its neurones.
+
+I have limited the discussion to animals in whom the connection-system
+is a differentiated organ, the neurones. In so far as the law of effect
+operates in an animal whose connection-system is not anatomically
+distinguishable and is favored and hindered in its life by the same
+conditions that favor and hinder the life of the animal as a whole,
+the satisfying and annoying will be those states of affairs which the
+connection-system, whatever it be, maintains and abandons.
+
+The other things that have to be equal in the case of the law of effect
+are: First, the frequency, energy and duration of the connection,—that
+is, the action of the law of exercise; second, the closeness with which
+the satisfaction is associated with the response; and, third, the
+readiness of the response to be connected with the situation.
+
+The first of these accessory conditions requires no comment. A slightly
+satisfying or indifferent response made often may win a closer connection
+than a more satisfying response made only rarely.
+
+The second is most clearly seen in the effect of increasing the interval
+between the response and the satisfaction or discomfort. Such an increase
+diminishes the rate of learning. If, for example, four boxes were
+arranged so that turning a button caused a door to open (and permit a cat
+to get freedom and food) in one, five, fifty and five hundred seconds,
+respectively, a cat would form the habit of prompt escape from the first
+box most rapidly and would almost certainly never form that habit in the
+case of the fourth. The electric shock administered just as an animal
+starts on the wrong path or touches the wrong mechanism, is potent, but
+the same punishment administered ten or twenty seconds after an act will
+have little or no effect upon that act.
+
+Close temporal sequence is not the only means of insuring the connection
+of the satisfaction with the response producing it. What is called
+attention to the response counts also. If a cat pushes a button around
+with its nose, while its main occupation, the act to which its general
+‘set’ impels it, to which, we say, it is chiefly attentive, is that of
+clawing at an opening, it will be less aided in the formation of the
+habit than if it had been chiefly concerned in what its nose was doing.
+The successful response is as a rule only a part of all that the animal
+is doing at the time. In proportion as it is an eminent, emphatic part of
+it, learning is aided. Similarly discomfort eliminates most the eminent,
+emphatic features of the total response which it accompanies or shortly
+follows.
+
+The third factor, the susceptibility of the response and situation to
+connection, is harder to illustrate. But, apparently, of those responses
+which are equally strongly connected with a situation by nature and
+equally attended to, some are more susceptible than others to a more
+intimate connection.
+
+The things which have to be equal in the case of the law of exercise
+are the force of satisfyingness; that is, the action of the law of
+effect, and again the readiness of the response to be connected with the
+situation.
+
+The operation of the laws of instinct, exercise and effect is
+conditioned further by (1) what may be called the law of assimilation or
+analogy,—that a situation, especially one to which no particular response
+is connected by original nature or previous experience, may connect with
+whatever response is bound to some situation _much like it_,—and (2) by
+the law of partial activity—that more or less of the total situation may
+be specially active in determining the response.
+
+The first of these laws is a result of the facts that conduction in the
+neurones follows the line of least resistance or closest connection, that
+the action-system is so organized that certain responses tend to be made
+in their totality if at all, and that slightly different situations may,
+therefore, produce some one response, the effects of their differences
+being in the accessories of that response.
+
+The second law is a result of the facts that the situation, itself a
+compound, produces a compound action in the neurones, and that by reason
+of inner conditions, the relative intensities of different parts of the
+compound may vary. The commonest response will be that due to the modal
+condition of the neural compound, but every condition of the compound
+will have its response.
+
+
+THE ADEQUACY OF THE LAWS OF EXERCISE AND EFFECT
+
+Behavior has been supposed to be modified in accordance with three
+other principles or laws besides the law of exercise and the law of
+effect. Imitation is often used as a name for the supposed law that the
+perception of a certain response to a situation by another animal tends
+in and of itself to connect that response to that situation. Common
+acceptance has been given to more or less of the law that the idea of an
+act, or of the result of an act, or of the immediate or remote sensations
+produced by the act, tends in and of itself to produce the act. Such a
+law of ‘suggestion’ or ‘ideo-motor’ action may be phrased differently,
+but in whatever form, it insists that the bond between a situation and
+some conscious representation of a response or of its consequences can do
+the work of the bond between the situation and the response itself. In
+acts of reasoning man has been supposed to connect with a given situation
+a response that could never have been predicted merely from knowledge
+of what responses were connected with that situation by his original
+nature or had been connected with it by the laws of exercise and effect.
+Inference has been supposed to create bonds in and of itself and to be
+above the mere laws of habit.
+
+Various forms of statement, most of them vague, have been and would be
+used in describing the potency of a perceived response, a thought-of
+response, or a train of inference, to produce a response and bind it to
+the given total situation. Any forms will do for the present argument,
+since all forms mean to assert that responses can be and often are bound
+to situations otherwise than by original bodily nature, satisfaction,
+discomfort, disuse and use. I shall try to show that they cannot; that,
+on the contrary, the laws of exercise and effect account for all learning.
+
+_The facts of imitation in human and animal behavior are explainable by
+the laws of instinct, exercise and effect._
+
+Some cases of imitation are undoubtedly mere instincts in which the
+situation responded to is an act by another of the same species. If the
+baby smiles at a smile, it is because of a special, inborn connection
+between that sight and that act,—he smiles at a smile for just the same
+reason that he draws down his mouth and wails at harsh words. At that
+stage of his life he does not imitate other simple acts. A man runs
+_with_ a crowd for the same reason that he runs _from_ a tiger. Returning
+a blow is no more due to a general tendency to imitate than warding it
+off is.
+
+Other cases of imitation are mere adjuncts to the ordinary process of
+habit-formation. In the first place, the act of another, or its result,
+may serve as a model by which the satisfyingness of one’s own responses
+are determined. Just as the touch and taste of food tells a baby that
+he has got it safely into his mouth, so the sound of a word spoken by
+another or the sight of another performing some act of skill tells us
+whether our pronunciation or technique is right or wrong.
+
+In the second place, the perception of another’s act may serve as a
+stimulus to a response whereby the situation is altered into one to
+which the animal responds from habit by an act like the one perceived.
+For example, the perception of another making a certain response (_A_)
+to a situation (_B_) may lead in me by the laws of habit to a response
+(_C_) which puts me in a situation (_D_) such that the response (_A_) is
+made by me by the laws of habit. Suppose that by previous training the
+act of taking off my hat (_A_) has become connected as response to the
+situation (_D_), ‘thought of hat off,’ and suppose that with the sight of
+others uncovering their heads (_A_) in church (_B_) there has, again by
+previous habituation, been connected, as response (_C_), ‘thought of hat
+off.’ Then the sight of others uncovering their heads would by virtue of
+the laws of habit lead me to uncover. Imitation of this sort, where the
+perception of the act or condition in another gives rise to the idea of
+performing the act or attaining the condition, the idea in turn giving
+rise to the appropriate act, is certainly very common.
+
+There may be cases of imitation which cannot be thus accounted for as
+special instinctive responses to the perception of certain acts by the
+same acts, as habits formed under the condition that the satisfyingness
+of a response is its likeness to the perceived act of another, or as the
+connection of two habits, one of getting, from the perceived act of
+another, a certain inner condition, the other of getting, from this inner
+condition, the act in question. There may be, that is, cases where the
+perceived act of another in and of itself creates a connection.
+
+It is apparently taken for granted by a majority of writers on human
+behavior that cases of such direct mental infection, as it were, not
+only exist, but are the rule. I am unable to find proof of such cases,
+however. Those commonly quoted are far from clear. Learning to talk in
+the human infant, for example, the stock case of imitation as a direct
+means of learning, offers only very weak and dubious evidence. Since
+what is true of it holds substantially for the other favored cases for
+learning by imitation, I shall examine it at some length.
+
+Let us first be clear as to the alternative explanations of linguistic
+imitation. The first is that seeing the movements of another’s
+mouth-parts or hearing a series of word-sounds in and of itself produces
+the response of making that series of sounds or one like it.
+
+The other is that the laws of instinct and habit are adequate to explain
+the fact in the following manner: A child instinctively produces a great
+variety of sounds and sound-series. Some of these, accepted as equal to
+words by the child’s companions, are rewarded, so that the child learns
+by the law of effect to use them in certain situations to attain certain
+results. It is possible also that a child instinctively feels a special
+satisfaction at babbling when spoken to and a special satisfaction at
+finding the sound he makes like one that rings in the ears of memory
+and has meaning. The latter would be like the instinctive satisfaction
+apparently felt in constructing an object which is like some real object
+whose appearance and meaning he knows.
+
+A child also meets frequently the situations ‘say dada,’ ‘say mama,’ ‘say
+good night’ and the like,[41] and is rewarded when his general babble
+produces something like the word spoken to him. He thus, by the law of
+effect, learns to respond to any ‘say’ situation by making _some_ sound
+and to each of many ‘say’ situations by making an appropriate sound, and
+to feel satisfaction at duplicating these words when heard. According
+to the amount of such training, the tendency to respond to words spoken
+to him by making some sound may become very strong, and the number of
+successful duplications very large. Satisfaction may be so connected
+with saying words that the child practices them by himself orally and
+even in inner speech. The second alternative relies upon the instinct
+of babbling, and the satisfaction of getting desirable effects from
+speech, either the effect which the word has by its meaning as a request
+(‘water,’ ‘milk,’ ‘take me outdoors’ and the like) or the effect which it
+has by its mere sound upon companions who notice, pet or otherwise reward
+a child for linguistic progress.
+
+There are many difficulties in the way of accepting the first
+alternative. First of all, no one can believe that _all_ of a child’s
+speech is acquired by direct imitation. On many occasions the process is
+undoubtedly one of the production of many sounds, irrespective of the
+model given, and the selection of the best one by parental reward. Any
+student who will try to get a child who is just beginning to speak, to
+say cat, dog and mouse and will record the sounds actually made by the
+child in the three cases, will find them very much alike. There will in
+fact be little that even _looks_ like direct imitation until the child
+has ‘learned’ at least forty or fifty words.
+
+The second difficulty lies in the fact that different children, in even
+the clearest cases of the imitation of one sound, vary from it in so many
+directions. A list of all the sounds made in response to one sound heard
+is more suggestive of random babble as modified by various habits of
+duplicating sounds, than of a direct potency of the model. Ten children
+of the same age may, in response to ‘Christmas,’ say, kiss, kissus,
+krismus, mus, kim, kimus, kiruss, i-us and even totally unlike vocables
+such as hi-yi or ya-ya.
+
+The third difficulty is that in those features of word-sounds which are
+hard to acquire, such as the ‘th’ sound, direct imitation is inadequate.
+The teacher has recourse to trial and chance success, the spoken word
+serving as a model to guide satisfaction and discomfort. In general no
+sound not included in the instinctive babble of children seems to be
+acquired by merely hearing and seeing it made.
+
+A fourth difficulty is that by the doctrine of direct imitation it should
+not be very much more than two or three times as hard to repeat a two-
+or three-syllable series as to repeat a single syllable. It is, in fact,
+enormously harder. This is, of course, just what is to be expected if
+learning a sound means the selection from random babbling plus previous
+habits. If, for instance, a child makes thirty monosyllabic sounds
+like pa, ga, ta, ma, pi, gi, li, mi, etc., there is, by chance, one
+chance in thirty that in response to a word or phrase he will make that
+one-syllable sound of his repertory which is most like it, but there is
+only one chance in nine hundred that he will make that _two-syllable_
+combination of his repertory which is most like it.
+
+On the other hand, two objections will be made to the opposite view that
+the word spoken acts only as a model to select from responses otherwise
+caused, or as a stimulus to habits already existing. First it will be
+said that clear, indubitable repetitions of words never practiced by
+the child, either as totals or in their syllables separately, _do_
+occur,—that children do respond by repeating a word in cases where full
+knowledge of all their previous habits would give no reason to expect
+them to make such a connection. To this the only retort is that such
+observations should be based on a very delicate and very elaborate record
+of a child’s linguistic history, and that until they are so made, it is
+wise to withhold acceptance.
+
+The second objection is that the rapid acquisition of a vocabulary
+such as occurs in the second and third year is too great a task to be
+accomplished by the laws of exercise and effect alone. This objection
+is based on an overestimation of the variety of sounds which children
+of the ages in question make. For example, a child who says 250 words,
+including say 400 syllables, comprising say 300 syllables which, when
+properly pronounced, are distinguishable, may actually use less than 50
+distinguishable syllables. _Ba_, may stand for the first syllable of
+father, water, barn, park and the like. _Ki_ may stand for cry, climb,
+and even carry. For a child to say a word commonly means that he makes
+a sound which his intimate companions can recognize as his version of
+that word. A child who can produce something like each one of a thousand
+words upon hearing them, may do so from actual control over less than
+a hundred syllables. If we suppose him to have acquired the habits,
+first, of saying _something_ in such a case, second, of responding to a
+certain hundred sounds when perceived or remembered by making, in each
+case, a similar sound, and, third, of responding to any other sound when
+perceived or remembered, by making that sound of his own repertory which
+is most like it,[42] we can account for a thousand ‘imitations,’ and
+still not have made a large demand upon childish powers of learning.
+
+No one should pretend to have disproved direct imitation in the case of
+learning to talk until he has subjected all these and other matters to
+crucial experiments. But the burden of proof does seem to belong upon
+those who deny the adequacy of the laws of exercise and effect. In so far
+as the choice is between accepting or rejecting a general law that, other
+things being equal, the perception of a response in another produces that
+response, we surely must reject it. Some of the cases of imitation may be
+unexplained by the laws of exercise and effect. But for others no law of
+imitation is required. And of what should happen by such a law not over a
+trivial fraction at most does happen.
+
+    _The idea of a response is in and of itself unable to produce
+    that response._
+
+The early students of behavior, considering human behavior and
+emphasizing behavior that was thought about and purposive, agreed that
+the sure way to connect a response with a situation was to choose, or
+will, or consent to, that response. Later students still agreed that
+to think about the response in some way, to have an image of it or of
+the sensations caused in you by previous performances of it, was a
+strong provocative to it. To get a response, get some sort of conscious
+representative of it, has been an acceptable maxim. Medicine, education
+and even advertising have based their practice upon the theory that ideas
+tended to issue in the particular sort of acts that they were ideas of.
+
+The laws of exercise and effect, on the contrary, if they are the sole
+laws of modifiability, insist that the thought of an act will produce
+that act only if the act has been connected with that thought (and
+without resulting discomfort) in the animal’s past.
+
+It seems plausible that there should be a peculiar bond between the
+thought of a response and the response. The plausibility is due to two
+reasons, one of which is sound but inadequate, the other being, in my
+opinion, entirely unsound. The first reason is that, as a mere matter
+of fact, the thought of a response does so often produce it. The second
+is that an idea of a response seems a natural and sufficient cause for
+it to appear. The first reason is inadequate to justify any law of the
+production of a response by its image or other representative, since
+evidence can be found to show that when a response is produced by an
+idea of it, it has been already bound to that idea by repetition or
+satisfaction. The second reason is unsound because, even if responses are
+brought to pass occasionally by their images, that is surely an extremely
+rare and unnatural method.
+
+It is certain that in at least nine cases out of ten a response is
+produced, not by an image or other representation of it, but by a
+situation nowise like it or any of its accessories. Hunger and the
+perception of edible objects, far outweigh ideas of grasping, biting and
+swallowing, as causes of the eating done in the world. Objects sensed,
+not images of eye-movements, cause a similar overwhelming majority of
+the eye’s responses. We walk, reach and grasp on most occasions, not
+because of anticipatory images of how it will feel to do so or verbal
+descriptions to ourselves of what we are to do, but because we are
+stimulated by the perception of some object.
+
+It is also certain that the idea of a response may be impotent to
+produce it. I cannot produce a sneeze by thinking of sneezing. A child
+may have, in the case of some simple bodily act, which he has done in
+response to certain situations thousands of times, as adequate ideas of
+it as are possessed by others, and yet be utterly unable to make himself
+do it; many adults show this same phenomenon, for instance, in the case
+of swallowing a pill. And, of course, one can have ideas of running a
+mile in two minutes, jumping a fence eight feet high, or drawing a line
+exactly equal to a hundred millimeter line, just as easily as of running
+the mile in ten minutes, or jumping four feet.
+
+It is further certain that the thought of doing one thing very often
+results in the man’s doing something quite different. The thought of
+moving the eyes smoothly without stops along a line of print has occurred
+to many people, who nevertheless actually did as a result move the eyes
+in a series of jumps with long stops.
+
+It is further certain that in many cases where an animal does connect a
+given response with the image or thought of that response, the connection
+has been built up by the laws of exercise and effect. Such cases as
+appropriate responses to, ‘I will go to bed,’ ‘I will get up,’ ‘I will
+eat,’ ‘I will write a letter,’ ‘I will read,’ or to the corresponding
+commands, requests or suggestions, are observably built up by training.
+The appropriate response follows the idea only if it has, by repetition
+or reward, been connected with it or something like it. If the only
+requirement in moral education were to have the idea of the right act
+at the right time, the lives of teachers and parents would be greatly
+alleviated. But the decision to get up, or the idea of getting up or of
+being up, is futile until the child has connected therewith the actual
+act of getting up.
+
+The defender of the direct potency of conscious representatives of a
+response to produce it may be tempted to complain at this point that what
+the laws of exercise and effect do is to reduce the strength of competing
+ideas, and leave the idea, say of getting up, free to exercise its direct
+potency. The complaint shows a weak sense for fact. The ordinary child is
+not a Hamlet, nor is he beguiled by the imagined delights of staying in
+bed, nor repelled by the image of getting up out of it. On the contrary,
+he may be entirely willing to _think of_ getting up. It is the actual
+delights that hold him, the actual discomforts that check him, and the
+only way to be sure that he will get up is so to arrange matters that it
+is more satisfactory to him to get up than not to when the situation,
+whatever it be, that is to suggest that response, makes its appearance.
+
+The experience of every schoolroom shows that it is not enough to get the
+idea of an act. The act must have gone with that idea or be now put with
+it. The bond must be created. Responses to the suggestions of language,
+whether addressed to us by others or by ourselves in inner speech, in
+a very large majority of cases owe their bonds to the laws of exercise
+and effect. We learn to do what we are told, or what we tell ourselves,
+by doing _something_ and rejecting or retaining what we do by virtue
+of its effects. So also in the case of a majority of responses to the
+suggestions of other than verbal imagery.
+
+The idea of a response, like the perception of a response by another,
+acts often as a guide to response _ex post facto_ by deciding what shall
+be satisfying. Where superficial inspection leaves the impression that
+the idea creates the act, a little care often shows it to have only
+selected from the acts produced by instinct and habit. For example, let
+the reader think of some act never performed hitherto, such as putting
+his left middle finger upon the upper right hand corner of this page,
+and make the movement. It may seem at first sight that having the idea
+entirely unopposed was the sufficient cause of the act. But careful
+experiment, including, for instance, the closure of the eyes and
+anesthesia of the fingers will reveal that the original propulsion of the
+idea is not to just that act, but to many possibilities, and that its
+chief potency lies in the fact that not to get the finger to that point
+is annoying, and that consequently the organism is at peace only when the
+act is done.
+
+So far it has been shown that: The majority of responses are not produced
+by ideas of them. The idea of a response may be impotent to produce it.
+The idea of one act may produce a different, even an opposite act. When
+an idea seems to produce a response in and of itself, it may really act
+by determining the satisfyingness of responses otherwise made. These
+facts are sufficient to destroy the pretensions of any general law that
+the image of an act will, other things being equal, produce it. But the
+possibility that such an image may occasionally exercise this peculiar
+potency remains.
+
+I despair of convincing the reader that it does not. Man is the
+only animal possessing a large fund of ideas of acts, and man’s
+connection-system is so complex and his ideas of acts are so intricately
+bound to situations that have by use and effect produced those acts,
+that the proof of this negative is a practical impossibility. But it is
+possible to show that even the most favored cases for the production of a
+response by securing an ideal representation of it may be explainable by
+use and effect alone.
+
+The extreme apparent potency of ideas representing acts to produce them
+regardless of bonds of use or effect is, of course, witnessed in the
+phenomena of suggestion in hypnosis and allied states. To try to reduce
+these phenomena to consequences of the laws of habit may seem fanatical.
+Here, it will be said, are the crucial cases where the idea of an act, if
+freed from all effects of opposing ideas, does inevitably produce the act
+so far as it is a possibility for the animal’s action-system.
+
+That is precisely what I cannot find proof of.
+
+Efficient suggestions to hypnotized subjects, on the contrary, are often
+ambiguous in the sense that they seem as likely to arouse a situation
+_to which the act has been bound by the law of habit_ as to arouse an
+idea of the act. Often they are far better suited to the former purpose.
+Direct commands—Walk, Dance, Get up, Sit down—obviously will operate by
+the law of habit provided the situations connected with disobedience are
+excluded. This is also the case with such indirect suggestions as ‘This
+is a knife (stick).’ ‘This is your sword (broom).’ ‘Have a cigar (a pen).’
+
+The release of a suggestion from inhibitions may as well be the release
+from _ideas connected as antecedents with_ not performing the act as
+the release from _ideas of_ not performing it. It is a question of fact
+whether, to get an act done by the subject, one must arouse in him an
+idea to which or to a part of which or to something like which the act
+has been bound by use or effect, or may arouse simply an idea of the act.
+
+Finally, if an idea has a tendency to connect with a certain response,
+over and above the bonds due to exercise and effect, it should _always_
+manifest that tendency. If the connection is not made, it must be due to
+the action of some contrary force. It is less my duty to show that the
+laws of habit can account for hypnotic suggestibility, obsessions, and
+the like, than it is my opponents’ duty to explain why a man can spend a
+half day in hospitably welcoming a hundred ideas of acts and yet perform
+no one of them, save those in the case of which he has learned to do the
+thing when he thinks of doing it. Again, how can the mere addition of
+the idea of a future date to the idea of an act so utterly deprive it of
+present potency.
+
+In view of all these facts it seems probable that ideas of responses act
+in connection just as do any other situations, and that the phenomena of
+suggestion and ideo-motor action really mean that any idea will, except
+for competing ideas, produce the response, not that _is like it_, but
+that _has gone with it_, or with some idea like it.
+
+    _Rational connections are, in their causation, like any others,
+    the difference being in what is connected._
+
+It remains to ask whether situation and response are bound together in
+the case of reasoning by any other forces than the forces of repetition,
+energy and satisfaction? Do the laws of inferential thinking transcend
+the laws of exercise and effect? Or does the mind, even in these novel
+and constructive responses, do only what it is forced to do by original
+nature or has done without discomfort?
+
+To defend the second alternative involves the reduction of the processes
+of abstraction, association by similarity and selective thinking to mere
+secondary consequences of the laws of exercise and effect. This I shall
+try to do.
+
+The gist of the fact of abstraction is that response may be made to some
+elements or aspects of a situation which have never been experienced
+in isolation, and may be made to the element in question regardless of
+the gross total situation in which it inheres. A baby thus learns to
+respond to its mother’s face regardless of what total visual field it is
+a part of. A child thus learns to respond by picking out any red object,
+regardless of whether the redness be in an apple, a block, a pencil, a
+ribbon or a ball. A student thus learns to respond to any plane surface
+inclosed by three straight lines regardless of its size, shape, color or
+other than geometrical meaning.
+
+What happens in such cases is that the response, by being connected with
+many situations alike in the presence of the element in question and
+different in other respects, is bound firmly to that element and loosely
+to each of its concomitants. Conversely any element is bound firmly to
+any one response that is made to all situations containing it and very,
+very loosely to each of those responses that are made to only a few of
+the situations containing it. The element of triangularity, for example,
+is bound firmly to the response of saying or thinking ‘triangle’ but only
+very loosely to the response of saying or thinking white, red, blue,
+large, small, iron, steel, wood, paper and the like. A situation thus
+acquires bonds not only with some response to it as a gross total, but
+also with responses to each of its elements that has appeared in any
+other gross totals.
+
+Appropriate response to an element regardless of its concomitants is a
+necessary consequence of the laws of exercise and effect if an animal
+learns to make that response to the gross total situations that contain
+the element and not to make it to those that do not. Such prepotent
+determination of the response by one or another element of the situation
+is no transcendental mystery, but, given the circumstances, a general
+rule of all learning. The dog who responds appropriately to ‘beg’ no
+matter when, where, or by whom spoken, manifests the same laws of
+behavior. There is no difficulty in understanding how each element of a
+situation may come to tend to produce a response peculiar to it as well
+as to play its part in determining the response to the situation as a
+total. There may be some difficulty in understanding how each element
+of a situation comes to be _felt_ whereas before only the gross total
+was felt. The change in consciousness from the ‘big, blooming, buzzing
+confusion’ to an aggregate of well-defined percepts and images, which
+accompanies the change in behavior from response to totals to response to
+parts or elements, may be mysterious. With the change in consciousness,
+however, we are not now concerned. The _behavior_ of man and other
+animals toward the abstract elements of color, size, number, form, time
+or value is explained by the laws of instinct, exercise and effect.
+
+When the perception or thought of a fact arouses the thought of some
+other fact identical in part with the former fact, we have so-called
+association by similarity. An element of the neurone-action is prepotent
+in determining the succeeding neurone-action. The particular way in which
+it determines it is by itself continuing and making connection with other
+associates. These it possesses by virtue of the law of exercise and
+effect.
+
+       *       *       *       *       *
+
+The changes in behavior classified under intellect and morality seem
+then to be all explainable by the two laws of exercise and effect. The
+facts of imitation really refer to certain specific original connections
+or to the efficiency of a model in determining what shall satisfy or
+to the provision of certain instructive situations in the form of the
+behavior of other animals. The facts variously referred to as suggestion,
+ideo-motor action or the motor power of ideas, really refer to the fact,
+common in the human animal only, that to those ideas that represent acts
+in thought the acts are often bound as responses. The bonds are due to
+the primary laws of effect and exercise. The facts of reasoning really
+refer to the fact of prepotency of one or another element in a situation
+in determining the response.
+
+The reduction of all learning to making and rewarding or avoiding and
+punishing connections between situation and response allows changes in
+intellect and character to be explained by changes in the neurones that
+are known either to be or to be possible. I have elsewhere sketched one
+such possible neural mechanism for the law of effect.[43]
+
+On the contrary, imitation, suggestion and reasoning, as commonly
+described, put an intolerable burden upon the neurones. To any one who
+has tried to imagine a possible action in the neurones to parallel the
+traditional power of the mere perception of an act in another or of the
+mere representation of an act as done by oneself to produce that act,
+this is a great merit. For the only adequate psychological parallel of
+traditional imitation and suggestion would be the original existence or
+the gratuitous formation of a connection between (1) each neurone-action
+corresponding to a percept of an act done by another or to the idea of
+an act done by oneself and (2) the neurone-action arousing that act. It
+is incredible that the neurone-action corresponding to the perception of
+a response in another, or to the idea of a response in oneself, or to
+the first term in an association by similarity, should have, in and of
+itself, a special power to determine that the next neurone-action should
+be that paralleling the response in question. And there is no possible
+physiological parallel of a power to jump from premise to conclusion for
+no other reason than the ideal fitness of the sequence.
+
+
+SIMPLIFICATIONS OF THE LAWS OF EXERCISE AND EFFECT
+
+There has been one notable attempt to explain the facts of learning by
+an even simpler theory than that represented in the laws of exercise
+and effect. Jennings has formulated as an adequate account of learning
+the law that: “When a certain physiological state has been resolved,
+through the continued action of an external agent, or otherwise, into
+a second physiological state, this resolution becomes easier, so that
+in course of time it takes place quickly and spontaneously” (‘Behavior
+of the Lower Organisms,’ p. 289). “The law may be expressed briefly as
+follows:—_The resolution of one physiological state into another becomes
+easier and more rapid after it has taken place a number of times._ Hence
+the behavior primarily characteristic for the second state comes to
+follow immediately upon the first state. The operations of this law are,
+of course, seen on a vast scale in higher organisms in the phenomena
+which we commonly call memory, association, habit formation and learning”
+(_ibid._, p. 291). This law may be expressed conveniently as a tendency
+of a series of states
+
+                           A -> B -> C -> D
+
+to become
+
+                                A -> D
+
+or
+
+                          A -> B¹ -> C¹ -> D
+
+B¹ and C¹ being states B and C passed rapidly and in a modified way so
+that they do not result in a reaction but are resolved directly into D.
+
+If Professor Jennings had applied to this law the same rigorous analysis
+which he has so successfully employed elsewhere, he would have found that
+it could be potent to cause learning only if supplemented by the law of
+effect and then only for a fraction of learning.
+
+For, the situations being the same, the state A cannot produce, at one
+time, now B and, at another time, abbreviated, rudimentary B¹ instead of
+B. If A with S produces B once, it must always. If D or a rudimentary B¹
+is produced, there must be something other than A; A must itself have
+changed. Something must have been added to or subtracted from it. In
+Professor Jennings’ own words, “Since the external conditions have not
+changed, the animal itself must have changed” (_ibid._, p. 286). And in
+adaptive learning something related to the results of the S A connection
+must have changed it.
+
+The series A—B—C—D does not become the series A—D or A—B¹—C¹—D by magic.
+If B and C are weakened and D is strengthened as sequents of A in
+response to S, it is because something other than repetition acts upon
+them. Repetition alone could not blow hot for D and cold for B.
+
+Moreover, as a mere matter of fact, “the resolution of one physiological
+state into another” through intermediate states does not with enough
+repetition “become easier so that in course of time it takes place
+quickly and spontaneously.”
+
+Paramecium does not change its response to, say, an obstacle in the
+water, from swimming backward, turning to one side and swimming forward
+by abbreviating and eventually omitting the turn and the backward
+movement. The schoolboy does not tend to count 1, 2, 10 or to say a, b,
+z, or give ablative plurals after nominative singulars.
+
+Repetition of a series of physiological states in and of itself on the
+contrary makes an animal increasingly _more_ likely to _maintain_ the
+series _in toto_. It is hard to give the first and then the last word of
+an oft repeated passage like Hamlet’s soliloquy or the Lord’s Prayer, or
+to make readily the first and then the last movement of writing a name or
+address. Repetition never eliminates absolutely and eliminates relatively
+the _less_ often or _less_ emphatically connected.
+
+Even if supplemented by the law of effect, so that some force is at hand
+to change the effect of S upon the animal to A D instead of the original
+A B C D, the law of the resolution of physiological states would be
+relevant to only a fraction of learning. For example, let a cat or dog be
+given an ordinary discrimination experiment, but so modified that whether
+the animal responds by the ‘right’ or the ‘wrong’ act _he is removed
+immediately after the reward or punishment_. That is, the event is either
+S R1 or S R2, never S R1 R2. Let the experiment be repeated at intervals
+so long that the physiological state, St. R1, or St. R2, leading to the
+response R1 or R2 in the last trial, has ceased before the next. The
+animal will come to respond to S by R2 only, though R2 has never been
+reached by the ‘resolution’ of S R1 R2.
+
+Cats in jumping for birds or mice, men in playing billiards, tennis or
+golf, and many other animals in many other kinds of behavior, often learn
+as the dog must in this experiment. The situation on different occasions
+is followed by different responses, but by only one per occasion.
+Professor Jennings was misled by treating as general the special case
+where the situation itself includes a condition of discomfort terminable
+only by a ‘successful’ response or by the animal’s exhaustion or death.
+
+Assuming as typical this same limited case of response to an annoying
+situation, so that success consists simply in replacing the situation
+by another, Stevenson Smith reduces the learning-process to the law of
+exercise alone. He argues that,—
+
+“For instance, let an organism at birth be capable of giving N reactions
+(a, b, c, ... N) to a definite stimulus S and let only one of these
+reactions be appropriate. If only one reaction can be given at a time
+and if the one given is determined by the state of the organism at the
+time S is received, there is one chance in N that it is the appropriate
+reaction. When the appropriate reaction is finally given, the other
+reactions are not called into play, S may cease to act, but until the
+appropriate reaction is given let the organism be such that it runs
+through the gamut of the others until the appropriate reaction is brought
+about. As there are N possible reactions, the chances are that the
+appropriate reaction will be given before all N are performed. At the
+next appearance of the stimulus, which we may call S₂, those reactions
+which were in the last case performed, are, through habit, more likely to
+be again brought about than those which were not performed. Let _u_ stand
+for the unperformed reactions. Then we have N - _u_ probable reactions
+to S₂. Habit rendering the previously most performed reactions the most
+probable throughout we should expect to find the appropriate reaction in
+response to
+
+  S₁ contained in N.
+  S₂ contained in N - _u₁_.
+  S₃ contained in N - _u₁_ - _u₂_.
+  ...
+  S_ₙ_ contained in N - _nu_, which approaches _one_ as a limit.
+
+Thus the appropriate reaction would be fixed through the laws of chance
+and habit. This law of habit is that when any action is performed
+a number of times under certain conditions, it becomes under those
+conditions more and more easily performed” (_Journal of Comparative
+Neurology and Psychology_, 1908, Vol. XVIII, pp. 503-504).
+
+This hypothesis is, like Professor Jennings’, adequate to account for
+only the one special case, and is adequate to account for that only
+upon a further limitation of the number of times that the animal may
+repeat any one of his varied responses to the situation before he has
+gone through them all once, or reached the one that puts an end to the
+situation.
+
+The second limitation may be illustrated in the simple hypothetical case
+of three responses, 1, 2 and 3, of which No. 2 is successful. Suppose the
+animal always to go through his repertory with _no_ repetitions until he
+reaches 2 and so closes the series.
+
+Only the following can happen:—
+
+  1 2
+  1 3 2
+  2
+  2
+  3 1 2
+  3 2
+
+and, in the long run, 2 will happen twice as often as 1 or 3 happens.
+
+Suppose the animal to repeat each response of his repertory six times
+before changing to another, the remaining conditions being as above. Then
+only the following can happen:—
+
+  1 1 1 1 1 1 2
+  1 1 1 1 1 1 3 3 3 3 3 3 2
+  2
+  2
+  3 3 3 3 3 3 1 1 1 1 1 1 2
+  3 3 3 3 3 3 2,
+
+and in the long run 2 will happen one third as often as 1 or 3 and,
+though always successful, must, by Smith’s theory, appear later and
+later, so that if the animal meets the situation often enough, he will
+eventually fail utterly in it!
+
+Animals do, as a matter of fact, commonly repeat responses many times
+before changing them,[44] so that if only the law of exercise operated,
+learning would not be adaptive. It is the _effect_ of 2 that gives it the
+advantage over 1 and 3. Of two responses to the same annoying situation,
+one continuing and the other relieving it, an animal could never learn to
+adopt the latter as a result of the law of exercise alone, if the former
+was, originally, twice as likely to occur. 1 1 2 would occur as often
+as 2 and exercise would be equal for both. The convincing cases are, of
+course, those where learning equals the strengthening to supremacy of an
+originally very weak connection and the weakening of originally strong
+bonds. An animal’s original nature may lead it to behave as shown below:—
+
+  1 1 1 3 1 1 4 1 1 2
+  1 1 1 1 3 1 1 1 3 1 1 4 2
+  4 1 1 3 3 1 1 4 4 1 1 1 1 1 2, etc.,
+
+and yet the animal’s eventual behavior may be to react to the situation
+always by 2. The law of effect is primary, irreducible to the law of
+exercise.
+
+
+THE EVOLUTION OF BEHAVIOR
+
+The acceptance of the laws of exercise and effect as adequate accounts of
+learning would make notable differences in the treatment of all problems
+that concern learning. I shall take, to illustrate this, the problem of
+the development of intellect and character in the animal series, the
+phylogenesis of intellectual and moral behavior.
+
+The difficulties in the way of understanding the evolution of
+intellectual and moral behavior have been that neither what had been
+evolved nor that from which it had been evolved was understood.
+
+The behavior of the higher animals, especially man, was thought to be
+a product of impulses and ideas which got into the mind in various
+ways and had power to arouse certain acts and other ideas more or
+less mysteriously, in the manner described by the laws of ideo-motor
+action, attention, association by contiguity, association by similarity,
+suggestion, imitation, dynamo-genesis and the like, with possibly a
+surplus of acts and ideas due to ‘free will.’ The mind was treated as
+a crucible in which a multifarious solution of ideas, impulses and
+automatisms boiled away, giving off, as a consequence of a subtle
+chemistry, an abundance of thoughts and movements. Human behavior was
+rarely viewed from without as a series of responses bound in various
+ways to a series of situations. The student of animal behavior passed as
+quickly as might be from such mere externals to the inner life of the
+creature, making it his chief interest to decide whether it had percepts,
+memories, concepts, abstractions, ideas of right and wrong, choices,
+a self, a conscience, a sense of beauty. The facts in intellect and
+character that are due to learning, that are not the inherited property
+of the species and that consequently are beyond the scope of evolution
+in the race, were not separated off from the facts of original nature.
+The comparative psychologist misspent his energy on such problems as the
+phylogenesis of the idea of self, moral judgments, or the sentiment of
+filial affection.
+
+At the other extreme, the behavior of the protozoa was either
+contemplated in the light of futile analogies,—for instance, between
+discriminative reactions and conscious choice, and between inherited
+instincts and memory,—or studied crudely in its results without
+observation of what the animals really did. The protozoa were regarded
+either as potential ‘conscious selves’ or as drifting lumps turned hither
+and thither by the direct effects of light, heat, gravity and chemical
+forces upon their tissues.
+
+The evolution of the intellectual and moral nature which a higher animal
+really possesses from the sort of a nature which the real activities of
+the protozoa manifest, is far less difficult to explain.
+
+In so far as the higher animal is a collection of original tendencies
+to respond to physical events without and within the body, subject to
+modification by the laws of exercise and effect and by these alone,
+and in so far as the protozoan is already possessed of a well-defined
+repertory of responses connected with physical events without and within
+the body in substantially the manner of the higher animal’s original
+tendencies, the problems of the evolution of behavior are definite and in
+the way of solution.
+
+The previous sections gave reason for the belief that the higher animals,
+including man, manifest no behavior beyond expectation from the laws
+of instinct, exercise and effect. The human mind was seen to do no
+more than connect in accord with original bonds, use and disuse, and
+the satisfaction and discomfort resulting to the neurones. The work
+of Jennings has shown that the protozoa already possess full-fledged
+instincts, homologous with the instincts of man. They too may have
+specialized receptors, an action-system with a well-defined repertory and
+a connecting system or means of influencing the bonds between the stimuli
+received and the motor reactions made. The difficulties of tracing the
+possible development of a super-man from an infra-animal thus disappear.
+
+There is, of course, an abundance of _bona fide_ difficulty in
+discovering the unlearned behavior of each group of animals and in
+tracing, throughout the animal series, changes in the physical events to
+which animals are sensitive so that to each a different response may be
+attached, changes in the movements of which animals are capable, and
+changes in the bonds by which particular movements follow particular
+physical events. To find when and how animals whose natures remained
+nearly or quite unchanged by the satisfying and annoying effects of their
+behavior, gave birth to animals that could learn, is perhaps a still
+harder task. But these tasks concern problems that are intelligible
+matters of fact. They do not require a student to get out of matter
+something defined as beyond matter, or to get volition out of tropisms,
+or to get ideas of space and time out of swimming and sleeping.
+
+The evolution of the sensitivities and of the action-systems of animals
+has already been subjected to matter-of-fact study by naturalists. The
+evolution of the connection-system will soon be. Each reflex, instinct
+or capacity, each bond between a given situation presented to a given
+physiological state and a given response, has its ancestral tree.
+Scratching at an irritated spot on the skin is older than arms. Following
+an object that is moving slowly does not have to be explained separately,
+as a ‘chance’ variation in dogs, sheep and babies. The mechanical trades
+of man are related to the miscellaneous manipulations of the apes. Little
+as we know of the connection-systems possessed by animals, we know enough
+to be sure that a bond between situation and response has ancestors and
+children as truly as does any bodily organ. Professor Whitman a decade
+ago showed the possibility of phylogenetic investigation of instinctive
+connections in a study which should be a stimulus and model for many
+others. In place of any further general account of the study of the
+phylogeny of the connection-system, I shall quote from his account of the
+concrete phylogeny of the instinct of incubation.
+
+                     “_b. The Incubation Instinct_
+
+    1. _Meaning to be Sought in Phyletic Roots._—It seems quite
+    natural to think of incubation merely as a means of providing
+    the heat needed for the development of the egg, and to assume
+    that the need was felt before the means was found to meet it.
+    Birds and eggs are thus presupposed, and as the birds could
+    not have foreseen the need, they could not have hit upon the
+    means except by accident. Then, what an infinite amount of
+    chancing must have followed before the first ‘cuddling’ became
+    a habit, and the habit a perfect instinct! We are driven to
+    such preposterous extremities as the result of taking a purely
+    casual feature to start with. Incubation supplies the needed
+    heat, but that is an incidental utility that has nothing to do
+    with the nature and origin of the instinct. It enables us to
+    see how natural selection has added some minor adjustments, but
+    explains nothing more. For the real meaning of the instinct we
+    must look to its phyletic roots.
+
+    If we go back to animals standing near the remote ancestors of
+    birds, to the amphibia and fishes, we find the same instinct
+    stripped of its later disguises. Here one or both parents
+    simply remain over or near the eggs and keep a watchful guard
+    against enemies. Sometimes the movements of the parent serve to
+    keep the eggs supplied with fresh water, but aëration is not
+    the purpose for which the instinct exists.
+
+    2. _Means Rest and Incidental Protection to Offspring._—The
+    instinct is a part of the reproductive cycle of activities,
+    and always holds the same relation in all forms that exhibit
+    it, whether high or low. It follows the production of eggs,
+    or young, and means primarily, as I believe, rest, with
+    incidental protection to offspring. That meaning is always
+    manifest, no less in worms, molluscs, crustacea, spiders and
+    insects, than in fishes, amphibia, reptiles and birds. The
+    instinct makes no distinction between eggs and young, and that
+    is true all along the line up to birds, which extend the same
+    blind instinct to one as to the other.
+
+    3. _Essential Elements of the Instinct._—Every essential
+    element in the instinct of incubation was present long
+    before the birds and eggs arrived. These elements are:
+    (1) the disposition to remain with or over the eggs; (2)
+    the disposition to resist and drive away enemies; and (3)
+    periodicity. The birds brought all these elements along in
+    their congenital equipment, and added a few minor adaptations,
+    such as cutting the period of incubation to the need of normal
+    development, and thus avoiding indefinite waste of time in case
+    of sterile or abortive eggs.
+
+    (1) _Disposition to Remain over the Eggs._—The disposition to
+    remain over the eggs is certainly very old, and is probably
+    bound up with the physiological necessity for rest after a
+    series of activities tending to exhaust the whole system. If
+    this suggestion seems far-fetched, when thinking of birds, it
+    will seem less so as we go back to simpler conditions, as we
+    find them among some of the lower invertebrate forms, which are
+    relatively very inactive and predisposed to remain quiet until
+    impelled by hunger to move. Here we find animals remaining
+    over their eggs, and thus shielding them from harm, from sheer
+    inability or indisposition to move. That is the case with
+    certain molluscs (_Crepidula_), the habits and development of
+    which have been recently studied by Professor Conklin. Here
+    full protection to offspring is afforded without any exertion
+    on the part of the parent, in a strictly passive way that
+    excludes even any instinctive care. In _Clepsine_ there is a
+    manifest unwillingness to leave the eggs, showing that the
+    disposition to remain over them is instinctive. If we start
+    with forms of similar sedentary mode of life, it is easy to see
+    that remaining over the eggs would be the most likely thing
+    to happen, even if no instinctive regard for them existed.
+    The protection afforded would, however, be quite sufficient
+    to insure the development of the instinct, natural selection
+    favoring those individuals which kept their position unchanged
+    long enough for the eggs to hatch.”[45]
+
+    Professor Whitman proceeds to study the ‘Disposition to Resist
+    Enemies’ and the ‘Periodicity’ in the same genetic way.
+
+The most important of all original abilities is the ability to learn. It,
+like other capacities, has evolved. The animal series shows a development
+from animals whose connection-system suffers little or no permanent
+modification by experience to animals whose connections are in large
+measure created by use and disuse, satisfaction and discomfort.
+
+Some of this development can be explained without recourse to differences
+in mere power to learn, by the fact that the latter animals are given
+greater stimuli to or rewards for learning. But part of it is due to
+differences in sheer ability to learn, that is, in the power of equally
+satisfying conditions to strengthen or of equally annoying conditions to
+weaken bonds in the animals’ connection-systems. This may be seen from
+the following simple and partial case:—
+
+Call 1 and 2 two animals.
+
+Call C₁ and C₂ the internal conditions of the two animals except for
+their connection-systems, each being the average condition of the animal
+in question.
+
+Call S₁ and S₂ two external states of affairs, each being near the
+indifference point for the animal in question,—that is, being one which
+the animal does little to either avoid or secure.
+
+Call G₁ and G₂ two responses which result in O₁ and O₂ the _optima_ or
+most satisfying state of affairs for 1 and 2.
+
+Call I₁ and I₂ two responses which result in the continuation of S₁ and
+S₂.
+
+The only responses possible for 1 are G₁ and I₁.
+
+The only responses possible for 2 are G₂ and I₂.
+
+Animal 1 upon the recurrence of S₁ and C₁ is little or no more likely to
+respond by G₁ than he was before.
+
+Animal 2 upon the recurrence of S₂ and C₂ is far more likely to respond
+by G₂ than he was before.
+
+The fact thus outlined might conceivably be due to an intrinsic
+inequality between O₁ and O₂, the power of equally satisfying _optima_ to
+influence, their antecedents being identical. This is not the case in the
+evolution of learning, however. For even if, instead of O₂, we had only
+a moderately satisfying state of affairs, such as the company of other
+chicks to (2) a 15-day-old chick, while O₁ was the optimum of darkness,
+dampness, coolness, etc., for (1) an earthworm, 2 would learn far, far
+more rapidly than 1.
+
+The fact is due, of course, to the unequal power of equally satisfying
+conditions to influence their antecedents. The same argument holds good
+for the influence of discomfort.
+
+The ability to learn,—that is, the possession of a connection-system
+subject to the laws of exercise and effect,—has been found in animals as
+‘low’ as the starfish and perhaps in the protozoa. It is hard to tell
+whether the changed responses observed in Stentor by Jennings and in
+Paramecium by Stevenson Smith are easily forgotten learnings or long
+retained excitabilities. Sooner or later clear learning appears, and
+then, from crabs to fish and turtle, from these to various birds and
+mammals, from these to monkeys, and from these to man, a fairly certain
+increase in sheer ability to learn, in the potency of a supposedly
+constant degree of satisfyingness or annoyingness to influence the
+connection preceding it, can be assumed. We cannot, of course, define
+just what we mean by equal satisfyingness to a mouse and a man, but the
+argument is substantially the same as that whereby we assume that the
+gifted boy has more sheer ability to learn than the idiot, so that if
+the two made the same response to the same situation and were equally
+satisfied thereby, the former would form the habit more firmly.
+
+We may, therefore, expect that when knowledge of the structure and
+behavior of the neurones comprising the connection-systems of animals (or
+of the neurones’ predecessors in this function) progresses far enough
+to inform us of just what happens when a connection is made stronger or
+weaker and of just what effects satisfying and annoying states of affairs
+exert upon the connection-system (and in particular upon the connections
+most recently in activity) the ability to learn will show as true an
+evolution as the ability to sneeze, oppose the thumb, or clasp an object
+touched by the hand.
+
+If my analysis is true, the evolution of behavior is a rather simple
+matter. Formally the crab, fish, turtle, dog, cat, monkey and baby have
+very similar intellects and characters. All are systems of connections
+subject to change by the law of exercise and effect. The differences
+are: first, in the concrete particular connections, in _what_ stimulates
+the animal to response, _what_ responses it makes, _which_ stimulus
+connects with _which_ response, and second, in the degree of ability to
+learn—in the amount of influence of a given degree of satisfyingness or
+annoyingness upon the connection that produced it.
+
+The peculiarly human features of intellect and character, responses to
+elements and symbols, are the results of: first, a receiving system that
+is easily stimulated by the external world bit by bit (as by focalized
+vision and touch with the moving hand) as well as in totals composed
+of various aggregates of these bits; second, of an action-system of
+great versatility (as in facial expression, articulation, and the
+hands’ movements); and third, of a connection-system that includes the
+connections roughly denoted by babbling, manipulation, curiosity, and
+satisfaction at activity, bodily or mental, for its own sake; that is
+capable of working in great detail, singling out elements of situations
+and parts of responses; and that allows satisfying and annoying states of
+affairs to exert great influence on their antecedent connections. Because
+he learns fast and learns much, in the animal way, man seems to learn by
+intuitions of his own.
+
+
+
+
+CHAPTER VII
+
+THE EVOLUTION OF THE HUMAN INTELLECT[46]
+
+
+To the intelligent man with an interest in human nature it must often
+appear strange that so much of the energy of the scientific world has
+been spent on the study of the body and so little on the study of the
+mind. ‘The greatest thing in man is mind,’ he might say, ‘yet the least
+studied.’ Especially remarkable seems the rarity of efforts to trace the
+evolution of the human intellect from that of the lower animals. Since
+Darwin’s discovery, the beasts of the field, the fowl of the air and
+the fish of the sea have been examined with infinite pains by hundreds
+of workers in the effort to trace our physical genealogy, and with
+consummate success; yet few and far between have been the efforts to find
+the origins of intellect and trace its progress up to human faculty. And
+none of them has achieved any secure success.
+
+It may be premature to try again, but a somewhat extended series of
+studies of the intelligent behavior of fishes, reptiles, birds and
+mammals, including the monkeys, which it has been my lot to carry out
+during the last five years, has brought results which seem to throw light
+on the problem and to suggest its solution.
+
+Experiments have been made on fishes, reptiles, birds and various
+mammals, notably dogs, cats, mice and monkeys, to see how they learned
+to do certain simple things in order to get food. All these animals
+manifest fundamentally the same sort of intellectual life. Their learning
+is after the same general type. What that type is can be seen best from
+a concrete instance. A monkey was kept in a large cage. Into the cage
+was put a box, the door of which was held closed by a wire fastened to
+a nail which was inserted in a hole in the top of the box. If the nail
+was pulled up out of the hole, the door could be pulled open. In this
+box was a piece of banana. The monkey, attracted by the new object,
+came down from the top of the cage and fussed over the box. He pulled
+at the wire, at the door, and at the bars in the front of the box. He
+pushed the box about and tipped it up and down. He played with the nail
+and finally pulled it out. When he happened to pull the door again, of
+course it opened. He reached in and got the food inside. It had taken
+him 36 minutes to get in. Another piece of food being put in and the
+door closed, the occurrences of the first trial were repeated, but there
+was less of the profitless pulling and tipping. He got in this time in
+2 minutes and 20 seconds. With repeated trials the animal finally came
+to drop entirely the profitless acts and to take the nail out and open
+the door as soon as the box was put in his cage. He had, we should say,
+learned to get in.
+
+The process involved in the learning was evidently a process of
+selection. The animal is confronted by a state of affairs or, as we may
+call it, a ‘situation.’ He reacts in the way that he is moved by his
+innate nature or previous training to do, by a number of acts. These
+acts include the particular act that is appropriate and he succeeds. In
+later trials the impulse to this one act is more and more stamped in,
+this one act is more and more associated with that situation, is selected
+from amongst the others by reason of the pleasure it brings the animal.
+The profitless acts are stamped out; the impulses to perform them in
+that situation are weakened by reason of the positive discomfort or the
+absence of pleasure resulting from them. So the animal finally performs
+in that situation only the fitting act.
+
+Here we have the simplest and at the same time the most widespread sort
+of intellect or learning in the world. There is no reasoning, no process
+of inference or comparison; there is no thinking about things, no putting
+two and two together; there are no ideas—the animal does not think of
+the box or of the food or of the act he is to perform. He simply comes
+after the learning to feel like doing a certain thing under certain
+circumstances which before the learning he did not feel like doing. Human
+beings are accustomed to think of intellect as the power of having and
+controlling ideas and of ability to learn as synonymous with ability to
+have ideas. But learning by having ideas is really one of the rare and
+isolated events in nature. There may be a few scattered ideas possessed
+by the higher animals, but the common form of intelligence with them,
+their habitual method of learning, is not by the acquisition of ideas,
+but by the selection of impulses.
+
+Indeed this same type of learning is found in man. When we learn to drive
+a golf ball or play tennis or billiards, when we learn to tell the price
+of tea by tasting it or to strike a certain note exactly with the voice,
+we do not learn in the main by virtue of any ideas that are explained
+to us, by any inferences that we reason out. We learn by the gradual
+selection of the appropriate act or judgment, by its association with the
+circumstances or situation requiring it, in just the way that the animals
+do.
+
+From the lowest animals of which we can affirm intelligence up to man
+this type of intellect is found. With it there are in the mammals obscure
+traces of the ideas which come in the mental life of man to outweigh
+and hide it. But it is the basal fact. As we follow the development of
+animals in time, we find the capacity to select impulses growing. We find
+the associations thus made between situation and act growing in number,
+being formed more quickly, lasting longer and becoming more complex
+and more delicate. The fish can learn to go to certain places, to take
+certain paths, to bite at certain things and refuse others, but not much
+more. It is an arduous proceeding for him to learn to get out of a small
+pen by swimming up through a hole in a screen. The monkey can learn to do
+all sorts of things. It is a comparatively short and easy task for him
+to learn to get into a box by unhooking a hook, pushing a bar around and
+pulling out a plug. He learns quickly to climb down to a certain place
+when he sees a letter T on a card and to stay still when he sees a K. He
+performs the proper acts nearly as well after 50 days as he did when they
+were fresh in his mind.
+
+This growth in the number, speed of formation, permanence, delicacy and
+complexity of associations possible for an animal reaches its acme in the
+case of man. Even if we leave out of question the power of reasoning,
+the possession of a multitude of ideas and abstractions and the power of
+control over impulses, purposive action, man is still the intellectual
+leader of the animal kingdom by virtue of the superior development
+in him of the power of forming associations between situations or
+sense-impressions and acts, by virtue of the degree to which the mere
+learning by selection possessed by all intelligent animals has advanced.
+In man the type of intellect common to the animal kingdom finds its
+fullest development, and with it is combined the hitherto nonexistent
+power of thinking about things and rationally directing action in accord
+with thought.
+
+Indeed it may be that this very reason, self-consciousness and
+self-control which seem to sever human intellect so sharply from that
+of all other animals are really but secondary results of the tremendous
+increase in the number, delicacy and complexity of associations which the
+human animal can form. It may be that the evolution of intellect has no
+breaks, that its progress is continuous from its first appearance to its
+present condition in adult civilized human beings. If we could prove that
+what we call ideational life and reasoning were not new and unexplainable
+species of intellectual life but only the natural consequences of an
+increase in the number, delicacy, and complexity of associations of
+the general animal sort, we should have made out an evolution of mind
+comparable to the evolution of living forms.
+
+In 1890 William James wrote, “The more sincerely one seeks to trace the
+actual course of psychogenesis, the steps by which as a race we may have
+come by the peculiar mental attributes which we possess, the more clearly
+one perceives ‘the slowly gathering twilight close in utter dark.’” Can
+we perhaps prove him a false prophet? Let us first see if there be any
+evidence that makes it probable that in some way or another the mere
+extension of the animal type of intellect has produced the human sort. If
+we do, let us proceed to seek a possible account of _how_ this might have
+happened, and finally to examine any evidence that shows this possible
+‘how’ to have been the real way in which human reason has evolved.
+
+It has already been shown that in the animal kingdom there is, as we
+pass from the early vertebrates down to man, a progress in the evolution
+of the general associative process which practically equals animal
+intellect, that this progress continues as we pass from the monkeys to
+man. Such a progress is a real fact; it does exist as a possible _vera
+causa_; it is thus at all events better than some imaginary cause of the
+origin of human intellect, the very existence of which is in doubt. In a
+similar manner we know that the neurones, which compose the brain and the
+connections between which are the physiological parallels of the habits
+that animals form, show, as we pass down through the vertebrate series,
+an evolution along lines of increased delicacy and complexity. That an
+animal associates a certain act with a certain felt situation means that
+he forms or strengthens connections between certain cells. The increase
+in number, delicacy and complexity of cell structures is thus the basis
+for an increase in the number, delicacy and complexity of associations.
+Now the evolution noted in cell structures affects man as well as the
+other vertebrates. He stands at the head of the scale in that respect as
+well. May not this obvious supremacy in the animal type of intellect and
+in the adaption of his brain to it be at the bottom of his supremacy in
+being the sole possessor of reasoning?
+
+This question becomes more pressing if we realize that we must have some
+sort of brain correlate for ideational life and reasoning. Some sort of
+difference in processes in the brain must be at the basis of the mental
+differences between man and the lower animals, we should all admit. And
+it would seem wise to look for that difference amongst differences which
+really do or at least may exist. Now the most likely brain difference
+between man and the lower animals for our purpose, to my mind indeed the
+only likely one, is just this difference in the fineness of organization
+of the cell structures. If we could show with any degree of probability
+how it might account for the presence of ideas and of reasoning, we
+should at least have the satisfaction of dealing with a cause actually
+known to exist.
+
+The next important fact is that the intellect of the infant six months
+to a year old is of the animal sort, that ideational and reasoning
+life are not present in his case, that the only obvious intellectual
+difference between him and a monkey is in the quantity and quality of
+the associations formed. In the evolution of the infant’s mind to its
+adult condition we have the actual transition within an individual from
+the animal to the human type of intellect. If we look at the infant and
+ask what is in him to make in the future a thinker and reasoner, we must
+answer either by invoking some mysterious capacity, the presence of which
+we cannot demonstrate, or by taking the difference we actually do find.
+That is the difference in the quality and quantity of associations of the
+animal sort. Even if we could never see how it came to cause the future
+intellectual life, it would seem wiser to believe that it did than to
+resort to faith in mysteries. Surely there is enough evidence to make it
+worth while to ask our second question, “How might this difference cause
+the life of ideas and reasoning?”
+
+To answer this question fully would involve a most intricate treatment of
+the whole intellectual life of man, a treatment which cannot be attempted
+without reliance on technical terms and psychological formulas. A fairly
+comprehensible account of the general features of such an answer can,
+however, be given. The essential thing about the thinking of the animals
+is that they feel things in gross. The kitten who learned to respond
+differently to the signals, “I must feed those cats” and “I will not
+feed them,” felt each signal as a vague total, including the tone, the
+movements of my head, etc. It did not have an idea of the sound of _I_,
+another of the sound of _must_, another of the sound _feed_, etc. It did
+not turn the complex impression into a set of elements, but felt it, as I
+have said, in gross. The dog that learned to get out of a box by pulling
+a loop of wire did not feel the parts of the box separately, the bolt as
+a definite circle of a certain size, did not feel his act as a sum of
+certain particular movements. The monkey who learned to know the letter
+K from the letter Y did not feel the separate lines of the letter, have
+definite ideas of the parts. He just felt one way when he saw one total
+impression and another way when he saw another.
+
+Strictly human thinking, on the contrary, has as its essential
+characteristic the breaking up of gross total situations into feelings
+of particular facts. When in the presence of ten jumping tigers we not
+only feel like running, but also feel the number of tigers, their color,
+their size, etc. When, instead of merely associating some act with some
+situation in the animal way, we think the situation out, we have a set
+of particular feelings of its elements. In some cases, it is true, we
+remain restricted to the animal sort of feelings. The sense impressions
+of suffocation, of the feeling of a new style of clothes, of the pressure
+of 10 feet of water above us, of malaise, of nausea and such like remain
+for most of us vague total feelings to which we react and which we feel
+most acutely but which do not take the form of definite ideas that we can
+isolate or combine or compare. Such feelings we say are not parts of our
+real intellectual life. They _are_ parts of our intellectual life if we
+mean by it the mental life concerned in learning, but they are not if we
+mean by it the life of reasoning.
+
+Can we now see how the vague gross feelings of the animal sort might turn
+into the well-defined particular ideas of the human sort, by the aid of a
+multitude of delicate associations?
+
+It seems to be a general law of mind that any mental element which occurs
+with a number of different mental elements, appears, that is, in a number
+of different combinations, tends to thereby acquire an independent life
+of its own. We show children six lines, six dots, six peas, six pieces
+of paper, etc., and thus create the definite feeling of sixness. Out of
+the gross feelings of a certain number of lines, of dots, etc., we evolve
+the definite elementary feeling of sixness by making the ‘six’ aspect of
+the situations appear in a number of different connections. We learn to
+feel whiteness as a definite idea by seeing white paper, white cloth,
+white eggs, white plates, etc. We learn to feel the meaning of _but_ or
+_in_ or _notwithstanding_ by feeling the meanings of many total phrases
+containing each of them. Now in this general law by which different
+associates for the same elementary process elevate it out of its position
+as an undifferentiated fragment of a gross total feeling, we have, I
+think, the manner in which the vague feelings of the nine-months-old
+infant become the definite ideas of the five-year-old boy, the manner in
+which in the race the animal mind has evolved into the human, and the
+explanation of the service performed by the increase in the delicacy of
+structure of the human brain and the consequent increase in the number of
+associations.
+
+The bottle to the six-months-old infant is a vague sense-impression which
+the infant does not think about or indeed in the common meanings of the
+words perceive or remember or imagine. Its presence does not arouse
+ideas, but action. It is not to him a thing so big, or so shaped, or so
+heavy, but is just a vaguely sizable thing to be reached for, grabbed and
+sucked. Like the lower animals, with the exception that as he grows a
+little older he reacts in very many more ways, the child feels things in
+gross in a way to lead to direct reactions. Vague sense-impressions and
+impulses make up his mental life. The bottle, which to a dog would be a
+thing to smell at and paw, to a kitten a thing to smell at and perhaps
+worry, is to the child a little later a thing to grab and suck and turn
+over and drop and pick up and pull at and finger and rub against its toes
+and so on. The sight of the bottle thus becomes associated with many
+different reactions, and thus by our general law tends to gain a position
+independent of any of them, to evolve from the condition of being a
+portion of the cycles see-grab, see-drop, see-turn over, etc., to the
+condition of being a definite idea.
+
+The increased delicacy and complexity of the cell structures in the human
+brain give the possibility of very small parts of the brain-processes
+forming different connections, allow the brain to work in very great
+detail, provide processes ready to be turned into definite ideas. The
+great number of associations which the human being forms furnish the
+means by which this last event is consummated. The infant’s vague
+feelings of total situations are by virtue of the detailed working of
+his brain all ready to split up into parts, and his general activity and
+curiosity provide the multitude of different connections which allow them
+to do so. The dog, on the other hand, has few or no ideas because his
+brain acts in coarse fashion and because there are few connections with
+each single process.
+
+When once the mind begins to function by having definite ideas, all the
+phenomena of reasoning soon appear. The transition from one idea to
+another is the feeling of their relationship, of similarity or difference
+or whatever it may be. As soon as we find any words or other symbols to
+express such a feeling, or to express our idea of an action or condition,
+we have explicit judgments. Observation of any child will show us that
+the mind cannot rest in a condition where it has a large body of ideas
+without comparing them and thinking about them. The ideas carry within
+them the forces that make abstractions, feelings of similarity, judgments
+and other characteristics of reasoning.
+
+In children two and three years of age we find all these elements of
+reasoning present and functioning. The product of children’s reasoning
+is often irrational, but the processes are all there. The following
+instances from a collection of children’s sayings by Mr. H. W. Brown show
+children making inductions and deductions after the same general fashion
+as adults:—
+
+    (2 yrs.) T. pulled the hairs on his father’s wrist. Father.
+    “Don’t, T., you hurt papa!” T. “It didn’t hurt grandpa.”
+
+    (2 yrs. 5 mos.) M. said, “Gracie can’t walk, she wears little
+    bits of shoes; if she had mine, she could walk. When I get some
+    new ones, I’m going to give her these, so she can walk.”
+
+    (2 yrs. 9 mos.) He usually has a nap in the forenoon, but
+    Friday he did not seem sleepy, so his mother did not put him
+    to bed. Before long he began to say, “Bolly’s sleepy; mamma
+    put him in the crib!” This he said very pleasantly at first;
+    but, as she paid no attention to him, he said, “Bolly cry, then
+    mamma will.” And he sat down on the floor and roared.
+
+    (3 yrs.) It was between five and six in the afternoon; the
+    mother was getting the baby asleep. J. had no one to play with.
+    He kept saying, “I wish R. would come home; mamma, put baby
+    to bed, so R. will come home.” I usually get home about six,
+    and as the baby is put to bed about half-past five, he had
+    associated the one with the other.
+
+    (3 yrs.) W. likes to play with oil paints. Two days ago my
+    father told W. he must not touch the paints any more, for he
+    was too small. This morning W. said, “When my papa is a very
+    old man, and when I am a big man and don’t need any papa, then
+    I can paint, can’t I, mamma?”
+
+    (3 yrs.) G.’s aunt gave him ten cents. G. went out, but soon
+    came back saying, “Mamma, we will be rich now.” “Why so, G.?”
+    “Because I planted my ten cents, and we will have lots of ten
+    cents growing.”
+
+    (3 yrs.) B. climbed up into a large express wagon, and would
+    not get out. I helped him out, and it was not a minute before
+    he was back in the wagon. I said, “B., how are you going to get
+    out of there now?” He replied, “I can stay here till it gets
+    little, and then I can get out my own self.”
+
+    (3 yrs.) F. is not allowed to go to the table to eat unless she
+    has her face and hands washed and her hair combed. The other
+    day she went to a lady visiting at her house and said, “Please
+    wash my face and hands and comb my hair; I am very hungry.”
+
+    (3 yrs.) If C. is told not to touch a certain thing, that it
+    will bite him, he always asks if it has a mouth. The other day
+    he was examining a plant, to see if it had a mouth. He was told
+    not to break it, and he said, “Oh, it won’t bite, because I
+    can’t find any mouth.”
+
+Nowhere in the animal kingdom do we find the psychological elements of
+reasoning save where there is a mental life made up of the definite
+feelings which I have called ‘ideas,’ but they spring up like magic
+as soon as we get in a child a body of such ideas. If we have traced
+satisfactorily the evolution of a life of ideas from the animal life of
+vague sense-impressions and impulses, we may be reasonably sure that no
+difficulty awaits us in following the life of ideas in its course from
+the chaotic dream of early childhood to the logical world-view of the
+adult scientist.
+
+In a very short time we have come a long way, from the simple learning of
+the minnow or chick to the science and logic of man. The general frame
+of mind which one acquires from the study of animal behavior and of the
+mental development of young children makes our hypothesis seem vital and
+probable. If the facts did eventually corroborate it, we should have an
+eminently simple genesis of human faculty, for we could put together the
+gist of our contention in a few words. We should say:—
+
+“The function of intellect is to provide a means of modifying our
+reactions to the circumstances of life, so that we may secure pleasure,
+the symptom of welfare. Its general law is that when in a certain
+situation an animal acts so that pleasure results, that act is selected
+from all those performed and associated with that situation, so that,
+when the situation recurs, the act will be more likely to follow than
+it was before; that on the contrary the acts which, when performed in a
+certain situation, have brought discomfort, tend to be dissociated from
+that situation. The intellectual evolution of the race consists in an
+increase in the number, delicacy, complexity, permanence and speed of
+formation of such associations. In man this increase reaches such a point
+that an apparently new type of mind results, which conceals the real
+continuity of the process. This mental evolution parallels the evolution
+of the cell structures of the brain from few and simple and gross to many
+and complex and delicate.”
+
+Nowhere more truly than in his mental capacities is man a part of nature.
+His instincts, that is, his inborn tendencies to feel and act in certain
+ways, show throughout marks of kinship with the lower animals, especially
+with our nearest relatives physically, the monkeys. His sense-powers
+show no new creation. His intellect we have seen to be a simple though
+extended variation from the general animal sort. This again is presaged
+by the similar variation in the case of the monkeys. Amongst the minds of
+animals that of man leads, not as a demigod from another planet, but as a
+king from the same race.
+
+
+
+
+FOOTNOTES
+
+
+[1] ‘Animal Intelligence: An Experimental Study of the Associative
+Processes in Animals’ (’98), ‘The Instinctive Reactions of Young Chicks’
+(’99), ‘A Note on the Psychology of Fishes’ (’99), and ‘The Mental Life
+of the Monkeys’ (’01). I have added a theoretical paper, ‘The Evolution
+of the Human Intellect,’ which appeared in the _Popular Science Monthly_
+in 1901, and which was a direct outgrowth of the experimental work. I am
+indebted to the management of the _Psychological Review_, and that of the
+_American Naturalist_ and _Popular Science Monthly_, for permission to
+reprint the three shorter papers.
+
+[2] Unless one assumes telepathic influences.
+
+[3] Reason in Common Sense, p. 154 ff.
+
+[4] This chapter originally appeared as Monograph Supplement No. 8 of the
+Psychological Review.
+
+[5] I do not mean that scientists have been too credulous with regard
+to spiritualism, but am referring to the cases where ten or twenty
+scientists have been sent to observe some trick-performance by a
+spiritualistic ‘medium,’ and have all been absolutely confident that they
+understood the secret of its performance, _each of them giving a totally
+different explanation_.
+
+[6] The phrase ‘practically utter hunger’ has given rise to
+misunderstandings. I have been accused of experimenting with starving or
+half-starved animals, with animals brought to a state of fear and panic
+by hunger, and the like!
+
+The desideratum is, of course, to have the motive as nearly as possible
+of equal strength in each experiment with any one animal with any one
+act. That is, the animal should be as hungry at the tenth or twentieth
+trial as at the first. To attain this, the animal was given after each
+‘success’ only a very small bit of food as a reward (say, for a young
+cat, one quarter of a cubic centimeter of fish or meat) and tested not
+too many times on any one day. ‘Utter hunger’ means that no diminution in
+his appetite was noted and that at the close of the experiment for the
+day he would still eat a hearty meal. After the experiments for the day
+were done, the cats received abundant food to maintain health, growth and
+spirits, but commonly somewhat less than they would of their own accord
+have taken. No one of the many visitors to the room mentioned anything
+extraordinary or distressful in the animals’ condition. There were no
+signs of fear or panic.
+
+Possibly I was wrong in choosing the term ‘utter hunger’ to denote the
+hunger of an animal in good, but not pampered, condition and without food
+for fourteen hours. It is not sure, however, that the term ‘utter hunger’
+is inappropriate. The few reports made of experiments in going without
+food seem to show that, in health, the feeling of hunger reaches its
+maximum intensity very early. It is of course not at all the same thing
+as the complex of discomforts produced by long-continued insufficiency of
+food. Hunger is not at all a synonym for starvation.
+
+[7] The experiments now to be described were for the most part made in
+the Psychological Laboratory of Columbia University during the year
+’97-’98, but a few of them were made in connection with a general
+preliminary investigation of animal psychology undertaken at Harvard
+University in the previous year.
+
+[8] No. 7 hit the string in his general struggling, apparently utterly
+without design. He did not realize that the door was open till, two
+seconds after it had fallen, he happened to look that way.
+
+[9] No. 6, in trying to crawl out at the top of the box, put its paw in
+above the string. It fell down and thus pulled the string. It did not
+claw at it, and it was 16 seconds before it noticed that the door was
+open. In all the other times that it escaped the movement was made in the
+course of promiscuous scrambling, never in anything like the same way
+that No. 2 made it.
+
+[10] No. 3 did not go out until 12 seconds had elapsed after it had
+pulled the string.
+
+[11] The back of the pen adjoined the elevator shaft, being separated
+from it by a partition 33 inches high. No. 2 heard the elevator coming up
+and put his paws up on the top of this partition so as to look over. In
+so doing he knocked the fastening of the cord at that end and opened the
+door. He did not turn to come out, and I shut the door again.
+
+[12] FF was a box 40 × 21 × 24 inches, the door of which could be opened
+by putting the paw out between the bars to its right and pulling a loop
+which hung 16 inches above the floor, 4 inches out from the box and 6
+inches to the right of the door.
+
+[13] KKK was box K with both bolts removed. All that had to be done was
+to poke the paw out at one side of the door and press down a little bar
+of wood.
+
+[14] The cats and chick were left in for two minutes at each trial, the
+dogs for from one to one and a half minutes.
+
+[15] One result of the application of experimental method to the study of
+the intellect of animals was the distinction of learning by the selection
+of impulses or acts from learning by the selection of ideas. The usual
+method of learning in the case of animals other than man was shown by
+the studies reprinted in this volume to be the direct selection, in a
+certain situation, of a desirable response and its association with that
+situation, not the indirect selection of such a response by the selection
+of some _idea_ which then of itself produced the response. The animals
+did not usually behave as if they _thought of_ getting freedom or food
+in a certain way and were thereby moved to do so, but as if the stimulus
+in question made immediate connection with the response itself or an
+intimately associated impulse.
+
+The experiments had in this respect both a negative or destructive and
+a positive or constructive meaning. On the one hand, they showed that
+animal learning was not homologous with human association of ideas; that
+animal learning was not human learning _minus_ abstract and conceptual
+thought, but was on a still ‘lower’ level. On the other hand, the first
+positive evidence that animals could, under certain circumstances, learn,
+as man so commonly does, by the indirect connection of a response with a
+situation through some non-sensory relic or representative of the latter,
+came from my experiments.
+
+It was perhaps natural that the more exciting denial of habitual learning
+by ideas should have attracted more attention than the somewhat tedious
+experiments to prove that under certain conditions they could so learn.
+At all events, a perverse tradition seems to have grown up to the effect
+that I denied the possibility of animals having images or learning in any
+case by representative thinking.
+
+There is some excuse for this tradition in the fact that whereas the
+proof that the habitual learning of these dogs and cats did not require
+‘ideas’ is clear and emphatic, my evidence that certain features of their
+behavior _did_ require ‘ideas’ is complicated and imperfect.
+
+The fact seems to be that a ‘free idea’ comes in the animals or in
+man only as a result of a somewhat elaborate process of analysis or
+extraction from a gross total sensory process. The primary level or grade
+of experience, common to animals and little babies, comprises states
+of mind such as an adult man gets if lost in anger, fear, suffocation,
+dyspepsia, looking at a panorama of unknown objects with head upside
+down, smelling the mixture of odors of a soap factory, driving a golf
+ball, dashing to the net in a game of tennis, warding off a blow, or
+swimming under water. For a man to get a distinct controllable percept of
+approaching asthma, of a carpet loom seen upside down, or of a successful
+‘carry through,’ or ‘smash’ or ‘lob,’ so that one knows just what one is
+experiencing or doing, and can recall just what one experienced or did,
+requires further experience of the element in question—contemplation of
+it in isolation or dealings with it in many varied connections. So for
+a cat to get a distinct controllable percept of a loop, or of its own
+clawing or nosing or pulling, it must have the capacity to analyze such
+elements out of the total gross complexes in which they inhere, and also
+certain means or stimuli to such analysis.
+
+This capacity or tendency the cats and dogs do, in my opinion, possess,
+though in a far less degree than the average child. They also suffer from
+lack of stimuli to the exercise of the capacity. Their confinement, for
+the most part, to the direct sensory experience of things and acts, is
+due in part to the weakness of the capacity or tendency of their neurones
+to act in great detail, and in part to the lack of such stimuli as visual
+exploration of things in detail, manual manipulation of the same thing
+in many ways, and the identification of elements of objects and acts by
+language. They get few free ideas because they are less ready than man to
+get them under the same conditions and because their instinctive behavior
+and social environment offer conditions that are less favorable. The task
+of getting an animal to have some free ideational representative of a red
+loop or of pushing up a button with the nose may be compared with that
+of getting a very stupid boy to have a free ideational representative of
+acceleration, or of the act of sounding _th_. The difference between them
+and man which is so emphasized in the text, though real and of enormous
+practical importance, is thus not at all a mysterious gap or trackless
+desert. We can see our way from animal to human learning.
+
+[16] A man may learn to swim from the general feeling, “I want to be
+able to swim.” While learning, he may think of this desire, of the
+difficulties of the motion, of the instruction given him, or of anything
+which may turn up in his mind. This is all extraneous and is not
+concerned in the acquisition of the association. Nothing like it, of
+course, goes on in the animal’s mind. Imagine a man thrown into the water
+repeatedly, and gradually floundering to the shore in better and better
+style until finally, when thrown in, he swims off perfectly, and deprive
+the man of all extraneous feelings, and you have an approximate homologue
+of the process in animals. He feels discomfort, certain impulses to
+flounder around, some of which are the right ones to move his body to
+the shore. The pleasure which follows stamps in these, and gradually the
+proper movements are made immediately on feeling the sense-impression of
+surrounding water.
+
+[17] See 10 in A, 3 in A, 10 in D; 10 in C, 4 in C, 3 in C; 6, 2, 5, 4 in
+E; 4 in F; 10 in H, 3 in H; 3, 4, 5, in I; 4 in G, 3 in G; 3 in K; 10 in
+L; dog 1 in N and CC; dog 1 in G and O.
+
+[18] This chapter appeared originally in the _Psychological Review_, Vol.
+VI, No. 3.
+
+[19] This double rating is necessary because of the fact that the chick
+often gives several distinct pecks in a single reaction. The ‘times
+reacted to’ mean the number of different times that the chicks noticed
+the color.
+
+[20] The crude experiments reported in this and the preceding paragraphs
+were not made to test the presence of color vision proper, that is,
+of differentiation of two colors of the same brightness, but only to
+ascertain how chicks reacted to ordinary colored objects. It was,
+however, almost certain from the relative frequency of the reactions that
+the intensity factor was not the cause of the response. For example, if
+it had been, black on white and yellow on black should have been pecked
+at oftener.
+
+[21] This chapter appeared originally in the _American Naturalist_, Vol.
+XXXIII, No. 396.
+
+[22] This chapter appeared originally as Monograph Supplement No. 15 to
+the _Psychological Review_.
+
+[23] Pp. 20 to 155 of this volume.
+
+[24] _American Journal of Psychology_, Vol. X, pp. 256-279; Vol. XI, pp.
+80-100, 131-165; Vol. XII, pp. 206-239.
+
+[25] Practically a memory trial of CC, done January 21, 1900.
+
+[26] Did it by pulling door and thus shaking lever.
+
+[27] Practically a memory trial of SS.
+
+[28] Did it by pulling door and biting wire.
+
+[29] This, I regret, was not done [E. L. T., 1911].
+
+[30] The acts and the number of chances to see me do each and the results
+were as follows; details can be found on the table on page 226. F =
+failed after tuition.
+
+  No. 1.—MM         21 F
+         Theta       5 F
+         QQ         10 F
+         RR          4 F
+         W           9 did in .22
+         Delta      15 F
+         Epsilon    40 F
+         QQ (f)     15 F
+         QQ (c)      1 did in 2.20
+
+  No. 3.—Theta      25 did in 3.00.
+         QQ         40 F
+         Gamma      30 F
+         Epsilon    25 F
+         QQ (ff)     5 F
+         QQ (c)     20 F, did in 1.30, F, 5 F, 5 F
+         QQ (e)      5 F, did in 2.00
+
+[31] He did push it once with his nose.
+
+[32] I inadvertently pulled the nail out in one of five cases when I was
+fingering it to see if attracting his attention to it would lead to the
+act.
+
+[33] Not significant. Due to inattention. Was temporary.
+
+[34] Pulled wire and door.
+
+[35] Pushed with head by chance.
+
+[36] Reached in at 9:30 and took out the banana, which I replaced.
+
+[37] Did by constant pulling at the door.
+
+[38] Did touch nail four times.
+
+[39] Did by pulling hard on wire (not loop); the loop got loose from nail.
+
+[40] Did by pulling at the door till the bar was worked around.
+
+[41] The ‘say,’ may be replaced by some bodily attitude, facial
+expression, or other verbal formula that identifies the situation as one
+to be responded to by speech.
+
+[42] This would, of course, result from a well-known corollary of the
+laws of habit.
+
+[43] In _Essays Philosophical and Psychological in Honor of William
+James_, pp. 591-599.
+
+[44] Professor Smith’s own experiments illustrate this.
+
+[45] Biological Lectures from the Marine Biological Laboratory of Woods
+Holl, 1898, p. 323 ff.
+
+[46] This chapter appeared originally in the _Popular Science Monthly_,
+Nov., 1901.
+
+
+
+
+INDEX
+
+
+  Abstraction, 120.
+    _See also_ Reasoning.
+
+  Action-system, importance of the study of the, 15 f.;
+    of monkeys, 190 f., 237.
+
+  Anecdotal school in animal psychology, 23 ff., 151 f.
+
+  Apparatus, descriptions of, 29 ff., 56 ff., 61 f., 169 f., 177 ff.,
+        196 ff.
+
+  Assimilation, 249 f.
+
+  Association, as a problem in animal psychology, 20 ff.;
+    by similarity, 116 ff.;
+    complexity of, 132 ff.;
+    conditions of, 43 ff.;
+    delicacy of, 128 ff., 195 ff.;
+    development of, in the animal kingdom, 285 ff.;
+    in cats, 38 ff.;
+    in chicks, 63 f.;
+    in dogs, 56 ff.;
+    in fishes, 169 ff.;
+    in man, 123 ff., 127, 285;
+    in monkeys, 182 ff., 194 f., 209 ff.;
+    in relation to attention, 44 ff.;
+    to individual differences, 52 ff.;
+    to inhibition, 142 ff.;
+    to instincts, 36 f., 142 ff.;
+    to previous experience, 48 ff.;
+    number of connections formed by, 135 ff.;
+    permanence of connections formed by, 138 ff., 194 f., 203 f.;
+    progress of, measurable by time-curves, 28, 40, 42;
+    the mental fact in, 98 ff.;
+    without ideas, 101 f., 127, 209 ff.
+    _See also_ Associations and Learning.
+
+  Associations, complexity, 132 ff.;
+    delicacy, 128 ff., 195 ff.;
+    number, 121, 135 ff.;
+    permanence, 138 ff., 194 f., 203 f.
+
+  Associative memory. _See_ Association.
+
+  Attention, 144 ff.;
+    and association, 44 ff.;
+    to imposed movements, 103 ff.
+
+
+  Behavior, acquired tendencies to, 244 ff. (_see also_ Association);
+    evolution of, 272 ff.;
+    general laws of, 241 ff.;
+    indefiniteness of the term, 5;
+    of cats, 35 ff., 88 f., and _passim_;
+    of chicks, 63 f., 138, 143 f., 156 ff., and _passim_;
+    of dogs, 59 ff., 92 ff.;
+    of fishes, 169 ff.;
+    of monkeys, 182 ff.;
+    original tendencies to, 242 f. (_see also_ Instincts);
+    predictability of, 241 f.;
+    proposed simplification of the laws of, 265 ff.;
+    _versus_ consciousness as an object of study, 1 ff.
+    _See also_ Association, Instincts, Learning, Memory, etc.
+
+  BOSWORTH, F. D., 240.
+
+
+  Cats, associative processes in, 35 ff.;
+    imitation in, 85 ff.;
+    the presence of ideas in, 100 ff.;
+    reasoning in, 67 ff.
+
+  Chicks, associative processes in, 61 ff.;
+    imitation in, 81 ff.;
+    instincts of, 156 ff.
+
+  Complexity, of associations, 132 ff.
+
+  Concepts, 116 ff.
+
+  Connection-systems, action of, in association, 246 ff., 266;
+    importance of the study of, 16 f.
+
+  Consciousness, amenability of, to scientific study, 7 ff.;
+    as pure experience, 13 f.;
+    as studied by the one who has or is it, 10 ff.;
+    of animals, 25 f., 67 ff., 98 ff., 123, 146 f., and _passim_;
+    social, 146 f.;
+    space-relations of, 14;
+    _versus_ behavior as an object of study, 1 ff.
+
+  Coördinations, of chicks, 160 ff.
+
+
+  DEAN, B., 161.
+
+  Delicacy of association, 128 ff., 195 ff.
+
+  DEWEY, J., 6.
+
+  Differences, between species of animals in the associative processes,
+        64 ff.
+
+  Discomfort, as an influence in learning, 245 ff.
+
+  Discrimination, in cats and dogs, 128 ff.;
+    in chicks, 156 ff.;
+    in monkeys, 195 ff.
+
+  Dogs, associative processes in, 56 ff.;
+    imitation in, 91 ff.;
+    the presence of ideas in, 115 f.;
+    reasoning in, 67 ff.
+
+
+  Education, applications of animal psychology in, 149 f.
+
+  Effect, the law of, 244 f., 266 ff.
+
+  Emotional reactions of chicks, 162 ff.
+
+  Evolution, of behavior, 272 ff.;
+    of human intellect, 282 ff.;
+    of ideas, 289 ff.
+
+  Exercise, the law of, 244 f.
+
+  Experience, the influence of previous, 48 ff.
+
+  Experiments, need of, in animal psychology, 26;
+    with cats, 35 ff., 85 ff., 103 ff., 111 f., 114 f., 129 ff., 138 f.;
+    with chicks, 61 ff., 81 ff., 132, 136, 143 f., 156 ff.;
+    with dogs, 56 ff., 91 ff., 103 ff., 115 f.;
+    with fishes, 169 ff.;
+    with monkeys, 176-235, _passim_.
+
+
+  Fears, of chicks, 162 ff.
+
+  Fishes, experiments with, 169 ff.
+
+
+  GALTON, F., 3.
+
+
+  Habit. _See_ Association.
+
+  HALL, G. S., 3.
+
+  Human. _See_ Man.
+
+  Hunger, effect of, on animal learning, 27 f.
+
+  HUNT, H. E., 163.
+
+
+  Ideas, development of, 121 f., 289 ff.;
+    existence of, as adjuncts in animal learning, 108 ff., 189 ff., 206
+        ff., 222 ff.;
+    impotence of, to create connections, 257 ff.
+
+  Ideo-motor action, 257 ff.
+
+  Images, 108 f. _See also_ Ideas.
+
+  Imitation, analysis of the supposed effects of, 251 ff.;
+    in cats, 85 ff.;
+    in chicks, 81 ff.;
+    in dogs, 91 ff.;
+    in general, 76 ff., 94 ff.;
+    in monkeys, 96, 211 ff., 219 ff.;
+    in speech, 253 ff.
+
+  Impulses, as features of the associative processes, 100 ff.;
+    defined, 37.
+
+  Incubation, the instinct of, 276 ff.
+
+  Individual differences in association, 52 ff.
+
+  Inhibition of instincts by association, 142 ff.
+
+  Instincts, as explanations of some cases of supposed imitation, 251;
+    inhibition of, 142 ff.;
+    of chicks, 156 ff.;
+    of incubation, 276 ff.;
+    of monkeys, 237;
+    the starting-point of animal learning, 36 f.
+
+  Intellect. _See_ Association, Ideas, Imitation, Memory, Reasoning,
+        etc.
+
+  Interaction, 147 f.
+
+  Introspection, the over-emphasis of, 3.
+
+
+  JAMES, W., 3, 120, 143, 286.
+
+  JENNINGS, H. S., 267, 268, 269, 270, 274, 279.
+
+
+  KLINE, L. W., 173.
+
+
+  Language, 253 ff.
+
+  Learning, evolution of, 278 ff.;
+    methods of, 174 f.
+    _See_ Association, Behavior, Ideas, Imitation, Reasoning.
+
+  LUBBOCK, J., 240.
+
+
+  Man, compared with lower animals in intellect, 123 ff., 239 f.;
+    mental evolution of, 282 ff.
+
+  Memory, 108 f., 138 ff., 203.
+    _See_ Association and Permanence of associations.
+
+  Methods in animal psychology, 22 ff.
+
+  MILLS, W., 191.
+
+  Monkeys, 172 ff.;
+    associative processes in, 182 ff.;
+    differences from lower mammals, 189 ff., 204 ff., 237 ff.;
+    general mental development of, 236 ff.;
+    imitation of man by, 211 ff.;
+    imitation of other monkeys by, 219 ff.;
+    possible mental degeneracy of, 151;
+    presence of ideas in, 189 ff., 206 ff., 222 ff.;
+    reasoning in, 184 ff.
+
+  MORGAN, C. L., 3, 80, 99 f., 101, 119, 120, 125 f., 146, 147, 162,
+        165 f.
+
+  Motives, used in the experiments, 26 ff.;
+    defined, 38.
+
+
+  Number of associations, 135 ff.;
+    as a cause of the development of free ideas, 121 f.
+
+
+  PECKHAM, G. W. and E. G., 240.
+
+  Pecking, accuracy of, in chicks, 159 f.
+
+  Pedagogy, applications of animal psychology to, 149 f.
+
+  Permanence of associations, 138 ff., 203.
+
+  Predictability of behavior, 241 f.
+
+  Primates. _See_ Monkeys.
+
+
+  Reasoning, 118 f.;
+    and free ideas, 291 ff.;
+    as a consequence of the laws of exercise and effect, 263 ff.;
+    in cats and dogs, 67 ff.;
+    in monkeys, 184 ff.
+
+  Recepts, 120.
+
+  Resolution, Jennings’ law of, 267 ff.
+
+  Responses to situations as the general form of behavior, 242 ff., 283
+        f.
+
+  ROMANES, G. J., 68 f., 70, 80.
+
+
+  SANTAYANA, G., 6, 18 f.
+
+  Satisfaction, the influence of, in learning, 147 f., 244 f.;
+    the nature of, 245 f.
+
+  Situation and response as the general form of behavior, 242 ff., 283
+        ff.
+
+  SMALL, W. S., 173.
+
+  SMITH, S., 269 f., 280.
+
+  Social consciousness of animals, 146 f.
+
+  SPALDING, D. A., 162, 163, 165.
+
+  STOUT, G. F., 3.
+
+  Swimming, by chicks, 161 f.
+
+
+  Time of achievement as a measure of the closeness of association,
+        28, 40, 42, 54.
+
+  Time-curves, 38 ff., 57 ff., 65, 185 f.;
+    as evidence against the existence of reasoning, 73 f.
+
+  TITCHENER, E. B., 2.
+
+
+  Vigor, as a factor in learning, 46.
+
+
+  WHITMAN, C. O., 275 ff.
+
+
+  YERKES, R. M., 240.
+
+
+
+
+
+The following pages contain advertisements of Macmillan books on kindred
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+but it will be read with much interest by all students of comparative
+psychology.”—_Journal of American Medical Association._
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+“It deserves commendation for its fascinating style, and for the fund of
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+_Scenes from Bird Life in Plain English for a Beginner_
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+“There is no other book in existence so well fitted for arousing
+and directing the interest that all children feel toward the
+birds.”—_Tribune_, Chicago.
+
+
+Flowers and Ferns _In their Haunts_
+
+By MABEL OSGOOD WRIGHT
+
+                                     _New Edition, cloth, 12mo, $2.00 net_
+
+The subjects are treated in their relation to landscape—the whole bound
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+McFarland.
+
+
+A Text-book on the Principles of Animal Histology
+
+By ULRIC DAHLGREN, M.S., Assistant Professor of Biology in Princeton
+University; and WILLIAM A. KEPNER, A.B., Adjunct Professor of Biology in
+the University of Virginia
+
+                                          _Cloth, 515 pp., 8vo, $3.75 net_
+
+“The name of the senior author alone leads us to expect much from this
+volume, and the most careful scrutiny reveals almost no defects. It
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+invaluable comparative element. With few exceptions, histologies,
+intended as they have been primarily for the medical student,
+have heretofore been based for the most part on the genus _Homo_.
+Morphologists and anatomists will welcome a general histology which in
+the widest sense holds to its title, treating its subject as a pure
+science.... One can scarcely imagine a clearer or better arranged
+text-book either for the general student or for the specialist in any of
+the many related sciences. Since scientists in many fields often have
+occasion to refer to or to verify some point in histology, the volume
+will appeal to readers outside of the domain of histology proper.”—_New
+York Evening Post._
+
+“In marked contrast to practically all the text-books of histology in
+the English language, which deal largely or exclusively with human
+or mammalian structures, this new book discusses the tissues of all
+classes of animals. It is therefore possible to treat the subject much
+more broadly and satisfactorily than has hitherto been done.”—_American
+Journal of Science._
+
+“When one considers the narrow, technical training which students in
+histology usually receive, whether they be medical students or not, one
+cannot but wish that a course similar to that outlined in this book might
+be given in every college and university.”—_Science._
+
+
+A Synoptic Text-book of Zoölogy for Colleges and Schools
+
+By ARTHUR WISSWALD WEYSSE, A.M., Ph.D. (Harvard), Instructor in Zoölogy
+at the Massachusetts Institute of Technology, and Associate Professor of
+Physiology at Boston University
+
+                                          _Cloth, 545 pp., 8vo, $2.25 net_
+
+“To relieve the tenseness of such a study as zoölogy, the author
+deals—whenever practicable—with some facts of everyday interest, such as
+the transmission of malaria by mosquitoes, the division of labor among
+ants and bees, the storing of food for the young, and several others
+of this character. These are pleasant little oases in the wilderness
+of rigidly scientific terms and facts. Not only is the author to be
+congratulated on the perseverance which made the volume possible, but
+also are the publishers for the mechanical part they have played. The
+book is entirely up to the high standard of the house that publishes it.
+The illustrative element is most meritorious.”—_Journal of Education._
+
+“A work of great value ... addressed to college students who do not
+necessarily intend to become specialists, but approach the subject with
+trained minds and with some knowledge of cognate sciences. We begin,
+if not literally at the beginning, yet with the protoplasmic cell, but
+pass almost immediately to the description of the various animal types
+in which classification in minute subdivisions is not attempted. A third
+part deals with the general principles of zoölogy. The book has been
+specially adapted for use in connection with laboratory and field work,
+as well as for systematic study.”—_Churchman._
+
+“The text is noteworthy for its simplicity and clearness, and the choice
+of subject-matter has been made with care. Considerable attention has
+been paid to the introduction of illustrative data which bear on general
+biological problems or are of economic or sanitary importance. The
+book is also free from the more technical terminology which only the
+specialist needs. The arrangement of the subject-matter is excellent.
+After laying down a few general principles, the various animal types are
+dealt with in detail, and the theoretical phases and general problems are
+discussed in the closing section. The book forms a clearly presented,
+well-balanced, comprehensive, and accurate epitome of zoölogy.”—_The
+Dial._
+
+
+Experimental Zoölogy
+
+By THOMAS HUNT MORGAN, Professor of Experimental Zoölogy, Columbia
+University
+
+                                          _Cloth, 454 pp., 8vo, $2.75 net_
+
+“The author long ago won his spurs in this field, through his unrivaled
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+summing up with a conservatism which is perhaps the most valuable feature
+of the book. The thoroughness and lucidity of the work make it serve
+three distinct purposes: the intelligent layman without any previous
+knowledge of the subject may read and appreciate any part of it; the
+student of experimental zoölogy will find it a veritable vade mecum; and
+the advanced scientist will be glad to refer to the generous summaries of
+literature relating to each subject.”—_Nation._
+
+“Professor Morgan has, however, done much sound and some brilliant work.
+In his special field, the regrowth of amputated parts and the relation
+of this property to the general theory of evolution, his experiments
+have become classic, and he is himself one of the first authorities
+in the world. His own eminence in the field, combined with a simple,
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+new science. This he has accomplished with marked success in the work
+before us. He has succeeded in bringing together a large body of fact
+without becoming dull; without being fatuously ‘popular,’ he has been
+untechnical and clear.”—_Boston Transcript._
+
+
+The Protozoa
+
+By GARY N. CALKINS, Ph.D., Instructor in Zoölogy, Columbia University
+
+                                          _Cloth, 347 pp., 8vo, $3.00 net_
+
+“The author has not aimed at putting forward an exhaustive, severely
+scientific treatise upon the group in question. His work may be described
+rather as a simple and intelligible introduction to the study of the
+Protozoa and of the many fascinating biological problems connected with,
+or illustrated by, this subdivision of the animal kingdom, in such a way
+as to awaken the interest of the beginner, no less than to strengthen the
+hands of the expert.”—_Nature._
+
+
+Text-book of Palæontology
+
+By KARL A. VON ZITTEL, Professor of Geology and Palæontology in the
+University of Munich. Translated and edited by CHARLES R. EASTMAN, Ph.D.,
+in charge of Vertebrate Palæontology in the Museum of Comparative Zoölogy
+at Harvard College, Cambridge, Mass.
+
+              _Vol. I. Cloth, 670 pp., with 1476 woodcuts, 8vo, $7.50 net_
+              _Vol. II. Cloth, 283 pp., with 373 woodcuts, $3.00 net_
+
+NOTE.—This English edition has been enlarged and revised by the author
+and editor in collaboration with the following specialists: C. E.
+Beecher, J. M. Clarke, W. H. Dall, G. J. Hinde, A. Hyatt, J. S. Kingsley,
+H. A. Pilsbry, C. Schuchert, S. H. Scudder, W. P. Sladen, E. O. Ulrich,
+C. Wachsmuth, A. S. Woodward, E. C. Case, J. B. Hatcher, H. F. Osborn, S.
+W. Williston, F. A. Lucas.
+
+
+A Text-book of General Bacteriology
+
+By WILLIAM DODGE FROST, Ph.D., Associate Professor of Bacteriology in the
+University of Wisconsin; and EUGENE FRANKLIN McCAMPBELL, Ph.D., Associate
+Professor of Bacteriology in the Ohio State University
+
+                                               _Cloth, 340 pp., $1.60 net_
+
+
+Comparative Anatomy of Vertebrates
+
+Adapted from the German of DR. ROBERT WIEDERSHEIM, Professor of Anatomy,
+and Director of the Institute of Human and Comparative Anatomy in the
+University of Freiburg-in-Baden. By W. N. PARKER, Ph.D., Professor of
+Zoölogy at the University College of South Wales and Monmouthshire in the
+University of Wales
+
+                                          _Cloth, 576 pp., 8vo, $3.75 net_
+
+
+Text-book of the Embryology of Man and Mammals
+
+By DR. OSCAR HERTWIG, Professor extraordinarius of Anatomy and
+Comparative Anatomy, Director of the II Anatomical Institute of the
+University of Berlin. Translated from the Third German Edition by EDWARD
+L. MARK, Ph.D., Hersey Professor of Anatomy in Harvard University
+
+                                          _Cloth, 670 pp., 8vo, $5.25 net_
+
+
+                               PUBLISHED BY
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+<p style='text-align:center; font-size:1.2em; font-weight:bold'>The Project Gutenberg eBook of Animal intelligence, by Edward Lee Thorndike</p>
+<div style='display:block; margin:1em 0'>
+This eBook is for the use of anyone anywhere in the United States and
+most other parts of the world at no cost and with almost no restrictions
+whatsoever. You may copy it, give it away or re-use it under the terms
+of the Project Gutenberg License included with this eBook or online
+at <a href="https://www.gutenberg.org">www.gutenberg.org</a>. If you
+are not located in the United States, you will have to check the laws of the
+country where you are located before using this eBook.
+</div>
+
+<p style='display:block; margin-top:1em; margin-bottom:0; margin-left:2em; text-indent:-2em'>Title: Animal intelligence</p>
+<p style='display:block; margin-left:2em; text-indent:0; margin-top:0; margin-bottom:1em;'>Experimental studies</p>
+<p style='display:block; margin-top:1em; margin-bottom:0; margin-left:2em; text-indent:-2em'>Author: Edward Lee Thorndike</p>
+<p style='display:block; text-indent:0; margin:1em 0'>Release Date: January 29, 2023 [eBook #69904]</p>
+<p style='display:block; text-indent:0; margin:1em 0'>Language: English</p>
+  <p style='display:block; margin-top:1em; margin-bottom:0; margin-left:2em; text-indent:-2em; text-align:left'>Produced by: Emmanuel Ackerman, Kobus Meyer and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive)</p>
+<div style='margin-top:2em; margin-bottom:4em'>*** START OF THE PROJECT GUTENBERG EBOOK ANIMAL INTELLIGENCE ***</div>
+
+<p><span class="pagenum"><a id="Page_i"></a>[i]</span></p>
+
+<p class="center largest">ANIMAL INTELLIGENCE</p>
+
+<p><span class="pagenum"><a id="Page_ii"></a>[ii]</span></p>
+
+<div class="figcenter illowp100" id="macmillan" style="max-width: 18.75em;">
+  <img class="w100" src="images/macmillan.jpg" alt="">
+</div>
+
+<p class="center">THE MACMILLAN COMPANY<br>
+<span class="smaller">NEW YORK · BOSTON · CHICAGO<br>
+SAN FRANCISCO</span></p>
+
+<p class="center"><span class="smcap">MACMILLAN &amp; CO., Limited</span><br>
+<span class="smaller">LONDON · BOMBAY · CALCUTTA<br>
+MELBOURNE</span></p>
+
+<p class="center"><span class="smcap">THE MACMILLAN CO. OF CANADA, Ltd.</span><br>
+<span class="smaller">TORONTO</span></p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<p><span class="pagenum"><a id="Page_iii"></a>[iii]</span></p>
+
+<p class="titlepage largest">ANIMAL INTELLIGENCE</p>
+
+<p class="center larger">EXPERIMENTAL STUDIES</p>
+
+<p class="titlepage"><span class="smaller">BY</span><br>
+EDWARD L. THORNDIKE<br>
+<span class="smaller">TEACHERS COLLEGE, COLUMBIA UNIVERSITY</span></p>
+
+<p class="titlepage"><span class="gothic">New York</span><br>
+THE MACMILLAN COMPANY<br>
+1911</p>
+
+<p class="center smaller"><i>All rights reserved</i></p>
+
+<p><span class="pagenum"><a id="Page_iv"></a>[iv]</span></p>
+
+<p class="titlepage smaller"><span class="smcap">Copyright, 1911,<br>
+By THE MACMILLAN COMPANY.</span></p>
+
+<p class="center smaller">Set up and electrotyped. Published June, 1911.</p>
+
+<p class="titlepage smaller"><span class="gothic">Norwood Press</span><br>
+J. S. Cushing Co.—Berwick &amp; Smith Co.<br>
+Norwood, Mass., U.S.A.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_v"></a>[v]</span></p>
+
+<h2 class="nobreak" id="PREFACE">PREFACE</h2>
+
+</div>
+
+<p>The main purpose of this volume is to make accessible
+to students of psychology and biology the author’s experimental
+studies of animal intellect and behavior.<a id="FNanchor_1" href="#Footnote_1" class="fnanchor">[1]</a> These
+studies have, I am informed by teachers of comparative
+psychology, a twofold interest. Since they represent the
+first deliberate and extended application of the experimental
+method in animal psychology, they are a useful
+introduction to the later literature of that subject. They
+mark the change from books of general argumentation
+on the basis of common experience interpreted in terms
+of the faculty psychology, to monographs reporting detailed
+and often highly technical experiments interpreted
+in terms of original and acquired connections between
+situation and response. Since they represent the point
+of view and the method of present animal psychology, but
+in the case of very general and simple problems, they are
+useful also as readings for students who need a general
+acquaintance with some sample of experimental work in
+this field.</p>
+
+<p><span class="pagenum"><a id="Page_vi"></a>[vi]</span></p>
+
+<p>It has seemed best to leave the texts unaltered except
+for the correction of typographical errors, renumbering
+of tables and figures, and redrawing the latter. In a
+few places, where the original text has been found likely
+to be misunderstood, brief notes have been added. It is
+hard to resist the impulse to temper the style, especially
+of the ‘Animal Intelligence,’ with a certain sobriety and
+restraint. What one writes at the age of twenty-three
+is likely to irritate oneself a dozen years later, as it doubtless
+irritated others at the time. The charitable reader
+may allay his irritation by the thought that a degree of
+exuberance, even of arrogance, is proper to youth.</p>
+
+<p>To the reports of experimental studies are added two
+new essays dealing with the general laws of human and
+animal learning.</p>
+
+<p><span class="smcap">January, 1911.</span></p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_vii"></a>[vii]</span></p>
+
+<h2 class="nobreak">CONTENTS</h2>
+
+</div>
+
+<table class="contents">
+  <tr>
+    <td></td>
+    <td class="tdpg smaller">PAGE</td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">The Study of Consciousness and the Study of Behavior</span></td>
+    <td class="tdpg"><a href="#CHAPTER_I">1</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">Animal Intelligence</span></td>
+    <td class="tdpg"><a href="#CHAPTER_II">20</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Introduction</td>
+    <td class="tdpg"><a href="#Page_20">20</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Description of Apparatus</td>
+    <td class="tdpg"><a href="#Page_29">29</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Experiments with Cats</td>
+    <td class="tdpg"><a href="#Page_35">35</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Experiments with Dogs</td>
+    <td class="tdpg"><a href="#Page_56">56</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Experiments with Chicks</td>
+    <td class="tdpg"><a href="#Page_61">61</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Reasoning or Inference</td>
+    <td class="tdpg"><a href="#Page_67">67</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Imitation</td>
+    <td class="tdpg"><a href="#Page_76">76</a></td>
+  </tr>
+  <tr>
+    <td class="h4">In Chicks</td>
+    <td class="tdpg"><a href="#Page_81">81</a></td>
+  </tr>
+  <tr>
+    <td class="h4">In Cats</td>
+    <td class="tdpg"><a href="#Page_85">85</a></td>
+  </tr>
+  <tr>
+    <td class="h4">In Dogs</td>
+    <td class="tdpg"><a href="#Page_92">92</a></td>
+  </tr>
+  <tr>
+    <td class="h3">The Mental Fact in Association</td>
+    <td class="tdpg"><a href="#Page_98">98</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Association by Similarity and the Formation of Concepts</td>
+    <td class="tdpg"><a href="#Page_116">116</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Criticism of Previous Theories</td>
+    <td class="tdpg"><a href="#Page_125">125</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Delicacy of Association</td>
+    <td class="tdpg"><a href="#Page_128">128</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Complexity of Associations</td>
+    <td class="tdpg"><a href="#Page_132">132</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Number of Associations</td>
+    <td class="tdpg"><a href="#Page_135">135</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Permanence of Associations</td>
+    <td class="tdpg"><a href="#Page_138">138</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Inhibition of Instincts by Habit</td>
+    <td class="tdpg"><a href="#Page_142">142</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Attention</td>
+    <td class="tdpg"><a href="#Page_144">144</a></td>
+  </tr>
+  <tr>
+    <td class="h3">The Social Consciousness of Animals</td>
+    <td class="tdpg"><a href="#Page_146">146</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Interaction</td>
+    <td class="tdpg"><a href="#Page_147">147</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Applications to Pedagogy, Anthropology, etc.</td>
+    <td class="tdpg"><a href="#Page_149">149</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Conclusion</td>
+    <td class="tdpg"><a href="#Page_153">153</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">The Instinctive Reactions of Young Chicks</span></td>
+    <td class="tdpg"><a href="#CHAPTER_III">156</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">A Note on the Psychology of Fishes</span></td>
+    <td class="tdpg"><a href="#CHAPTER_IV">169</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">The Mental Life of the Monkeys</span></td>
+    <td class="tdpg"><a href="#CHAPTER_V">172</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Introduction</td>
+    <td class="tdpg"><a href="#Page_173">173</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Apparatus</td>
+    <td class="tdpg"><a href="#Page_177">177</a><span class="pagenum"><a id="Page_viii"></a>[viii]</span></td>
+  </tr>
+  <tr>
+    <td class="h3">Learning without Tuition</td>
+    <td class="tdpg"><a href="#Page_182">182</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Tests with Mechanisms</td>
+    <td class="tdpg"><a href="#Page_184">184</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Tests with Signals</td>
+    <td class="tdpg"><a href="#Page_195">195</a></td>
+  </tr>
+  <tr>
+    <td class="h3">Experiments on the Influence of Tuition</td>
+    <td class="tdpg"><a href="#Page_209">209</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Introduction</td>
+    <td class="tdpg"><a href="#Page_209">209</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Imitation of Human Beings</td>
+    <td class="tdpg"><a href="#Page_211">211</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Imitation of Other Monkeys</td>
+    <td class="tdpg"><a href="#Page_219">219</a></td>
+  </tr>
+  <tr>
+    <td class="h4">Learning apart from Motor Impulses</td>
+    <td class="tdpg"><a href="#Page_222">222</a></td>
+  </tr>
+  <tr>
+    <td class="h3">General Mental Development of the Monkeys</td>
+    <td class="tdpg"><a href="#Page_236">236</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">Laws and Hypotheses of Behavior</span></td>
+    <td class="tdpg"><a href="#CHAPTER_VI">241</a></td>
+  </tr>
+  <tr class="chap">
+    <td><span class="smcap">The Evolution of the Human Intellect</span></td>
+    <td class="tdpg"><a href="#CHAPTER_VII">282</a></td>
+  </tr>
+</table>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_1"></a>[1]</span></p>
+
+<h1>ANIMAL INTELLIGENCE</h1>
+
+<h2 class="nobreak" id="CHAPTER_I">CHAPTER I<br>
+<span class="smcap">The Study of Consciousness and the Study of Behavior</span></h2>
+
+</div>
+
+<p>The statements about human nature made by psychologists
+are of two sorts,—statements about <i>consciousness</i>,
+about the inner life of thought and feeling, the ‘self as
+conscious,’ the ‘stream of thought’; and statements about
+<i>behavior</i>, about the life of man that is left unexplained
+by physics, chemistry, anatomy and physiology, and is
+roughly compassed for common sense by the terms ‘intellect’
+and ‘character.’</p>
+
+<p>Animal psychology shows the same double content.
+Some statements concern the conscious states of the animal,
+what he is to himself as an inner life; others concern his
+original and acquired ways of response, his behavior, what
+he is to an outside observer.</p>
+
+<p>Of the psychological terms in common use, some refer
+only to conscious states, and some refer to behavior regardless
+of the consciousness accompanying it; but the majority
+are ambiguous, referring to the man or animal in question,
+at times in his aspect of inner life, at times in his aspect of
+reacting organism, and at times as an undefined total
+nature. Thus ‘intensity,’ ‘duration’ and ‘quality’ of
+sensations, ‘transitive’ and ‘substantive’ states and ‘imagery’
+almost inevitably refer to states of consciousness.<span class="pagenum"><a id="Page_2"></a>[2]</span>
+‘Imitation,’ ‘invention’ and ‘practice’ almost
+inevitably refer to behavior observed from the outside.
+‘Perception,’ ‘attention,’ ‘memory,’ ‘abstraction,’ ‘reasoning’
+and ‘will’ are samples of the many terms which
+illustrate both ways of studying human and animal
+minds. That an animal perceives an object, say, the sun,
+may mean either that his mental stream includes an awareness
+of that object distinguished from the rest of the visual
+field; or that he reacts to that object as a unit. ‘Attention’
+may mean a clearness, focalness, of the mental state;
+or an exclusiveness and devotion of the total behavior. It
+may, that is, be illustrated by the sharpness of objects
+illumined by a shaft of light, or by the behavior of a cat
+toward the bird it stalks. ‘Memory’ may be consciousness
+of certain objects, events or facts; or may be the permanence
+of certain tendencies in either thought or action.
+‘To recognize’ may be to feel a certain familiarity and
+surety of being able to progress to certain judgments about
+the thing recognized; or may be to respond to it in certain
+accustomed and appropriate ways. ‘Abstraction’ may
+refer to ideas of qualities apart from any consciousness of
+their concrete accompaniments, and to the power of having
+such ideas; or to responses to qualities irrespective of their
+concrete accompaniments, and to the power of making such
+responses. ‘Reasoning’ may be said to be present when
+certain sorts of consciousness, or when certain sorts of
+behavior, are present. An account of ‘the will’ is an
+account of consciousness as related to action or an account
+of the actions themselves.</p>
+
+<p>Not only in psychological judgments and psychological
+terms, but also in the work of individual psychologists,
+this twofold content is seen. Amongst writers in this
+country, for example, Titchener has busied himself almost<span class="pagenum"><a id="Page_3"></a>[3]</span>
+exclusively with consciousness ‘as such’; Stanley Hall,
+with behavior; and James, with both. In England Stout,
+Galton and Lloyd Morgan have represented the same division
+and union of interests.</p>
+
+<p>On the whole, the psychological work of the last quarter
+of the nineteenth century emphasized the study of consciousness
+to the neglect of the total life of intellect and character.
+There was a tendency to an unwise, if not bigoted, attempt
+to make the science of human nature synonymous with the
+science of facts revealed by introspection. It was, for
+example, pretended that the only value of all the measurements
+of reaction-times was as a means to insight into the
+reaction-consciousness,—that the measurements of the
+amount of objective difference in the length, brightness or
+weight of two objects that men could judge with an assigned
+degree of correctness were of value only so far as they
+allowed one to infer something about the difference between
+two corresponding consciousnesses. It was affirmed that
+experimental methods were not to aid the experimenter to
+know what the subject did, but to aid the subject to know
+what he experienced.</p>
+
+<p>The restriction of studies of human intellect and character
+to studies of conscious states was not without influence on
+scientific studies of animal psychology. For one thing, it
+probably delayed them. So long as introspection was
+lauded as the chief method of psychology, a psychologist
+would tend to expect too little from mere studies, from the
+outside, of creatures who could not report their inner experiences
+to him in the manner to which he was accustomed.
+In the literature of the time will be found many comments
+on the extreme difficulty of studying the psychology of
+animals and children. But difficulty exists only in the
+case of their <i>consciousness</i>. Their <i>behavior</i>, by its simpler<span class="pagenum"><a id="Page_4"></a>[4]</span>
+nature and causation, is often far easier to study than that
+of adults. Again, much time was spent in argumentation
+about the criteria of consciousness, that is, about what certain
+common facts of behavior meant in reference to inner
+experience. The problems of inference about consciousness
+from behavior distracted attention from the problems of
+learning more about behavior itself. Finally, when psychologists
+began to observe and experiment upon animal
+behavior, they tended to overestimate the resulting insight
+into the stream of the animal’s thought and to neglect
+the direct facts about what he did and how he did it.</p>
+
+<p>Such observations and experiments are, however, themselves
+a means of restoring a proper division of attention
+between consciousness and behavior. A psychologist
+may think of himself as chiefly a stream of consciousness.
+He may even think of other men as chiefly conscious
+selves whose histories they report by word and deed. But
+it is only by an extreme bigotry that he can think of a dog
+or cat as chiefly a stream or chain or series of consciousness
+or consciousnesses. One of the lower animals is so obviously
+a bundle of original and acquired connections between
+situation and response that the student is led to
+attend to the whole series,—situation, response and connection
+or bond,—rather than to just the conscious state
+that may or may not be one of the features of the bond.
+It is so useful, in understanding the animal, to see what it
+does in different circumstances and what helps and what
+hinders its learning, that one is led to an intrinsic interest
+in varieties of behavior as well as in the kinds of consciousness
+of which they give evidence.</p>
+
+<p>What each open-minded student of animal psychology
+at first hand comes thus to feel vaguely, I propose in this
+essay to try to make definite and clear. The studies<span class="pagenum"><a id="Page_5"></a>[5]</span>
+reprinted in this volume produced in their author an increased
+respect for psychology as the science of behavior,
+a willingness to make psychology continuous with physiology,
+and a surety that to study consciousness for the sake
+of inferring what a man can or will do, is as proper as to
+study behavior for the sake of inferring what conscious
+states he can or will have. This essay will attempt to
+defend these positions and to show further that psychology
+may be, at least in part, as independent of introspection
+as physics is.</p>
+
+<p>A psychologist who wishes to broaden the content of
+the science to include all that biology includes under the
+term ‘behavior,’ or all that common sense means by the
+words ‘intellect’ and ‘character,’ has to meet certain
+objections. The first is the indefiniteness of this content.</p>
+
+<p>The indefiniteness is a fact, but is not in itself objectionable.
+It is true that by an animal’s behavior one means
+the facts about the animal that are left over after geometry,
+physics, chemistry, anatomy and physiology have taken
+their toll, and that are not already well looked after by
+sociology, economics, history, esthetics and other sciences
+dealing with certain complex and specialized facts of behavior.
+It is true that the boundaries of psychology,
+from physiology on the one hand, and from sociology,
+economics and the like on the other, become dubious and
+changeable. But this is in general a sign of a healthy
+condition in a science. The pretense that there is an impassable
+cleft between physiology and psychology should
+arouse suspicion that one or the other science is studying
+words rather than realities.</p>
+
+<p>The same holds against the objection that, if psychology
+is the science of behavior, it will be swallowed up by biology.
+When a body of facts treated subjectively, vaguely<span class="pagenum"><a id="Page_6"></a>[6]</span>
+and without quantitative precision by one science or group
+of scientists comes to be treated more objectively, definitely
+and exactly by another, it is of course a gain, a symptom of
+the general advance of science. That geology may become
+a part of physics, or physiology a part of chemistry, is testimony
+to the advance of geology and physiology. Light
+is no less worthy of study by being found to be explainable
+by laws discovered in the study of electricity. Meteorology
+had to reach a relatively high development to provoke
+the wit to say that “All the science in meteorology is
+physics, the rest is wind.”</p>
+
+<p>These objections to be significant should frankly assert
+that between physical facts and mental facts, between
+bodies and minds, between any and all of the animal’s
+movements and its states of consciousness, there is an impassable
+gap, a real discontinuity, found nowhere else in
+science; and that by making psychology responsible for
+territory on both sides of the gap, one makes psychology
+include two totally disparate groups of facts, things and
+thoughts, requiring totally different methods of study.
+This is, of course, the traditional view of the scope of
+psychology, reiterated in the introductions to the standard
+books and often accepted in theory as axiomatic.</p>
+
+<p>It has, however, already been noted that in practice
+psychologists do study facts in disregard of this supposed
+gap, that the same term refers to facts belonging some on
+one side of it and some on the other, and that, in animal
+psychology, it seems very unprofitable to try to keep on
+one side or the other. Moreover, the practice to which the
+study of animal and child psychology leads is, if I understand
+their writings, justified as a matter of theory by
+Dewey and Santayana. If then, as a matter of scientific
+fact, human and animal behavior, with or without consciousness,<span class="pagenum"><a id="Page_7"></a>[7]</span>
+seems a suitable subject for a scientific student,
+we may study it without a too uneasy sense of philosophic
+heresy and guilt.</p>
+
+<p>The writer must confess not only to the absence of any special
+reverence for the supposed axiom, but also to the presence
+of a conviction that it is false, the truth being that
+whatever feature of any animal, say John Smith, of <i>Homo
+sapiens</i>, is studied—its length, its color of hair, its body
+temperature, its toothache, its anxiety, or its thinking of
+9 × 7—the attitude and methods of the student may properly
+be substantially the same.</p>
+
+<p>Of the six facts in the illustration just given, the last
+three would by the traditional view be all much alike for
+study, and all much unlike any of the first three. The
+same kind of science, physical science, would be potent for
+the first three and impotent for the last three (save to give
+facts about certain physical facts which ‘paralleled’ them).
+Conversely one kind of science, psychology, would by the
+traditional view deal with the last three, but have nothing
+to say about the first three.</p>
+
+<p>But is there in actual fact any such radical dichotomy
+of these six facts as objects of science? Take any task
+of science with respect to them, for example, identification.
+A score of scientific men, including John Smith himself, are
+asked to identify John’s stature at a given moment. Each
+observes it carefully, getting, let us say, as measures: 72.10
+inches, 72.11, 72.05, 72.08, 72.09, 72.11, etc.</p>
+
+<p>In the case of color of hair each observes as before, the
+reports being brown, light brown, brown, light brown,
+between light brown and brown, and so forth.</p>
+
+<p>In the case of body temperature, again, each observes
+as before, there being the same variability in the reports;
+but John <i>may also observe in a second way</i>, not by observing<span class="pagenum"><a id="Page_8"></a>[8]</span>
+a thermometer with eyes, but by observing the temperature
+of his body through other sense-organs so situated that
+they lead to knowledge of only his own body’s temperature.
+It is important to note that for efficient knowledge
+of his own body-temperature, John does not use the sense
+approach peculiar to him, but that available for all observers.
+He identifies and measures his ‘feverishness’ by
+studying himself as he would study any other animal, by
+thermometer and eye.</p>
+
+<p>In the case of the toothache the students proceed as
+before, except that they use John’s gestures, facial expression,
+cries and verbal reports, as well as his mere
+bodily structure and condition. They not only observe the
+cavities in his teeth, the signs of ulcer and the like, but they
+also ask him, tapping a tooth, “Does it hurt?” “How
+long has it hurt?” “Does it hurt very much?” and the
+like. John, if their equal in knowledge of dentistry, would
+use the same methods, testing himself, asking himself
+questions and using the replies made by himself to himself
+in inner speech. But, as with temperature, he would get
+data, for his identification of the toothache, from a source
+unavailable for the others, the sense-organs in his teeth.</p>
+
+<p>It is worth while to consider how they and he would proceed
+to an exact identification or measure of the intensity
+of his toothache such as was made of his stature or body-temperature.
+First, they would need a scale of toothaches
+of varying intensities. Next, they would need means of
+comparing the intensity of his toothache with those of
+this scale to see which it was most like. Given this scale
+and means of comparison, they would turn John’s attention
+from the original toothache to one of given intensity, and
+compare the two, both by his facial expression, gestures and
+the like, and by the verbal reports made. John would<span class="pagenum"><a id="Page_9"></a>[9]</span>
+do likewise, reporting to himself instead of to them. The
+similarity of the procedure to that in studying a so-called
+physical fact is still clearer if we suppose a primitive condition
+of the scales of length and temperature. Suppose
+for example that for the length of a man we had only
+‘short’ or ‘tall as a deer,’ ‘medium’ or ‘tall as a moose,’
+and ‘tall’ or ‘tall as a horse’; and for the intensity of the
+toothache of a man ‘little’ or ‘intense as a pin-prick,’
+‘medium’ or ‘intense as a knife-cut,’ and ‘great’ or ‘intense
+as a spear-thrust.’ Then obviously the only difference
+between the identification of the length of a man’s body and
+the identification of the intensity of his toothache would
+be that the latter was made by all on the basis of behavior
+as well as anatomy, and made by the individual having
+it on the basis of data from an additional sense-organ.</p>
+
+<p>In actual present practice, if observers were asked to
+identify the intensity of John’s toothache on a scale running
+from zero intensity up, the variability of the reports
+would be very great in comparison with those of stature
+or body-temperature. Supposing the most intense toothache
+to be called <i>K</i>, we might well have reports of from
+say .300 <i>K</i> to .450 <i>K</i>, some observers identifying the fact
+with a condition one and a half times as intense as that
+chosen by others. But such a variability might also occur
+in primitive men’s judgments of length or temperature.</p>
+
+<p>It is important to note that the accuracy of John’s own
+identification of it depends in any case on his knowledge
+of the scale and his power of comparing his toothache therewith.
+Well-trained outside observers might identify the
+intensity of John’s toothache more accurately than he
+could.</p>
+
+<p>In the case of John’s anxiety, the most striking fact is
+the low degree of accuracy in identification. The quality of<span class="pagenum"><a id="Page_10"></a>[10]</span>
+the anxiety and its intensity would both be so crudely
+measured by present means that even if the observers
+were from the score of most competent psychologists, their
+reports would probably be not much better than, say, the
+descriptions now found in masterpieces of fiction and drama.
+Science could not tell at all closely how much John’s anxiety
+at this particular time resembled either his anxiety on
+some other occasion or anything else. This inferiority
+is due in part to the fact that the manifestations of anxiety
+in behavior, including verbal reports, are so complicated
+by facts other than the anxiety itself, by, for example,
+the animal’s health, temperament, concomitant ideas
+and emotions, knowledge of language, clearness in expression
+and the like. It is due in part to the very low status
+of our classification of kinds of anxieties and of our units
+and scales for measuring the amount of each kind. Hence
+the variation amongst observers would be even greater
+than in the case of the toothache, and the confidence of
+all in their judgments would be less, and far, far less than
+their confidence in their judgment of John’s stature. The
+best possible present knowledge of John’s anxiety, though
+scientific in comparison with ordinary opinion about it,
+would seem grossly unscientific in comparison with knowledge
+of his stature or weight. Knowledge of the anxiety
+would improve with better knowledge of its manifestations,
+including verbal reports by John, and with better means of
+classification and measurement.</p>
+
+<p>John’s knowledge of his own anxiety would be in part the
+same as that of the other observers. He too would judge
+his condition by its external manifestations, would name
+its sort and rate its amount on the basis of his own behavior,
+as he saw his own face, heard his own groans, and read the
+notes he wrote describing his condition. But he would<span class="pagenum"><a id="Page_11"></a>[11]</span>
+also, as with the toothache, have data from internal sense-organs
+and perhaps from centrally initiated neural actions.
+In so far as he could report these data to himself for use
+in scientific thought more efficiently than he could report
+them to the other observers, he would have, as with the
+toothache, an advantage comparable to the advantage
+of a criminologist who happened also to be or to have been
+a thief, or of a literary critic who happened to have written
+what he judged. It is important to note that only in so
+far as he who has ‘immediate experience’ of or participates
+in or is ‘directly conscious’ of the anxiety, reports it to
+himself as thinker or scientific student, in common with
+the other nineteen, that this advantage accrues. To
+really <i>be</i> or <i>have</i> the anxiety is not to correctly <i>know</i> it.
+An insane man must become sane in order to know his
+insane condition. Bigotry, stupidity and false reasoning
+can be understood only by one who never was them or has
+ceased to be them.</p>
+
+<p>In our last illustration, John’s thinking of ‘9 × 7 equals
+63,’ the effect on John’s behavior may be so complicated
+by other conditions in John, and is so subject to the particular
+conditions which we name John’s ‘will,’ that the
+observers would often be at loss except for John’s verbal
+report. Not that the observer is restricted to that. If
+John does the example 217 × 69 in the usual way, it is a very
+safe inference that he thought 9 × 7 equals 63, regardless
+of the absence of a verbal report from him. But often there
+is little else to go by. To John himself, on the contrary,
+it is easier to be sure that he is thinking of 9 × 7 equals
+63, than that he has a particular sort and strength of toothache.
+Consequently if we suppose John to be thinking
+of that fact while under observation, and the twenty observers<span class="pagenum"><a id="Page_12"></a>[12]</span>
+to be required to identify the fact he is thinking
+of, it is sure that there might be an enormous variability in
+their guesses as to what the fact was and that his testimony
+might be worth far more than that of all the other nineteen
+without his testimony. His observation is influenced by
+the action of the neurones in his central nervous system as
+theirs is not, and, in the case of the thought ‘9 × 7 equals
+63,’ the action of these neurones is of special importance.</p>
+
+<p>Our examination of the way science treats these six facts
+shows no impassable cleft between knowledge of a man’s
+body and knowledge of his mind. Scientific statements
+about the toothache, anxiety and numerical judgment are
+in general more variable than statements about length,
+hair-color and body-temperature, but there is here no
+difference save of degree. Some physical facts, such as
+hair-color, eye-color or health, are, in fact, judged more
+variably than some mental facts, such as rate of adding,
+accuracy of perception of a certain sort and the like. So
+far as the lack of agreement amongst impartial observers
+goes, there is continuity from the identification of a length
+to that of an ideal.</p>
+
+<p>Scientific judgments about the facts of John’s mind
+also depend, in general, more upon his verbal reports than
+do judgments about his body. But here also the difference
+is only of degree. The physician studying wounds, ulcers,
+tumors, infections and other facts of a man’s body may
+depend more upon his verbal reports than does the moralist
+who is studying the man’s character. Verbal reports
+too are themselves a gradual and continuous extension of
+coarser forms of behavior. They signify consciousness
+no more truly than do signs, gestures, facial expression
+and the general bodily motions of pursuit, retreat, avoidance
+or seizure.</p>
+
+<p><span class="pagenum"><a id="Page_13"></a>[13]</span></p>
+
+<p>Nor is it true that physical facts are known to many
+observers and mental facts to but one, who <i>is</i> or <i>has</i> or
+<i>directly experiences</i> them. If it were true, sociology,
+economics, history, anthropology and the like would
+either be physical sciences or represent no knowledge at
+all. The kind of knowledge of which these sciences and
+the common judgments of our fellow men are made up is
+knowledge possessed by many observers in common, the
+individual of whom the facts is known, knowing the fact
+in part in just the same way that the others know it.</p>
+
+<p>The real difference between a man’s scientific judgments
+about himself and the judgment of others about him is
+that he has <i>added sources of knowledge</i>. Much of what
+goes on in him influences him in ways other than those
+in which it influences other men. But this difference is
+not coterminous with that between judgments about his
+‘mind’ and about his ‘body.’ As was pointed out in the
+case of body-temperature, a man knows certain facts about
+his own body in such additional ways.</p>
+
+<p>Furthermore, there is no more truth in the statement
+that a man’s pain or anxiety or opinions are matters of
+direct consciousness, pure experience, than in the statement
+that his length, weight and temperature are, or that the sun,
+moon and stars are. If by the pain we must mean the pain
+as felt by some one, then by the sun we can mean only the
+sun as seen by some one. Pain and sun are equally subjects
+for a science of ‘consciousness as such.’ But if by the
+sun is meant the sun of common sense, physics and astronomy,
+the sun as known by any one, then by the pain we
+can mean the pain of medicine, economics and sociology, the
+pain as known by any one, and by the sufferer long after
+he <i>was</i> or <i>had</i> it.</p>
+
+<p>All facts emerge from the matrix of pure experience;<span class="pagenum"><a id="Page_14"></a>[14]</span>
+but they become facts for science only after they have
+emerged therefrom. A man’s anxiety may be the anxiety
+as directly felt by the man, or as thought of by him, or as
+thought of by the general consensus of scientific observers.
+But so also may be his body-temperature or weight or the
+composition of the blood in his veins. There can be no
+valid reason other than a pragmatic one for studying a
+man’s anxiety solely as <i>felt</i> by him while studying his body-temperature
+as <i>thought of</i> by him and others. And the
+practical reasons are all in favor of studying all facts as they
+exist for any impartial observer. A man’s mind as it is to
+thinking men is all that thinking men can deal with and
+all that they have any interest in dealing with.</p>
+
+<p>Finally, the subject-matter of psychology is not sharply
+marked off from the subject-matter of physiology by being
+absolutely non-spatial. On the contrary, the toothache,
+anxiety and judgment are referred unequivocally, by every
+sane man who thinks of them, to the space occupied by
+the body of the individual in question. That is the surest
+fact about them. It is true that we do not measure the
+length, height, thickness and weight of an animal’s pain
+or anxiety, but neither do we those of his pulse, temperature,
+health, digestion, metabolism, patellar reflex or
+heliotropism.</p>
+
+<p>Two noteworthy advantages are secured by the study
+of behavior. First, the evidence about intellect and
+character offered by action and the influence of intellect
+and character upon action are given due attention. Second,
+the connections of conscious states are studied as well as
+their composition.</p>
+
+<p>The mind or soul of the older psychology was the cause
+not only of consciousness, but also of modifiability in
+thought and action. It was the substance or force in man<span class="pagenum"><a id="Page_15"></a>[15]</span>
+whereby he was sensitive to certain events, was able to
+make certain movements, and not only had ideas but connected
+them one with another and with various impressions
+and acts. It was supposed to account for actual bodily
+action as well as for the action-consciousness. It explained
+the connections between ideas as well as their internal
+composition. If a modern psychologist defines mind as the
+sum total of consciousness, and lives up to that definition,
+he omits the larger portion of the task of his predecessors.
+To define our subject-matter as the nature and behavior
+of men, beginning where anatomy and physiology leave
+off, is, on the contrary, to deliberately assume responsibility
+for the entire heritage. Behavior includes consciousness
+<i>and</i> action, states of mind <i>and</i> their connections.</p>
+
+<p>Even students devoted to ‘consciousness as such’ must
+admit that the movements of an animal and their connections
+with other features of his life deserve study, by even
+their kind of psychologist. For the fundamental means
+of knowing that an animal has a certain conscious state
+are knowledge that it makes certain movements and knowledge
+of what conscious states are connected with those
+movements. Knowledge of the action-system of an animal
+and its connections is a prerequisite to knowledge of its
+stream of consciousness.</p>
+
+<p>There are better reasons for including the action-system
+of an animal in the psychologist’s subject-matter. An
+animal’s conscious stream is of no account to the rest of
+the world except in so far as it prophesies or modifies his
+action.<a id="FNanchor_2" href="#Footnote_2" class="fnanchor">[2]</a> There can be no moral warrant for studying
+man’s nature unless the study will enable us to control
+his acts. If a psychologist is to study man’s consciousness
+without relation to movement, he might as well fabricate<span class="pagenum"><a id="Page_16"></a>[16]</span>
+imaginary consciousnesses to describe and analyze. The
+lovers of consciousness for its own sake often do this unwittingly,
+but would scarcely take pride therein!</p>
+
+<p>The truth of the matter is, of course, that an animal’s
+mind is, by any definition, something intimately associated
+with his connection-system or means of binding various
+physical activities to various physical impressions. The
+whole series—external situations and motor responses as
+well as their bonds—must be studied to some extent in
+order to understand whatever we define as mind. The
+student of behavior, by frankly accepting the task of supplying
+any needed information not furnished by physiology,
+and of studying the animal in action as well as in thought,
+is surer of getting an adequate knowledge of whatever
+features of an animal’s life may be finally awarded the title
+of mind.</p>
+
+<p>The second advantage in studying total behavior rather
+than consciousness as such is that thereby the connections
+of mental facts one with another and with non-mental facts
+receive due attention.</p>
+
+<p>The original tendencies to connect certain thoughts,
+feelings and acts with certain situations—tendencies
+which we call reflexes, instincts and capacities—are not
+themselves states of consciousness; nor are the acquired
+connections which we call habits, associations of ideas,
+tendencies to attend, select and the like. No state of
+consciousness bears within itself an account of when and
+how it will appear, or of what bodily act will be its sequel.
+What any given person will think in any given situation is
+unpredictable by mere descriptions and analyses of his
+previous thoughts each by itself. To understand the <i>when</i>,
+<i>how</i> and <i>why</i> of states of consciousness one must study
+other facts than states of consciousness. These non-conscious<span class="pagenum"><a id="Page_17"></a>[17]</span>
+relations or connections, knowledge of which
+informs us of the result to come from the action of a given
+situation on a given animal, may be expected to be fully
+half of the subject-matter of mental science.</p>
+
+<p>As was noted in the early pages of this chapter, the psychologist
+commonly does adopt the attitude of treating mind
+as a system of connections long enough to give some account
+of the facts of instinct, habit, memory, and the like. But
+the dogma that psychology deals exclusively with the inner
+stream of mind-stuff has made these accounts needlessly
+scanty and vague.</p>
+
+<p>One may appreciate fully the importance of finding out
+whether the attention-consciousness is clearness or is something
+else, and whether it exists in two or three discrete
+degrees or in a continuous series of gradations, and still
+insist upon the equal importance of finding out to what
+facts and for what reasons human beings do attend. There
+would appear, for example, to be an unfortunate limitation
+to the study of human nature by the examination of its
+consciousnesses, when two eminent psychologists, writing
+elaborate accounts of attention from that point of view,
+tell us almost nothing whereby we can predict what any
+given animal will attend to in any given situation, or can
+cause in any given animal a state of attention to any given
+fact.</p>
+
+<p>One may enjoy the effort to define the kind of mind-stuff
+in which one thinks of classes of facts, relations between
+facts and judgments about facts, and still protest that a
+proper balance in the study of intellect demands equal or
+greater attention to the problems of why any given animal
+thinks of any given fact, class or relation in any given
+situation and why he makes this or that judgment about it.</p>
+
+<p>In the case of the so-called action-consciousness the<span class="pagenum"><a id="Page_18"></a>[18]</span>
+neglect of the connections becomes preposterous. The
+adventitious scraps of consciousness called ‘willing’ which
+may intervene between a situation productive of a given
+act and the act itself are hopelessly uninstructive in comparison
+with the bonds of instinct and habit which cause the
+situation to produce the act. In conduct, at least, that
+kind of psychology which Santayana calls ‘the perception
+of character’ seems an inevitable part of a well-balanced
+science of human nature. I quote from his fine description
+of the contrast between the external observation of a
+mind’s connections and the introspective recapitulation of
+its conscious content, though it is perhaps too pronounced
+and too severe.</p>
+
+<p>“<i>Perception of Character.</i>—There is, however, a wholly
+different and far more positive method of reading the mind,
+or what in a metaphorical sense is called by that name.
+This method is to read character. Any object with which
+we are familiar teaches us to divine its habits; slight
+indications, which we should be at a loss to enumerate
+separately, betray what changes are going on and what
+promptings are simmering in the organism.... The gift
+of reading character ... is directed not upon consciousness
+but upon past or eventual action. Habits and passions,
+however, have metaphorical psychic names, names indicating
+dispositions rather than particular acts (a disposition
+being mythically represented as a sort of wakeful and haunting
+genius waiting to whisper suggestions in a man’s ear).
+We may accordingly delude ourselves into imagining that
+a pose or a manner which really indicates habit indicates
+feeling instead.</p>
+
+<p>“<i>Conduct Divined, Consciousness Ignored.</i>... As the
+weather prophet reads the heavens, so the man of experience
+reads other men. Nothing concerns him less than<span class="pagenum"><a id="Page_19"></a>[19]</span>
+their consciousness; he can allow that to run itself off
+when he is sure of their temper and habits. A great
+master of affairs is usually unsympathetic. His observation
+is not in the least dramatic or dreamful, he does
+not yield himself to animal contagion or reënact other
+people’s inward experience. He is too busy for that,
+and too intent on his own purposes. His observation,
+on the contrary, is straight calculation and inference,
+and it sometimes reaches truths about people’s character
+and destiny which they themselves are very far from
+divining. Such apprehension is masterful and odious to
+weaklings, who think they know themselves because they
+indulge in copious soliloquy (which is the discourse of
+brutes and madmen), but who really know nothing of
+their own capacity, situation, or fate.”<a id="FNanchor_3" href="#Footnote_3" class="fnanchor">[3]</a></p>
+
+<p>Mr. Santayana elsewhere hints that both psychology and
+history will become studies of human behavior considered
+from without,—a part, that is, of what he calls physics,—if
+they are to amount to much.</p>
+
+<p>Such a prediction may come true. But for the present
+there is no need to decide which is better—to study an
+animal’s self as conscious, its stream of direct experience,
+or to study the intellectual and moral nature that causes its
+behavior in thought and action and is known to many
+observers. Since worthy men have studied both, both are
+probably worthy of study. All that I wish to claim is the
+right of a man of science to study an animal’s intellectual
+and moral behavior, following wherever the facts lead—to
+“the sum total of human experience considered as dependent
+upon the experiencing person,” to the self as conscious, or to
+a connection-system known to many observers and born
+and bred in the animal’s body.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_20"></a>[20]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_II">CHAPTER II<br>
+<span class="smcap">Animal Intelligence; an Experimental Study of the
+Associative Processes in Animals</span><a id="FNanchor_4" href="#Footnote_4" class="fnanchor">[4]</a></h2>
+
+</div>
+
+<p>This monograph is an attempt at an explanation of the
+nature of the process of association in the animal mind. Inasmuch
+as there have been no extended researches of a character
+similar to the present one either in subject-matter or
+experimental method, it is necessary to explain briefly its
+standpoint.</p>
+
+<p>Our knowledge of the mental life of animals equals in
+the main our knowledge of their sense-powers, of their
+instincts or reactions performed without experience, and
+of their reactions which are built up by experience. Confining
+our attention to the latter, we find it the opinion of
+the better observers and analysts that these reactions can
+all be explained by the ordinary associative processes without
+aid from abstract, conceptual, inferential thinking.
+These associative processes then, as present in animals’
+minds and as displayed in their acts, are my subject-matter.
+Any one familiar in even a general way with the literature
+of comparative psychology will recall that this part of the
+field has received faulty and unsuccessful treatment. The
+careful, minute and solid knowledge of the sense-organs of
+animals finds no counterpart in the realm of associations and
+habits. We do not know how delicate or how complex or
+how permanent are the possible associations of any given
+group of animals. And although one would be rash who
+said that our present equipment of facts about instincts<span class="pagenum"><a id="Page_21"></a>[21]</span>
+was sufficient or that our theories about it were surely sound,
+yet our notion of what occurs when a chick grabs a worm
+are luminous and infallible compared to our notion of what
+happens when a kitten runs into the house at the familiar
+call. The reason that they have satisfied us as well as they
+have is just that they are so vague. We say that the kitten
+associates the sound ‘kitty kitty’ with the experience of
+nice milk to drink, which does very well for a common-sense
+answer. It also suffices as a rebuke to those who would
+have the kitten ratiocinate about the matter, but it fails
+to tell what real mental content is present. Does the kitten
+feel “<i>sound of call, memory-image of milk in a saucer in the
+kitchen, thought of running into the house, a feeling, finally,
+of ‘I will run in’</i>”? Does he perhaps feel only the sound
+of the bell and an impulse to run in, similar in quality to
+the impulses which make a tennis player run to and fro
+when playing? The word ‘association’ may cover a multitude
+of essentially different processes, and when a writer
+attributes anything that an animal may do to association,
+his statement has only the negative value of eliminating
+reasoning on the one hand and instinct on the other.
+His position is like that of a zoölogist who should to-day
+class an animal among the ‘worms.’ To give to the word a
+positive value and several definite possibilities of meaning
+is one aim of this investigation.</p>
+
+<p>The importance to comparative psychology in general of
+a more scientific account of the association-process in animals
+is evident. Apart from the desirability of knowing
+all the facts we can, of whatever sort, there is the especial
+consideration that these associations and consequent habits
+have an immediate import for biological science. In the
+higher animals the bodily life and preservative acts are
+largely directed by these associations. They, and not<span class="pagenum"><a id="Page_22"></a>[22]</span>
+instinct, make the animal use the best feeding grounds,
+sleep in the same lair, avoid new dangers and profit by new
+changes in nature. Their higher development in mammals
+is a chief factor in the supremacy of that group. This,
+however, is a minor consideration. The main purpose of
+the study of the animal mind is to learn the development of
+mental life down through the phylum, to trace in particular
+the origin of human faculty. In relation to this chief purpose
+of comparative psychology the associative processes
+assume a rôle predominant over that of sense-powers or
+instinct, for in a study of the associative processes lies the
+solution of the problem. Sense-powers and instincts have
+changed by addition and supersedence, but the cognitive
+side of consciousness has changed not only in quantity but
+also in quality. Somehow out of these associative processes
+have arisen human consciousnesses with their sciences and
+arts and religions. The association of ideas proper, imagination,
+memory, abstraction, generalization, judgment, inference,
+have here their source. And in the metamorphosis
+the instincts, impulses, emotions and sense-impressions
+have been transformed out of their old natures. For the
+origin and development of human faculty we must look
+to these processes of association in lower animals. Not
+only then does this department need treatment more, but
+promises to repay the worker better.</p>
+
+<p>Although no work done in this field is enough like the
+present investigation to require an account of its results,
+the <i>method</i> hitherto in use invites comparison by its contrast
+and, as I believe, by its faults. In the first place, most of
+the books do not give us a psychology, but rather a <i>eulogy</i>,
+of animals. They have all been about animal <i>intelligence</i>,
+never about animal <i>stupidity</i>. Though a writer derides
+the notion that animals have reason, he hastens to add that<span class="pagenum"><a id="Page_23"></a>[23]</span>
+they have marvelous capacity of forming associations, and
+is likely to refer to the fact that human beings only rarely
+reason anything out, that their trains of ideas are ruled
+mostly by association, as if, in this latter, animals were on a
+par with them. The history of books on animals’ minds
+thus furnishes an illustration of the well-nigh universal tendency
+in human nature to find the marvelous wherever it
+can. We wonder that the stars are so big and so far apart,
+that the microbes are so small and so thick together, and
+for much the same reason wonder at the things animals
+do. They used to be wonderful because of the mysterious,
+God-given faculty of instinct, which could almost remove
+mountains. More lately they have been wondered at because
+of their marvelous mental powers in profiting by
+experience. Now imagine an astronomer tremendously
+eager to prove the stars as big as possible, or a bacteriologist
+whose great scientific desire is to demonstrate the microbes
+to be very, very little! Yet there has been a similar eagerness
+on the part of many recent writers on animal psychology
+to praise the abilities of animals. It cannot help leading to
+partiality in deductions from facts and more especially in
+the choice of facts for investigation. How can scientists
+who write like lawyers, defending animals against the charge
+of having no power of rationality, be at the same time
+impartial judges on the bench? Unfortunately the real
+work in this field has been done in this spirit. The level-headed
+thinkers who might have won valuable results
+have contented themselves with arguing against the theories
+of the eulogists. They have not made investigations of
+their own.</p>
+
+<p>In the second place, the facts have generally been derived
+from anecdotes. Now quite apart from such pedantry as
+insists that a man’s word about a scientific fact is worthless<span class="pagenum"><a id="Page_24"></a>[24]</span>
+unless he is a trained scientist, there are really in this field
+special objections to the acceptance of the testimony about
+animals’ intelligent acts which one gets from anecdotes.
+Such testimony is by no means on a par with testimony
+about the size of a fish or the migration of birds, etc. For
+here one has to deal not merely with ignorant or inaccurate
+testimony, but also with prejudiced testimony. Human
+folk are as a matter of fact eager to find intelligence in
+animals. They like to. And when the animal observed is
+a pet belonging to them or their friends, or when the story
+is one that has been told as a story to entertain, further
+complications are introduced. Nor is this all. Besides
+commonly misstating what facts they report, they report
+only such facts as show the animal at his best. Dogs get
+lost hundreds of times and no one ever notices it or sends an
+account of it to a scientific magazine. But let one find his
+way from Brooklyn to Yonkers and the fact immediately
+becomes a circulating anecdote. Thousands of cats on
+thousands of occasions sit helplessly yowling, and no one
+takes thought of it or writes to his friend, the professor;
+but let one cat claw at the knob of a door supposedly as a
+signal to be let out, and straightway this cat becomes the
+representative of the cat-mind in all the books. The unconscious
+distortion of the facts is almost harmless compared
+to the unconscious neglect of an animal’s mental life
+until it verges on the unusual and marvelous. It is as if
+some denizen of a planet where communication was by
+thought-transference, who was surveying humankind and
+reporting their psychology, should be oblivious to all our
+intercommunication save such as the psychical-research
+society has noted. If he should further misinterpret the
+cases of mere coincidence of thoughts as facts comparable
+to telepathic communication, he would not be more wrong<span class="pagenum"><a id="Page_25"></a>[25]</span>
+than some of the animal psychologists. In short, the
+anecdotes give really the <i>abnormal</i> or <i>supernormal</i> psychology
+of animals.</p>
+
+<p>Further, it must be confessed that these vices have been
+only ameliorated, not obliterated, when the observation is
+first-hand, is made by the psychologist himself. For as men
+of the utmost scientific skill have failed to prove good
+observers in the field of spiritualistic phenomena,<a id="FNanchor_5" href="#Footnote_5" class="fnanchor">[5]</a> so biologists
+and psychologists before the pet terrier or hunted
+fox often become like Samson shorn. They, too, have
+looked for the intelligent and unusual and neglected the
+stupid and normal.</p>
+
+<p>Finally, in all cases, whether of direct observation or
+report by good observers or bad, there have been three other
+defects. Only a single case is studied, and so the results
+are not necessarily true of the type; the observation is not
+repeated, nor are the conditions perfectly regulated; the
+previous history of the animal in question is not known.
+Such observations may tell us, if the observer is perfectly
+reliable, that a certain thing takes place; but they cannot
+assure us that it will take place universally among the animals
+of that species, or universally with the same animal.
+Nor can the influence of previous experience be estimated.
+All this refers to means of getting knowledge about what
+animals <i>do</i>. The next question is, “What do they <i>feel</i>?”
+Previous work has not furnished an answer or the material
+for an answer to this more important question. Nothing
+but carefully designed, crucial experiments can. In abandoning<span class="pagenum"><a id="Page_26"></a>[26]</span>
+the old method one ought to seek above all to
+replace it by one which will not only tell more accurately
+<i>what they do</i>, and give the much-needed information <i>how
+they do it</i>, but also inform us <i>what they feel</i> while they act.</p>
+
+<p>To remedy these defects, experiment must be substituted
+for observation and the collection of anecdotes. Thus you
+immediately get rid of several of them. You can repeat the
+conditions at will, so as to see whether or not the animal’s
+behavior is due to mere coincidence. A number of animals
+can be subjected to the same test, so as to attain typical
+results. The animal may be put in situations where its
+conduct is especially instructive. After considerable preliminary
+observation of animals’ behavior under various
+conditions, I chose for my general method one which, simple
+as it is, possesses several other marked advantages besides
+those which accompany experiment of any sort. It was
+merely to put animals when hungry in inclosures from which
+they could escape by some simple act, such as pulling at a
+loop of cord, pressing a lever, or stepping on a platform. (A
+detailed description of these boxes and pens will be given
+later.) The animal was put in the inclosure, food was left
+outside in sight, and his actions observed. Besides recording
+his general behavior, special notice was taken of how he
+succeeded in doing the necessary act (in case he did succeed),
+and a record was kept of the time that he was in the box
+before performing the successful pull, or clawing, or bite.
+This was repeated until the animal had formed a perfect
+association between the sense-impression of the interior of
+that box and the impulse leading to the successful movement.
+When the association was thus perfect, the time taken to
+escape was, of course, practically constant and very short.</p>
+
+<p>If, on the other hand, after a certain time the animal did
+not succeed, he was taken out, but <i>not fed</i>. If, after a sufficient<span class="pagenum"><a id="Page_27"></a>[27]</span>
+number of trials, he failed to get out, the case was recorded
+as one of complete failure. Enough different sorts
+of methods of escape were tried to make it fairly sure that
+association in general, not association of a particular sort of
+impulse, was being studied. Enough animals were taken
+with each box or pen to make it sure that the results were
+not due to individual peculiarities. None of the animals
+used had any previous acquaintance with any of the
+mechanical contrivances by which the doors were opened.
+So far as possible the animals were kept in a uniform state
+of hunger, which was practically utter hunger.<a id="FNanchor_6" href="#Footnote_6" class="fnanchor">[6]</a> That is,
+no cat or dog was experimented on, when the experiment
+involved any important question of fact or theory,<span class="pagenum"><a id="Page_28"></a>[28]</span>
+unless I was sure that his motive was of the standard
+strength. With chicks this is not practicable, on account of
+their delicacy. But with them dislike of loneliness acts as
+a uniform motive to get back to the other chicks. Cats (or
+rather kittens), dogs and chicks were the subjects of the
+experiments. All were apparently in excellent health, save
+an occasional chick.</p>
+
+<p>By this method of experimentation the animals are put
+in situations which call into activity their mental functions
+and permit them to be carefully observed. One may, by
+following it, observe personally more intelligent acts than
+are included in any anecdotal collection. And this actual
+vision of animals in the act of using their minds is far more
+fruitful than any amount of history of what animals have
+done without the history of how they did it. But besides
+affording this opportunity for purposeful and systematic
+observation, our method is valuable because it frees the
+animal from any influence of the observer. The animal’s
+behavior is quite independent of any factors save its own
+hunger, the mechanism of the box it is in, the food outside,
+and such general matters as fatigue, indisposition, etc.
+Therefore the work done by one investigator may be repeated
+and verified or modified by another. No personal
+factor is present save in the observation and interpretation.
+Again, our method gives some very important results
+which are quite uninfluenced by <i>any</i> personal factor in any
+way. The curves showing the progress of the formation of
+associations, which are obtained from the records of the
+times taken by the animal in successive trials, are facts which
+may be obtained by any observer who can tell time. They
+are absolute, and whatever can be deduced from them is
+sure. So also the question of whether an animal does or
+does not form a certain association requires for an answer<span class="pagenum"><a id="Page_29"></a>[29]</span>
+no higher qualification in the observer than a pair of eyes.
+The literature of animal psychology shows so uniformly and
+often so sadly the influence of the personal equation that
+any method which can partially eliminate it deserves a trial.</p>
+
+<p>Furthermore, although the associations formed are such
+as could not have been previously experienced or provided
+for by heredity, they are still not too remote from the animal’s
+ordinary course of life. They mean simply the connection
+of a certain act with a certain situation and resultant
+pleasure, and this general type of association is found
+throughout the animal’s life normally. The muscular
+movements required are all such as might often be required
+of the animal. And yet it will be noted that the acts required
+are nearly enough like the acts of the anecdotes to
+enable one to compare the results of experiment by this
+method with the work of the anecdote school. Finally, it
+may be noticed that the method lends itself readily to experiments
+on imitation.</p>
+
+<p>We may now start in with the description of the apparatus
+and of the behavior of the animals.<a id="FNanchor_7" href="#Footnote_7" class="fnanchor">[7]</a></p>
+
+<h3><span class="smcap">Description of Apparatus</span></h3>
+
+<div class="figcenter illowp100" id="figure01" style="max-width: 31.25em;">
+  <img class="w100" src="images/figure01.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 1.</span></p>
+</div>
+
+<p>The shape and general apparatus of the boxes which were
+used for the cats is shown by the accompanying drawing of
+box K. Unless special figures are given, it should be understood
+that each box is approximately 20 inches long, by 15
+broad, by 12 high. Except where mention is made to the
+contrary, the door was pulled open by a weight attached to a<span class="pagenum"><a id="Page_30"></a>[30]</span>
+string which ran over a pulley and was fastened to the door,
+just as soon as the animal loosened the bolt or bar which
+held it. Especial care was taken not to have the widest
+openings between the bars at all near the lever, or wire
+loop, or what not, which governed the bolt on the door.
+For the animal instinctively attacks the large openings first,
+and if the mechanism which governs the opening of the door
+is situated near one of them, the animal’s task is rendered
+easier. You do not then get the association-process so free
+from the helping hand of instinct as you do if you make the
+box without reference to the position of the mechanism to
+be set up within it. These various mechanisms are so
+simple that a verbal description will suffice in most cases.
+The facts which the reader should note are the nature of the
+movement which the cat had to make, the nature of the
+object at which the movement was directed, and the position
+of the object in the box. In some special cases attention<span class="pagenum"><a id="Page_31"></a>[31]</span>
+will also be called to the force required. In general,
+however, that was very slight (20 to 100 grams if applied
+directly). The various boxes will be designated by capital
+letters.</p>
+
+<p>A. A string attached to the bolt which held the door ran
+up over a pulley on the front edge of the box, and was tied
+to a wire loop (2½ inches in diameter) hanging 6 inches
+above the floor in front center of box. Clawing or biting it,
+or rubbing against it even, if in a certain way, opened the
+door. We may call this box A ‘<i>O at front</i>.’</p>
+
+<p>B. A string attached to the bolt ran up over a pulley on
+the front edge of the door, then across the box to another
+pulley screwed into the inside of the back of the box 1¼
+inches below the top, and passing over it ended in a wire loop
+(3 inches in diameter) 6 inches above the floor in back center
+of box. Force applied to the loop or <i>to the string</i> as it ran
+across the top of the box between two bars would open the
+door. We may call B ‘<i>O at back</i>.’</p>
+
+<p>B1. In B1 the string ran outside the box, coming down
+through a hole at the back, and was therefore inaccessible
+and invisible from within. Only by pulling the loop could
+the door be opened. B1 may be called ‘<i>O at back 2d</i>.’</p>
+
+<p>C. A door of the usual position and size (as in <a href="#figure01">Fig. 1</a>) was
+kept closed by a wooden button 3½ inches long, ⅞ inch
+wide, ½ inch thick. This turned on a nail driven into the
+box ½ inch above the middle of the top edge of the door.
+The door would fall inward as soon as the button was turned
+from its vertical to a horizontal position. A pull of 125
+grams would do this if applied sideways at the lowest point
+of the button 2¼ inches below its pivot. The cats usually
+clawed the button round by downward pressure on its top
+edge, which was 1¼ inches above the nail. Then, of course,
+more force was necessary. C may be called ‘<i>Button</i>.’</p>
+
+<p><span class="pagenum"><a id="Page_32"></a>[32]</span></p>
+
+<p>D. The door was in the extreme right of the front.
+A string fastened to the bolt which held it ran up
+over a pulley on the top edge and back to the top edge
+of the back side of the box (3 inches in from the right
+side) and was there firmly fastened. The top of the box
+was of wire screening and arched over the string ¾ inch
+above it along its entire length. A slight pull on the
+string anywhere opened the door. This box was 20 × 16,
+but a space 7 × 16 was partitioned off at the left by a wire
+screen. D may be called ‘<i>String</i>.’</p>
+
+<p>D1 was the same box as B, but had the string fastened
+firmly at the back instead of running over a pulley and
+ending in a wire loop. We may call it ‘<i>String 2d</i>.’</p>
+
+<p>E. A string ran from the bolt holding the door up over a
+pulley and down to the floor outside the box, where it was
+fastened 2 inches in front of the box and 1½ inches to the
+left of the door (looking from the inside). By poking a paw
+out between the bars and pulling this string inward the door
+would be opened. We may call E ‘<i>String outside</i>.’</p>
+
+<p>In F the string was not fastened to the floor but ended in a
+loop 2½ inches in diameter which could be clawed down so as
+to open the door. Unless the pull was in just the right direction,
+the string was likely to catch on the pulley. This loop
+hung 3 inches above the floor, and 1¾ inches in front of the
+box. We may call F ‘<i>String outside unfastened</i>.’</p>
+
+<p>G was a box 29 × 20½ × 22½, with a door 29 × 12 hinged
+on the left side of the box (looking from within), and kept
+closed by an ordinary thumb latch placed 15 inches from
+the floor. The remainder of the front of the box was closed
+in by wooden bars. The door was a wooden frame covered
+with screening. It was <i>not</i> arranged so as to open as soon as
+the latch was lifted, but required a force of 400 grams, even
+when applied to the best advantage. The bar of the thumb<span class="pagenum"><a id="Page_33"></a>[33]</span>
+latch, moreover, would fall back into place again unless the
+door were pushed out at least a little. The top of this box
+was not of bars or screening, but solid. We may call G
+‘<i>Thumb latch</i>.’</p>
+
+<p>H was, except for the opening where the door was situated,
+a perfectly solid and dark box. In the front was cut an
+opening about 9 × 7 inches. A wooden frame covered with
+wire netting hung in front of this. It was fastened to the
+box only by a screw through the middle of the frame’s top
+piece, and could therefore be pushed to either side so as to
+permit escape from the box if it were prevented from swinging
+back into place.</p>
+
+<p>I was a box 12 × 14 × 23. The door was 8 inches wide, 4
+high, and hinged at the left side. It was held closed by a
+wooden bar which moved easily on a pivot and which could
+be pushed up by another bar which projected 5 inches into
+the box. This second bar was pivoted so that downward
+pressure on it pushed the first bar up and let the door swing
+open. The second bar entered the box at a point 4 inches
+above the floor and 2½ inches in from the right side of the
+box. In its normal position its inner end was 5½ inches
+above the floor. A depression of 2 inches at that end was
+necessary to open the door. Of course, nearer the pivot a
+shorter depression would do. The front of the box was
+closed by bars, but the rest by solid boards. We may call I
+‘<i>Lever</i>.’</p>
+
+<p>J was the same as B except that the door was not opened
+by a weight as soon as the bolt was pulled up. On the contrary,
+the door was held closed by a small piece of board
+(4 × 3½ × ¾ thick) placed against it outside. After
+pulling the loop at the back the cat had to knock down
+this support and push the door open. We may call J
+‘<i>Double</i>.’</p>
+
+<p><span class="pagenum"><a id="Page_34"></a>[34]</span></p>
+
+<p>K was a box arranged so that three separate acts were required
+to open the door, which was held by two bolts at the
+top and two bars outside. One of the bolts was connected
+with a platform in the back center of the box so that depressing
+the platform raised the bolt. The other was raised by a
+string which ran up over a pulley in the front, across the
+box 1 inch above the bars, over a pulley near the corner of
+the box, and down to the floor, where it was fastened. Pulling
+on this string, either by clawing at it where it was running
+vertically from the last pulley to the floor, or by putting
+the paw out between the bars which covered the top of the
+box, and clawing the string downward, would raise the bolt.
+If both bolts were raised and <i>either</i> bar was pushed up or
+down far enough to be out of the way, the cat could escape.
+K, or ‘<i>Triple</i>,’ as it may be called, is the box reproduced in
+<a href="#figure01">Figure 1</a>.</p>
+
+<p>L was a box that also required three acts to open the door.
+It was a combination of A (O at front), D (string), I (lever).
+The lever or bar to be depressed was 2 inches to the right of
+the door, which was in the front center. The string to be
+clawed or bitten ran from front center to back center 1 inch
+below the top of the box.</p>
+
+<p>Z was a box with back and sides entirely closed, with
+front and top closed by bars and screening, with a small
+opening in the left-hand corner. A box was held in front
+of this and drawn away when the cats happened to lick
+themselves. Thus escape and food followed always upon
+the impulse to lick themselves, and they soon would immediately
+start doing so as soon as pushed into the box.
+The same box was used with the impulse changed to that
+for scratching themselves. The size of this box was
+15 × 10 × 16.</p>
+
+<p><span class="pagenum"><a id="Page_35"></a>[35]</span></p>
+
+<h3><span class="smcap">Experiments with Cats</span></h3>
+
+<p>In these various boxes were put cats from among the
+following. I give approximately their ages while under
+experiment.</p>
+
+<ul>
+<li>No. 1. 8-10 months.</li>
+<li>No. 2. 5-7 months.</li>
+<li>No. 3. 5-11 months.</li>
+<li>No. 4. 5-8 months.</li>
+<li>No. 5. 5-7 months.</li>
+<li>No. 6. 3-5 months.</li>
+<li>No. 7. 3-5 months.</li>
+<li>No. 8. 6-6½ months.</li>
+<li>No. 10. 4-8 months.</li>
+<li>No. 11. 7-8 months.</li>
+<li>No. 12. 4-6 months.</li>
+<li>No. 13. 18-19 months.</li>
+</ul>
+
+<p>The behavior of all but 11 and 13 was practically the same.
+When put into the box the cat would show evident signs of
+discomfort and of an impulse to escape from confinement.
+It tries to squeeze through any opening; it claws and bites
+at the bars or wire; it thrusts its paws out through any
+opening and claws at everything it reaches; it continues its
+efforts when it strikes anything loose and shaky; it may
+claw at things within the box. It does not pay very much
+attention to the food outside, but seems simply to strive
+instinctively to escape from confinement. The vigor with
+which it struggles is extraordinary. For eight or ten
+minutes it will claw and bite and squeeze incessantly.
+With 13, an old cat, and 11, an uncommonly sluggish cat,
+the behavior was different. They did not struggle vigorously
+or continually. On some occasions they did not even
+struggle at all. It was therefore necessary to let them out
+of some box a few times, feeding them each time. After
+they thus associate climbing out of the box with getting
+food, they will try to get out whenever put in. They do not,
+even then, struggle so vigorously or get so excited as the
+rest. In either case, whether the impulse to struggle be<span class="pagenum"><a id="Page_36"></a>[36]</span>
+due to an instinctive reaction to confinement or to an association,
+it is likely to succeed in letting the cat out of the
+box. The cat that is clawing all over the box in her impulsive
+struggle will probably claw the string or loop or button
+so as to open the door. And gradually all the other non-successful
+impulses will be stamped out and the particular
+impulse leading to the successful act will be stamped in by
+the resulting pleasure, until, after many trials, the cat will,
+when put in the box, immediately claw the button or loop
+in a definite way.</p>
+
+<p>The starting point for the formation of any association
+in these cases, then, is the set of instinctive activities which
+are aroused when a cat feels discomfort in the box either
+because of confinement or a desire for food. This discomfort,
+plus the sense-impression of a surrounding, confining
+wall, expresses itself, prior to any experience, in squeezings,
+clawings, bitings, etc. From among these movements one
+is selected by success. But this is the starting point only
+in the case of the first box experienced. After that the cat
+has associated with the feeling of confinement certain impulses
+which have led to success more than others and are
+thereby strengthened. A cat that has learned to escape
+from A by clawing has, when put into C or G, a greater tendency
+to claw at things than it instinctively had at the start,
+and a less tendency to squeeze through holes. A very
+pleasant form of this decrease in instinctive impulses was
+noticed in the gradual cessation of howling and mewing.
+However, the useless instinctive impulses die out slowly,
+and often play an important part even after the cat has had
+experience with six or eight boxes. And what is important
+in our previous statement, namely, that the activity of an
+animal when first put into a new box is not directed by any
+appreciation of <i>that</i> box’s character, but by certain general<span class="pagenum"><a id="Page_37"></a>[37]</span>
+impulses to act, is not affected by this modification. Most
+of this activity is determined by heredity; some of it, by
+previous experience.</p>
+
+<p>My use of the words <i>instinctive</i> and <i>impulse</i> may cause
+some misunderstanding unless explained here. Let us,
+throughout this book, understand by instinct any reaction
+which an animal makes to a situation <i>without experience</i>.
+It thus includes unconscious as well as conscious acts.
+Any reaction, then, to totally new phenomena, when first
+experienced, will be called instinctive. Any impulse then
+felt will be called an instinctive impulse. Instincts include
+whatever the nervous system of an animal, as far as inherited,
+is capable of. My use of the word will, I hope, everywhere
+make clear what fact I mean. If the reader gets the
+fact meant in mind it does not in the least matter whether
+he would himself call such a fact instinct or not. Any
+one who objects to the word may substitute ‘hocus-pocus’
+for it wherever it occurs. The definition here made will not
+be used to prove or disprove any theory, but simply as a
+signal for the reader to imagine a certain sort of fact.</p>
+
+<p>The word <i>impulse</i> is used against the writer’s will, but
+there is no better. Its meaning will probably become clear
+as the reader finds it in actual use, but to avoid misconception
+at any time I will state now that <i>impulse</i> means the
+consciousness accompanying a muscular innervation <i>apart
+from that feeling of the act which comes from seeing oneself
+move, from feeling one’s body in a different position, etc.</i> It
+is the <i>direct feeling of the doing</i> as distinguished from the
+<i>idea of the act done</i> gained through eye, etc. For this
+reason I say ‘impulse <i>and</i> act’ instead of simply ‘act.’
+Above all, it must be borne in mind that by impulse I never
+mean the <i>motive</i> to the act. In popular speech you may say
+that hunger is the impulse which makes the cat claw. That<span class="pagenum"><a id="Page_38"></a>[38]</span>
+will never be the use here. The word <i>motive</i> will always
+denote that sort of consciousness. Any one who thinks
+that the act ought not to be thus subdivided into impulse
+and deed may feel free to use the word <i>act</i> for <i>impulse</i> or <i>impulse
+and act</i> throughout, if he will remember that the act
+in this aspect of being felt as to be done or as doing is in
+animals the important thing, is the thing which gets associated,
+while the act as done, as viewed from outside, is a
+secondary affair. I prefer to have a separate word, <i>impulse</i>,
+for the former, and keep the word <i>act</i> for the latter, which it
+commonly means.</p>
+
+<p>Starting, then, with its store of instinctive impulses,
+the cat hits upon the successful movement, and gradually
+associates it with the sense-impression of the interior of the
+box until the connection is perfect, so that it performs the
+act as soon as confronted with the sense-impression. The
+formation of each association may be represented graphically
+by a time-curve. In these curves lengths of one millimeter
+along the abscissa represent successive experiences
+in the box, and heights of one millimeter above it each
+represent ten seconds of time. The curve is formed by
+joining the tops of perpendiculars erected along the abscissa
+1 mm. apart (the first perpendicular coinciding with the <i>y</i>
+line), each perpendicular representing the time the cat was
+in the box before escaping. Thus, in <a href="#figure02">Fig. 2 on page 39</a> the
+curve marked <i>12 in A</i> shows that, in 24 experiences or
+trials in box A, cat 12 took the following times to perform
+the act, 160 sec., 30 sec., 90 sec., 60, 15, 28, 20, 30, 22, 11, 15,
+20, 12, 10, 14, 10, 8, 8, 5, 10, 8, 6, 6, 7. A short vertical line
+below the abscissa denotes that an interval of approximately
+24 hours elapsed before the next trial. Where the interval
+was longer it is designated by a figure 2 for two days, 3 for
+three days, etc. If the interval was shorter, the number of
+hours is specified by 1 hr., 2 hrs., etc. In many cases the
+animal failed in some trial to perform the act in ten or
+fifteen minutes and was then taken out by me. Such failures
+are denoted by a break in the curve either at its start
+or along its course. In some cases there are short curves
+after the main ones. These, as shown by the figures beneath,
+represent the animal’s mastery of the association
+after a very long interval of time, and may be called memory-curves.
+A discussion of them will come in the last part of
+the chapter.</p>
+
+<p><span class="pagenum"><a id="Page_39"></a>[39]</span></p>
+
+<div class="figcenter illowp48" id="figure02" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure02.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 2.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_40"></a>[40]</span></p>
+
+<p>The time-curve is obviously a fair representation of the
+progress of the formation of the association, for the two
+essential factors in the latter are the disappearance of all
+activity save the particular sort which brings success with
+it, and perfection of that particular sort of act so that it is
+done precisely and at will. Of these the second is, on deeper
+analysis, found to be a part of the first; any clawing at a
+loop except the particular claw which depresses it is theoretically
+a useless activity. If we stick to the looser phraseology,
+however, no harm will be done. The combination of these
+two factors is inversely proportional to the time taken,
+provided the animal surely wants to get out at once. This
+was rendered almost certain by the degree of hunger.
+Theoretically a perfect association is formed when both
+factors are perfect,—when the animal, for example, does
+nothing but claw at the loop, and claws at it in the most
+useful way for the purpose. In some cases (<i>e.g.</i> 2 in K on
+<a href="#Page_53">page 53</a>) neither factor ever gets perfected in a great many
+trials. In some cases the first factor does but the second
+does not, and the cat goes at the thing not always in the
+desirable way. In all cases there is a fraction of the time
+which represents getting oneself together after being
+dropped in the box, and realizing where one is. But for
+our purpose all these matters count little, and we may take
+the general slope of the curve as representing very fairly
+the progress of the association. The slope of any particular
+part of it may be due to accident. Thus, very often the
+second experience may have a higher time-point than the
+first, because the first few successes may all be entirely
+due to accidentally hitting the loop, or whatever it is, and
+whether the accident will happen sooner in one trial than
+another is then a matter of chance. Considering the general
+slope, it is, of course, apparent that a gradual descent—say,
+from initial times of 300 sec. to a constant time of 6 or 8 sec.
+in the course of 20 to 30 trials—represents a difficult
+association; while an abrupt descent, say in 5 trials, from a
+similar initial height, represents a very easy association.
+Thus, 2 in Z, on <a href="#Page_57">page 57</a>, is a hard, and 1 in I, on <a href="#Page_49">page 49</a>,
+an easy association.</p>
+
+<p><span class="pagenum"><a id="Page_41"></a>[41]</span></p>
+
+<div class="figcenter illowp48" id="figure03" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure03.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 3.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_42"></a>[42]</span></p>
+
+<p>In boxes A, C, D, E, I, 100 per cent of the cats given a
+chance to do so, hit upon the movement and formed the
+association. The following table shows the results where
+some cats failed:—</p>
+
+<h4><span class="smcap">Table 1</span></h4>
+
+<table>
+  <tr>
+    <th></th>
+    <th><span class="smcap">No. Cats<br>Tried</span></th>
+    <th><span class="smcap">No. Cats<br>Failed</span></th>
+  </tr>
+  <tr>
+    <td class="tdc">F</td>
+    <td class="tdc bl bt">5</td>
+    <td class="tdc bl br bt">4</td>
+  </tr>
+  <tr>
+    <td class="tdc">G</td>
+    <td class="tdc bl">8</td>
+    <td class="tdc bl br">5</td>
+  </tr>
+  <tr>
+    <td class="tdc">H</td>
+    <td class="tdc bl">9</td>
+    <td class="tdc bl br">2</td>
+  </tr>
+  <tr>
+    <td class="tdc">J</td>
+    <td class="tdc bl">5</td>
+    <td class="tdc bl br">2</td>
+  </tr>
+  <tr>
+    <td class="tdc">K</td>
+    <td class="tdc bl bb">5</td>
+    <td class="tdc bl br bb">2</td>
+  </tr>
+</table>
+
+<p>The time-curves follow. By referring to the description
+of apparatus they will be easily understood. Each mm.
+along the abscissa represents one trial. Each mm. above
+it represents 10 seconds.</p>
+
+<p><span class="pagenum"><a id="Page_43"></a>[43]</span></p>
+
+<div class="figcenter illowp48" id="figure04" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure04.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 4.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_44"></a>[44]</span></p>
+
+<div class="figcenter illowp95" id="figure05" style="max-width: 31.25em;">
+  <img class="w100" src="images/figure05.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 5.</span></p>
+</div>
+
+<p>These time-curves show, in the first place, what associations
+are easy for an animal to form, and what are hard.
+The act must be one which the animal will perform in the
+course of the activity which its inherited equipment incites
+or its previous experience has connected with the sense-impression
+of a box’s interior. The oftener the act naturally
+occurs in the course of such activity, the sooner it
+will be performed in the first trial or so, and this is one condition,
+sometimes, of the ease of forming the association.
+For if the first few successes are five minutes apart, the
+influence of one may nearly wear off before the next, while
+if they are forty seconds apart the influences may get summated.
+But this is not the only or the main condition of
+the celerity with which an association may be formed. It
+depends also on the amount of attention given to the act.
+An act of the sort likely to be well attended to will be learned
+more quickly. Here, too, accident may play a part, for a
+cat may merely happen to be attending to its paw when it
+claws. The kind of acts which insure attention are those
+where the movement which works the mechanism is one
+which the cat makes definitely to get out. Thus A (O at
+front) is easier to learn than C (button), because the cat
+does A in trying to claw down the front of the box and so
+is attending to what it does; whereas it does C generally
+in a vague scramble along the front or while trying to claw
+outside with the other paw, and so does not attend to the
+little unimportant part of its act which turns the button
+round. Above all, <i>simplicity</i> and <i>definiteness</i> in the act
+make the association easy. G (thumb latch), J (double)
+and K and L (triples) are hard, because complex. E is
+easy, because directly in the line of the instinctive impulse
+to try to pull oneself out of the box by clawing at
+anything outside. It is thus very closely attended to.
+The extreme of ease is reached when a single experience
+stamps the association in so completely that ever after the
+act is done at once. This is approached in I and E.</p>
+
+<p><span class="pagenum"><a id="Page_45"></a>[45]</span></p>
+
+<div class="figcenter illowp48" id="figure06" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure06.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 6.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_46"></a>[46]</span></p>
+
+<p>In these experiments the sense-impressions offered no
+difficulty one more than the other.</p>
+
+<p>Vigor, abundance of movements, was observed to make
+differences between individuals in the same association.
+It works by shortening the first times, the times when the
+cat still does the act largely by accident. Nos. 3 and 4
+show this throughout. Attention, often correlated with lack
+of vigor, makes a cat form an association more quickly after
+he gets started. No. 13 shows this somewhat. The absence
+of a fury of activity let him be more conscious of what
+he did do.</p>
+
+<p><span class="pagenum"><a id="Page_47"></a>[47]</span></p>
+
+<div class="figcenter illowp48" id="figure07" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure07.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 7.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_48"></a>[48]</span></p>
+
+<p>The curves on <a href="#Page_57">pages 57 and 58</a>, showing the history of
+cats 1, 5, 13 and 3, which were let out of the box Z when
+they licked themselves, and of cats 6, 2 and 4, which were
+let out when they scratched themselves, are interesting because
+they show associations where there is no congruity
+(no more to a cat than to a man) between the act and the
+result. One chick, too, was thus freed whenever he pecked
+at his feathers to dress them. He formed the association,
+and would whirl his head round and poke it into his feathers
+as soon as dropped in the box. There is in all these cases
+a noticeable tendency, of the cause of which I am ignorant,
+to diminish the act until it becomes a mere vestige of a
+lick or scratch. After the cat gets so that it performs the
+act soon after being put in, it begins to do it less and less
+vigorously. The licking degenerates into a mere quick
+turn of the head with one or two motions up and down with
+tongue extended. Instead of a hearty scratch, the cat
+waves its paw up and down rapidly for an instant. Moreover,
+if sometimes you do not let the cat out after this
+feeble reaction, it does not at once repeat the movement,
+as it would do if it depressed a thumb piece, for instance,
+without success in getting the door open. Of the reason for
+this difference I am again ignorant.</p>
+
+<p>Previous experience makes a difference in the quickness
+with which the cat forms the associations. After getting
+out of six or eight boxes by different sorts of acts the cat’s
+general tendency to claw at loose objects within the box is
+strengthened and its tendency to squeeze through holes
+and bite bars is weakened; accordingly it will learn associations
+along the general line of the old more quickly. Further,
+its tendency to pay attention to what it is doing gets
+strengthened, and this is something which may properly
+be called a change in degree of intelligence. A test was
+made of the influence of experience in this latter way by
+putting two groups of cats through I (lever), one group
+(1, 2, 3, 4, 5) after considerable experience, the other (10,
+11, 12) after experience with only one box. As the act in I
+was not along the line of the acts in previous boxes, and as
+a decrease in the squeezings and bitings would be of little
+use in the box as arranged, the influence of experience in
+the former way was of little account. The curves of all
+are shown on <a href="#Page_49">page 49</a>.</p>
+
+<p><span class="pagenum"><a id="Page_49"></a>[49]</span></p>
+
+<div class="figcenter illowp48" id="figure08" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure08.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 8.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_50"></a>[50]</span></p>
+
+<p>If the whole set of curves are examined in connection with
+the following table, which gives the general order in which
+each animal took up the different associations which he
+eventually formed, many suggestions of the influence of
+experience will be met with. The results are not exhaustive
+enough to justify more than the general conclusion that
+there is such an influence. By taking more individuals
+and thus eliminating all other factors besides experience,
+one can easily show just how and how far experience facilitates
+association.</p>
+
+<p>When, in this table, the letters designating the boxes are
+in italics it means that, though the cat formed the association,
+it was in connection with other experiments and so is
+not recorded in the curves.</p>
+
+<h4><span class="smcap">Table 2</span></h4>
+
+<table class="borders">
+  <tr>
+    <td class="bl bt">Cat 1</td>
+    <td class="bt"><i>A</i> <i>B</i> <i>C</i> <i>D₁</i> <i>D</i> Z I</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 2</td>
+    <td><i>C</i> <i>D₁</i> <i>D</i> E Z H J I K</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 3</td>
+    <td>A C E G H J Z I K</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 4</td>
+    <td>C F G D Z H J I K</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 5</td>
+    <td>C E Z H I</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 6</td>
+    <td><i>A</i> <i>C</i> E Z</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 7</td>
+    <td><i>A</i> <i>C</i></td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 10</td>
+    <td>C I A H D L</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 11</td>
+    <td>C I A H D L</td>
+  </tr>
+  <tr>
+    <td class="bl">Cat 12</td>
+    <td>C I A H D L</td>
+  </tr>
+  <tr>
+    <td class="bl bb br">Cat 13</td>
+    <td class="bb">A C D G Z</td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_51"></a>[51]</span></p>
+
+<div class="figcenter illowp48" id="figure09" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure09.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 9.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_52"></a>[52]</span></p>
+
+<p>The advantage due to experience in our experiments is
+not, however, the same as ordinarily in the case of trained
+animals. With them the associations are with the acts or
+voice of man or with sense-impressions to which they naturally
+do not attend (<i>e.g.</i> figures on a blackboard, ringing of
+a bell, some act of another animal). Here the advantage
+of experience is mainly due to the fact that by such experience
+the animals gain the habit of attending to the
+master’s face and voice and acts and to sense-impressions
+in general.</p>
+
+<p>I made no attempt to find the differences in ability to
+acquire associations due to age or sex or fatigue or circumstances
+of any sort. By simply finding the average slope
+in the different cases to be compared, one can easily demonstrate
+any such differences that exist. So far as this discovery
+is profitable, investigation along this line ought now
+to go on without delay, the method being made clear.
+Of differences due to differences in the species, genus, etc.,
+of the animals I will speak after reviewing the time-curves
+of dogs and chicks.</p>
+
+<p>In the present state of animal psychology there is another
+value to these results which was especially aimed at by the investigator
+from the start. They furnish a quantitative estimate
+of what the average cat can do, so that if any one has an
+animal which he thinks has shown superior intelligence or
+perhaps reasoning power, he may test his observations and
+opinion by taking the time-curves of the animal in such
+boxes as I have described.</p>
+
+<p><span class="pagenum"><a id="Page_53"></a>[53]</span></p>
+
+<div class="figcenter illowp48" id="figure10" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure10.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 10.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_54"></a>[54]</span></p>
+
+<p>If his animal in a number of cases forms the associations
+very much more quickly, or deals with the situation in a
+more intelligent fashion than my cats did, then he may have
+ground for claiming in his individual a variation toward
+greater intelligence and, possibly, intelligence of a different
+order. On the other hand, if the animal fails to rise above
+the type in his dealings with the boxes, the observer should
+confess that his opinion of the animal’s intelligence may
+have been at fault and should look for a correction of it.</p>
+
+<p>We have in these time-curves a fairly adequate measure
+of what the ordinary cat can do, and how it does it, and in
+similar curves soon to be presented a less adequate measure
+of what a dog may do. If other investigators, especially
+all amateurs who are interested in animal intelligence, will
+take other cats and dogs, especially those supposed by owners
+to be extraordinarily intelligent, and experiment with
+them in this way, we shall soon get a notion of how much
+variation there is among animals in the direction of more or
+superior intelligence. The beginning here made is meager
+but solid. The knowledge it gives needs to be much extended.
+The variations found in individuals should be
+correlated, not merely with supposed superiority in intelligence,
+a factor too vague to be very serviceable, but with
+observed differences in vigor, attention, memory and muscular
+skill. No phenomena are more capable of exact and
+thorough investigation by experiment than the associations
+of animal consciousness. Never will you get a better
+psychological subject than a hungry cat. When the crude
+beginnings of this research have been improved and replaced
+by more ingenious and adroit experimenters, the
+results ought to be very valuable.</p>
+
+<p>Surely every one must agree that no man now has a right
+to advance theories about what is in animals’ minds or to
+deny previous theories unless he supports his thesis by
+systematic and extended experiments. My own theories,
+soon to be proclaimed, will doubtless be opposed by many.
+I sincerely hope they will, provided the denial is accompanied
+by actual experimental work. In fact, I shall be tempted
+again and again in the course of this book to defend some
+theory, dubious enough to my own mind, in the hope of
+thereby inducing some one to oppose me and in opposing
+me to make the experiments I have myself had no opportunity
+to make yet. Probably there will be enough opposition
+if I confine myself to the theories I feel sure of.</p>
+
+<p><span class="pagenum"><a id="Page_55"></a>[55]</span></p>
+
+<div class="figcenter illowp48" id="figure11" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure11.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 11.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_56"></a>[56]</span></p>
+
+<h3><span class="smcap">Experiments with Dogs</span></h3>
+
+<p>The boxes used were as follows:</p>
+
+<p>AA was similar to A (O at front), except that the loop was
+of stiff cord ⅜ inch in diameter and was larger (3½ inches
+diameter); also it was hung a foot from the floor and 8
+inches to the right of the door. The box itself was 41 × 20
+× 23.</p>
+
+<p>BB was similar to B, the loop being the same as in AA,
+and being hung a foot from the floor. The box was of the
+same size and shape as AA.</p>
+
+<p>BB1 was like BB, but the loop was hung 18 inches from
+the floor.</p>
+
+<p>CC was similar to C (button), but the button was 6
+inches long, and the box was 36½ × 22 × 23.</p>
+
+<p>II was similar to I, but the box was 30 × 20 × 25 inches;
+the door (11 inches wide, 6 high) was in the left front corner,
+and the lever was 6 inches long and entered the box at a
+point 2 inches to the right of the door and 4 inches above
+the floor.</p>
+
+<p><span class="pagenum"><a id="Page_57"></a>[57]</span></p>
+
+<div class="figcenter illowp48" id="figure12" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure12.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 12.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_58"></a>[58]</span></p>
+
+<p>In M the same box as in II was used, but instead of a
+lever projecting inside the box, a lever running outside
+parallel to the plane of the front of the box and 18 inches
+long was used. This lay close against the bars composing
+the front of the box, and could be pawed down by
+sticking the paw out an inch or so between two bars, at
+a point about 15 inches high and 6 inches in from the
+right edge of the front. We may call M ‘<i>Lever outside</i>.’</p>
+
+<div class="figcenter illowp48" id="figure13" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure13.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 13.</span></p>
+</div>
+
+<p>N was a pen 5 × 3 feet made of wire netting 46 inches
+high. The door, 31 × 20, was in the right half of the front.
+A string from the bolt passed up over a pulley and back to
+the back center, where it was fastened 33 inches above the
+floor. Biting or pawing this string opened the door.</p>
+
+<p><span class="pagenum"><a id="Page_59"></a>[59]</span></p>
+
+<p>O was like K, except that there was only one bar, that
+the string ran inside the box, so that it was easily accessible,
+and that the bolt raised in K by depression of the platform
+could be raised in O (and was by the dog experimented on)
+by sticking the muzzle out between two bars just above
+the bolt and by biting the string, at the same time jerking
+it upward. O was 30 × 20 × 25 in size.</p>
+
+<p>The box G was used for both dogs and cats, without any
+variation save that for dogs the resistance of the door to
+pressure outwards was doubled.</p>
+
+<p>In these boxes were put in the course of the experiments
+dog 1 (about 8 months old), and dogs 2 and 3, adults, all
+of small size.</p>
+
+<p>A dog who, when hungry, is shut up in one of these boxes
+is not nearly so vigorous in his struggles to get out as is the
+young cat. And even after he has experienced the pleasure
+of eating on escape many times he does not try to get out
+so hard as a cat, young or old. He does try to a certain
+extent. He paws or bites the bars or screening, and tries
+to squeeze out in a tame sort of way. He gives up his
+attempts sooner than the cat, if they prove unsuccessful.
+Furthermore his attention is taken by the food, not the
+confinement. He wants to get <i>to</i> the food, not <i>out of</i> the
+box. So, unlike the cat, he confines his efforts to the front
+of the box. It was also a practical necessity that the dogs
+should be kept from howling in the evening, and for this
+reason I could not use as motive the utter hunger which
+the cats were made to suffer. In the morning, when the
+experiments were made, the dogs were surely hungry,
+and no experiment is recorded in which the dog was not
+in a state to be willing to make a great effort for a bit of
+meat, but the motive may not have been even and equal
+throughout, as it was with the cats.</p>
+
+<p><span class="pagenum"><a id="Page_60"></a>[60]</span></p>
+
+<div class="figcenter illowp48" id="figure14" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure14.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 14.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_61"></a>[61]</span></p>
+
+<p>The curves on <a href="#Page_60">page 60</a> are to be interpreted in the same
+way as those for the cats, and are on the same scale. The
+order in which No. 1 took up the various associations was
+AA, BB, BB1, G, N, CC, II, O.</p>
+
+<p>The percentage of dogs succeeding in the various boxes
+is given below, but is of no consequence, because so few
+were tried, and because the motive, hunger, was not perhaps
+strong enough, or equal in all cases.</p>
+
+<p>In AA 3 out of 3.</p>
+
+<p>In BB 0 out of 2 (that is, without previous experience
+of AA).</p>
+
+<p>In CC 1 out of 2.</p>
+
+<p>In II 3 out of 3.</p>
+
+<p>In M 1 out of 2.</p>
+
+<p>In N 1 out of 3.</p>
+
+<p>In G 1 out of 3.</p>
+
+<h3><span class="smcap">Experiments with Chicks</span></h3>
+
+<p>The apparatus was as follows:</p>
+
+<div class="figcenter illowp100" id="figure15-17" style="max-width: 31.25em;">
+  <img class="w100" src="images/figure15-17.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 15.</span> <span class="smcap">Fig. 16.</span> <span class="smcap">Fig. 17.</span></p>
+</div>
+
+<p>P was simply a small pen arranged with two exits, one
+leading to the inclosure where were the other chicks and
+food, one leading to another pen with no exit. The drawing
+(<a href="#figure15-17">Fig. 15</a> on this page) explains itself. A chick was<span class="pagenum"><a id="Page_62"></a>[62]</span>
+placed at A and left to find its way out. The walls were
+made of books stuck up on end.</p>
+
+<p>Q was a similar pen arranged so that the real exit was
+harder to find. (See <a href="#figure15-17">Fig. 16</a>.)</p>
+
+<p>R was still another pen similarly constructed, with four
+possible avenues to be taken. (See <a href="#figure15-17">Fig. 17</a>.)</p>
+
+<p>S was a pen with walls 11 inches high. On the right side
+an inclined plane of wire screening led from the floor of the
+pen to the top of its front wall. Thence the chick could
+jump down to where its fellows and the food and drink
+were. S was 17 × 14 in size.</p>
+
+<p>T was a pen of the same size as S, with a block of wood 3
+inches by 3 and 2 inches high in the right back corner.
+From this an inclined plane led to the top of the front wall
+(on the right side of the box). But a partition was placed
+along the left edge of this plane, so that a chick could reach
+it only <i>via</i> the wooden block, not by a direct jump.</p>
+
+<p>U was a pen 16 × 14 × 10 inches. Along the back
+toward the right corner were placed a series of steps 1½
+inches wide, the first 1, the second 2, and the third 3 inches
+high. In the corner was a platform 4 × 4, and 4 high, from
+which access to the top of the front wall of the pen could
+be gained by scrambling up inside a stovepipe 11 inches
+long, inclined upward at an angle of about 30°. From
+the edge of the wall the chick could, of course, jump down to
+food and society. The top of the pen was covered so that
+the chick could not from the platform jump onto the edge
+of the stovepipe or the top of the pen wall. The only
+means of exit was to go up the steps to the platform, up
+through the stovepipe to the front wall, and then jump
+down.</p>
+
+<p>The time-curves for chicks 90, 91, 92, 93, 94 and 95, all
+2-8 days old when experimented on, follow on <a href="#Page_65">page 65</a>.<span class="pagenum"><a id="Page_63"></a>[63]</span>
+The scale is the same as that in the curves of the cats and
+dogs. Besides these simple acts, which any average chick
+will accidentally hit upon and associate, there are, in the
+records of my preliminary study of animal intelligence,
+a multitude of all sorts of associations which some chicks
+have happened to form. Chicks have escaped from confinement
+by stepping on a little platform in the back of the box,
+by jumping up and pulling a string like that in D, by pecking
+at a door, by climbing up a spiral staircase and out
+through a hole in the wall, by doing this and then in addition
+walking across a ladder for a foot to another wall
+from which they jump down, etc. Not every chick will
+happen upon the right way in these cases, but the chicks
+who did happen upon it all formed the associations perfectly
+after enough trials.</p>
+
+<p>The behavior of the chicks shows the same general character
+as that of the cats, conditioned, of course, by the different
+nature of the instinctive impulses. Take a chick put in T
+(inclined plane) for an example. When taken from the food
+and other chicks and dropped into the pen he shows evident
+signs of discomfort; he runs back and forth, peeping loudly,
+trying to squeeze through any openings there may be,
+jumping up to get over the wall, and pecking at the bars
+or screen, if such separate him from the other chicks.
+Finally, in his general running around he goes up the inclined
+plane a way. He may come down again, or he may go on
+up far enough to see over the top of the wall. If he does,
+he will probably go running up the rest of the way and jump
+down. With further trials he gains more and more of an
+impulse to walk up an inclined plane when he sees it, while
+the vain running and pecking, etc., are stamped out by the
+absence of any sequent pleasure. Finally, the chick goes
+up the plane as soon as put in. In scientific terms this<span class="pagenum"><a id="Page_64"></a>[64]</span>
+history means that the chick, when confronted by loneliness
+and confining walls, responds by those acts which in similar
+conditions in nature would be likely to free him. Some one
+of these acts leads him to the successful act, and the resulting
+pleasure stamps it in. Absence of pleasure stamps all
+others out. The case is just the same as with dogs and cats.
+The time-curves are shown in <a href="#figure18">Fig. 18</a>.</p>
+
+<p>Coming now to the question of differences in intelligence
+between the different animals, it is clear that such differences
+are hard to estimate accurately. The chicks are
+surely very much slower in forming associations and less
+able to tackle hard ones, but the biggest part of the difference
+between what they do and what the dogs and cats do
+is not referable so much to any difference in intelligence as to
+a difference in their bodily organs and instinctive impulses.
+As between dogs and cats, the influence of the difference
+in quantity of activity, in the direction of the instinctive
+impulses, in the versatility of the fore limb, is hard to
+separate from the influence of intelligence proper. The
+best practical tests to judge such differences in general
+would be differences in memory, which are very easily got
+at, differences in the delicacy and complexity attainable,
+and, of course, differences in the slope of the curves for the
+same association. If all these tests agreed, we should have
+a right to rank one animal above the other in a scale of
+intelligence. But this whole question of grading is, after
+all, not so important for comparative psychology as its
+popularity could lead one to think. Comparative psychology
+wants first of all to trace human intellection back
+through the phylum to its origin, and in this aim is helped
+little by knowing that dogs are brighter than cats, or
+whales than seals, or horses than cows. Further, the whole
+question of ‘intelligence’ should be resolved into particular
+inquiries into the development of attention, activity,
+memory, etc.</p>
+
+<p><span class="pagenum"><a id="Page_65"></a>[65]</span></p>
+
+<div class="figcenter illowp48" id="figure18" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure18.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 18.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_66"></a>[66]</span></p>
+
+<p>So far as concerns dogs and cats, I should decide that
+the former were more generally intelligent. The main
+reason, however, why dogs seem to us so intelligent is not
+a good reason for the belief. It is because, more than any
+other domestic animal, they direct their attention to <i>us</i>, to
+what we do, and so form associations connected with acts
+of ours.</p>
+
+<p>Having finished our attempt to give a true description of
+the facts of association, so far as observed from the outside,
+we may now progress to discuss its inner nature. A little
+preface about certain verbal usages is necessary before doing
+so. Throughout I shall use the word ‘animal’ or ‘animals,’
+and the reader might fancy that I took it for granted that
+the associative processes were the same in all animals as
+in these cats and dogs of mine. Really, I claim for my
+animal psychology only that it is the psychology of just
+these particular animals. What this warrants about animals
+in general may be left largely to the discretion of
+the reader. As I shall later say, it is probable that in regard
+to imitation and the power of forming associations
+from a lot of free ideas, the anthropoid primates are essentially
+different from the cats and dogs.</p>
+
+<p>The reasons why I say ‘animals’ instead of ‘dogs and
+cats of certain ages’ are two. I do think that the probability
+that the other mammals, barring the primates, offer no
+objections to the theories here advanced about dogs and
+cats is a very strong probability, strong enough to force
+the burden of proof upon any one who should, for instance,
+say that horse-goat psychology was not like cat-dog psychology
+in these general matters. I should claim that,
+till the contrary was shown in any case, my statements<span class="pagenum"><a id="Page_67"></a>[67]</span>
+should stand for the mammalian mind in general, barring the
+primates. My second reason is that I hate to burden the
+reader with the disgusting rhetoric which would result if
+I had to insert particularizations and reservations at every
+step. The word ‘animal’ is too useful, rhetorically, to be
+sacrificed. Finally, inasmuch as most of my theorizing
+will be in the line of denying certain relatively high functions
+to animals, the evidence from cats and dogs is sufficient,
+for they are from among the most intelligent animals, and
+functions of the kind to be discussed, if absent in their
+case, are probably absent from the others.</p>
+
+<h3><span class="smcap">Reasoning or Inference</span></h3>
+
+<p>The first great question is whether or not animals are ever
+led to do any of their acts by reasoning. Do they ever conclude
+from inference that a certain act will produce a certain
+desired result, and so do it? The best opinion has been that
+they do not. The best interpretation of even the most
+extraordinary performances of animals has been that they
+were the result of accident and association or imitation.
+But it has after all been only opinion and interpretation,
+and the opposite theory persistently reappears in the literature
+of the subject. So, although it is in a way superfluous to
+give the <i>coup de grâce</i> to the despised theory that animals
+reason, I think it is worth while to settle this question once
+for all.</p>
+
+<p>The great support of those who do claim for animals the
+ability to infer has been their wonderful performances which
+resemble our own. These could not, they claim, have happened
+by accident. No animal could learn to open a latched
+gate by accident. The whole substance of the argument
+vanishes if, as a matter of fact, animals do learn those things<span class="pagenum"><a id="Page_68"></a>[68]</span>
+by accident. <i>They certainly do.</i> In this investigation
+choice was made of the intelligent performances described
+by Romanes in the following passages. I shall quote at
+some length because these passages give an admirable
+illustration of an attitude of investigation which this research
+will, I hope, render impossible for any scientist in
+the future. Speaking of the general intelligence of cats,
+Romanes says:</p>
+
+<div class="blockquote">
+
+<p>“Thus, for instance, while I have only heard of one solitary
+case ... of a dog which, without tuition, divined the use of a
+thumb latch so as to open a closed door by jumping on the handle
+and depressing the thumb-piece, I have received some half-dozen
+instances of this display of intelligence on the part of
+cats. These instances are all such precise repetitions of one
+another that I conclude the fact to be one of tolerably ordinary
+occurrence among cats, while it is certainly rare among dogs.
+I may add that my own coachman once had a cat which, certainly
+without tuition, learnt thus to open a door that led into
+the stables from a yard into which looked some of the windows
+of the house. Standing at these windows when the cat did not
+see me, I have many times witnessed her <i>modus operandi</i>.
+Walking up to the door with a most matter-of-course kind of air,
+she used to spring at the half hoop handle just below the thumb
+latch. Holding on to the bottom of this half-hoop with one
+fore paw, she then raised the other to the thumb piece, and
+while depressing the latter finally with her hind legs scratched
+and pushed the door posts so as to open the door....</p>
+
+<p>“Of course in all such cases the cats must have previously
+observed that the doors are opened by persons placing their
+hands upon the handles and, having observed this, the animals
+act by what may be strictly termed rational imitation. But
+it should be observed that the process as a whole is something
+more than imitative. For not only would observation alone be
+scarcely enough (within any limits of thoughtful reflection that<span class="pagenum"><a id="Page_69"></a>[69]</span>
+it would be reasonable to ascribe to an animal) to enable a cat
+upon the ground to distinguish that the essential part of the
+process consists not in grasping the handle, but in depressing
+the latch; but the cat certainly never saw any one, after having
+depressed the latch, pushing the door posts with his legs; and
+that this pushing action is due to an originally deliberate intention
+of opening the door, and not to having accidentally found
+this action to assist the process, is shown by one of the cases
+communicated to me; for in this case, my correspondent says,
+‘the door was not a loose-fitting one, by any means, and I was
+surprised that by the force of one hind leg she should have been
+able to push it open after unlatching it.’ Hence we can only
+conclude that the cats in such cases have a very definite idea as
+to the mechanical properties of a door: they know that to make
+it open, even when unlatched, it requires to be <i>pushed</i>—a very
+different thing from trying to imitate any particular action which
+they may see to be performed for the same purpose by man.
+The whole psychological process, therefore, implied by the fact
+of a cat opening a door in this way is really most complex.
+First the animal must have observed that the door is opened by
+the hand grasping the handle and moving the latch. Next she
+must reason, by ‘the logic of feelings’—‘If a hand can do it,
+why not a paw?’ Then strongly moved by this idea she makes
+the first trial. The steps which follow have not been observed,
+so we cannot certainly say whether she learns by a succession
+of trials that depression of the thumb piece constitutes the
+essential part of the process, or, perhaps more probably, that her
+initial observations supplied her with the idea of clicking the
+thumb piece. But, however this may be, it is certain that the
+pushing with the hind feet after depressing the latch must
+be due to adaptive reasoning unassisted by observation; and
+only by the concerted action of all her limbs in the performance
+of a highly complex and most unnatural movement is
+her final purpose attained.” (Animal Intelligence, pp. 420-422.)</p>
+
+</div>
+
+<p><span class="pagenum"><a id="Page_70"></a>[70]</span></p>
+
+<p>A page or two later we find a less ponderous account of
+a cat’s success in turning aside a button and so opening a
+window:—</p>
+
+<div class="blockquote">
+
+<p>“At Parara, the residence of Parker Bowman, Esq., a full-grown
+cat was one day accidentally locked up in a room without
+any other outlet than a small window, moving on hinges, and
+kept shut by means of a swivel. Not long afterwards the window
+was found open and the cat gone. This having happened
+several times, it was at last found that the cat jumped upon the
+window sill, placed her fore paws as high as she could reach
+against the side, deliberately reached with one over to the
+swivel, moved it from its horizontal to a vertical position, and
+then, leaning with her whole weight against the window, swung
+it open and escaped.” (Animal Intelligence, p. 425.)</p>
+
+</div>
+
+<p>A description has already been given on <a href="#Page_31">page 31</a> of the
+small box (C), whose door fell open when the button was
+turned, and also of a large box (CC) for the dogs, with a
+similar door. The thumb-latch experiment was carried
+on with the same box (G) for both cats and dogs, but the
+door was arranged so that a greater force (1.3 kilograms)
+was required in the case of the dogs. It will be remembered
+that the latch was so fixed that if the thumb piece were
+pressed down, without contemporaneous outward pressure
+of the door, the latch bar would merely drop back into its
+catch as soon as the paw was taken off the door. If, however,
+the door were pushed outward, the latch bar, being
+pressed closely against the outer edge of its catch, would,
+if lifted, be likely to fall outside it and so permit the door
+to open if then or later sufficient pressure were exerted.
+Eight cats (Nos. 1, 2, 3, 4, 5, 6, 7 and 13) were, one at a time,
+left in this thumb-latch box. All exhibited the customary
+instinctive clawings and squeezings and bitings. Out of
+the eight all succeeded in the course of their vigorous<span class="pagenum"><a id="Page_71"></a>[71]</span>
+struggles in pressing down the thumb piece, so that if the
+door had been free to swing open, they could have escaped.
+Six succeeded in pushing both thumb-piece down and door
+out, so that the bar did not fall back into its place. Of
+these five succeeded in also later pushing the door open,
+so that they escaped and got the fish
+outside. Of these, three, after repeated
+trials, associated the complicated
+movements required with
+the sight of the interior of the box so
+firmly that they attacked the thumb
+latch the moment they were put in.
+The history of the formation of the
+association in the case of 3 and of 4 is
+shown in the curves in <a href="#figure06">Figs. 6 and 7</a>.
+In the case of 13 the exact times were
+not taken. The combination of accidents
+required was enough to make
+No. 1 and No. 6 take a long time
+to get out. Consequently, weariness
+and failure inhibited their impulses
+to claw, climb, etc., more than the
+rare pleasure from getting out
+strengthened them, and they failed
+to form the association. Like the
+cats who utterly failed to get out, they finally ceased
+to try when put in. The history of their efforts is as in
+Table 3: the figures in the columns represent the time (in
+minutes and seconds) the animal was in the box before
+escaping or before being taken out if he failed to escape.
+Cases of failure are designated by an F after the
+figures. Double lines represent an interval of twenty-four
+hours.</p>
+
+<h4><span class="smcap">Table 3</span></h4>
+
+<table>
+  <tr>
+    <th colspan="2" class="bl br bt">No. 1.</th>
+    <th colspan="2" class="br bt">No. 6.</th>
+  </tr>
+  <tr>
+    <td class="tdr bl bt2">13.00</td>
+    <td class="bt2 br">F</td>
+    <td class="tdr bt2">17.50</td>
+    <td class="bt2 br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">9.30</td>
+    <td class="br"></td>
+    <td class="tdr">3.30</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">1.40</td>
+    <td class="br"></td>
+    <td class="tdr">9.00</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">.50</td>
+    <td class="br"></td>
+    <td class="tdr">2.10</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">15.00</td>
+    <td class="br"></td>
+    <td class="tdr">1.45</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">6.00</td>
+    <td class="br">F</td>
+    <td class="tdr">1.55</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl bt2">14.00</td>
+    <td class="bt2 br"></td>
+    <td class="tdr">13.00</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">20.00</td>
+    <td class="br">F</td>
+    <td class="tdr bt2">5.00</td>
+    <td class="bt2 br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">4.30</td>
+    <td class="br"></td>
+    <td class="tdr">2.30</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">20.00</td>
+    <td class="br">F</td>
+    <td class="tdr">15.00</td>
+    <td class="br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl">20.00</td>
+    <td class="br">F</td>
+    <td class="tdr">10.00</td>
+    <td class="br">F</td>
+  </tr>
+  <tr>
+    <td class="tdr bl">15.00</td>
+    <td class="br">F</td>
+    <td class="tdr bt2">5.00</td>
+    <td class="bt2 br"></td>
+  </tr>
+  <tr>
+    <td class="tdr bl bt2">60.00</td>
+    <td class="bt2 br">F</td>
+    <td class="tdr">15.00</td>
+    <td class="br">F</td>
+  </tr>
+  <tr>
+    <td class="tdr bl"></td>
+    <td class="br"></td>
+    <td class="tdr bt2">10.00</td>
+    <td class="bt2 br">F</td>
+  </tr>
+  <tr>
+    <td class="tdr bl bb"></td>
+    <td class="bb br"></td>
+    <td class="tdr bt2 bb">10.00</td>
+    <td class="bt2 br bb">F</td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_72"></a>[72]</span></p>
+
+<p>It should be noted that, although cats 3 and 4 had had
+some experience in getting out of boxes by clawing at loops
+and turning buttons, they had never had anything at all
+like a thumb latch to claw at, nor had they ever seen the
+door opened by its use, nor did they even have any experience
+of the fact that the part of the box where the thumb
+piece was was the door. And we may insert here, what
+will be stated more fully later, that there was displayed
+no observation of the surroundings or deliberation upon
+them. It was just a mad scramble to get out.</p>
+
+<p>Three dogs (1, 2 and 3) were given a chance to liberate
+themselves from this same box. 2 and 3, who were rather
+inactive, failed to even push the thumb piece down. No. 1,
+who was very active, did push it down at the same time
+that she happened to be pushing against the door. She
+repeated this and formed the association as shown in the
+curve on <a href="#Page_60">page 60</a>. She had had experience only of escaping
+by pulling a loop of string.</p>
+
+<p>Out of 6 cats who were put in the box whose door opened
+by a button, not one failed, in the course of its impulsive
+activity, to push the button around. Sometimes it was
+clawed to one side from below; sometimes vigorous pressure
+on the top turned it around; sometimes it was pushed up
+by the nose. No cat who was given repeated trials failed
+to form a perfect association between the sight of the interior
+of that box and the proper movements. Some of
+these cats had been in other boxes where pulling a loop of
+string liberated them, 3 and 4 had had considerable experience
+with the boxes and probably had acquired a general
+tendency to claw at loose objects. 10, 11 and 12 had never
+been in <i>any box</i> before. The curves are on <a href="#Page_41">pages 41 and 43</a>.</p>
+
+<p>Of two dogs, one, when placed in a similar but larger
+box, succeeded in hitting the button in such a way as to let<span class="pagenum"><a id="Page_73"></a>[73]</span>
+the door open, and formed a permanent association, as
+shown by the curves on <a href="#Page_41">page 41</a>. No one who had seen the
+behavior of these animals when trying to escape could
+doubt that their actions were directed by instinctive impulses,
+not by rational observation. It is then absolutely
+sure that a dog or cat <i>can</i> open a door closed by a thumb
+latch or button, merely by the accidental success of its
+natural impulses. If <i>all</i> cats, when hungry and in a <i>small</i>
+box, will accidentally push the button that holds the door,
+an <i>occasional</i> cat in a <i>large</i> room may very well do the same.
+If three cats out of eight will accidentally press down a
+thumb piece and push open a small door, three cats out of
+a thousand may very well open doors or gates in the same
+way.</p>
+
+<p>But besides thus depriving of their value the facts which
+these theorizers offer as evidence, we may, by a careful
+examination of the method of formation of these associations
+as it is shown in the time-curves, gain positive evidence that
+no power of inference was present in the subjects of the experiments.
+Surely if 1 and 6 had possessed any power of
+inference, they would not have failed to get out after having
+done so several times. Yet they did. (See <a href="#Page_71">p. 71</a>.) If they
+had once even, much less if they had six or eight times,
+inferred what was to be done, they should have made the
+inference the seventh or ninth time. And if there were in
+these animals any power of inference, however rudimentary,
+however sporadic, however dim, there should have appeared
+among the multitude some cases where an animal, seeing
+through the situation, knows the proper act, does it, and
+from then on does it immediately upon being confronted
+with the situation. There ought, that is, to be a sudden
+vertical descent in the time-curve. Of course, where the
+act resulting from the impulse is very simple, very obvious,<span class="pagenum"><a id="Page_74"></a>[74]</span>
+and very clearly defined, a single experience may make the
+association perfect, and we may have an abrupt descent
+in the time-curve without needing to suppose inference.
+But if in a complex act, a series of acts or an ill-defined act,
+one found such a sudden consummation in the associative
+process, one might very well claim that reason was at work.
+Now, the scores of cases recorded show no such phenomena.
+The cat does not look over the situation, much less <i>think</i> it
+over, and then decide what to do. It bursts out at once
+into the activities which instinct and experience have
+settled on as suitable reactions to the situation ‘<i>confinement
+when hungry with food outside</i>.’ It does not ever in the
+course of its successes realize that such an act brings food
+and therefore decide to do it and thenceforth do it immediately
+from <i>decision</i> instead of from impulse. The one
+impulse, out of many accidental ones, which leads to pleasure,
+becomes strengthened and stamped in thereby, and
+more and more firmly associated with the sense-impression
+of that box’s interior. Accordingly it is sooner and sooner
+fulfilled. Futile impulses are gradually stamped out.
+The gradual slope of the time-curve, then, shows the absence
+of reasoning. They represent the wearing smooth of
+a path in the brain, not the decisions of a rational consciousness.</p>
+
+<p>In a later discussion of imitation further evidence that
+animals do not reason will appear. For the present, suffice
+it to say, that a dog, or cat, or chick, who does not in his
+own impulsive activity learn to escape from a box by pulling
+the proper loop, or stepping on a platform, or pecking at a
+door, will not learn it from seeing his fellows do so. They
+are incapable of even the inference (if the process may be
+dignified by that name) that what gives another food will
+give it to them also. So, also, it will be later seen that an<span class="pagenum"><a id="Page_75"></a>[75]</span>
+animal cannot learn an act by being put through it. For
+instance, a cat who fails to push down a thumb piece and
+push out the door cannot be taught by having one take
+its paw and press the thumb piece down with it. This
+<i>could</i> be learned by a certain type of associative process
+without inference. <i>Were there inference, it surely would be
+learned.</i></p>
+
+<p>Finally, attention may be called to the curves which
+show the way that the animal mind deals with a series
+of acts (<i>e.g.</i> curves for G, J, K, L and O, found on <a href="#Page_45">pages 45
+to 55</a> and <a href="#Page_60">60</a>). Were there any reasoning the animals ought
+early to master the method of escape in these cases (see
+descriptions on <a href="#Page_31">pages 31 to 34</a>) so as to do the several
+acts in order, and not to repeat one after doing it once, or
+else ought utterly to fail to master the thing. But, in all
+these experiments, where there was every motive for the
+use of any reasoning faculty, if such existed, where the animals
+literally lived by their intellectual powers, one finds
+no sign of abstraction, or inference, or judgment.</p>
+
+<p>So far I have only given facts which are quite uninfluenced
+by any possible incompetence or prejudice of the observer.
+These alone seem to disprove the existence of any rational
+faculty in the subjects experimented on. I may add that
+my observations of all the conduct of all these animals
+during the months spent with them, failed to find any act
+that even <i>seemed</i> due to reasoning. I should claim that this
+quarrel ought now to be dropped for good and all,—that
+investigation ought to be directed along more sensible and
+profitable lines. I should claim that the psychologist who
+studies dogs and cats in order to defend this ‘reason’ theory
+is on a level with a zoölogist who should study fishes with
+a view to supporting the thesis that they possessed clawed
+digits. The rest of this account will deal with more promising<span class="pagenum"><a id="Page_76"></a>[76]</span>
+problems, of which the first, and not the least important,
+concerns the facts and theories of <i>imitation</i>.</p>
+
+<h3><span class="smcap">Imitation</span></h3>
+
+<p>To the question, ‘Do animals imitate?’ science has
+uniformly answered, ‘Yes.’ But so long as the question
+is left in this general form, no correct answer to it is possible.
+It will be seen, from the results of numerous experiments
+soon to be described, that imitation of a certain sort is
+not possible for animals, and before entering upon that
+description it will be helpful to differentiate this matter of
+imitation into several varieties or aspects. The presence
+of some sorts of imitation does not imply that of other
+sorts.</p>
+
+<p>There are, to begin with, the well-known phenomena
+presented by the imitative birds. The power is extended
+widely, ranging from the parrot who knows a hundred or
+more articulate sounds to the sparrow whom a patient
+shoemaker taught to get through a tune. Now, if a bird
+really gets a sound in his mind from hearing it and sets out
+forthwith to imitate it, as mocking birds are said at times to
+do, it is a mystery and deserves closest study. If a bird,
+out of a lot of random noises that it makes, chooses those
+for repetition which are like sounds that he has heard, it
+is again a mystery <i>why</i>, though not as in the previous case
+a mystery <i>how</i>, he does it. The important fact for our purpose
+is that, though the imitation of sounds is so habitual,
+there does not appear to be any marked general imitative
+tendency in these birds. There is no proof that parrots do
+muscular acts from having seen other parrots do them.
+But this should be studied. At any rate, until we know
+what sort of sounds birds imitate, what circumstances<span class="pagenum"><a id="Page_77"></a>[77]</span>
+or emotional attitudes these are connected with, how they
+learn them and, above all, whether there is in birds which
+repeat sounds any tendency to imitate in other lines, we
+cannot, it seems to me, connect these phenomena with
+anything found in the mammals or use them to advantage
+in a discussion of animal imitation as the forerunner of
+human. In what follows they will be left out of account,
+will be regarded as a specialization removed from the general
+course of mental development, just as the feathers or right
+aortic arch of birds are particular specializations of no consequence
+for the physical development of mammals. For
+us, henceforth, imitation will mean imitation minus the
+phenomena of imitative birds.</p>
+
+<p>There are also certain pseudo-imitative or semi-imitative
+phenomena which ought to be considered by themselves.
+For example, the rapid loss of the fear of railroad trains or
+telegraph wires among birds, the rapid acquisition of arboreal
+habits among Australian rodents, the use of proper
+feeding grounds, etc., may be held to be due to imitation.
+The young animal stays with or follows its mother from a
+specific instinct to keep near that particular object, to wit,
+its mother. It may thus learn to stay near trains, or
+scramble up trees, or feed at certain places and on certain
+plants. Actions due to following pure and simple may thus
+simulate imitation. Other groups of acts which now seem
+truly imitative may be indirect fruits of some one instinct.
+This must be kept in mind when one estimates the supposed
+imitation of parents by young. Further, it is certain that
+in the case of the chick, where early animal life has been
+carefully observed, instinct and individual experience between
+them rob imitation of practically all its supposed influence.
+Chicks get along without a mother very well.
+Yet no mother takes more care of her children than the<span class="pagenum"><a id="Page_78"></a>[78]</span>
+hen. Care in other cases, then, need not mean instruction
+through imitation.</p>
+
+<p>These considerations may prevent an unreserved acceptance
+of the common view that young animals get a great
+number of their useful habits from imitation, but I do not
+expect or desire them to lead to its summary rejection.
+I should not now myself reject it, though I think it quite
+possible that more investigation and experiment may
+finally reduce all the phenomena of so-called imitation of
+parents by young to the level of indirect results of instinctive
+acts.</p>
+
+<p>Another special department of imitation may be at least
+vaguely marked off: namely, apparent imitation of certain
+limited sorts of acts which are somewhat frequent in the
+animal’s life. An example will do better than further
+definition.</p>
+
+<p>Some sheep were being driven on board ship one at a time.
+In the course of their progress they had to jump over a
+hurdle. On this being removed before all had passed it,
+the next sheep was seen to jump as if to get over a hurdle,
+and so on for five or six, apparently sure evidence that they
+imitated the action, each of the one in front. Now, it is
+again possible that among gregarious animals there may be
+elaborate connections in the nervous system which allow
+the sight of certain particular acts in another animal to
+arouse the innervation leading to those acts, but that these
+connections are <i>limited</i>. The reactions on this view are
+specific responses to definite signals, comparable to any
+other instinctive or associational reaction. The sheep
+jumps when he sees the other sheep jump, not because of
+a general ability to do what he sees done, but because he is
+furnished with the instinct to jump at such a sight, or
+because his experience of following the flock over boulders<span class="pagenum"><a id="Page_79"></a>[79]</span>
+and brooks and walls has got him into the habit of jumping
+at the spot where he sees one ahead of him jump; and so
+he jumps even though no obstacle be in his way. If due
+to instinct, the only peculiarity of such a reaction would be
+that the sense-impression calling forth the act would be the
+same act as done by another. If due to experience, there
+would be an exact correspondence to the frequent acts
+called forth <i>originally</i> by several elements in a sense-impression,
+one of which is essential, and done <i>afterwards</i>
+when only the <i>non-essentials</i> are present. These two
+possibilities have not been sufficiently realized, yet they
+may contain the truth. On the other hand, these limited
+acts may be the primitive, sporadic beginnings of the
+general imitative faculty which we find in man. To this
+general faculty we may now turn, having cleared away
+some of the more doubtful phenomena which have shared
+its name.</p>
+
+<p>It should be kept in mind that an imitative act may be
+performed quite unthinkingly, as when a man in the mob
+shouts what the others shout or claps when the others clap;
+may be done from an inference that since A by doing X makes
+pleasure for himself, I by doing X may get pleasure for myself;
+may, lastly, be done from what may be called a transferred
+association. This process is the one of interest in
+connection with our general topic, and most of my experiments
+on imitation were directed to the investigation
+of it. Its nature is simple. One sees the following sequence:
+‘A turning a faucet, A getting a drink.’ If one
+can free this association from its narrow confinement to A,
+so as to get from it the association, ‘impulse to turn faucet,
+<i>me</i> getting a drink,’ one will surely, if thirsty, turn the
+faucet, though he had never done so before. If one can
+from an act witnessed learn to do the act, he in some way<span class="pagenum"><a id="Page_80"></a>[80]</span>
+makes use of the sequence seen, transfers the process to
+himself; in the common human sense of the word, he
+<i>imitates</i>. This kind of imitation is surely common in
+human life. It may be apparent in ontogeny before any
+power of inference is shown. After that power does appear,
+it still retains a wide scope, and teaches us a majority, perhaps,
+of the ordinary accomplishments of our practical life.</p>
+
+<p>Now, as the writers of books about animal intelligence
+have not differentiated this meaning from the other possible
+ones, it is impossible to say surely that they have uniformly
+credited it to animals, and it is profitless to catalogue here
+their vague statements. Many opposers of the ‘reason’
+theory have presupposed such a process and used it to replace
+reason as the cause of some intelligent performances. The
+upholders of the reason theory have customarily recognized
+such a process and claimed to have discounted it in their
+explanations of the various anecdotes. So we found
+Mr. Romanes, in the passage quoted, discussing the possibility
+that such an imitative process, without reason, could
+account for the facts. In his chapter on Imitation in
+‘Habit and Instinct,’ Principal C. Lloyd Morgan, the sanest
+writer on comparative psychology, seems to accept imitation
+of this sort as a fact, though he could, if attacked,
+explain most of his illustrations by the simple forms. The
+fact is, as was said before, that no one has analyzed or
+systematized the phenomena, and so one cannot find clear,
+decisive statements to quote.</p>
+
+<p>At any rate, whether previous authorities have agreed
+that such a process is present or not, it is worth while to
+tackle the question; and the formation of associations by
+imitation, if it occurs, is an important division of the formation
+of associations in general. The experiments and their
+results may now be described.</p>
+
+<p><span class="pagenum"><a id="Page_81"></a>[81]</span></p>
+
+<h4><span class="smcap">Imitation in Chicks</span></h4>
+
+<p>No. 64 learned to get out of a certain pen (16 × 10 inches)
+by crawling under the wire screening at a certain spot.
+There was also a chance to get out by walking up an inclined
+plane and then jumping down. No. 66 was put in with 64.
+After 9 minutes 20 seconds, 66 went out by the inclined
+plane, although 64 had in the meantime crawled out under
+the screen 9 times. (As soon as he got out and ate a little
+he was put back.) It was impossible to judge how many
+of these times 66 really saw 64 do this. He was looking in
+that direction 5 of the times. So also, in three more trials,
+66 used the inclined plane, though 64 crawled under each
+time. 67 was then tried. In 4 minutes 10 seconds, he
+crawled under, 64 having done so twice. Being then put
+in <i>alone</i>, he, without the chance to imitate, still crawled
+under. So probably he went under <i>when with 64</i> not by
+imitation but by accident, just as 64 had learned the thing
+himself.</p>
+
+<div class="figcenter illowp100" id="figure19-20" style="max-width: 25em;">
+  <img class="w100" src="images/figure19-20.jpg" alt="">
+  <p class="caption">Fig. 19. Fig. 20.</p>
+</div>
+
+<p>The accompanying figure (<a href="#figure19-20">19</a>) shows the apparatus used
+in the next experiment. A represents the top of a box
+(5 × 4 inches), 13 inches above the level of the floor C.
+On the floor C were the chicks and food. B is the top of
+a box 10 inches high. Around the edges of A except the
+one next B a wire screen was placed, and 65 was repeatedly<span class="pagenum"><a id="Page_82"></a>[82]</span>
+put upon A until he learned to go quickly back to C <i>via</i> B.
+Then the screen was bent outward at X so that a chick
+could barely squeeze through and down (A to C). Eleven
+chicks were then one at a time placed on A with 65. In
+every case but one they went A-C. In the case of the chick
+(75) who went A-B-C, there could have been no imitation,
+for he went down <i>before</i> 65 did. One other went through
+the hole before 65 went to B. The remaining nine all had
+a chance to imitate 65 and to save the uncomfortable
+struggle to get through the hole, 65 going A-B-C 8 times
+before 68 went A-C, 2 times when with 66 and 76, once in
+the case of each of the others.</p>
+
+<p>In still another experiment the apparatus was (as shown in
+<a href="#figure19-20">Fig. 20</a>) a pen 14 inches square, 10 inches high, with a wire
+screen in front and a hole 3½ inches square in the back.
+This hole opened into a passageway (B) leading around to C,
+where were the other chicks and food. Chicks who had
+failed, when put in alone, to find the way out, were put in
+with other chicks who had learned the way, to see if by
+seeing them go out they would learn the way. Chick 70
+was given 4 trials alone, being left in the box 76 minutes all
+told. He was then given 9 trials (165 minutes) with another
+chick who went out <i>via</i> B 36 times. 70 failed to follow him
+on any occasion. The trials were all given in the course
+of two days. Chick 73 failed in 1 trial (12 minutes) to get
+out of himself, and was then given 4 trials (94 minutes)
+with another chick who went out <i>via</i> B 33 times. In this
+experiment, as in all others reported, sure evidence that the
+animals wanted to get out, was afforded by their persistent
+peckings and jumpings at the screen or bars that stood
+between them and C. Chick 72, after 8 unsuccessful trials
+alone (41 minutes), was given 8 trials with a chance to
+imitate. After the other chick had gone out 44 times, 72<span class="pagenum"><a id="Page_83"></a>[83]</span>
+<i>did go out</i>. He did not follow the other but went 20 seconds
+later. It depends upon one’s general opinion whether one
+shall attribute this one case out of three to accident or
+imitation.</p>
+
+<p>I also took two chicks, one of whom learned to escape
+from A (in <a href="#figure19-20">Fig. 19</a>) by going to B and jumping down the
+side to the <i>right</i> of A, the other of whom learned to jump
+down the side to the <i>left</i>, and placed them together upon A.
+Each took his own course uninfluenced by the other in 10 trials.</p>
+
+<p>Chicks were also tried in several pens where there was only
+one possible way of escape to see if they would learn it <i>more
+quickly</i> when another chick did the thing several times before
+their eyes. The method was to give some chicks their first
+trial with an imitation possibility and their second without,
+while others were given their first trial without and their
+second with. If the ratio of the average time of the first
+trial to the average time of the second is smaller in the first
+class than it is in the second class, we may find evidence of
+this sort of influence by imitation. Though imitation may
+not be able to make an animal <i>do</i> what he would otherwise
+<i>not do</i>, it may make him do <i>quicker</i> a thing he would have
+done sooner or later any way. As a fact the ratio is <i>much
+larger</i>. This is due to the fact that a chick, when in a pen
+with another chick, is not afflicted by the discomfort of loneliness,
+and so does not try so hard to get out. So the other
+chick, who is continually being put in with him to teach
+him the way out, really prolongs his stay in. This factor
+destroys the value of these quantitative experiments, and
+I do not insist upon them as evidence against imitation,
+though they certainly offer none for it. I do not give
+descriptions of the apparatus used in these experiments or a
+detailed enumeration of the results, because in this discussion
+we are not dealing primarily with imitation as a<span class="pagenum"><a id="Page_84"></a>[84]</span>
+slight general factor in forming experience, but as a definite
+associational process in the mind. The utter absence of
+imitation in this limited sense is apparently demonstrated
+by the results of the following experiments.</p>
+
+<p>V was a box 16 × 12 × 8½, with the front made of wire
+screening and at the left end a little door held by a bolt but
+in such a way that a sharp peck at the top of the door would
+force it open.</p>
+
+<p>W was a box of similar size, with a door in the same place
+fixed so that it was opened by raising a bolt. To this bolt
+was tied a string which went up over the top of the edge of
+the box and back across the box, as in D. By jumping up
+and coming down with the head over this thread, the bolt
+would be pulled up. The thread was 8½ inches above the floor.</p>
+
+<p>X was a box of similar size, with door, bolt and string
+likewise. But here the string continued round a pulley at
+the back down to a platform in the corner of the box. By
+stepping on the platform the door was opened.</p>
+
+<p>Y was a box 12 × 8 × 8½, with a door in the middle of the
+front, which I myself opened when a chick pecked at a tack
+which hung against the front of the box 1½ inches above the
+top of the door.</p>
+
+<p>These different acts, pecking at a door, jumping up and
+with the neck pulling down a string, stepping on a platform,
+and pecking at a tack, were the ones which various chicks
+were given a chance to imitate. The chicks used were from
+16 to 30 days old. The method of experiment was to put
+a chick in, leave him 60 to 80 seconds, then put in another
+who knew the act, and on his performing it, to let both
+escape. No cases were counted unless the imitator apparently
+saw the other do the thing. After about ten such
+chances to learn the act, the imitator was left in alone for
+ten minutes. The following table gives the results. The<span class="pagenum"><a id="Page_85"></a>[85]</span>
+imitators, of course, had previously failed to form the association
+of themselves. F denotes failure to perform the act:</p>
+
+<h5><span class="smcap">Table 4</span></h5>
+
+<table class="borders">
+  <tr>
+    <th><span class="smcap">Chick</span></th>
+    <th><span class="smcap">Act</span></th>
+    <th><span class="smcap">No. Times<br>Saw</span></th>
+    <th colspan="2"><span class="smcap">Time in<br>Which Failed</span></th>
+    <th colspan="2"><span class="smcap">Final Time</span></th>
+  </tr>
+  <tr>
+    <td class="tdc">84</td>
+    <td class="tdc">V</td>
+    <td class="tdr">38</td>
+    <td class="tdr">45.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">85</td>
+    <td class="tdc">V</td>
+    <td class="tdr">30</td>
+    <td class="tdr">30.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">86</td>
+    <td class="tdc">V</td>
+    <td class="tdr">44</td>
+    <td class="tdr">55.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">87</td>
+    <td class="tdc">V</td>
+    <td class="tdr">26</td>
+    <td class="tdr">35.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">80</td>
+    <td class="tdc">W</td>
+    <td class="tdr">54</td>
+    <td class="tdr">60.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">81</td>
+    <td class="tdc">W</td>
+    <td class="tdr">40</td>
+    <td class="tdr">45.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">87</td>
+    <td class="tdc">W</td>
+    <td class="tdr">27</td>
+    <td class="tdr">30.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">81</td>
+    <td class="tdc">X</td>
+    <td class="tdr">18</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">82</td>
+    <td class="tdc">X</td>
+    <td class="tdr">21</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">8.40</td>
+    <td class="nobl"><i>Did</i></td>
+  </tr>
+  <tr>
+    <td class="tdc">83</td>
+    <td class="tdc">X</td>
+    <td class="tdr">33</td>
+    <td class="tdr">35.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">84</td>
+    <td class="tdc">X</td>
+    <td class="tdr">46</td>
+    <td class="tdr">55.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">84</td>
+    <td class="tdc">Y</td>
+    <td class="tdr">45</td>
+    <td class="tdr">55.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td class="tdc">83</td>
+    <td class="tdc">Y</td>
+    <td class="tdr">29</td>
+    <td class="tdr">35.00</td>
+    <td class="nobl">F</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+</table>
+
+<p>Thus out of all these cases only one did the act in spite of
+the ample chance for imitation. I have no hesitation in
+declaring 82’s act in stepping on the platform the result
+of mere accident, and am sure that any one who had watched
+the experiments would agree.</p>
+
+<h4><span class="smcap">Imitation in Cats</span></h4>
+
+<p>By reference to the previous descriptions of apparatus, it
+will be seen that box D was arranged with two compartments,
+separated by a wire screen. The larger of these had
+a front of wooden bars with a door which fell open when a
+string stretched across the top was bitten or clawed down.
+The smaller was closed by boards on three sides and by the
+wire screen on the fourth. Through the screen a cat within
+could see the one to be imitated pull the string, go out<span class="pagenum"><a id="Page_86"></a>[86]</span>
+through the door thus opened and eat the fish outside.
+When put in this compartment, the top being covered by
+a large box, a cat soon gave up efforts to claw through the
+screen, quieted down and watched more or less the proceedings
+going on in the other compartment. Thus this apparatus
+could be used to test the power of imitation. A cat who
+had no experience with the means of escape from the large
+compartment was put in the closed one; another cat, who
+would do it readily, was allowed to go through the performance
+of pulling the string, going out, and eating the
+fish. Record was made of the number of times he did so
+and of the number of times the imitator had his eyes clearly
+fixed on him. These were called ‘times seen.’ Cases
+where the imitator was looking in the general direction
+of the ‘imitatee’ and might very well have seen him and
+probably did, were marked ‘doubtful.’ In the remaining
+cases the cat did not see what was done by his instructor.
+After the imitatee had done the thing a number of times,
+the other was put in the big compartment alone, and the
+time it took him before pulling the string was noted and
+his general behavior closely observed. If he failed in 5 or 10
+or 15 minutes to do so, he was released and not fed. This
+entire experiment was repeated a number of times. From
+the times taken by the imitator to escape and from observation
+of the way that he did it, we can decide whether imitation
+played any part. The history of several cases are
+given in the following tables. In the first column are given
+the lengths of time that the imitator was shut up in the box
+watching the imitatee. In the second column is the number
+of times that the latter did the trick. In the third and
+fourth are the times that the imitator surely and possibly
+saw it done, while in the last is given the time that, when
+tried alone, the imitator took to pull the string, or if<span class="pagenum"><a id="Page_87"></a>[87]</span>
+he failed, the time he was in the box trying to get out.
+Times are in minutes and seconds, failures denoted by F:</p>
+
+<h5><span class="smcap">Table 5</span> (a)</h5>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="3"><span class="smcap">No. 7 Imitating No. 2</span></th>
+    <th colspan="2"></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Time<br>Watching</th>
+    <th>No. of times<br>2 did</th>
+    <th>No. of times<br>7 saw</th>
+    <th>No. of times<br>Doubtful</th>
+    <th colspan="2">Time of 7<br>when alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">11</td>
+    <td class="tdr">3</td>
+    <td class="tdr">5</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">11.00</td>
+    <td class="tdr">10</td>
+    <td class="tdr">4</td>
+    <td class="tdr">2</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">12.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">4</td>
+    <td class="tdr">13</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">1.00</td>
+    <td class="nobl"><a id="FNanchor_8" href="#Footnote_8" class="fnanchor">[8]</a></td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">8.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">6</td>
+    <td class="tdr">11</td>
+    <td class="tdr">3.30</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">13.00</td>
+    <td class="tdr">25</td>
+    <td class="tdr">8</td>
+    <td class="tdr">12</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">9.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">4</td>
+    <td class="tdr">11</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">12.00</td>
+    <td class="tdr">35</td>
+    <td class="tdr">5</td>
+    <td class="tdr">21</td>
+    <td class="tdr">30.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 2 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">25</td>
+    <td class="tdr">3</td>
+    <td class="tdr">8</td>
+    <td class="tdr">25.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">15.00</td>
+    <td class="tdr">35</td>
+    <td class="tdr">6</td>
+    <td class="tdr">21</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">6.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">0</td>
+    <td class="tdr">7</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td colspan="3" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">43</td>
+    <td class="tdr nobl">111</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<h5><span class="smcap">Table 5</span> (b)</h5>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="3"><span class="smcap">No. 5 Imitating No. 2</span></th>
+    <th colspan="2"></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Time<br>Watching</th>
+    <th>No. of times<br>2 did</th>
+    <th>No. of times<br>5 saw</th>
+    <th>No. of times<br>Doubtful</th>
+    <th colspan="2">Time of 5<br>when alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">12.00</td>
+    <td class="tdr">15</td>
+    <td class="tdr">3</td>
+    <td class="tdr">8</td>
+    <td class="tdr">5.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After  2 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">8</td>
+    <td class="tdr">4</td>
+    <td class="tdr">4</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">5.00</td>
+    <td class="tdr">5</td>
+    <td class="tdr">0</td>
+    <td class="tdr">3</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">14.00</td>
+    <td class="tdr">10</td>
+    <td class="tdr">5</td>
+    <td class="tdr">3</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">13.00</td>
+    <td class="tdr">22</td>
+    <td class="tdr">7</td>
+    <td class="tdr">11</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">7.00</td>
+    <td class="tdr">15</td>
+    <td class="tdr">3</td>
+    <td class="tdr">8</td>
+    <td class="tdr">5.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">18.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">2</td>
+    <td class="tdr">9</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">14.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">2</td>
+    <td class="tdr">10</td>
+    <td class="tdr">30.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">7</td>
+    <td class="tdr">12</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td colspan="3" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">33</td>
+    <td class="tdr nobl">68</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_88"></a>[88]</span></p>
+
+<h5><span class="smcap">Table 5</span> (c)</h5>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="3"><span class="smcap">No. 6 Imitating No. 2</span></th>
+    <th colspan="2"></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Time<br>Watching</th>
+    <th>No. of times<br>2 did</th>
+    <th>No. of times<br>6 saw</th>
+    <th>No. of times<br>Doubtful</th>
+    <th colspan="2">Time of 6<br>when alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">12.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">0</td>
+    <td class="tdr">19</td>
+    <td class="tdr">1.10</td>
+    <td class="nobl"><a id="FNanchor_9" href="#Footnote_9" class="fnanchor">[9]</a></td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">11.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">0</td>
+    <td class="tdr">11</td>
+    <td class="tdr">9.30</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 72 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">0</td>
+    <td class="tdr">15</td>
+    <td class="tdr">3.00</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 72 Hours</td>
+    <td class="tdr">6.00</td>
+    <td class="tdr">20</td>
+    <td class="tdr">3</td>
+    <td class="tdr">7</td>
+    <td class="tdr">1.50</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">9.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">1</td>
+    <td class="tdr">13</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">6</td>
+    <td class="tdr">9</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">1</td>
+    <td class="tdr">8</td>
+    <td class="tdr">9.40</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td colspan="3" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">11</td>
+    <td class="tdr nobl">82</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<h5><span class="smcap">Table 5</span> (d)</h5>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="3"><span class="smcap">No. 3 Imitating No. 2</span></th>
+    <th colspan="2"></th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">8.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">2</td>
+    <td class="tdr">19</td>
+    <td class="tdr">3.30</td>
+    <td class="nobl"><a id="FNanchor_10" href="#Footnote_10" class="fnanchor">[10]</a></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">3.30</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">2</td>
+    <td class="tdr">14</td>
+    <td class="tdr">.20</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">.20</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 72 Hours</td>
+    <td class="tdr">10.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">2</td>
+    <td class="tdr">8</td>
+    <td class="tdr">.18</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">.08</td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td colspan="3" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">6</td>
+    <td class="tdr nobl">41</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<p>Before entering upon a discussion of the facts shown by
+these tables, we must describe the behavior of the imitators,
+when, after seeing 2 pull the string, they were put in alone.
+In the opinion of the present observer there was not the<span class="pagenum"><a id="Page_89"></a>[89]</span>
+slightest difference between their behavior and that of cats
+4, 10, 11, 12 and 13, who were put into the same position
+without ever having seen 2 escape from it. 6, 7, 5 and 3
+paid no more attention to the string than they did, but
+struggled in just the same way. No one, I am sure, who had
+seen them, would have claimed that their conduct was at all
+influenced by what they had seen. When they did hit the
+string the act looked just like the accidental success of the
+ordinary association experiment. But, besides these personal
+observations, we have in the impersonal time-records
+sufficient proofs of the absence of imitation. If the animals
+pulled the string from having seen 2 do so, they ought
+to pull it in each individual case at an approximately regular
+length of time after they were put in, and presumably pretty
+soon thereafter. That is, if an association between the sight
+of that string in that total situation and a certain impulse
+and consequent freedom and food had been formed in their
+minds by the observation of the acts of 2, they ought to pull
+it <i>on seeing it</i>, and if any disturbing factor required that a
+certain time should elapse before the imitative faculty got
+in working order, that time ought to be somewhere near
+constant. The times were, as a fact, long and irregular in
+the extreme. Furthermore, if the successful cases were
+even in part due to imitation, the times ought to decrease
+the more they saw 2 do the thing. Except with 3, they <i>increase</i>
+or give place to failures. Whereas 6 and 7, if they
+had been put in again immediately after their first successful
+trial and from then on repeatedly, would have unquestionably
+formed the association, they did not, when put in
+after a further chance to increase their knowledge by imitation,
+do the thing as soon as before. The case of 3 is not
+here comparable to the rest because he <i>was</i> given three trials
+in immediate succession. He was a more active cat and<span class="pagenum"><a id="Page_90"></a>[90]</span>
+quicker to learn, as may be seen by comparing his time
+curves with those of 7, 6 and 5. That the mere speed with
+which he mastered this association is no sign that imitation
+was present may be seen by reference to the time curves of
+4 and 13 (on <a href="#Page_43">p. 43</a>).</p>
+
+<p>Some cats were also experimented with in the following
+manner. They were put into a box [No. 7 into box A (O at
+front), No. 5 into B (O at back)] and left for from 45 to 75 seconds.
+Then a cat who knew the way to get out was put in,
+and, of course, pulled at the loop and opened the door. <i>Both
+cats then went out and both were fed.</i> After the cat had been
+given a number of such chances to learn by imitation, he
+was put in and left until he did the thing, or until 5 or 10
+minutes elapsed. As in the preceding experiments, no
+change in their behavior which might signify imitation was
+observed. No. 7 acted exactly like 3, or 10, or 11, when put
+in the box, apparently forming the association by accident
+in just the same way. Good evidence that he did not imitate
+is the fact that, whereas 1 (whom he saw) pulled the
+loop with his teeth, 7 pulled it with his paw. 5 failed to form
+the association, though he saw 3 do it 8 times and probably
+saw him 18 times more. He did get out twice by clawing
+the <i>string</i> in the <i>front</i> of the box, not the <i>loop</i> in the <i>back</i>,
+as 3 did. These successes took place early in the experiment.
+After that he failed when left alone to get out at
+all.</p>
+
+<p>Another experiment was made by a still different method.
+My cats were kept in a large box about 4 ft. high, the front
+of which was covered with poultry-yard netting. Its top
+was a board which could be removed. To save opening the
+door and letting them all loose, I was in the habit of taking
+them out by the top when I wanted to experiment with
+them. Of course the one who happened to climb up (perhaps<span class="pagenum"><a id="Page_91"></a>[91]</span>
+attracted by the smell of fish on my fingers) was most
+likely to be taken out and experimented with and fed. Thus
+they formed the habit of climbing up the front of the box
+whenever I approached. Of three cats which I obtained at
+the same time, one did not after 8 or 10 days acquire this
+habit. Even though I held out a piece of fish through the
+netting, he would not climb after it. It was reasonable to
+suppose that imitation might overcome this sluggishness,
+if there were any imitation. I therefore put two cats with
+him and had them climb up 80 times before his eyes and get
+fish. He never followed or tried to follow them.</p>
+
+<p>4 and 3 had been subjected to the following experiment.
+I would make a certain sound and after 10 seconds would go
+up to the cage and hold the fish out to them through the
+netting at the top. They would then, of course, climb up
+and eat it. After a while, they began to climb up upon
+hearing the signal (4) or before the 10 seconds were up. I
+then took 12 and 10, who were accustomed to going up when
+they saw me approach, but who had no knowledge of the
+fact that the signal meant anything, and gave them each a
+chance to imitate 3. That is, one of them would be left in
+the box with 3, the signal would be given, and after from 5
+to 10 seconds 3 would climb up. At 10 seconds I would
+come up with food, and then, of course, 12 would climb up.
+This was repeated again and again. The question was
+whether imitation would lead them to form the association
+more quickly than they would have done alone. It did not.
+That when at last they did climb up before 10 seconds
+was past, that is, before I approached with food, it was not
+due to imitation, is shown by the fact that on about half
+of such occasions they climbed up <i>before 3 did</i>. That is,
+they reacted to the <i>signal</i> by <i>association</i>, not to his <i>movements</i>
+by <i>imitation</i>.</p>
+
+<p><span class="pagenum"><a id="Page_92"></a>[92]</span></p>
+
+<h3><span class="smcap">Imitation in Dogs</span></h3>
+
+<p>Here the method was not to see if imitation could arouse
+more quickly an act which accident was fairly likely to bring
+forth sooner or later, but to see if, where accident failed,
+imitation would succeed.</p>
+
+<p>3 was found to be unable of himself to escape from box
+BB1, and was then given a chance to learn from watching 1.
+The back of box BB1 was torn off and wire netting substituted
+for it. Another box with open front was placed directly
+behind and against box BB1. No. 3, who was put in
+this second box, could thus see whatever took place in and
+in front of box BB1 (O at back, high). The record follows:—</p>
+
+<h4><span class="smcap">Table 6</span> (a)</h4>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="4"><span class="smcap">Dog 3 Imitating Dog 1</span></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Times<br>1 did</th>
+    <th>Times<br>3 saw</th>
+    <th>Times<br>probably<br>3 saw</th>
+    <th colspan="2">Time<br>in alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">30</td>
+    <td class="tdr">7</td>
+    <td class="tdr">14</td>
+    <td class="tdr">3.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">35</td>
+    <td class="tdr">9</td>
+    <td class="tdr">14</td>
+    <td class="tdr">3.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">10</td>
+    <td class="tdr">3</td>
+    <td class="tdr">3</td>
+    <td class="tdr">5.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">20</td>
+    <td class="tdr">6</td>
+    <td class="tdr">8</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">30</td>
+    <td class="tdr">8</td>
+    <td class="tdr">13</td>
+    <td class="tdr">6.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">25</td>
+    <td class="tdr">8</td>
+    <td class="tdr">11</td>
+    <td class="tdr">8.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">25</td>
+    <td class="tdr">6</td>
+    <td class="tdr">12</td>
+    <td class="tdr">6.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">25</td>
+    <td class="tdr">9</td>
+    <td class="tdr">7</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">10</td>
+    <td class="tdr">11</td>
+    <td class="tdr">40.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td colspan="2" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">66</td>
+    <td class="tdr nobl">93</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<p>A similar failure to imitate was observed in the case of
+another simple act. No. 1, as may be seen on <a href="#Page_60">page 60</a>,
+had learned to escape from a pen about 8 by 5 feet by jumping
+up and biting a cord which ran from one end of the pen to
+the other and at the front end was tied to the bolt which
+held the door. Dogs 2 and 3 had failed in their accidental<span class="pagenum"><a id="Page_93"></a>[93]</span>
+jumping and pawing to hit this cord, and were then given a
+chance to learn by seeing 1 do so, escape, and, of course, be
+fed. 1 always jumped in the same way, biting the cord at
+the same place, namely, where a loose end from a knot in it
+hung down 4 or 5 inches. 2 and 3 would either be tied up
+in the pen or left in a pen at one side. They had a perfect
+chance to see 1 perform his successful act. After every
+twenty or thirty performances by 1, 2 and 3 would be put in
+alone. It should be remembered that here, as also in the
+previous experiment and all others, the imitators certainly
+<i>wanted</i> to get out when thus left in alone. They struggled
+and jumped and pawed and bit, but they never jumped <i>at
+the cord</i>. Their records follow:—</p>
+
+<h4><span class="smcap">Table 6</span> (b)</h4>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="4"><span class="smcap">Dog 2 Imitating Dog 1</span></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Times<br>1 did</th>
+    <th>Times<br>2 saw</th>
+    <th>Times<br>Doubtful</th>
+    <th colspan="2">Time 2 was<br>in alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">30</td>
+    <td class="tdr">9</td>
+    <td class="tdr">11</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">30</td>
+    <td class="tdr">10</td>
+    <td class="tdr">9</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">25</td>
+    <td class="tdr">8</td>
+    <td class="tdr">8</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">10</td>
+    <td class="tdr">3</td>
+    <td class="tdr">4</td>
+    <td class="tdr">9.00</td>
+    <td class="nobl">F<a id="FNanchor_11" href="#Footnote_11" class="fnanchor">[11]</a></td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">8</td>
+    <td class="tdr">12</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 1 Hour</td>
+    <td class="tdr">30</td>
+    <td class="tdr">9</td>
+    <td class="tdr">12</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">20</td>
+    <td class="tdr">7</td>
+    <td class="tdr">6</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">20</td>
+    <td class="tdr">8</td>
+    <td class="tdr">7</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">6</td>
+    <td class="tdr">8</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">15</td>
+    <td class="tdr">2</td>
+    <td class="tdr">4</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td colspan="2" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">70</td>
+    <td class="tdr nobl">81</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_94"></a>[94]</span></p>
+
+<h4><span class="smcap">Table 6</span> (c)</h4>
+
+<table class="borders">
+  <tr>
+    <th colspan="2"></th>
+    <th colspan="4"><span class="smcap">Dog 3 Imitating Dog 1</span></th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Times<br>1 did</th>
+    <th>Times<br>3 saw</th>
+    <th>Times<br>Doubtful</th>
+    <th colspan="2">Time 3 was<br>in alone</th>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">30</td>
+    <td class="tdr">10</td>
+    <td class="tdr">10</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After  1 Hour</td>
+    <td class="tdr">30</td>
+    <td class="tdr">9</td>
+    <td class="tdr">10</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After  1 Hour</td>
+    <td class="tdr">15</td>
+    <td class="tdr">6</td>
+    <td class="tdr">4</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">9</td>
+    <td class="tdr">11</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">10</td>
+    <td class="tdr">12</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After  1 Hour</td>
+    <td class="tdr">30</td>
+    <td class="tdr">8</td>
+    <td class="tdr">9</td>
+    <td class="tdr">10.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">20</td>
+    <td class="tdr">6</td>
+    <td class="tdr">7</td>
+    <td class="tdr">40.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After  1 Hour</td>
+    <td class="tdr">20</td>
+    <td class="tdr">6</td>
+    <td class="tdr">5</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+  <tr>
+    <td>After 48 Hours</td>
+    <td class="tdr">30</td>
+    <td class="tdr">8</td>
+    <td class="tdr">9</td>
+    <td class="tdr">15.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td>After 24 Hours</td>
+    <td class="tdr">15</td>
+    <td class="tdr">3</td>
+    <td class="tdr">4</td>
+    <td class="tdr">20.00</td>
+    <td class="nobl">F</td>
+  </tr>
+  <tr>
+    <td colspan="2" class="nw">Total times surely and possibly seen,—</td>
+    <td class="tdr nobl">75</td>
+    <td class="tdr nobl">81</td>
+    <td class="tdr"></td>
+    <td class="nobl"></td>
+  </tr>
+</table>
+
+<p>Another corroborative, though not very valuable, experiment
+was the following: Dog 3 had been taught for the purpose
+of another experiment to jump up on a box and beg
+when I held a piece of meat above the box. I then caused
+him to do this 110 times (within two days) in the presence of
+1. Although 1 saw him at least 20 per cent of the times (3
+was always fed each time he jumped on the box), he never
+tried to imitate him.</p>
+
+<p>It seems sure from these experiments that the animals
+were unable to form an association leading to an act from
+having seen the other animal, or animals, perform the act in
+a certain situation. Thus we have further restricted the
+association process. Not only do animals not have associations
+accompanied, more or less permeated and altered,
+by inference and judgment; they do not have associations
+of the sort which may be acquired from other animals by
+imitation. What this implies concerning the actual mental<span class="pagenum"><a id="Page_95"></a>[95]</span>
+content accompanying their acts will be seen later on. It
+also seems sure that we should give up imitation as an <i>a
+priori</i> explanation of any novel intelligent performance.
+To say that a dog who opens a gate, for instance, need not
+have reasoned it out <i>if he had seen another dog do the same
+thing</i>, is to offer, instead of one false explanation, another
+equally false. Imitation in any form is too doubtful a
+factor to be presupposed without evidence. And if a
+general imitative faculty is not sufficiently developed to
+succeed with such simple acts as those of the experiments
+quoted, it must be confessed that the faculty is in these
+higher mammals still rudimentary and capable of influencing
+to only the most simple and habitual acts, or else
+that for some reason its sphere of influence is limited to
+a certain class of acts, possessed of some <i>qualitative difference</i>
+other than mere simplicity, which renders them imitable.
+The latter view seems a hard one to reconcile with a sound
+psychology of imitation or association at present, without
+resorting to instinct. Unless a certain class of acts are by
+the innate mental make-up especially tender to the influence
+of imitation, the theory fails to find good psychological
+ground to stand on. The former view may very well be
+true. But in any case the burden of proof would now seem
+to rest upon the adherents to imitation; the promising
+attitude would seem to be one which went without imitation
+as long as it could, and that is, of course, until it surely found
+it present.</p>
+
+<p>Returning to imitation considered in its human aspect, to
+imitation as a transferred association in particular, we find
+that here our analytical study of the animal mind promises
+important contributions to general comparative psychology.
+If it is true, and there has been no disagreement about it,
+that the primates do imitate acts of such novelty and complexity<span class="pagenum"><a id="Page_96"></a>[96]</span>
+that only this out-and-out kind of imitation can explain
+the fact, we have located one great advance in mental
+development. Till the primates we get practically nothing
+but instincts and individual acquirement through impulsive
+trial and error. Among the primates we get also acquisition
+by imitation, one form of the increase of mental
+equipment by tradition. The child may learn from the
+parent quickly without the tiresome process of seeing for
+himself. The less active and less curious may share the
+progress of their superiors. The brain whose impulses
+hitherto could only be dislodged by specific sense-impressions
+may now have any impulse set agoing by the sight of
+the movement to which it corresponds.</p>
+
+<p>All this on the common supposition that the primates <i>do</i>
+imitate, that a monkey in the place of these cats and dogs
+<i>would</i> have pulled the string. My apology for leaving the
+matter in this way without experiments of my own is that
+the monkey which I procured for just this purpose failed in
+two months to become tame enough to be thus experimented
+on. Accurate information about the nature and extent of
+imitation among the primates should be the first aim of
+further work in comparative psychology, and will be sought
+by the present writer as soon as he can get subjects fit for
+experiments.</p>
+
+<div class="blockquote">
+
+<p>In a questionnaire which was sent to fifteen animal trainers,
+the following questions were asked:—</p>
+
+<p>1. “If one dog was in the habit of ‘begging’ to get food and
+another dog saw him do it ten or twenty times, would the second
+dog then beg himself?”</p>
+
+<p>2. “In general is it easier for you to teach a cat or dog a trick
+if he has seen another do it?”</p>
+
+<p>3. “In general do cats imitate each other? Do dogs? Do
+monkeys?”</p>
+
+<p><span class="pagenum"><a id="Page_97"></a>[97]</span></p>
+
+<p>4. “Give reasons for your opinion, and please write all the
+reasons you have.”</p>
+
+</div>
+
+<p>Five gentlemen (Messrs. R. C. Carlisle, C. L. Edwards, V. P.
+Wormwood, H. S. Maguire and W. E. Burke) courteously responded
+to my questionnaire. All are trainers of acknowledged
+reputation. To these questions on imitation four replied.</p>
+
+<p>To the first question we find the following answers: (<i>a</i>)
+“Most dogs would.” (<i>b</i>) “Yes; he will very likely do it. He
+will try and imitate the other dog <i>generally</i>.” (<i>c</i>) “If a young
+dog with the mother, it would be very apt to.... With
+older dogs, it would depend very much upon circumstances.”
+(<i>d</i>) “He would not.”</p>
+
+<p>To 2 the answers were: (<i>a</i>) “Very much easier.” (<i>b</i>) “It
+is always easier if they see another one do it often.” (<i>c</i>) “This
+would also depend on certain conditions. In teaching to jump
+out of a box and in again, seeing another might help, but in
+teaching something very difficult, I do not think it would be the
+case.” (<i>d</i>) “It is not.”</p>
+
+<p>To 3 the answers were: (<i>a</i>) “Yes. Some. More than
+either dogs or cats.” (<i>b</i>) “Yes. Yes. Yes.” (<i>c</i>) “In certain
+things, yes; mostly in those things which are in compliance to
+the laws of their own nature.” (<i>d</i>) “No. No. Yes, they are
+born imitators.”</p>
+
+<p>The only definite answer to question 4 was: “Take a dog or
+cat and close them up in a room and go in and out several times,
+and you will find that they will go to the door and stand up on
+their hind legs with front paws on the door knob and try to open
+the door to get out. I could also give you a hundred more such
+reasons.” This was given by (<i>b</i>).</p>
+
+<p>The replies to a test question, however, go to show that
+these opinions regarding imitation may be mistaken. Question
+8 was: “If you wanted to teach a cat to get out of a
+cage by opening an ordinary thumb latch and then pushing
+the door, would you take the cat’s paw and push down the
+thumb piece with it and then push the door open with the<span class="pagenum"><a id="Page_98"></a>[98]</span>
+paw, or would you just leave the cat inside until it learned
+the trick itself?” The second is certainly the better way,
+as will be seen in a later part of this paper, and pushing the
+latch with the cat’s paw has absolutely no beneficial influence
+on the formation of the association, yet (<i>a</i>) and (<i>b</i>)
+both chose the first way, and (<i>c</i>) answered ambiguously.
+Further, the only reason given is, of course, no reason at all.
+It proves too much, for if there were such imitation as that,
+my cats and dogs would surely have done the far simpler
+things required of them. I cannot find that trainers
+make any practical use of imitation in teaching animals
+tricks, and on the whole I think these replies leave the matter
+just where it was before. They are mere opinions—not
+records of observed facts. It seems arrogant and may
+seem to some unjustifiable thus to discard testimony, to
+stick to a theory based on one’s own experiments in the face
+of these opinions. If I had wished to gain applause and
+avoid adverse criticism, I would have abstained from upholding
+the radical view of the preceding pages. At times
+it seems incredible to me that the results of my experiments
+should embody the truth of the matter, that there
+should be no imitation. The theory based on them seems,
+even to me, too radical, too novel. It seems highly improbable
+that I should be right and all the others wrong. But I
+cannot avoid the responsibility of giving what seems to my
+judgment the most probable explanation of the results of
+the experiments; and that is the radical explanation already
+given.</p>
+
+<h3><span class="smcap">The Mental Fact in Association</span></h3>
+
+<p>It is now time to put the question as to just what is in an
+animal’s mind when, having profited by numerous experiences,<span class="pagenum"><a id="Page_99"></a>[99]</span>
+he has formed the association and does the proper act
+when put in a certain box. The commonly accepted view
+of the mental fact then present is that the sight of the inside
+of the box reminds the animal of his <i>previous pleasant experience
+after escape</i> and <i>of the movements</i> which he made which
+were immediately followed by and so associated with that
+escape. It has been taken for granted that <i>if the animal
+remembered the pleasant experience and remembered the movement,
+he would make the movement</i>. It has been assumed
+that the association was <i>an association of ideas</i>; that when
+one of the ideas was of a movement the animal was capable
+of making the movement. So, for example, Morgan says, in
+the ‘Introduction to Comparative Psychology’: “If a chick
+takes a ladybird in its beak forty times and each time finds
+it nasty, this is of no practical value to the bird unless the
+sight of the insect suggests <i>the nasty taste</i>” (p. 90).</p>
+
+<p>Again, on page 92, Morgan says, “<i>A race after the ball</i> had
+been suggested through the channel of olfactory sensations.”
+Also, on page 86 “... the visual impression suggested
+the idea or representation of unpleasant gustatory experience.”
+The attitude is brought out more completely in a
+longer passage on page 118: “On one of our first ascents
+one of them put up a young coney, and they both gave chase.
+Subsequently they always hurried on to this spot, and,
+though they never saw another coney there, reiterated disappointment
+did not efface <i>the memory of that first chase</i>, or
+so it seemed.” That is, according to Morgan, the dogs
+thought of the chase and its pleasure, on nearing the spot
+where it had occurred, and so hurried on. On page 148 of
+‘Habit and Instinct,’ we read, “Ducklings so thoroughly
+associated water with the sight of their tin that they tried
+to drink from it and wash in it when it was empty, nor did
+they desist for some minutes,” and this with other similar<span class="pagenum"><a id="Page_100"></a>[100]</span>
+phenomena is attributed to the ‘association by contiguity’
+of human psychology.</p>
+
+<p>From these quotations it seems fairly sure that if we
+should ask Mr. Morgan, who is our best comparative psychologist,
+what took place in the mind of one of these cats
+of our experiments during the performance of one of the
+‘tricks’ he would reply: “The cat performs the act because
+of the association of ideas. He is reminded by the sight of
+the box and loop of his experience of pulling that loop and of
+eating fish outside. So he goes and pulls it again.” This
+view has stood unchallenged, but its implication is false. It
+implies that an animal, whenever it thinks of an act, can
+supply an <i>impulse to do</i> the act. It takes for granted
+that the performance of a cat who gets out of a box is mentally
+like that of a man who thinks of going down street
+or of writing a letter and then does it. The mental process
+is not alike in the two cases, for animals can <i>not</i> provide the
+impulse to <i>do</i> whatever act they think of. <i>No cat can form
+an association leading to an act unless there is included in the
+association an impulse of its own which leads to the act.</i> There
+is no general storehouse from which the impulse may be supplied
+after the association is formed.</p>
+
+<p>Before describing the experiments which justify these
+statements, it will be worth while to recall the somewhat obvious
+facts about the composition of one of these associations.
+There might be in an association, such as is formed
+after experience with one of our boxes, the following elements:—</p>
+
+<p>1. Sense-impression of the interior of the box, etc.</p>
+
+<p>2. (<i>a</i>) Discomfort and (<i>b</i>) desire to get out.</p>
+
+<p>3. Representation of oneself pulling the loop.</p>
+
+<p>4. Fiat comparable to the human “I’ll do it.”</p>
+
+<p>5. The impulse which actually does it.</p>
+
+<p><span class="pagenum"><a id="Page_101"></a>[101]</span></p>
+
+<p>6. Sense-impression of oneself pulling the loop, seeing
+one’s paw in a certain place, feeling one’s body in a certain
+way, etc.</p>
+
+<p>7. Sense-impression of going outside.</p>
+
+<p>8. Sense-impression of eating, and the included pleasure.</p>
+
+<p>Also between 1 and 4 we may have 9, representations of
+one’s experience in going out, 10, of the taste of the food, etc.
+6, 7 and 8 come after the act and do not influence it, of
+course, except in so far as they are the basis of the future
+3’s, 9’s and 10’s. About 2 we are not at present disputing.
+Our question is as to whether 3 or 5 is the essential thing.
+In human associations 3 certainly often is, and the animals
+have been credited with the same kind. Whatever he <i>thinks</i>,
+Professor Morgan surely <i>talks</i> as if 1 aroused 9 and 10 and 3
+and leaves 5 to be supplied at will. We have affirmed that
+5 is the essential thing, that no association without a specific
+5 belonging to it and acquired by it can lead to an act. Let
+us look at the reasons.</p>
+
+<p>A cat has been made to go into a box through the door,
+which is then closed. She pulls a loop and comes out and
+gets fish. She is made to go in by the door again, and again
+lets herself out. After this has happened enough times, the
+cat will of her own accord go into the box after eating the
+fish. It will be hard to keep her out. The old explanation
+of this would be that the cat associated the memory of being
+in the box with the subsequent pleasure, and therefore performed
+the equivalent of saying to herself, “Go to! I will
+go in.” The thought of <i>being in</i>, they say, makes her <i>go in</i>.
+<i>The thought of being in will not make her go in.</i> For if, instead
+of pushing the cat toward the doorway or holding it
+there, and thus allowing it to itself give the impulse, to innervate
+the muscles, to walk in, you shut the door first and
+drop the cat in through a hole in the top of the box, she will,<span class="pagenum"><a id="Page_102"></a>[102]</span>
+after escaping as many times as in the previous case, <i>not</i> go
+into the box of her own accord. She has had exactly the
+same opportunity of connecting the idea of being in the box
+with the subsequent pleasure. Either a cat cannot connect
+ideas, representations, at all, or she has not the power of
+progressing from the thought of being in to the act of going
+in. The only difference between the first cat and the second
+cat is that the first cat, in the course of the experience,
+has the impulse to crawl through that door, while the second
+has not the impulse to crawl through the door or to drop
+through that hole. So, though you put the second cat on
+the box beside the hole, she doesn’t try to get into the box
+through it. The impulse is the <i>sine qua non</i> of the association.
+The second cat has everything else, but cannot supply
+that. These phenomena were observed in six cats, three
+of which were tried by the first method, three by the
+second. Of the first three, one went in himself on the 26th
+time and frequently thereafter, one on the 18th and the other
+on the 37th; the two last as well as the first did that frequently
+in later trials. The other three all failed to go in
+themselves after 50, 60 and 75 trials, respectively.</p>
+
+<p>The case of No. 7 was especially instructive, though not
+among these six. No. 7 had had some trials in which it was
+put in through the door, but ordinarily in this particular
+experiment was dropped in. After about 80 trials it would
+frequently exhibit the following phenomena: It would,
+after eating the fish, go up to the doorway and, rushing
+from it, search for fish. The kitten was very small and
+would go up into the doorway, whirl round and dash out,
+all in one quick movement. The best description of its
+behavior is the paradoxical one that it went out without
+going in. The association evidently concerned what it had
+<i>done</i>, what it had an impulse for, namely, <i>coming out through<span class="pagenum"><a id="Page_103"></a>[103]</span>
+that door</i> to get fish, not what it remembered, had a representation
+of.</p>
+
+<p>Still more noteworthy evidence is found in the behavior of
+cats and dogs who were put in these boxes, left one or two
+minutes, and then put through the proper movement.
+For example, a cat would be put in B (O at back) and left
+two minutes. I would then put my hand in through the
+top of the box, take the cat’s paw and with it pull down the
+loop. The cat would then go out and eat the fish. This
+would be done over and over again, and after every ten
+or fifteen such trials the cat would be left in alone. If in
+ten or twenty minutes he did not escape, he would be taken
+out through the top and not fed. In one series of experiments
+animals were taken and thus treated in boxes from
+which their own impulsive activity had failed to liberate
+them. The results, given in the table below, show that no
+animal who fails to perform an act in the course of his own
+impulsive activity will learn it by being put through it.</p>
+
+<p>In these experiments some of the cats and all of the dogs
+but No. 1 showed no agitation or displeasure at my handling
+from the very start. Nor was there any in Dog 1 or the other
+cats after a few trials. It may also be remarked that in
+the trials alone which took place during and at the end of
+the experiment the animals without exception showed that
+they did not fail to perform the act from lack of a desire to
+get out. They all tried hard enough to get out and would
+surely have used the association if they had formed it.</p>
+
+<p><span class="pagenum"><a id="Page_104"></a>[104]</span></p>
+
+<h4><span class="smcap">Table 7</span></h4>
+
+<table class="borders">
+  <tr>
+    <th>Individual</th>
+    <th>Apparatus</th>
+    <th>Time in which impulsive activity failed to lead to the act</th>
+    <th>Number of times the animal was put through the movement</th>
+    <th>Time in which this experience failed to lead to the act</th>
+    <th>Time of final trial</th>
+  </tr>
+  <tr>
+    <td>Cat 1</td>
+    <td class="nw">F (String outside unfastened)</td>
+    <td class="tdr">55.00</td>
+    <td class="tdr">77</td>
+    <td class="tdr">120.00</td>
+    <td class="tdr">20.00</td>
+  </tr>
+  <tr>
+    <td>Cat 5</td>
+    <td>G (Thumb latch)</td>
+    <td class="tdr">57.00</td>
+    <td class="tdr">59</td>
+    <td class="tdr">55.00</td>
+    <td class="tdr">10.00</td>
+  </tr>
+  <tr>
+    <td>Cat 7</td>
+    <td>G (Thumb latch)</td>
+    <td class="tdr">50.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">35.00</td>
+    <td class="tdr">10.00</td>
+  </tr>
+  <tr>
+    <td>Cat 2</td>
+    <td>G (Thumb latch)</td>
+    <td class="tdr">54.00</td>
+    <td class="tdr">141</td>
+    <td class="tdr">110.00</td>
+    <td class="tdr">20.00</td>
+  </tr>
+  <tr>
+    <td>Dog 2</td>
+    <td>BB1 (O at back, high)</td>
+    <td class="tdr">48.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">80.00</td>
+    <td class="tdr">60.00</td>
+  </tr>
+  <tr>
+    <td>Dog 3</td>
+    <td>BB1 (O at back, high)</td>
+    <td class="tdr">20.00</td>
+    <td class="tdr">85</td>
+    <td class="tdr">55.00</td>
+    <td class="tdr">10.00</td>
+  </tr>
+  <tr>
+    <td>Dog 2</td>
+    <td>M (Lever outside)</td>
+    <td class="tdr">15.00</td>
+    <td class="tdr">95</td>
+    <td class="tdr">140.00</td>
+    <td class="tdr">30.00</td>
+  </tr>
+  <tr>
+    <td>Dog 1</td>
+    <td>FF<a id="FNanchor_12" href="#Footnote_12" class="fnanchor">[12]</a></td>
+    <td class="tdr">30.00</td>
+    <td class="tdr">110</td>
+    <td class="tdr">135.00</td>
+    <td class="tdr">60.00</td>
+  </tr>
+  <tr>
+    <td>Chick 89</td>
+    <td>X (see <a href="#Page_53">page 53</a>)</td>
+    <td class="tdr">20.00</td>
+    <td class="tdr">30</td>
+    <td class="tdr">60.00</td>
+    <td class="tdr">30.00</td>
+  </tr>
+  <tr>
+    <td>Cat 13</td>
+    <td>KKK,<a id="FNanchor_13" href="#Footnote_13" class="fnanchor">[13]</a><a id="FNanchor_14" href="#Footnote_14" class="fnanchor">[14]</a></td>
+    <td class="tdr">40.00</td>
+    <td class="tdr">65</td>
+    <td class="tdr">60.00</td>
+    <td class="tdr">10.00</td>
+  </tr>
+</table>
+
+<p>Now, the only difference between the experiences of the
+animals in these experiments and their experiences in those
+where they let themselves out, is that here they only saw
+and felt themselves making the movement, whereas in the
+other case they also felt the impulse, gave the innervation.
+That, then, is the essential. It may be objected that the
+animals failed because they did not <i>attend</i> to the process
+of being put through the movement, that, had they attended
+to it, they would later themselves have made the movement.
+It is, however, improbable that out of fifty times an animal
+should not have attended to what was going on at least two
+or three times. But if seeing himself do it was on a par with
+feeling an impulse to and so doing it, even two or three
+times would suffice to start the habit. And it is even more
+improbable that an experience should be followed by keen
+pleasure fifty times and not be attended to with might and<span class="pagenum"><a id="Page_105"></a>[105]</span>
+main, unless animals attend <i>only</i> to their own impulses and
+the excitements thereof. But if the latter be true, it simply
+affirms our view from a more fundamental standpoint.</p>
+
+<p>In another set of experiments animals were put in boxes
+with whose mechanisms they had had no experience, and
+from which they might or might not be able to escape by
+their own impulsive acts. The object was to see whether
+the time taken to form the association could be altered by
+my instruction. The results turned out to give a better
+proof of the inability to form an association by being put
+through the act than any failure to change the time-curve.
+For it happened in all but one of the cases that the movement
+which the animal made to open the door was different
+from the movement which I had put him through. Thus,
+several cats were put through (in Box C [button]) the following
+movement: I took the right paw and, putting it against
+the lower right-hand side of the button, pushed it round
+to a horizontal position. The cats’ ways were as follows:
+No. 1 turned it by clawing vigorously at its top; No. 6,
+by pushing it round with his nose; No. 7, in the course of
+an indiscriminate scramble at first, in later trials either by
+pushing with his nose or clawing at the top, settling down
+finally to the last method. Nos. 2 and 5 did it as No. 1 did.
+Cat 2 was tried in B (O at back). I took his paw and pressed
+the loop with it, but he formed the habit of clawing and
+biting the string at the top of the box near the front. No. 1
+was tried in A. I pressed the loop with his paw, but he
+formed the habit of biting at it.</p>
+
+<p>In every case I kept on putting the animal through the act
+every time, if at the end of two minutes (one in several
+cases) it had not done it, even after it had shown, by using
+a different way, that my instruction had no influence. I
+never succeeded in getting the animal to change its way for<span class="pagenum"><a id="Page_106"></a>[106]</span>
+mine. Moreover, if any one should fancy that the animal
+really profited by my instruction so as to learn what result
+to attain, namely, the turning of a certain button, but
+chose a way of his own to turn it, he would be deluding
+himself. The time taken to learn the act with instruction
+was no shorter than without.</p>
+
+<p>If, then, an animal happens to learn an act by being put
+through it, it is just happening, nothing more. Of course,
+you may <i>direct</i> the animal’s efforts so that he will perform
+the act himself the sooner. For instance, you may hold
+him so that his accidental pawing will be sure to hit the vital
+point of the contrivance. But the animal cannot form
+an association leading to an act unless the particular impulse
+to that act is present as an element of the association;
+he cannot supply it from a general stock. The groundwork
+of animal associations is not the association of <i>ideas</i>, but
+the association of idea or sense-impression with <i>impulse</i>.</p>
+
+<p>In the questionnaire mentioned elsewhere, some questions
+were asked with a view to obtaining corroboration or refutation
+of this theory that an impulse or innervation is a
+necessary element in every association formed if that association
+leads to an act. The questions and answers were:—</p>
+
+<p><i>Question 1</i>: “If you wanted to teach a horse to tap
+seven times with his hoof when you asked him, ‘How many
+days are there in a week?,’ would you teach him by taking
+his leg and making him go through the motions?”</p>
+
+<p><i>A</i> answered, “Yes! at first.”</p>
+
+<p><i>B</i> answered, “No! I would not.”</p>
+
+<p><i>C</i> answered, “At first, yes!”</p>
+
+<p><i>D</i> answered, “No!”</p>
+
+<p><i>Question 2</i>: “Do you think you <i>could</i> teach him that way,
+even if naturally you would take some other way?”</p>
+
+<p><i>A</i> answered, “In time, yes!”</p>
+
+<p><span class="pagenum"><a id="Page_107"></a>[107]</span></p>
+
+<p><i>B</i> answered, “I think it would be a very hard way.”</p>
+
+<p><i>C</i> answered, “Certainly I do.”</p>
+
+<p><i>D</i> answered, “I do not think I could.”</p>
+
+<p><i>E</i> answered, “Yes.”</p>
+
+<p><i>Question 3</i>: “How would you teach him?”</p>
+
+<p><i>A</i> answered, “I should tap his foot with a whip, so that
+he would raise it, and reward him each time.”</p>
+
+<p><i>B</i> answered, “I should teach him by the motion of the
+whip.”</p>
+
+<p><i>C</i> answered, “First teach him by pricking his leg the
+number of times you wanted his foot lifted.”</p>
+
+<p><i>D</i> answered, “You put figure 2 on blackboard and touch
+him on leg twice with cane, and so on.”</p>
+
+<p><i>E</i> answered ambiguously.</p>
+
+<p>It is noteworthy that even those who think they <i>could</i>
+teach an animal by putting him through the trick do not
+use that method, except at first. And what they really do
+then is probably to stimulate the animal to the reflex act
+of raising his hoof. The hand simply replaces the cane or
+whip as the means of stimulus. The answers are especially
+instructive, because the numerous counting tricks done by
+trained horses seem, at first, to be incomprehensible, unless
+the trainer can teach the horse by putting it through the
+movement the proper number of times. The counting
+tricks performed by Mascot, Professor Maguire’s horse,
+were quoted to me by a friend as incomprehensible on my
+theory. The answers given above show how simple the
+thing really is. All the counting-tricks of all the intelligent
+horses depend on the fact that a horse raises his hoof when
+a certain stimulus is given. One simple reaction gives the
+basis for a multitude of tricks. In the same way other
+tricks, which at first sight seem to require that the animal
+should learn by being put through the movement, may
+depend on some simple reflex or natural impulse.</p>
+
+<p><span class="pagenum"><a id="Page_108"></a>[108]</span></p>
+
+<p>Another question was, “How would you teach a cat to
+get out of a box, the door of which was closed with a thumb
+latch?”</p>
+
+<p><i>A</i> answered, “I should use a puffball as a plaything for
+the cat to claw at.” This means, I suppose, that he would get
+the cat to claw at the puffball and thus direct its clawings
+to the vicinity of the thumb piece.</p>
+
+<p><i>B</i> answered, “I would put the cat in and get it good and
+hungry and then open the door by lifting the latch with my
+finger. Then put some food that the cat likes outside, and
+she will soon try to imitate you and so learn the trick.”</p>
+
+<p><i>C</i> answered, “I would first adjust all things in connection
+with the surroundings of the cat so they would be applicable
+to the laws of its nature, and then proceed to teach the
+trick.”</p>
+
+<p>I suppose this last means that he would fix the box so that
+some of the cat’s instinctive acts would lead it to perform
+the trick. The answer given by <i>B</i> means apparently that
+he would simply leave the thing to accident, for any such
+imitation as he supposes is out of the question. At all
+events, none of these would naturally start to teach the
+trick by putting the animal through the motions, which,
+were it a possible way, would probably be a traditional
+one among trainers. On the whole, I see in these data no
+reason for modifying our dogma that animals cannot learn
+acts without the impulse.</p>
+
+<p>Presumably the reader has already seen budding out of
+this dogma a new possibility, a further simplification of
+our theories about animal consciousness. The possibility
+is that animals may have <i>no images or memories at all, no
+ideas to associate</i>. Perhaps the entire fact of association
+in animals is the presence of sense-impressions with which
+are associated, by resultant pleasure, certain impulses,<span class="pagenum"><a id="Page_109"></a>[109]</span>
+and that, therefore, and therefore only, a certain situation
+brings forth a certain act. Returning to our analysis of
+the association, this theory would say that there was no (9)
+or (10) or (3) or (4), that the sense-impression gave rise,
+when accompanied by the feeling of discomfort, to the impulse
+(5) directly, without the intervention of any representations
+of the taste of the food, or the experience of being
+outside, or the sight of oneself doing the act. This theory
+might be modified so as to allow that the representations
+could be there, but to deny that they were necessary, were
+inevitably present, that the impulse was connected to the
+sense-impression through them. It would then claim that
+the effective part of the association was a direct bond between
+the situation and the impulse, but would not cut off
+the possibility of there being an aura of memories along with
+the process. It then becomes a minor question of interpretation
+which will doubtless sooner or later demand an
+answer. I shall not try to answer it now. The more
+radical question, the question of the utter exclusion of representative
+trains of thought, of any genuine association
+of <i>ideas</i> from the mental life of animals, is worth serious
+consideration. I confess that, although certain authentic
+anecdotes and certain experiments, to be described soon,
+lead me to reject this exclusion, there are many qualities
+in animals’ behavior which seem to back it up. If one takes
+his stand by a rigid application of the law of parsimony, he
+will find justification for this view which no experiments of
+mine can overthrow.</p>
+
+<p>Of one thing I am sure, and that is that it is worth while
+to state the question and how to solve it, for although the
+point of view involved is far removed from that of our leading
+psychologists to-day, it cannot long remain so. I am
+sorry that I cannot pretend to give a final decision.</p>
+
+<p><span class="pagenum"><a id="Page_110"></a>[110]</span></p>
+
+<p>The view seems preposterous because, if an animal has
+sense-impressions when his brain is excited by currents starting
+in the end-organs, it seems incredible that he should not
+be conscious in imagination and memory by having similar
+excitations caused from within. We are accustomed to
+think of memory as the companion of sensation. But,
+after all, it is a question of fact whether the connections in
+the cat brain include connections between present sensation-neuroses
+and past sensation-neuroses. The only connections
+may be those between the former and impulse-neuroses,
+and there is no authoritative reason why we should
+suppose any others unless they are demonstrated by the
+cat’s behavior. This is just the point at issue. Such evidence
+as the phenomena of animals’ dreams does not at all
+prove the presence of memory or imagination. A dog may
+very well growl in his sleep without any idea of a hostile
+dog. The impulse to growl <i>may</i> be caused by chance excitement
+of its own neurosis without any sensation-neurosis
+being concerned. <i>Acts</i> of recognition may have no
+<i>feelings</i> of recognition going with or causing them. A
+sense-impression of me gets associated in my dog’s mind
+with the impulses to jump on me, lick my hand, wag
+his tail, etc. If, after a year, the connection between the
+two has lasted, he will surely jump on me, lick my hand
+and wag his tail, though he has not and never had any
+representation of me.</p>
+
+<p>The only logical way to go at this question and settle it
+is, I think, to find some associations the formation of which
+requires the presence of images, of ideas. You have to give
+an animal a chance to associate sense-impression A with
+sense-impression B and then to associate B with some act
+C so that the presence of B in the mind will lead to the
+performance of C. Presumably the representation of B,<span class="pagenum"><a id="Page_111"></a>[111]</span>
+if present, will lead to C just as the sense-impression B did.
+Now, if the chance to associate B with A has been improved,
+you ought, when the animal is confronted with the sense-impression
+A, to get a revival of B and so the act C. Such
+a result would, if all chance to associate C with A had been
+eliminated, demonstrate the presence of representations
+and their associations. I performed such an experiment
+in a form modified so as to make it practicable with my
+animals and resources. Unfortunately, this modification
+spoils the crucial nature of the experiment and robs it of
+much of its authority. The experiment was as follows:—</p>
+
+<p>A cat was in the big box where they were kept (see <a href="#Page_90">p. 90</a>)
+very hungry. As I had been for a long time the source
+of all food, the cats had grown to watch me very carefully.
+I sat, during the experiment, about eight feet from the box,
+and would at intervals of two minutes clap my hands four
+times and say, “I must feed those cats.” Of course the
+cat would at first feel no impulse except perhaps to watch me
+more closely when this signal was given. After ten seconds
+had elapsed I would take a piece of fish, go up to the cage
+and hold it through the wire netting, three feet from the
+floor. The cat would then, of course, feel the impulse to
+climb up the front of the cage. In fact, experience had
+previously established the habit of climbing up whenever
+I moved toward the cage, so that in the experiment the
+cat did not ordinarily wait until I arrived there with the
+fish. In this experiment</p>
+
+<p>A = The sense-impression of my movements and voice
+when giving the signal.</p>
+
+<p>B = The sense-impression of my movements in taking
+fish, rising, walking to box, etc.</p>
+
+<p>C = The act of climbing up, with the impulse leading
+thereunto.</p>
+
+<p><span class="pagenum"><a id="Page_112"></a>[112]</span></p>
+
+<p>The question was whether after a while A would remind
+the cat of B, and cause him to do C before he got the <i>sense-impression</i>
+of B, that is, before the ten seconds were up. If
+A leads to C through a memory of B, animals surely <i>can</i>
+have association of ideas proper, and probably often <i>do</i>.
+Now, as a fact, after from thirty to sixty trials, the cat does
+perform C immediately on being confronted by A or some
+seconds later, at all events before B is presented. And it is
+my present opinion that their action is to be explained by
+the presence, through association, of the idea B. But it is
+not impossible that A was associated <i>directly</i> with the impulse
+to C, although that impulse was removed from it by
+ten seconds of time. Such an association is, it seems to me,
+highly improbable, unless the neurosis of A, and with it the
+psychosis, continues until the impulse to C appears. But
+if it does so continue during the ten seconds, and thus get
+directly linked to C, we have exactly a representation, an
+image, a memory, in the mind for eight of those ten seconds.
+It does not help the deniers of images to substitute an image
+of A for an image of B. Yet, unless they do this, they have
+to suppose that A comes and goes, and that after ten seconds
+C comes, and, passing over the intervening blank,
+willfully chooses out A and associates itself with it. There
+are some other considerations regarding the behavior of the
+cats from the time the signal was given till they climbed up,
+which may be omitted in the hope that it will soon be possible
+to perform a decisive experiment. If an observer can
+make sure of the animal’s attention to a sequence A-B,
+where B does not arouse any impulse to an act, and then
+later get the animal to associate B with C, leaving A out this
+time, he may then, if A, when presented anew, arouses C,
+bid the deniers of representations to forever hold their
+peace.</p>
+
+<p><span class="pagenum"><a id="Page_113"></a>[113]</span></p>
+
+<p>Another reason for allowing animals representations and
+images is found in the longer time taken to form the association
+between the act of licking or scratching and the consequent
+escape. If the associations in general were simply
+between situation and impulse and act, one would suppose
+that the situation would be associated with the impulse to
+lick or scratch as readily as with the impulse to turn a button
+or claw a string. Such is not the case. By comparing the
+curves for Z on <a href="#Page_57">pages 57-58</a> with the others, one sees that for
+so simple an act it takes a long time to form the association.
+This is not a final reason, for lack of attention, a slight increase
+in the time taken to open the door after the act was
+done, or an absence of preparation in the nervous system
+for connections between these particular acts and definite
+sense-impressions, may very well have been the cause of the
+difficulty in forming the associations. Nor is it certain that
+<i>ideas</i> of clawing loops would be easier to form than ideas of
+scratching or licking oneself. The matter is still open to
+question. But, as said before, my opinion would be that
+animals <i>do</i> have representations and that such are the
+beginning of the rich life of ideas in man. For the most part,
+however, such are confined to specific and narrow practical
+lines. There was no evidence that my animals habitually
+<i>did</i> form associations of ideas from their experience throughout,
+or that such were constantly revived without the spur
+of immediate practical advantage.<a id="FNanchor_15" href="#Footnote_15" class="fnanchor">[15]</a></p>
+
+<p><span class="pagenum"><a id="Page_114"></a>[114]</span></p>
+
+<p>Before leaving the topic an account may be given of experiments
+similar to the one described above as performed
+on Cats 3 and 4, which were undertaken with Cat 13 and
+Dogs 1, 2 and 3.</p>
+
+<p>Cat 13 was fed with pieces of fish at the top of the wire
+netting 45 times, to accustom it to climbing up when it saw<span class="pagenum"><a id="Page_115"></a>[115]</span>
+me come with fish. I then went through the same process
+as with 3 and 4, but at intervals of 60 to 90 seconds instead
+of 120. After 90 such trials it occasionally climbed up a
+little way, but though 135 trials in all were given, it never
+made the uniform and definite reaction which 3 and 4 did.
+It reacted, when it reacted at all, at from 5 to 9 seconds after
+the signal. Whether age, weight, lack of previous habitual
+climbing when I approached, or a slowness in forming the
+association made the difference, is uncertain.</p>
+
+<p>Dog 1 was experimented on in the following manner: I
+would put him in a big pen, 20×10 feet, and sit outside facing
+it, he watching me as was his habit. I would pound with a
+stick and say, “Go over to the corner.” After an interval
+(10 seconds for 35 trials, 5 seconds for 60 trials) I would go
+over to the corner (12 feet off) and drop a piece of meat
+there. He, of course, followed and secured it. On the 6th,<span class="pagenum"><a id="Page_116"></a>[116]</span>
+7th, 16th, 17th, 18th and 19th trials he did perform the act
+before the 10 seconds were up, then for several times went
+during the two-minute intervals without regarding the signal,
+and finally abandoned the habit altogether, although
+he showed by his behavior when the signal was given that
+he was not indifferent to it.</p>
+
+<p>Dogs 1, 2 and 3 were also given 95, 135 and 95 trials, respectively,
+the acts done being (1) standing up against the
+wire netting inclosing the pen, (2) placing the paws on top of
+a keg, and (3) jumping up onto a box. The time intervals
+were 5 seconds in each case. No dog of these ever performed
+the act before I started to take the meat to feed
+them, but they did show, by getting up if they were lying
+down when the signal was given, or by coming to me if they
+were in some other part of the pen, that something was suggested
+to them by it. Why these cases differ from the cases
+of Cats 3 and 4 (10 and 12 also presented phenomena like
+those reported in the cases of 3 and 4) is an interesting
+though not very important question. The dogs were not
+kept so hungry as were the cats, and experience had certainly
+not rendered the particular impulses involved so
+sensitive, so ready to discharge. Dogs 2 and 3 were older.
+There is no reason to invoke any qualitative difference in the
+mental make-up of the animals until more illuminating experiments
+are made.</p>
+
+<h3><span class="smcap">Association by Similarity and the Formation of Concepts</span></h3>
+
+<p>What there is to say on this subject from the standpoint of
+my experiments will be best introduced by an account of
+the experiments themselves.</p>
+
+<p>Dog 1 had escaped from AA (O at front) 26 times. He<span class="pagenum"><a id="Page_117"></a>[117]</span>
+was then put in BB (O at back). Now, whereas 2 and 3, who
+were put in without previous experience with AA, failed to
+paw the loop in BB, No. 1 succeeded. His times were 7.00,
+.35, 2.05, .40, .32, .10, 1.10, .38, .10, .05, and from then on he
+pawed the loop as soon as put in the box. After a day or so
+he was put in BB1 (O at back high). Although the loop
+was in a new position, his times were only .20, .10, .10, etc.
+After nine days he was put in a box arranged with a little
+wooden platform 2½ inches square, hung where the loop was
+in BB1. Although the platform resembled the loop not
+the least save in position, his times were only .10, .07, .05,
+etc.</p>
+
+<div class="figcenter illowp100" id="figure21" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure21.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 21.</span></p>
+</div>
+
+<p>From the curves given in <a href="#figure21">Figure 21</a>, which tell the history
+of 10, 11 and 12 in B1 (O at back) after each had previously
+been familiarized with A (O at front), we see this same
+influence of practice in reacting to one mechanism upon the
+time taken to react to a mechanism at all similar. It naturally
+takes a cat a longer time to accidentally claw a loop in
+the back than in the front, yet a comparison of these curves
+with those on page 39, <a href="#figure02">Figure 2</a>, shows the opposite to have
+been the case with 10, 11 and 12. The same remarkable<span class="pagenum"><a id="Page_118"></a>[118]</span>
+quickness was noted in Cats 1 and 3 when put into B (O at
+back) after learning A (O at front). Moreover, the loops
+were not alike. The loop in A was of smaller wire, covered
+with a bluish thread, while the loop in B was covered with
+a black rubber compound, the diameter of the loop being
+three times that of A’s loop.</p>
+
+<p>If any advocate of reason in animals has read so far, I
+doubt not that his heart has leaped with joy at these two
+preceding paragraphs. “How,” he will say, “can you explain
+these facts without that prime factor in human reason,
+association by similarity? Surely they show the animal
+perceiving likenesses and acting from general ideas.” <i>This
+is the very last thing that they show.</i> Let us see why they do
+not show this and what they do show. He who thinks that
+these animals had a general notion of a loop-like thing as the
+thing to be clawed, that they felt the loop in B, different
+as it was in size, color and position, to be still a loop, to
+have the essential quality of the other, must needs presuppose
+that the cat has a clear, accurate sensation and
+representation of both. Only if the cat discriminates can
+it later associate by noticing similarities. This is what such
+thinkers do presuppose. A bird, for instance, dives in the
+same manner into a river of yellow water, a pond or an ocean.
+It has a general notion, they say, of water. It knows that
+river water is one thing and pond water another thing, but it
+knows that both are water, <i>ergo</i>, fit to dive into. The cat
+who reacts to a loop of small wire of a blue color knows
+just what that loop is, and when it sees a different loop,
+knows its differences, but knows also its likeness, and reacts
+to the essential. Thus crediting the cat with our differentiation
+and perception of individuality, they credit it with
+our conceptions and perceptions of similarity. Unless the
+animal has the first, there is no reason to suppose the last.<span class="pagenum"><a id="Page_119"></a>[119]</span>
+Now, <i>the animal does not have either</i>. It does not in the first
+place react to that particular loop in A, with recognition of
+its qualities. It reacts to a vague, ill-defined sense-impression,
+undiscriminated and even unperceived in the technical
+sense of the word. Morgan’s phrase, “a bit of pure experience,”
+is perhaps as good as any. The loop is to the cat
+what the ocean is to a man, when thrown into it when half-asleep.
+Thus the cat who climbed up the front of the cage
+whenever I said, “I must feed those cats,” would climb up
+just as inevitably when I said, “My name is Thorndike,”
+or “To-day is Tuesday.” So cats would claw at the loop
+or button when the door was open. So cats would paw at
+the place where a loop had been, though none was there.
+The reaction is not to a well-discriminated object, but to a
+vague situation, and any element of the situation may
+arouse the reaction. The whole situation in the case of man
+is speedily resolved into elements; the particular elements
+are held in focus, and the non-essential is systematically kept
+out of mind. In the animal the whole situation sets loose
+the impulse; all of its elements, including the non-essentials,
+get yoked with the impulse, and the situation may be
+added to or subtracted from without destroying the association,
+provided you leave something which will set off
+the impulse. The animal does not think one is like the other,
+nor does it, as is so often said, mistake one for the other. It
+does not think <i>about</i> it at all; it just thinks <i>it</i>, and the <i>it</i> is
+the kind of “pure experience” we have been describing. In
+human mental life we have accurate, discriminated sensations
+and perceptions, realized as such, and general notions,
+also realized as such. Now, what the phenomena in animals
+which we have been considering show is that they
+have neither. Far from showing an advanced stage of mentality,
+they show a very primitive and unspecialized stage.<span class="pagenum"><a id="Page_120"></a>[120]</span>
+They are to be explained not by the presence of <i>general</i> notions,
+but by the absence of notions of <i>particulars</i>. The
+idea that animals react to a particular and absolutely defined
+and realized sense-impression, and that a similar
+reaction to a sense-impression which varies from the first
+proves an association by similarity, is a myth. We shall see
+later how an animal does come in certain cases to discriminate,
+in one sense of the word, with a great degree of delicacy,
+but we shall also see then what must be emphasized
+now, that naturally the animal’s brain reacts very coarsely
+to sense-impressions, and that the animal does not think
+about his thoughts at all.</p>
+
+<p>This puts a new face upon the question of the origin and
+development of human abstractions and consequent general
+ideas. It has been commonly supposed that animals had
+‘recepts’ or such semi-abstractions as Morgan’s ‘predominants,’
+and that by associating with these, arbitrary and permanent
+signs, such as articulate sounds, one turned them
+into genuine ideas of qualities. Professor James has made
+the simple but brilliant criticism that all a recept really
+means is <i>a tendency to react in a certain way</i>. But I have
+tried to show that the fact that an animal reacts alike to a lot
+of things gives no reason to believe that it is conscious of
+their common quality and reacts to that consciousness, because
+the things it reacts to in the first place are not the
+hard-and-fast, well-defined ‘things’ of human life. What
+a ‘recept’ or ‘predominant’ really stands for is no thing
+which can be transformed into a notion of a quality by
+being labelled with a name. This easy solution of the
+problem of abstraction is impossible. A true idea of the
+problem itself is better than such a solution.</p>
+
+<p>My statement of what has been the course of development
+along this line is derived from observations of animals’<span class="pagenum"><a id="Page_121"></a>[121]</span>
+behavior and Professor James’ theory of the nature of and
+presumable brain processes going with the abstractions and
+conceptions of human consciousness, but it is justified chiefly
+by its harmony with the view that conception, the faculty
+of having general notions, has been naturally selected by
+reason of its utility. The first thing is for an animal to learn
+to react alike only to things which resemble each other in the
+<i>essential</i> qualities. On an artificial, analytic basis, feelings
+of abstract qualities might grow out of reacting alike to objects
+similar in such a respect that the reaction would be
+useless or harmful. But in the actual struggle for existence,
+starting with the mammalian mind as we have found it,
+you will tend to get reactions to the <i>beneficial</i> similarities
+by selection from among these so-called mistakes, <i>before
+you get any general faculty of noticing similarities</i>. In
+order that this faculty of indifferent reaction to different
+things shall grow into the useful faculty of indifferent reaction
+to different things <i>which have all some quality that makes
+the reaction a fit one</i>, there must be a tremendous range of
+associations. For a lot of the similarities which are non-essential
+have to be stamped out, not by a power of feeling
+likeness, but by their failure to lead to pleasure. With
+such a wide range of associations we may get reactions on
+the one hand where impulses have been connected with one
+particular sense-impression because when connected with
+all others they had failed to give pleasure, and on the other
+hand, reactions where an impulse has been connected with
+numerous different impressions possessing one common
+quality, and disconnected with all impressions, otherwise
+like these, which fail to have that one quality.</p>
+
+<p>Combined with this multiplication of associations, there is,
+I think, an equally important factor, the loosening of the
+elements of an association from one another and from it as a<span class="pagenum"><a id="Page_122"></a>[122]</span>
+whole. Probably the idea of the look of the loop or lever or
+thumb latch never entered the mind of any one of my cats
+during the months that they were with me, except when the
+front end of the association containing it was excited by putting
+the cat into the box. In general, the unit of their consciousness,
+apart from impulses and emotions, is a whole
+association-series. Such soil cannot grow general ideas, for
+the ideas, so long as they never show themselves except for
+a particular practical business, will not be thought about or
+realized in their nature or connections. If enough associations
+are provided by a general curiosity, such as is seen
+among the monkeys, if the mental elements of the association
+are freed, isolated, felt by themselves, <i>then</i> a realization
+of the ideas, feelings of their similarity by transition from
+one to the other, feelings of qualities and of meanings, may
+gradually emerge. Language will be a factor in the isolation
+of the ideas and a help to their realization. But when
+any one says that language has been the cause of the change
+from brute to man, when one talks as if <i>nothing but it</i> were
+needed to turn animal consciousness into human, he is speaking
+as foolishly as one who should say that a proboscis added
+to a cow would make it an elephant.</p>
+
+<p>This is all I have to say, in this connection, about association
+by similarity and conception, and with it is concluded
+our analysis of the nature of the association-process in animals.
+Before proceeding to treat of the delicacy, complexity,
+number and permanence of these associations, it
+seems worth while to attempt to describe graphically, not by
+analysis, the mental fact we have been studying, and also
+to connect our results with the previous theories of association.</p>
+
+<p>One who has seen the phenomena so far described, who
+has watched the life of a cat or dog for a month or more<span class="pagenum"><a id="Page_123"></a>[123]</span>
+under test conditions, gets, or fancies he gets, a fairly definite
+idea of what the intellectual life of a cat or dog feels
+like. It is most like what we feel when consciousness contains
+little thought about anything, when we feel the sense-impressions
+in their first intention, so to speak, when we feel
+our own body, and the impulses we give to it. Sometimes
+one gets this animal consciousness while in swimming, for
+example. One feels the water, the sky, the birds above, but
+with no thoughts <i>about</i> them or memories of how they looked
+at other times, or æsthetic judgments about their beauty;
+one feels no <i>ideas</i> about what movements he will make, but
+feels himself make them, feels his body throughout. Self-consciousness
+dies away. Social consciousness dies away.
+The meanings, and values, and connections of things die
+away. One feels sense-impressions, has impulses, feels the
+movements he makes; that is all.</p>
+
+<p>This pictorial description may be supplemented by an account
+of some associations in human life which are learned in
+the same way as are animal associations; associations, therefore,
+where the process of formation is possibly homologous
+with that in animals. When a man learns to swim, to play
+tennis or billiards, or to juggle, the process is something like
+what happens when the cat learns to pull the string to get
+out of the box, provided, of course, we remove, in the man’s
+case, all the accompanying mentality which is not directly
+concerned in learning the feat.<a id="FNanchor_16" href="#Footnote_16" class="fnanchor">[16]</a> Like the latter, the former<span class="pagenum"><a id="Page_124"></a>[124]</span>
+contains desire, sense-impression, impulse, act and possible
+representations. Like it, the former is learned gradually.
+Moreover, the associations concerned cannot be formed
+by imitation. One does not know how to dive just by seeing
+another man dive. You cannot form them from being
+put through them, though, of course, this helps indirectly,
+in a way that it does not with animals. One makes use of
+no feelings of a common element, no perceptions of similarity.
+The tennis player does not feel, “This ball coming
+at this angle and with this speed is similar in angle, though
+not in speed, to that other ball of an hour ago, therefore I
+will hit it in a similar way.” He simply feels an impulse
+from the sense-impression. Finally, the elements of the
+associations are not isolated. No tennis player’s stream of
+thought is filled with free-floating representations of any
+of the tens of thousands of sense-impressions or movements
+he has seen and made on the tennis court. Yet there
+is consciousness enough at the time, keen consciousness of
+the sense-impressions, impulses, feelings of one’s bodily acts.
+So with the animals. There is consciousness enough, but
+of this kind.</p>
+
+<p>Thus, the associations in human life, which compare with
+the simple connections learned by animals, are associations
+involving connections between novel, complex and often
+inconstant sense-impressions and impulses to acts similarly
+novel, complex and often inconstant. Man has the elements
+of most of his associations in isolated form, attended
+to separately, possessed as a permanent fund, recallable at
+will, and multifariously connected among themselves, but<span class="pagenum"><a id="Page_125"></a>[125]</span>
+with these associations which we have mentioned, and with
+others like them, he deals as the animals deal with theirs.
+The process, in the man’s mind, leaving out extraneous mental
+stuff, may be homologous to the association-process in
+animals. Of course, by assiduous attention to the elements
+of these associations, a man may isolate them, may thus get
+these associations to the same plane as the rest. But they
+pass through the stage we have described, even then, and
+with most men, stay there. The abstraction, the naming,
+etc., generally come from observers of the game or action,
+and concern things as felt by them, not by the participant.</p>
+
+<h3><span class="smcap">Criticism of Previous Theories</span></h3>
+
+<p>We may now look for a moment at what previous writers
+have said about the nature of association in animals. The
+complaint was made early in this book that all the statements
+had been exceedingly vague and of no value, except as
+retorts to the ‘reason’ school. In the course of the discussion
+I have tried to extricate from this vagueness definite
+statements about imitation, association of ideas, association
+by ideas. There is one more theory, more or less hidden in
+the vagueness,—the theory that association in animals is the
+same as association in man, that the animal mind differs
+from the human mind only by the absence of reason and
+what it implies. Presumably, silence about what association
+is, means that it is the association which human psychology
+discusses. When the silence is broken, we get such
+utterances of this theory as the following:—</p>
+
+<p>“I think we may say then that the higher animals are able
+to proceed a long way in the formation and definition of
+highly complex constructs, analogous to but probably differing
+somewhat from those which we form ourselves. These<span class="pagenum"><a id="Page_126"></a>[126]</span>
+constructs, moreover, through association with reconstructs,
+or representations, link themselves in trains so that a sensation,
+or group of sensations, may suggest a series of reconstructs,
+or a series of remembered phenomena.” (C. L.
+Morgan, Animal Life and Intelligence, p. 341.)</p>
+
+<p>“Lastly, before taking leave of the subject of the chapter,
+I am most anxious that it should not be thought that, in contending
+that intelligence is not reason, I wish in any way to
+disparage intelligence. Nine tenths at least of the actions of
+average men are intelligent and not rational. Do we not all
+of us know hundreds of practical men who are in the highest
+degree intelligent, but in whom the rational, analytic
+faculty is but little developed? Is it any injustice to the
+brutes to contend that their inferences are of the same order
+as those of these excellent practical folk? In any case, no
+such injustice is intended; and if I deny them self-consciousness
+and reason, I grant to the higher animals perceptions
+of marvelous acuteness and intelligent inferences of wonderful
+accuracy and precision—intelligent inferences in
+some cases, no doubt, more perfect even than those of man,
+who is often disturbed by many thoughts” (<i>ibid.</i>, pp. 376-377).</p>
+
+<p>“Language and the analytic faculty it renders possible
+differentiate man from the brute” (<i>ibid.</i>, p. 376).</p>
+
+<p>Here, as elsewhere, it should be remembered that Lloyd
+Morgan is not quoted because he is the worst offender or because
+he represents the opposite in general of what the present
+writer takes to be the truth. On the contrary, Morgan
+is quoted because he is the least offender, because he
+has taken the most advanced stand along the line of the
+present investigation, because my differences from him are
+in the line of his differences from other writers. With the
+theory of the passages just quoted, however, which attribute<span class="pagenum"><a id="Page_127"></a>[127]</span>
+extensive association of ideas and general powers comparable
+to those of men minus reason, to the brutes, and which
+repeat the time-honored distinction by language, I do not,
+in the least, agree. Association in animals does not equal
+association in man. The latter is built over and permeated
+and transformed by inference and judgment and comparison;
+it includes imitation in our narrow sense of transferred
+association; it obtains where no impulse is included; it
+thus takes frequently the form of long trains of thought
+ending in no pleasure-giving act; its elements are often
+loose, existing independently of the particular association;
+the association is not only thought, but at the same time
+thought <i>about</i>. None of these statements may be truthfully
+made of animal association. Only a small part of human
+association is at all comparable to it. My opinion of what
+that small part is has already been given. Moreover,
+further differences will be found as we consider the data
+relating to the delicacy, complexity, number, and permanence
+of associations in animals. I said a while ago that
+man was no more an animal with language than an elephant
+was a cow with a proboscis. We may safely broaden
+the statement and say that <i>man is not an animal plus reason</i>.
+It has been one great purpose of this investigation
+to show that even after leaving reason out of account,
+there are tremendous differences between man and the
+higher animals. The problem of comparative psychology is
+not only to get human reason from some lower faculties,
+but to get human <i>association</i> from animal association.</p>
+
+<p>Our analysis, necessarily imperfect because the first attempted,
+of the nature of the association-process in animals
+is finished, and we have now to speak of its limitations in
+respect to delicacy, complexity, number and permanence.</p>
+
+<p><span class="pagenum"><a id="Page_128"></a>[128]</span></p>
+
+<h3><span class="smcap">Delicacy of Associations</span></h3>
+
+<p>It goes without saying that the possible delicacy of associations
+is conditioned by the delicacy of sense-powers. If
+an animal doesn’t feel differently at seeing two objects, it
+cannot associate one with one reaction, the other with another.
+An equally obvious factor is attention; what is not
+attended to will not be associated. Beyond this there is no
+<i>a priori</i> reason why an animal should not react differently
+to things varying only by the most delicate difference, and
+I am inclined to think an animal could; that any two objects
+with a difference appreciable by sensation which are
+also able to win attention may be reacted to differently.
+Experiments to show this are very tedious, and the practical
+question is, “What will the animal naturally attend to?”
+The difficulty, as all trainers say, is to get the animal’s
+attention to your signal somehow. Then he will in time
+surely react differently, if you give him the chance, to a
+figure 7 on the blackboard from the way he does to a figure
+8, to your question, “How many days are there in a week?”
+and to your question, “How many legs have you?” The
+chimpanzee in London that handed out 3, 4, 5, 6, or 7 straws
+at command was not thereby proved of remarkable intelligence
+or of remarkably delicate associative power. Any
+reputable animal trainer would be ashamed to exhibit a
+horse who could not do as much ‘counting’ as that. The
+maximum of delicacy in associating exhibited by any animal,
+to my knowledge, is displayed in the performance of the dog
+‘Dodgerfield,’ exhibited by a Mr. Davis, who brings from
+four cards, numbered 1, 2, 3 and 4, whichever one his master
+shall <i>think of</i>. That is, you write out an arbitrary list, e.g.
+4, 2, 1, 3, 3, 2, 2, 1, 4, 2, etc., and hand it to Mr. Davis, who
+looks at the list, thinks of the first number, says “Attention!<span class="pagenum"><a id="Page_129"></a>[129]</span>
+Dodger!” and then, “Bring it.” This the dog does and so
+on through the list. Mr. Davis makes no signals which anyone
+sitting even right beside or in front of him can detect.
+Thus the dog exceeds the human observers in delicacy and
+associates each with a separate act four attitudes of his master,
+which to human observers seem all alike. Mr. Davis
+says he thinks the dog is a mind reader. I think it quite
+possible that whatever signs the dog goes by are given unconsciously
+and consist only of some very delicate general
+differences in facial expression or the manner of saying the
+words, “Bring it,” or slight sounds made by Mr. Davis in
+thinking to himself the words one or two or three or four.
+Mr. Davis keeps his eyes shut and his hands behind a newspaper.
+The dog looks directly at his face.</p>
+
+<p>To such a height possible delicacy may attain, but possible
+delicacy is quite another thing from actual untrained and
+unstimulated delicacy. The difference in reaction has to be
+brought about by associating with pleasure the reaction
+to the different sense-impression when it itself differs and
+associating with pain tendencies to confuse the reactions.
+The animal does not naturally as a function of sense-powers
+discriminate at all delicately. Thus the cat who climbed
+up the wire netting when I said, “I must feed those cats!”
+did not have a delicate association of just that act with just
+those words. For after I had dropped the clapping part
+of the signal and simply used those words, it would react just
+as vigorously to the words, “To-morrow is Tuesday” or
+“My name is Thorndike.” The reaction naturally was to
+a very vague stimulus. Taking cat 10 when just beginning
+to learn to climb up at the signal, “I must feed those cats!”
+I started in to improve the delicacy, by opposing to this
+formula the formula, “I will not feed them,” after saying
+which, I kept my word. That is, I gave sometimes the<span class="pagenum"><a id="Page_130"></a>[130]</span>
+former signal and fed the cats, sometimes the latter and did
+not. The object was to see how long the cat would be in
+learning always to go up when I gave the first, never to do
+so when I gave the second signal. I said the words in both
+cases as I naturally would do, so that there was a difference
+in emphasis and tone as well as in the mere nature of the
+syllables. The two signals were given in all sorts of combinations
+so that there was no regularity in the recurrence of
+either which might aid the animal. The cat at first did
+not always climb up at the first signal and often <i>did</i> climb
+up at the wrong one. The change from this condition to
+one of perfect discrimination is shown in the accompanying
+curves (<a href="#figure22">Fig. 22</a>), one showing
+the decrease in <i>failures</i>
+to respond to the
+wrong signal. The first
+curve is formed by a line
+joining the tops of perpendiculars erected at intervals of
+1 mm. along the abscissa. The height of a perpendicular
+represents the number of times the cat failed to respond
+to the food-signal in 20 trials, a height of 1 mm. being the
+representative of one failure. Thus, the entire curve
+stands for 280 trials, there being no failures after 60 trials,
+and only 1 after the 40th.</p>
+
+<div class="figcenter illowp100" id="figure22" style="max-width: 18.75em;">
+  <img class="w100" src="images/figure22.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 22.</span></p>
+</div>
+
+<p>In the other curve, also, each 1 mm. along the abscissa
+stands for 20 trials, and the perpendiculars whose tops the
+curve unites represent the number of times the cat in each
+20 <i>did</i> climb up at the signal which meant no food. It will
+be seen that 380 experiences were necessary before the animal
+learned that the second signal was different from the
+first. The experiment shows beautifully the animal method
+of acquisition. If at any stage the animal could have
+isolated the two ideas of the two sense-impressions, and felt<span class="pagenum"><a id="Page_131"></a>[131]</span>
+them together in comparison, this long and tedious process
+would have been unnecessary.</p>
+
+<p>It might be stated here that the animals also acquired
+associations of moderate delicacy in discriminating between
+the different boxes. No cat tried to get out of A or B by
+licking herself, for instance.</p>
+
+<p>The question may naturally be raised that if naturally
+associations are thus vague, the common phenomenon of a
+dog obeying his master’s commands, and no one else’s, is
+inexplicable. The difference between one man and another,
+one voice and another, it may be said, is not much of a difference,
+yet is here uniformly discriminated, although we
+cannot suppose any such systematic training to reject the
+other slightly differing commands. My cats did not so
+discriminate. If any one else sat in my chair and called
+out, “I must feed the cats,” they reacted, and probably very
+many animals would, if untroubled by emotions of curiosity
+or fear at the new individual, go through their tricks as well
+at another’s voice as at that of their master. The other
+cases exemplify the influence of attention. Repeated
+attention to these sense-impressions has rendered them
+clear-cut and detailed, and the new impression consequently
+does not equal them in calling forth the reaction.</p>
+
+<p>The main thing to carry away from this discussion is
+the assurance that the delicacy of the animal in associating
+acts with impressions is nothing like the delicacy of the man
+who feels that a certain tone is higher, or weight is heavier,
+than another, but <i>is</i> like the delicacy of the man who runs
+to a certain spot to hit one tennis ball and to a different spot
+to hit one coming with a slightly different speed.</p>
+
+<p><span class="pagenum"><a id="Page_132"></a>[132]</span></p>
+
+<h3><span class="smcap">Complexity of Associations</span></h3>
+
+<p>An important question, especially if one wishes to rate an
+animal on a scale of intelligence, is the question of how complex
+an association it can form. A man can learn that to
+open a door he has to put the key in its hole, turn it, turn
+the knob, and pull the door. Here, then, is a complex act
+connected with the simple sense-impression. Or, conversely,
+a man knows that when the ringing of a bell is
+followed by a whistle and that by a red light he is to do a
+certain thing, while if any of the three happens alone, he is
+not to. How far, then, we ask, can animals go along the
+line of increased complexity in the associations?</p>
+
+<p>We must not mistake for a complex association a series
+of associations, where one sense-impression leads to an act
+such as to present a new sense-impression which leads to
+another act which in its turn leads to a new sense-impression.
+Of the formation of such <i>series</i> animals are capable to a
+very high degree. Chicks from 10 to 25 days old learned to
+go directly through a sort of big labyrinth requiring a series
+of 23 distinct and in some cases fairly difficult associations,
+of which 11 involved choices between two paths. By this
+power of acquiring a long series animals find their way to
+distant feeding grounds and back again. But all such cases
+are examples of the <i>number</i>, not of the complexity, of animal
+associations.</p>
+
+<p>Some of my boxes were such as did give a chance for a
+complex association to be formed. Such were G (thumb
+latch), J (double), K and L (triples) for the cats, and O (triple)
+for the dogs. It would be possible for a cat, after stepping
+on the platform in K, to notice that the platform was in a
+different position, and so feel then a different sense-impression
+from before, and thus turn the thing into a serial association.<span class="pagenum"><a id="Page_133"></a>[133]</span>
+The cat would then be like a man who on seeing
+a door should feel only the impulse to stick the key in the
+hole, but then, seeing the door plus a key in the hole, should
+feel the impulse to turn the key and so on through. My
+cats did not give any signs of this, so that with them it was
+either a complex association or an irregular happening of
+the proper impulses. Probably the same was the case with
+Dog 1. Cats 10, 11, 12 in L knew all the movements
+separately before being experimented on with the combination.
+Cats 2, 3, 4 had had some experience of D, which
+worked by a string something like the string part of K. The
+string in K was, however, quite differently situated and
+required an altogether different movement to pull it. Since
+further No. 2, who had had ten times as much experience
+in D as 3 or 4, succeeded no better with the string element
+of K than they, it is probable that the experience did not
+help very much. All else in all these compound associations
+was new. At the same time the history of these animals’
+dealings with these boxes would not fairly represent that of
+animals without general experience of clawing at all sorts
+of loose or shaky things in the inside of a box. These
+cats had learned to claw at all sorts of things. The
+time-curves were taken as in the formation of the other
+associations, and, in addition, the order in which the animal
+did the several things required was recorded in every trial.</p>
+
+<p>In the case of all the curves, except the latter part of 3
+in G, one notices a very gradual slope and an excessive
+irregularity in the curve throughout. Within the limits
+of the trials given the animals are unable to form a perfect
+association and what advancement they make is very slow.
+The case of 3 in G is not an exception to this, but a proof of
+it. For 3 succeeded in making a perfect association, by
+accidentally hitting on a way to turn the compound association<span class="pagenum"><a id="Page_134"></a>[134]</span>
+into a simple one. He happened one time to paw
+down the thumb piece at the same time that his other
+fore limb, with which he was holding on between the door
+and the top of the box, was pressing against the door.
+This giving him success he repeated it in later trials and in a
+short time had it fixed as an element in a perfect association.
+The marked change in his curve, from an irregular and gradual
+slope at such a height as displayed a very imperfect
+association, to a constant and very slight height, shows precisely
+the change from a compound to a simple association.</p>
+
+<p>Compound associations are formed slowly and not at all
+well. Further observation shows that they were really not
+formed at all. For the animals did not, except 3 in K for a
+certain period, do the several things in a constant order, nor
+did they do them only once apiece. On the contrary, an
+animal would pull the string several times after the bolt
+had gone up with its customary click, and would do sometimes
+one thing first, sometimes another. It may also be
+noted here, in advance of its proper place, that these compound
+associations are far below the simple in point of
+permanence. The conduct of the animals is clearly not
+that of minds having associated with a certain box’s interior
+the idea of a succession of three movements. The animal
+does not feel, “I did this and that and that and got out,”
+or, more simply still, “this and that and that means getting
+out.” If it did, we should soon see it doing what was
+necessary without repetition and in a fairly constant time.</p>
+
+<p>I imagine, however, that an animal could learn to associate
+with one sense-impression a compound act so as to
+perform its elements in a regular order. By arranging
+the box so that the second and third elements of the act
+could be performed <i>only after the first had been</i>, and the
+third <i>only after the first and second</i>, I am inclined to think<span class="pagenum"><a id="Page_135"></a>[135]</span>
+you could get a very vigorous cat to learn the elements in
+order and form the association perfectly. The case is
+comparable to that of delicacy. The cat does not <i>tend</i> to
+know what he is doing or to depart from the hit-or-miss
+method of learning, but by associating the other combinations
+of elements with failure to get pleasure, as in delicacy
+experiments we associated the reactions to all but the one
+signal, you could probably stamp out all but the 1, 2, 3
+order.</p>
+
+<p>The fact that you have to thus maneuver to get the
+animals to have the three impulses in a regular order shows
+that even when they are so, there is no idea of the three as
+in an order, no thinking about them. Representations do
+not get beyond their first intention. They are not carried
+up into a free life which works them over anew. A complex
+<i>act</i> does not imply a complex <i>thought</i>, or, more exactly, a
+performance of a series does not imply the thought of a
+series. Consequently, since the complexity of the act
+depends on the power which failure has to stamp out all
+other combinations, it is far more limited than in man.</p>
+
+<h3><span class="smcap">Number of Associations</span></h3>
+
+<p>The patent and important fact is that there are so few in
+animals compared to the human stock. Even after taking
+into account the various acts associated with various
+smells, and exaggerating the possibility of getting an equipment
+of associations in this field which man lacks, one must
+recognize how far below man any animal is in respect to
+mere quantity of associations. The associations with words
+alone of an average American child of ten years far outnumber
+those of any dog. A good billiard player probably
+has more associations in connection with this single pastime<span class="pagenum"><a id="Page_136"></a>[136]</span>
+than a dog with his whole life’s business. In the associations
+which are homologous with those of animals man
+outdoes them and adds an infinity of associations of a
+different sort. The primates would seem, by virtue of their
+incessant curiosity and addition to experience not for any
+practical purpose but merely for love of mental life, to
+represent an advanced stage toward this tremendous
+quantity of associations. In man not only this activity
+and curiosity, but also education, increases the number of
+associations. Associations are formed more quickly, and
+the absence of need for self-support during a long infancy
+gives time. Associations thus formed work back upon
+practical life, and by showing better ways decrease the
+need of work, and so again increase the chance to form
+associations. The result in the case of a human mind to-day
+is the possession of a thesaurus of valuable associations,
+if the time has been wisely spent. The free life of ideas,
+imitation, all the methods of communication, and the
+original accomplishments which we may include under the
+head of invention, make the process of acquisition in many
+cases quite a different one from the trial and error method
+of the animals, and in general much shorten it.</p>
+
+<p>Small as it is, however, the number of associations which
+an animal may acquire is probably much larger than popularly
+supposed.</p>
+
+<p>My cats and dogs did not mix up their acts with the
+wrong sense-impressions. The chicks that learned the
+series of twenty-three associations did not find it a task
+beyond their powers to retain them. Several three-day-old
+chicks, which I caused to learn ten simple associations in
+the same day, kept the things apart and on the next morning
+went through each act at the proper stimulus. In the hands
+of animal trainers some animals get a large number of<span class="pagenum"><a id="Page_137"></a>[137]</span>
+associations perfectly in hand. The horse Mascot is claimed
+to know the meaning of fifteen hundred signals! He
+certainly knows a great many, and such as are naturally
+difficult of acquisition. It would be an enlightening
+investigation if some one could find out just how many
+associations a cat or dog could form, if he were carefully
+and constantly given an opportunity. The result would
+probably show that the number was limited only by the
+amount of motive available and the time taken to acquire
+each. For there is probably nothing in their brain structure
+which limits the number of connections that can be formed,
+or would cause such connections, as they grew numerous,
+to become confused.</p>
+
+<p>In their anxiety to credit animals with human powers,
+the psychologists have disregarded or belittled, perhaps,
+the possibilities of the strictly animal sort of association.
+They would think it more wonderful that a horse should
+respond differently to a lot of different numbers on the blackboard
+than that he should infer a consequence from premises.
+But if it be made a direct question of pleasure or
+pain to an animal, he can associate any number of acts with
+different stimuli. Only he does not form any associations
+until he has to, until the direct benefit is apparent, and, for
+his ordinary life, comparatively few are needed.</p>
+
+<p>On the whole our judgment from a comparison of man’s
+associations with the brutes’ must be that a man’s are naturally
+far more delicate, complex and numerous, and that
+in as far as the animals attain delicacy, complexity, or a
+great number of associations, they do it by methods which
+man uses only in a very limited part of the field.</p>
+
+<p><span class="pagenum"><a id="Page_138"></a>[138]</span></p>
+
+<h3><span class="smcap">Permanence of Associations</span></h3>
+
+<p>Once formed, the connections by which, when an animal
+feels a certain sense-impression, he does a certain thing,
+persist over considerable intervals of time. With the curves
+on <a href="#Page_39">pages 39 to 58</a> and <a href="#Page_60">60 to 65</a> are given in many instances<a id="FNanchor_17" href="#Footnote_17" class="fnanchor">[17]</a>
+additional curves showing the animal’s proficiency after an
+interval without experience. To these data may be added
+the following:—</p>
+
+<p>The three chicks that had learned to escape through
+the long labyrinth (involving twenty-three associations)
+succeeded in repeating the performance after ten days’
+interval. Similarly the chicks used as imitators in V, W, X
+and Y did not fail to perform the proper act after an interval
+of twenty days. Cat 6, who had had about a hundred
+experiences in C (button), had the association as perfect after
+twenty days as when it left off. Cat 2, who had had 36 experiences
+with C and had attained a constant time of 8 seconds,
+escaped fourteen days later in 3, 9 and 8 seconds, respectively,
+in three trials. Cat 1, after an interval of twenty
+days, failed in 10 minutes to escape from C. The signal
+for climbing up the front of the cage was reacted to by No. 3
+after an interval of twenty-four days. No. 10, who had
+learned to discriminate between ‘I must feed those cats’
+and ‘I will not feed them,’ was tried after <i>eighty</i> days. It
+was given 50 trials with the second signal mingled indiscriminately
+with 25 trials with the first. I give the full record of
+these, ‘yes’ equalling a trial in which she ‘forgot’ and
+climbed up, ‘no’ equalling a trial in which she wisely stayed
+down. Dashes represent intervening trials with the first<span class="pagenum"><a id="Page_139"></a>[139]</span>
+signal, <i>to which she always reacted</i>. It will be observed
+that 50 trials put the cat in the same position that 350 had
+done in her first experience, although in that first experience
+she had had only about a hundred trials after the association
+had been perfected. The association between the first
+signal and climbing up was perfect after the eighty days.</p>
+
+<h4><span class="smcap">Table 8</span></h4>
+
+<table class="borders">
+  <tr>
+    <th><span class="smcap">Trials 1-7</span></th>
+    <th><span class="smcap">Trials 8-17</span></th>
+    <th><span class="smcap">Trials 18-27</span></th>
+    <th><span class="smcap">Trials 28-35</span></th>
+    <th><span class="smcap">Trials 36-42</span></th>
+    <th><span class="smcap">Trials 43-50</span></th>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+    <td class="tdc">—</td>
+    <td class="tdc">—</td>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+  </tr>
+  <tr>
+    <td class="tdc">yes</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+  </tr>
+  <tr>
+    <td class="tdc">yes</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+    <td class="tdc">—</td>
+  </tr>
+  <tr>
+    <td class="tdc">no</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">yes</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">—</td>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+  </tr>
+  <tr>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">no</td>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">—</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc">no</td>
+    <td class="tdc">no</td>
+    <td class="tdc"></td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc">—</td>
+    <td class="tdc">yes</td>
+    <td class="tdc"></td>
+    <td class="tdc"></td>
+    <td class="tdc"></td>
+    <td class="tdc">no</td>
+  </tr>
+  <tr>
+    <td class="tdc"></td>
+    <td class="tdc">—</td>
+    <td class="tdc"></td>
+    <td class="tdc"></td>
+    <td class="tdc"></td>
+    <td class="tdc"></td>
+  </tr>
+</table>
+
+<p>All these data show that traces of the connections once
+formed are very slow in being lost. If we allow that part
+of the time in the first trial in all these cases is due to the
+time taken to realize the situation (time not needed in the
+trials when the association is forming and the animal is
+constantly being dropped into boxes), we may say that the
+association is as firm as ever for a considerable time after
+practice at it is stopped. How long a time would be required
+to annul the influence of any given quantity of
+experience, say of an association which had been gone
+through with ten times, I cannot say. It could, if profitable,<span class="pagenum"><a id="Page_140"></a>[140]</span>
+easily be determined in any case. The only case of total
+loss of the association (No. 1 in C) is so exceptional that I
+fancy something other than lapse of time was its cause.
+The main interest of these data, considered as quantitative
+estimates, is not psychological, but biological. They show
+what a tremendous advantage the well-developed association-process
+is to an animal. The ways to different feeding
+grounds, the actions of enemies, the appearance of noxious
+foods, are all connected permanently with the proper reaction
+by a few experiences which need be reënforced only
+very rarely. Of course, associations without any permanence
+would be useless, but the usefulness increases immensely
+with such a degree of permanence as these results
+witness. An interesting experiment from the biological
+point of view would be to see how infrequently an experience
+could occur and yet lead eventually to a perfect association.
+An experiment approximating this is recorded in the time-curves
+for Box H in <a href="#figure07">Figure 7, on page 47</a>. Three trials at a
+time were given, the trials being two or three days apart.
+As may be seen from the curves, the association was readily
+formed.</p>
+
+<p>The chief psychological interest of these data is that they
+show that permanence of associations <i>is not memory</i>. The
+fact that a cat, when after an interval she is put into box G,
+proceeds to immediately press the thumb piece and push
+the door, does not at all mean that the cat feels the box
+to be the same from which she weeks ago freed herself by
+pushing down that thumb piece, or thinks about ever
+having felt or done anything in that box. She does not
+refer the present situation to a situation of the past and realize
+that it is the same, but simply feels on being confronted
+with that situation the same impulse which she felt before.
+She does the thing now for just the same reason that she<span class="pagenum"><a id="Page_141"></a>[141]</span>
+did it before, namely, because pleasure has connected that
+act above all others with that sense-impression, so that it
+is the one she feels like doing. Her condition is that of the
+swimmer who starts his summer season after a winter’s
+deprivation. When he jumps off the pier and hits the water,
+he swims, not because he remembers that this is the way he
+dealt with water last summer and so applies his remembrance
+to present use, but just because experience has taught him
+to feel like swimming when he hits the water. All talk
+about recognition and memory in animals, if it asserts the
+presence of anything more than this, is a gross mistake.
+For real memory is an absolute thing, including everything
+but forgetfulness. If the cat had real memory, it would,
+when after an interval dropped into a box, remember that
+from this box it escaped by doing this or that and consequently,
+either immediately or after a time of recollection,
+go do it, or else it would not remember and would fail
+utterly to do it. On the contrary, we have all grades of
+<i>partial</i> ‘forgetfulness,’ just like the grades of swimming one
+might find if he dropped a dozen college professors into the
+mill ponds of their boyhood, just like the grades of forgetfulness
+of the associations once acquired on the ball field
+which are manifested when on the Fourth of July the
+‘solid men’ of a town get out to amuse their fellow citizens.
+The animal makes attacks on a spot around the vital one,
+or claws at the thing—but not so precisely as before, or
+goes at it a while and then resorts to instinctive methods
+of getting out. Its actions are exactly what would be
+expected of an animal in whom the sense-impression aroused
+the impulse imperfectly, or weakly, or intermittently, but
+are not at all like the actions of one who felt, “I used to
+get out of this box by pulling that loop down.” In fact,
+the record of No. 10 given on <a href="#Page_139">page 139</a> seems to be final on<span class="pagenum"><a id="Page_142"></a>[142]</span>
+this point. If at any time in the course of the 50 trials it
+had <i>remembered</i> that ‘I will not feed them’ meant ‘no fish,’
+it would thenceforth have failed to react. It would have
+stopped short in the ‘yes’ reactions, instead of gradually
+decreasing their percentage. ‘Memory’ in animals, if one
+still chooses to use the word, is <i>permanence of associations</i>,
+not the presence of an idea of an experience attributed to
+the past.</p>
+
+<p>To this proposition two corollaries may be added. First,
+these phenomena of incomplete forgetfulness extend the
+evidence that animals do not have a stock of independent
+ideas, the return of which, plus past associates, equals
+memory. Second, there is, properly speaking, no continuity
+in their mental streams. The present thought does not
+clutch the past to its bosom or hold the future in its womb.
+The animal’s self is not a being ‘looking before and after,’
+but a direct practical association of feelings and impulses.
+So far as experiences come continuously, they may be said
+to form a continuous mental life, but there is no continuity
+imposed from within. The feelings of its own body are
+always present, and impressions from outside may come as
+they come to us. When the habit of attending to the
+elements of its associations and raising them up into the
+life of free ideas is acquired, these permanent bodily associations
+may become the basis of a feeling of self-hood and the
+trains of ideas may be felt as a continuous life.</p>
+
+<h3><span class="smcap">Inhibition of Instincts by Habit</span></h3>
+
+<p>One very important result of association remains to be
+considered, its inhibition of instincts and previous associations.
+An animal who has become habituated to getting
+out of a box by pulling a loop and opening the door will<span class="pagenum"><a id="Page_143"></a>[143]</span>
+do so even though the hole in the top of the box be uncovered,
+whereas, if, in early trials, you had left any such hole,
+he would have taken the instinctive way and crawled
+through it. Instances of this sort of thing are well-nigh
+ubiquitous. It is a tremendous factor in animal life,
+and the strongest instincts may thus be annulled. The
+phenomenon has been already recognized in the literature
+of the subject, a convenient account being found in James’
+‘Psychology,’ Vol. II, pages 394-397. In addition to such
+accounts, one may note that the influence of association is
+exerted in two ways. The instinct may wane by not being
+used, because the animal forms the habit of meeting the
+situation in a different way, or it may be actually inhibited.
+An instance of the former sort is found in the history of
+a cat which learns to pull a loop and so escape from a box
+whose top is covered by a board nailed over it. If, after
+enough trials, you remove a piece of the board covering
+the box, the cat, when put in, will still pull the loop instead
+of crawling out through the opening thus made. But, at
+any time, if she happens to notice the hole, she <i>may</i> make
+use of it. An instance of the second sort is that of a chick
+which has been put on a box with a wire screen at its edge,
+preventing her from jumping directly down, as she would
+instinctively do, and forcing her to jump to another box on
+one side of it and thence down. In the experiments which
+I made, the chick was prevented by a second screen from
+jumping directly from the second box also. That is, if in
+the accompanying figure, A is a box 34 inches high, B a box
+25 inches high, C a box 16 inches high, and D the pen with
+the food and other chicks, the subject had to go A-B-C-D.
+The chick tried at first to get through the screen,
+pecked at it and ran up and down along it, looking at the
+chicks below and seeking for a hole to get through. Finally<span class="pagenum"><a id="Page_144"></a>[144]</span>
+it jumped to B and, after a similar process, to C. After
+enough trials it forms the habit and when put on A goes
+immediately to B, then
+to C and down. Now
+if, after 75 or 80 trials,
+you take away the
+screens, giving the chick
+a free chance to go to D
+from either A or B, and
+then put it on A, the
+following phenomenon
+appears. The chick goes
+up to the edge, looks over, walks up and down it for a while,
+still looking down at the chicks below, and then goes and
+jumps to B as habit has taught it to do. The same actions
+take place on B. No matter how clearly the chick sees
+the chance to jump to D, it does not do so. The impulse has
+been truly inhibited. It is not the mere habit of going the
+other way, but the impossibility of going <i>that</i> way. In one
+case I observed a chick in whom the instinct was all but, yet
+not quite, inhibited. When tried without the screen, it went
+up to the edge to look over <i>nine times</i>, and at last, after
+seven minutes, did jump straight down.</p>
+
+<div class="figcenter illowp100" id="figure23" style="max-width: 18.75em;">
+  <img class="w100" src="images/figure23.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 23.</span></p>
+</div>
+
+<h3><span class="smcap">Attention</span></h3>
+
+<p>I have presupposed throughout one function which it
+will be well to now recognize explicitly, attention. As
+usual, attention emphasizes and facilitates the process
+which it accompanies. Unless the sense-impression is
+focussed by attention, it will not be associated with the
+act which comes later. Unless two differing boxes are attended
+to, there will be no difference in the reactions to<span class="pagenum"><a id="Page_145"></a>[145]</span>
+them. The really effective part of animal consciousness,
+then, as of human, is the part which is attended to; attention
+is the ruler of animal as well as human mind.</p>
+
+<p>But in giving attention its deserts we need not forget
+that it is not here comparable to the whole of human attention.
+Our attention to the other player and the ball
+in a game of tennis <i>is</i> like the animal’s attention, but our
+attention to a passage in Hegel, or the memory which
+flits through our mind, or the song we hear, or the player
+we idly watch, is <i>not</i>. There ought, I think, to be a separate
+name for attention when working for immediate practical
+associations. It is a different species from that which
+holds objects so that we may define them, think about them,
+remember them, etc., and the difference is, as our previous
+sentence shows, not that between voluntary and involuntary
+attention. The cat watching me for signs of my walking
+to the cage with fish is not in the condition of the man
+watching a ball game, but in that of the player watching
+the ball speeding toward him. There is a notable difference
+in the permanence of the impression. The man watching
+the game can remember just how that fly was hit and how
+the fielder ran for it, though he bestowed only a slight
+quantity of attention on the matter, while the fielder may
+attend to the utmost to the ball and yet not remember at
+all how it came or how he ran for it. The one sort of attention
+leads you to <i>think</i> about a thing, the other to <i>act</i> with
+reference to it. We must be careful to remember that
+when we say that the cat attended to what was said, we
+do not mean that he thereby established an idea of it.
+Animals are not proved to form separate ideas of sense-impressions
+because they attend to them, for the kind of
+attention they give is the kind which, when given by men,
+results in practical associations, not in establishing ideas<span class="pagenum"><a id="Page_146"></a>[146]</span>
+of objects. If attention rendered clear the idea, we should
+not have the phenomena of incomplete forgetfulness lately
+mentioned. The animal would get a definite idea of just
+the exact thing done and would do it or nothing. The
+human development of attention is in closest connection
+with the acquisition of a stock of free ideas.</p>
+
+<h3><span class="smcap">Social Consciousness</span></h3>
+
+<p>Besides attention there is another topic somewhat apart
+from our general one, which yet deserves a few words. It
+concerns animals’ social consciousness, their consciousness
+of the feelings of their fellows. Do animals, for example,
+when they see others feeding, feel that the others are feeling
+pleasure? Do they, when they fight, feel that the other
+feels pain? So level-headed a thinker as Lloyd Morgan has
+said that they do, but the conduct of my animals would
+seem to show that they did not. For it has given us good
+reason to suppose that they do not possess <i>any</i> stock of isolated
+ideas, much less any abstracted, inferred, or transferred
+ideas. These ideas of others’ feelings imply a power to transfer
+states felt in oneself to another and realize them as there.
+Now it seems that any ability to thus transfer and realize
+an idea ought to carry with it an ability to form a transferred
+association, to imitate. If the animal realizes the mental
+states of the other animal who before his eyes pulls the
+string, goes out through the door, and eats fish, he ought to
+form the association, ‘impulse to pull string, pleasure of
+eating fish.’ This we saw the animal could not do.</p>
+
+<p>In fact, pleasure in another, pain in another, is not a
+sense-presentation or a representation or feeling of an object
+of any sort, but rather a ‘meaning,’ a feeling ‘<i>of the
+fact that</i>.’ It can exist only as something thought <i>about</i>.<span class="pagenum"><a id="Page_147"></a>[147]</span>
+It is never ‘a bit of direct experience,’ but an abstraction
+from our own life referred to that of another.</p>
+
+<p>I fancy that these feelings of others’ feelings may be connected
+pretty closely with imitation, and for that reason
+may begin to appear in the monkeys. There we have some
+fair evidence for their presence in the tricks which monkeys
+play on each other. Such feelings seem the natural explanation
+of the apparently useless tail-pullings and such like
+which make up the attractions of the monkey cage. These
+may, however, be instinctive forms of play-activity or
+merely examples of the general tendency of the monkeys
+to fool with everything.</p>
+
+<h3><span class="smcap">Interaction</span></h3>
+
+<p>I hope it will not be thought impertinent if from the standpoint
+of this research I add a word about a general psychological
+problem, the problem of interaction. I have spoken
+all along of the connection between the situation and a certain
+impulse and act being stamped in when pleasure results
+from the act and stamped out when it doesn’t. In this fact,
+which is undeniable, lies a problem which Lloyd Morgan
+has frequently emphasized. <i>How are pleasurable results able
+to burn in and render predominant the association which led to
+them?</i> This is perhaps the greatest problem of both human
+and animal psychology. Unfortunately in human psychology
+it has been all tangled up with the problems of free
+will, mental activity, voluntary attention, the creation of
+novel acts, and almost everything else. In our experiments
+we get the data which give rise to the problem, in a very
+elementary form.</p>
+
+<p>It should first be noted about the <i>fact</i> that the pleasure
+does not burn in an impulse and act themselves, but an impulse<span class="pagenum"><a id="Page_148"></a>[148]</span>
+and act <i>as connected with that particular situation</i>. No
+cat ever goes around clawing, clawing, clawing all the time,
+because clawing in these boxes has resulted in pleasure.
+Secondly, the connection thus stamped in is <i>not contemporaneous,
+but prior to</i> the pleasure. So much for the fact;
+now for the explanation. I do not wish to rehearse or add
+to the arguments with which so many pages have been already
+filled by scientists and philosophers both. What we
+need most is not argument, but accurate accounts of the
+mental fact and of the brain-process. But I do wish to say
+to the parallelist, what has not to my knowledge been said,
+that if he presupposes, to account for this fact, a ‘physical
+analogue of the hedonic consciousness,’ it is his bounden
+duty to first show how any motion in any neurone or group
+of neurones in the nervous system can possess this power of
+stamping in any current which causes it. For no one would,
+from our present knowledge of the brain, judge <i>a priori</i> that
+any motion in any part of it could be conceived which should
+be thus regnant over all the others. And next he must show
+the possibility of the current which represents the association
+being the excitant of the regnant motion in a manner
+direct enough for the purpose.</p>
+
+<p>I wish also to say that whoever thinks that, going along
+with the current which parallels the association, there is an
+accompanying minor current, which parallels the pleasure
+and which stamps in the first current when present with it,
+flies directly in the face of the facts. <i>There is no pleasure
+along with the association. The pleasure does not come until
+after the association is done and gone.</i> It is caused by no
+such minor current, but by the excitation of peripheral
+sense-organs when freedom from confinement is realized or
+food is secured. Of course, the notion of such a secondary
+subcurrent is mythology, anyway.</p>
+
+<p><span class="pagenum"><a id="Page_149"></a>[149]</span></p>
+
+<p>To the interactionist I would say: “Do not any more
+repeat in tiresome fashion that consciousness <i>does</i> alter
+movement, but get to work and show when, where, in what
+forms and to what degrees it does so. Then, even if it turns
+out to have been a physical parallel that did the work, you
+will, at least, have the credit of attaining the best knowledge
+about the results and their conditions, even though you misnamed
+the factor.”</p>
+
+<p>Besides this contribution to general psychology, I think
+we may safely offer one to pedagogical science. At least
+some of our results possess considerable pedagogical interest.
+The fundamental form of intellection, the association-process
+in animals, is one, we decided, which requires the
+personal experience of the animal in all its elements. The
+association cannot be taught by putting the animal through
+it or giving it a chance to imitate. Now every observant
+teacher realizes how often the cleverest explanation and the
+best models for imitation fail. Yet often, in such cases, a
+pupil, if somehow enticed to do the thing, even without
+comprehension of what it means, even without any real
+knowledge of what he is doing, will finally get hold of it.
+So, also, in very many kinds of knowledge, the pupil who
+does anything from imitation, or who does anything from
+being put through it, fails to get a real and permanent mastery
+of the thing. I am sure that with a certain type of
+mind the only way to teach fractions in algebra, for example,
+is to get the pupil to do, do, do. I am inclined to think that
+in many individuals certain things cannot be learned save by
+actual performance. And I think it is often a fair question,
+when explanation, imitation and actual performance are all
+possible methods, which is the best. We are here alongside
+the foundations of mental life, and this hitherto unsuspected
+law of animal mind may prevail in human mind to an extent<span class="pagenum"><a id="Page_150"></a>[150]</span>
+hitherto unknown. The best way with children may often
+be, in the pompous words of an animal trainer, ‘to arrange
+everything in connection with the trick so that the animal
+will be compelled by the laws of his own nature to perform
+it.’</p>
+
+<p>This does not at all imply that I think, as a present school
+of scientists seem to, that because a certain thing <i>has been</i> in
+phylogeny we ought to repeat it in ontogeny. Heaven
+knows that Dame Nature herself in ontogeny abbreviates
+and skips and distorts the order of the appearance of organs
+and functions, and for the best of reasons. We ought to
+make an effort, as she does, to omit the useless and antiquated
+and get to the best and most useful as soon as possible;
+we ought to change what <i>is</i> to what <i>ought to be</i>, as far as we
+can. And I would not advocate this animal-like method of
+learning in place of the later ones unless it does the same
+work better. I simply suggest that in many cases where
+at present its use is never dreamed of, it may be a good
+method. As the fundamental form of intellection, every
+student of <i>theoretical</i> pedagogy ought to take it into account.</p>
+
+<p>There is one more contribution, this time to anthropology.
+If the method of trial and error, with accidental success, be
+the method of acquiring associations among the animals, the
+slow progress of primitive man, the long time between stone
+age and iron age, for instance, becomes suggestive. Primitive
+man probably acquired knowledge by just this process,
+aided possibly by imitation. At any rate, progress was not
+by seeing through things, but by accidentally hitting upon
+them. Very possibly an investigation of the history of
+primitive man and of the present life of savages in the light
+of the results of this research might bring out old facts in a
+new and profitable way.</p>
+
+<p>Comparative psychology has, in the light of this research,<span class="pagenum"><a id="Page_151"></a>[151]</span>
+two tasks of prime importance. One is to study the passage
+of the child mind from a life of immediately practical associations
+to the life of free ideas; the other is to find out how far
+the anthropoid primates advance toward a similar passage,
+and to ascertain accurately what faint beginnings or preparations
+for such an advance the early mammalian stock may
+be supposed to have had. In this latter connection I think
+it will be of the utmost importance to bear in mind the possibility
+that <i>the present anthropoid primates may be mentally
+degenerate</i>. Their present aimless activity and incessant,
+but largely useless, curiosity may be the degenerated
+vestiges of such a well-directed activity and useful curiosity
+as led <i>homo sapiens</i> to important practical discoveries,
+such as the use of tools, the art of making fire, etc. It is
+even a remote possibility that their chattering is a <i>relic</i>
+of something like language, not a <i>beginning</i> of such. Comparative
+psychology should use the phenomena of the
+monkey mind of to-day to find out what the primitive mind
+from which man’s sprung off was like. That is the important
+thing to get at, and the question whether the present
+monkey mind has not gone back instead of ahead is an all-important
+question. A natural and perhaps sufficient cause
+of degeneracy would be arboreal habits. The animal that
+found a means of survival in his muscles might well lose the
+means before furnished by his brain.</p>
+
+<p>To these disconnected remarks still another must be added,
+addressed this time to the anecdote school. Some member
+of it who has chanced to read this may feel like saying:
+“This experimental work is all very well. Your cats and
+dogs represent, it is true, specimens from the top stratum
+of animal intelligence, and your negations, based on their
+conduct, may be authoritative so far as concerns the
+average, typical mammalian mind. But our anecdotes<span class="pagenum"><a id="Page_152"></a>[152]</span>
+do not claim to be stories of the conduct of the average
+or type, but of those exceptional individuals who have
+begun to attain higher powers. And, if even a few
+dogs and cats have these higher powers, our contention
+is, in a modified form, upheld.” To all this I agree,
+provided the anecdote school now realize just what
+sort of a position they hold. They are clearly in pretty
+much the same position as spiritualists. Their anecdotes
+are on pretty much the same level as the anecdotes of
+thought-transference, materializations of spirits, supernormal
+knowledge, etc. Not in quite the same position, for
+far greater care has been given by the Psychical Research
+Society to establishing the criteria of authenticity, to insuring
+good observation, to explaining by normal psychology
+all that can be so explained, in the case of the latter than
+the anecdote school has done in the case of the former. The
+off-hand explanation of certain anecdotes by invoking reason,
+or imitation, or recognition, or feelings of qualities, is
+on a par with the explanation of trance-phenomena and such
+like by invoking the spirits of dead people. I do not deny
+that we may get lawfully a supernormal psychology, or
+that the supernormal acts it finds may turn out to be explained
+by these functions which I have denied to the normal
+animal mind. But I must soberly declare that I think
+there is less likelihood that such functions are the explanation
+of animal acts than that the existence of the spirits of
+dead people is the true explanation of the automatisms of
+spiritualistic phenomena. So much for the anecdote school,
+if it calls itself by its right name and pretends only to give
+an <i>abnormal</i> animal psychology. The sad fact has been that
+it has always pushed forward these exceptions as the essential
+phenomena of animal mind. It has built up a general
+psychology from abnormal data. It is like an anatomy
+written from observations on dime-museum freaks.</p>
+
+<p><span class="pagenum"><a id="Page_153"></a>[153]</span></p>
+
+<h3><span class="smcap">Conclusion</span></h3>
+
+<p>I do not think it is advisable here, at the close of this
+paper, to give a summary of its results. The paper itself
+is really only such a summary with the most important evidence,
+for the extent of territory covered and the need of
+brevity have prevented completeness in explanation or illustration.
+If the reader cares here, at the end, to have the
+broadest possible statement of our conclusions and will take
+the pains to supply the right meaning, we might say that
+our work has described a method, crude but promising, and
+has made the beginning of an exact estimate of just what
+associations, simple and compound, an animal can form,
+how quickly he forms them, and how long he retains them.
+It has described the method of formation, and, on the condition
+that our subjects were representative, has rejected
+reason, comparison or inference, perception of similarity,
+and imitation. It has denied the existence in animal consciousness
+of any important stock of free ideas or impulses,
+and so has denied that animal association is homologous
+with the association of human psychology. It has homologized
+it with a certain limited form of human association. It
+has proposed, as necessary steps in the evolution of human
+faculty, a vast increase in the number of associations, signs
+of which appear in the primates, and a freeing of the elements
+thereof into independent existence. It has given us
+an increased insight into various mental processes. It has
+convinced the writer, if not the reader, that the old speculations
+about what an animal could do, what it thought,
+and how what it thought grew into what human beings
+think, were a long way from the truth, and <i>not on the road
+to it</i>.</p>
+
+<p>Finally, I wish to say that, although the changes proposed<span class="pagenum"><a id="Page_154"></a>[154]</span>
+in the conception of mental development have been suggested
+somewhat fragmentarily and in various connections,
+that has not been done because I think them unimportant.
+On the contrary, I think them of the utmost importance. I
+believe that our best service has been to show that animal
+intellection is made up of a lot of specific connections, whose
+elements are restricted to them, and which subserve practical
+ends <i>directly</i>, and to homologize it with the intellection
+involved in such human associations as regulate the conduct
+of a man playing tennis. The fundamental phenomenon
+which I find presented in animal consciousness is one which
+can harden into inherited connections and reflexes, on the
+one hand, and thus connect naturally with a host of the
+phenomena of animal life; on the other hand, it emphasizes
+the fact that our mental life has grown up as a mediation between
+stimulus and reaction. The old view of human consciousness
+is that it is built up out of elementary sensations,
+that very minute bits of consciousness come first and gradually
+get built up into the complex web. It looks for the
+beginnings of consciousness to <i>little</i> feelings. This our view
+abolishes and declares that the progress is not from little and
+simple to big and complicated, but from direct connections to
+indirect connections in which a stock of isolated elements plays
+a part, is from ‘pure experience’ or undifferentiated feelings,
+to discrimination, on the one hand, to generalizations, abstractions,
+on the other. If, as seems probable, the primates
+display a vast increase of associations, and a stock of free-swimming
+ideas, our view gives to the line of descent a meaning
+which it never could have so long as the question was
+the vague one of more or less ‘intelligence.’ It will, I hope,
+when supported by an investigation of the mental life of
+the primates and of the period in child life when these directly
+practical associations become overgrown by a rapid<span class="pagenum"><a id="Page_155"></a>[155]</span>
+luxuriance of free ideas, show us the real history of the
+origin of human faculty. It turns out apparently that
+a modest study of the facts of association in animals
+has given us a working hypothesis for a comparative
+psychology.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_156"></a>[156]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_III">CHAPTER III<br>
+<span class="smcap">The Instinctive Reactions of Young Chicks</span><a id="FNanchor_18" href="#Footnote_18" class="fnanchor">[18]</a></h2>
+
+</div>
+
+<p>The data to be presented in this article were obtained in
+the course of a series of experiments conducted in connection
+with the psychological laboratory of Harvard University
+during the year 1896-1897. About sixty chicks were
+used as subjects. In general their experiences were entirely
+under my control from birth. Where this was not true, the
+conditions of their life previous to the experiments were
+known, and were such as would have had no influence in
+determining the quality of their reactions in the particular
+experiments to which they were subjected. It is not worth
+while to recount the means taken so to regulate the chick’s
+environment that his experience along certain lines should
+be in its entirety known to the observer and that consequently
+his inherited abilities could be surely differentiated.
+The nature of the experiments will, in most cases, be such
+that little suspicion of the influence of education by experience
+will be possible. In the other cases I will mention
+the particular means then taken to prevent such influence.</p>
+
+<p>Some of my first experiments were on color vision in
+chicks from 18 to 30 hours old, just old enough to move
+about readily and to be hungry. On backgrounds of white
+and black cardboard were pasted pieces of colored paper
+about 2 mm. square. On each background there were six<span class="pagenum"><a id="Page_157"></a>[157]</span>
+of these pieces,—one each of yellow, red, orange, green,
+blue and black (on the white ground) or white (on the black).
+They were in a row about half an inch apart. The chicks
+had been in darkness for all but three or four hours of their
+life so far. During those few hours the incubator had been
+illuminated and the chicks had that much chance to learn
+color.</p>
+
+<p>The eight chicks were put, one at a time, on the sheet of
+cardboard facing the colored spots. Count was kept of the
+number of times that they pecked at each spot and, of
+course, they were watched to see whether they would peck
+at all at random. In the experiments with the white background
+all the colors were reacted to (<i>i.e.</i> pecked at) except
+black (but the letters on a newspaper were pecked at by
+the same chicks the same day). One of the chicks pecked
+at all five, one at four, three at three, one at two and one at
+yellow only. These differences are due probably to accidental
+position or movements. Taking the sums of the reactions
+to each color-spot we get the following table:—</p>
+
+<h3>I</h3>
+
+<table class="borders">
+  <tr>
+    <th></th>
+    <th><span class="smcap">Times<br>Reacted to</span></th>
+    <th><span class="smcap">Total Number<br>of Pecks</span><a id="FNanchor_19" href="#Footnote_19" class="fnanchor">[19]</a></th>
+  </tr>
+  <tr>
+    <td>Red</td>
+    <td class="tdr">12</td>
+    <td class="tdr">31</td>
+  </tr>
+  <tr>
+    <td>Yellow</td>
+    <td class="tdr">9</td>
+    <td class="tdr">21</td>
+  </tr>
+  <tr>
+    <td>Orange</td>
+    <td class="tdr">6</td>
+    <td class="tdr">34</td>
+  </tr>
+  <tr>
+    <td>Green</td>
+    <td class="tdr">5</td>
+    <td class="tdr">11</td>
+  </tr>
+  <tr>
+    <td>Blue</td>
+    <td class="tdr">1</td>
+    <td class="tdr">3</td>
+  </tr>
+</table>
+
+<p>I should attach no importance whatever to the quantitative
+estimate given in the table. The only fact of value so<span class="pagenum"><a id="Page_158"></a>[158]</span>
+far is the evidence that from the first the chick reacts to all
+colors. In no case was there any random pecking at the
+white surface of the cardboard.</p>
+
+<p>On a black background the same chicks reacted to all the
+colors.</p>
+
+<p>II is a table of the results.</p>
+
+<h3>II</h3>
+
+<table class="borders">
+  <tr>
+    <th></th>
+    <th><span class="smcap">Times<br>Reacted to</span></th>
+    <th><span class="smcap">Total Number<br>of Pecks</span></th>
+  </tr>
+  <tr>
+    <td>White</td>
+    <td class="tdr">6</td>
+    <td class="tdr">19</td>
+  </tr>
+  <tr>
+    <td>Blue</td>
+    <td class="tdr">4</td>
+    <td class="tdr">11</td>
+  </tr>
+  <tr>
+    <td>Red</td>
+    <td class="tdr">4</td>
+    <td class="tdr">8</td>
+  </tr>
+  <tr>
+    <td>Green</td>
+    <td class="tdr">4</td>
+    <td class="tdr">4</td>
+  </tr>
+  <tr>
+    <td>Orange</td>
+    <td class="tdr">2</td>
+    <td class="tdr">7</td>
+  </tr>
+  <tr>
+    <td>Yellow</td>
+    <td class="tdr">2</td>
+    <td class="tdr">4</td>
+  </tr>
+</table>
+
+<p>In other experiments chicks were tried with green spots on
+a red ground, red spots on a green ground, yellow spots on an
+orange ground, green spots on a blue ground, and black spots
+on a white ground. All were reacted to. Thus, what is apparently
+a long and arduous task to the child is heredity’s
+gift to the chick. It is conceivable, though to me incredible,
+that what the chick reacts to is not the color, but the
+very minute elevation of the spot. My spots were made so
+that they were only the thickness of thin paper above pasteboard.
+Any one who cares to resort to the theory that this
+elevation caused the reaction can settle the case by using
+color-spots absolutely level with the surface.<a id="FNanchor_20" href="#Footnote_20" class="fnanchor">[20]</a></p>
+
+<p><span class="pagenum"><a id="Page_159"></a>[159]</span></p>
+
+<h3><span class="smcap">Instinctive Reactions to Distance, Direction, Size, etc.</span></h3>
+
+<p>I have purposely chosen this awkward heading rather
+than the simple one, Space-Perception, because I do not wish
+to imply that there is in the young chick such consciousness
+of space-facts as there is in human beings. All that will be
+shown here is that he reacts appropriately in the presence of
+space-facts, reacts in a fashion which would in the case of a
+man go with genuine perception of space.</p>
+
+<p>If one puts a chick on top of a box in sight of his fellows
+below, the chick will regulate his conduct by the height of
+the box. To be definite, we may take the average chick of
+about 95 hours. If the height is less than 10 inches, he will
+jump down as soon as you put him up. At 16 inches he will
+jump in from 5 seconds to 3 or 4 minutes. At 22 inches he
+will still jump down, but after more hesitation. At 27½
+inches 6 chicks out of eight at this age jumped within 5 minutes.
+At 39 inches the chick <i>will <span class="smcap">not</span> jump down</i>. The
+numerical values given here would, of course, vary with the
+health, development, hunger and degree of lonesomeness of
+the chick. All that they are supposed to show is that at any
+given age the chick without experience of heights regulates
+his conduct rather accurately in accord with the space-fact
+of distance which confronts him. The chick does not peck
+at objects remote from him, does not, for instance, confuse
+a bird a score of feet away with a fly near by, or try to get
+the moon inside his bill. Moreover, he reacts in pecking
+with considerable accuracy at the very start. Lloyd Morgan
+has noted that in his very first efforts the chick often
+fails to seize the object, though he hits it, and on this ground
+has denied the perfection of the instinct. But, as a matter
+of fact, the pecking reaction may be as perfect at birth as it is<span class="pagenum"><a id="Page_160"></a>[160]</span>
+after 10 or 12 days’ experience. It certainly is not perfect
+then. I took nine chicks from 10 to 14 days old and placed
+them one at a time on a clear surface over which were scattered
+grains of cracked wheat (the food they had been eating
+in this same way for a week) and watched the accuracy
+of their pecking. Out of 214 objects pecked at, 159 were
+seized, 55 <i>were not</i>. Out of the 159 that were seized, <i>only</i>
+116 were seized on the first peck, 25 on the second, 16 on the
+third, and the remaining two on the fourth. Of the 55 that
+were not successfully seized, 31 were pecked at only once,
+10 twice, 10 three times, 3 four times and 1 five times. I
+fancy one would find that adult fowls would show by no
+means a perfect record. So long as chicks with ten days’
+experience fail to seize on the first trial 45 per cent of the
+time, it is hardly fair to argue against the perfection of the
+instinct on the ground of failures to seize during the first day.</p>
+
+<p>The chick’s practical appreciation of space-facts is seen
+further in his attempts to escape when confined. Put chicks
+only twenty or thirty hours old in a box with walls three or
+four inches high and they will react to the perpendicularity
+of the confining walls by trying to jump over them. In fact,
+in the ways he moves, the directions he takes and the objects
+he reacts to, the chicken has prior to experience the power
+of appropriate reaction to colors and facts of all three dimensions.</p>
+
+<h3><span class="smcap">Instinctive Muscular Coördinations</span></h3>
+
+<p>In the acts already described we see fitting coördinations
+at work in the chick’s reactions to space-facts. A few more
+samples may be given. In jumping down from heights the
+chick does not walk off or fall off (save rarely), but jumps
+off. He meets the situation “loneliness on a small eminence”
+by walking around the edge and peering down; he meets the<span class="pagenum"><a id="Page_161"></a>[161]</span>
+situation “sight of fellow chicks below” by (after an amount
+of hesitation varying roughly with the height) jumping off,
+holding his stubby wings out and keeping right side up. He
+lands on his feet almost every time and generally very
+cleverly. A four days’ chick will jump down a distance
+eight times his own height without hurting himself a bit. If
+one takes a chick two or three weeks old who has never had
+a chance to jump up or down, and puts him in a box with
+walls three times the height of the chick’s back, he will
+find that the chick will jump, or rather fly, nearly, if not
+quite, over the wall, flapping his wings lustily and holding
+on to the edge with his neck while he clambers over. Chicks
+one day old will, in about 57 per cent of the cases, balance
+themselves for five or six seconds when placed on a stiff
+perch. If eight or nine days old, they will, though never
+before on any perch or anything like one, balance perfectly
+for a minute or more. The muscular coördination required
+is invoked immediately when the chick feels the situation
+“feet on a perch.” The <i>strength</i> is lacking in the first few
+days. From the fifth or sixth day on chicks are also able
+(their ability increases with age) to balance themselves on a
+slowly swinging perch.</p>
+
+<p>Another complex coördination is seen in the somewhat remarkable
+instinct of swimming. Chicks only a day or two
+old will, if tossed into a pond, head straight for the shore and
+swim rapidly to it. It is impossible to compare their movements
+in so doing with those of ducklings, for the chick is
+agitated, paddles his feet very fast and swims to get out,
+not for swimming’s sake. Dr. Bashford Dean, of Columbia
+University, has suggested to me that the movements
+may not be those of swimming, but only of running. At all
+events, they are utterly different from those of an adult fowl.
+In the case of the adult there is no vigorous instinct to strike<span class="pagenum"><a id="Page_162"></a>[162]</span>
+out toward the shore. The hen may try to fly back into the
+boat if it is dropped overboard, and whether dropped in or
+slung in from the shore, will float about aimlessly for a while
+and only very slowly reach the shore. The movements the
+chick makes do look to be such as trying to run in water
+might lead to, but it is hard to see why a hen shouldn’t run
+to get out of cold water as well as a chick. If, on the other
+hand, the actions of the chick are due to a real swimming instinct,
+it is easy to see that, being unused, the instinct might
+wane as the animal grew up.</p>
+
+<p>Such instinctive coördinations as these, together with the
+walking, running, preening of feathers, stretching out of leg
+backward, scratching the head, etc., noted by other observers,
+make the infant chick a very interesting contrast to the
+infant man. That the helplessness of the child is a sacrifice
+to plasticity, instability and consequent power to develop we
+all know; but one begins to realize how much of a sacrifice
+when one sees what twenty-one days of embryonic life do for
+the chick brain. And one cannot help wondering whether
+some of the space-perception we trace to experience, some
+of the coördinations which we attribute to a gradual development
+from random, accidentally caused movements may
+not be more or less definitely provided for by the child’s
+inherited brain structure. Walking has been found to be
+instinctive; why not other things?</p>
+
+<h3><span class="smcap">Instinctive Emotional Reactions</span></h3>
+
+<p>The only experiments to which I wish to refer at length
+under this heading are some concerning the chick’s instinctive
+fears. Before describing them, it may be well to mention
+their general bearing on the results obtained by Spalding
+and Morgan. They corroborate Morgan’s decision that
+no well-defined specific fears are present; that the fears of<span class="pagenum"><a id="Page_163"></a>[163]</span>
+young chicks are of strange moving objects in general, shock
+in general, strange sounds in general. On the other hand, no
+such general disturbances of the chick’s environment led to
+such well-marked reactions as Spalding described. And so
+when Morgan thinks that such behavior as Spalding witnessed
+on the part of the chick that heard the hawk’s cry
+demands for its explanation nothing more than a general
+fear of strange sounds, my experiments do not allow me to
+agree with him. If Spalding really saw the conduct which
+he says the chick exhibited on the third day of its life in the
+presence of man, and later at the stimulus of the sight or
+sound of the hawk, there are specific reactions. For the
+running, crouching, silence, quivering, etc., that one gets
+by yelling, banging doors, tormenting a violin, throwing
+hats, bottles, or brushes at the chick is never anything like so
+pronounced and never lasts one tenth as long as it did with
+Spalding’s chicks. But, as to the fear of man, Spalding
+must have been deluded. In the second, third and fourth
+days there is no such reaction to the sight of man as he
+thought he saw. Miss Hattie E. Hunt, in the <i>American
+Journal of Psychology</i>, Vol. IX., No. 1, asserts that there is
+no instinctive fear of a cat. Morgan did not find such. I
+myself put chicks of 2, 5, 9 and 17 days (different individuals
+each time, 11 in all) in the presence of a cat. They
+showed no fear, but went on eating as if there was nothing
+about. The cat was still, or only slowly moving. I further
+put a young kitten (eight inches long) in the pen with
+chicks. He felt of them with his paw, and walked around
+among them for five or ten minutes, yet they showed no fear
+(nor did he instinctively attack them). If, however, you let
+a cat jump at chicks in real earnest, they will not stay to be
+eaten, but will manifest fear—at least chicks three to four
+weeks old will. I did not try this experiment with chicks<span class="pagenum"><a id="Page_164"></a>[164]</span>
+at different ages, because it seemed rather cruel and degrading
+to the experimenter. When in the case of the older chicks
+nature happened to make the experiment, it was hard to decide
+whether there was more violent fear of the jumping cat
+than there was when one threw a basket or football into the
+pen. There was not very much more.</p>
+
+<p>We may now proceed to a brief recital of the facts shown
+by the experiments in so far as they are novel. It should be
+remembered throughout that in every case chicks of different
+ages were tested so as to demonstrate transitory instincts
+if such existed, <i>e.g.</i>, the presence of a fear of flame
+was tested with chicks 59 and 60, one day old, 30 and 32, two
+days old, 21 and 22, three days old, 23 and 24, seven days
+old, 27 and 29, nine days old, 16 and 19, eleven days old,
+and so on up to twenty-days-old chicks. By thus using
+different subjects at each trial one, of course, eliminates any
+influence of experience.</p>
+
+<p>The first notable fact is that there develops in the first
+month a general fear of novel objects in motion. For four
+or five days there seems to be no such. You may throw a
+hat or slipper or shaving mug at a chick of that age, and he
+will do no more than get out of the way of it. But a twenty-five-days-old
+chick will generally chirr, run and crouch for
+five or ten seconds. My records show this sort of thing beginning
+about the tenth day, but it is about ten days more
+before it is very marked. In general, also, the reaction is
+more pronounced if many chicks are together, and is then
+displayed earlier (only two at a time were taken in the experiments
+the results of which have just been quoted).
+Thus the reaction is to some degree a social performance, the
+presence of other chicks combining with the strange object
+to increase the vigor of the reaction. Chicks ordinarily
+scatter apart when they thus run from an object.</p>
+
+<p><span class="pagenum"><a id="Page_165"></a>[165]</span></p>
+
+<p>One witnesses a similar gradual growth of the fear of man
+(not as such probably, but merely as a large moving object).
+For four or five days you can jump at the chick, grab at it
+with your hands, etc., without disturbing it in the least. A
+chick twenty days old, however, although he has never been
+touched or approached by a man, and in some cases never
+seen one except as the daily bringer of food, and has never
+been in any way injured by any large moving object of any
+sort, will run from you if you try to catch him or even get
+very near him. There is, however, even then, nothing like
+the utter fear described by Spalding.</p>
+
+<p>Up to thirty days there was no fear of a mocking bird into
+whose cage the chicks were put, no fear of a stuffed hawk or a
+stuffed owl (kept stationary). Chicks try to escape from
+water (even though warmed to the temperature of their
+bodies) from the very first. Up to forty days there appears
+no marked waning of the instinct. They did not show any
+emotional reaction to the flame produced by six candles
+stuck closely together. From the start they react instinctively
+to confinement, to loneliness, to bodily restraint, but
+their feeling in these cases would better be called discomfort
+than fear. From the 10th or 12th to the 20th day, and
+probably later and very possibly earlier, one notices in
+chicks a general avoidance of open places. Turn them out
+in your study and they will not go out into the middle of the
+room, but will cling to the edges, go under chairs, around
+table legs and along the walls. One sees nothing of the sort
+up through the fourth day. Some experiments with feeding
+hive bees to the chicks are interesting in connection with
+the following statement by Lloyd Morgan: “One of my
+chicks, three or four days old, snapped up a hive bee and
+ran off with it. Then he dropped it, shook his head much
+and often, and wiped his bill repeatedly. I do not think<span class="pagenum"><a id="Page_166"></a>[166]</span>
+he had been stung: <i>probably he tasted the poison</i>” (‘Introduction
+to Comparative Psychology,’ p. 86). I fed seven
+bees apiece to three chicks from ten to twenty days old.
+<i>They ate them all greedily</i>, first smashing them down on the
+ground violently in a rather dexterous manner. Apparently
+this method of treatment is peculiar to the object. Chicks
+<i>three</i> days old did not eat the bees. Some pecked at
+them, but none would snap them up, and when the bee
+approached, they sometimes sounded the danger note.</p>
+
+<p>Finally an account may be given of the reaction of chicks
+at different ages, up to twenty-six days, to loud sounds.
+These were the sounds made by clapping the hands, slamming
+a door, whistling sharply, banging a tin pan on the
+floor, mewing like a cat, playing a violin, thumping a coal
+scuttle with a shovel, etc. Two chicks were together in
+each experiment. Three fourths of the times no effect
+was produced. On the other occasions there was some running
+or crouching or, at least, starting to run or crouch;
+but, as was said, nothing like what Spalding reports as the
+reaction to the ‘cheep’ of the hawk. It is interesting to
+notice that the two most emphatic reactions were to the
+imitation mew. One time a chick ran wildly, chirring, and
+then crouched and stayed still until I had counted 105. The
+other time a chick crouched and stayed still until I counted
+40. But the other chick with them did not; and in a dozen
+other cases the ‘meaw’ had no effect.</p>
+
+<p>I think that the main interest of most of these experiments
+is the proof they afford that instinctive reactions are not
+necessarily definite, perfectly appropriate and unvarying responses
+to accurately sensed and, so to speak, estimated
+stimuli. The old notion that instinct was a God-given substitute
+for reason left us an unhappy legacy in the shape
+of the tendency to think of all inherited powers of reaction as<span class="pagenum"><a id="Page_167"></a>[167]</span>
+definite particular acts invariably done in the presence of
+certain equally definite situations. Such an act as the
+spider’s web-spinning might be a stock example. Of
+course, there are many such instinctive reactions in which a
+well-defined act follows a well-defined stimulus with the
+regularity and precision with which the needle approaches
+the magnet. But our experiments show that there are acts
+just as truly instinctive, depending in just the same way on
+inherited brain-structure, but characterized by being vague,
+irregular, and to some extent dissimilar, reactions to vague,
+complex situations.</p>
+
+<p>The same stimulus doesn’t always produce just the same
+effect, doesn’t produce precisely the same effect in all individuals.
+The chick’s brain is evidently prepared in a
+general way to react more or less appropriately to certain
+stimuli, and these reactions are among the most important
+of its instincts or inherited functions. But yet one cannot
+take these and find them always and everywhere. This
+helps us further to realize the danger of supposing that in
+observation of animals you can depend on a rigid uniformity.
+One would never suppose because one boy twirled
+his thumb when asked a question that all boys of that age
+did. But naturalists have been ready to believe that
+because one young animal made a certain response to a certain
+stimulus, the thing was an instinct common to all in precisely
+that same form. But a loud sound may make one
+chick run, another crouch, another give the danger call, and
+another do nothing whatever.</p>
+
+<p>In closing this article I may speak of one instinct which
+shows itself clearly from at least as early as the sixth day,
+which is preparatory to the duties of adult life and of no
+other use whatsoever. It is interesting in connection with
+the general matter of animal play. The phenomenon is as<span class="pagenum"><a id="Page_168"></a>[168]</span>
+follows: The chicks are feeding quietly when suddenly two
+chicks rush at each other, face each other a moment and then
+go about their business. This thing keeps up and grows
+into the ordinary combat of roosters. It is rather a puzzle
+on any theory that an instinct needed so late should begin
+to develop so early.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_169"></a>[169]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_IV">CHAPTER IV<br>
+<span class="smcap">A Note on the Psychology of Fishes</span><a id="FNanchor_21" href="#Footnote_21" class="fnanchor">[21]</a></h2>
+
+</div>
+
+<p>Numerous facts witness in a vague way to the ability of
+fishes to profit by experience and fit their behavior to situations
+unprovided for by their innate nervous equipment.
+All the phenomena shown by fishes as a result of taming are,
+of course, of this sort. But such facts have not been exact
+enough to make clear the mental or nervous processes involved
+in such behavior, or simple enough to be available as
+demonstrations of such processes. It seemed desirable to
+obtain evidence which should demonstrate both the fact and
+the process of learning or intelligent activity in the case of
+fishes and demonstrate them so readily that any student
+could possess the evidence first hand.</p>
+
+<p>Through the kindness of the officials of the United States
+Fish Commission at Woods Holl, especially of the director,
+Dr. Bumpus, I was able to test the efficiency of some simple
+experiments directed toward this end. The common Fundulus
+was chosen as a convenient subject, and also because
+of the neurological interest attaching to the formation of
+intelligent habits by a vertebrate whose forebrain lacks a
+cortex.</p>
+
+<p>The fishes studied were kept in an aquarium (about 4 feet
+long by 2 feet wide, with a water depth of about 9 inches)
+represented by <a href="#figure24">Fig. 24</a>. The space at one end, as represented<span class="pagenum"><a id="Page_170"></a>[170]</span>
+by the lines in the figure, was shaded from the sun by
+a cover, and all food was dropped in at this end. Along each
+side of the aquarium were
+fastened simple pairs of
+cleats, allowing the experimenter
+to put across
+it partitions of wood,
+glass or wire screening.
+One of these in position
+is shown in the figure by
+the dotted line. These partitions were made each with an
+opening, as shown in <a href="#figure25">Fig. 25</a>. If now we cause the fish to
+leave his shady corner and swim up to
+the sunny end by putting a slide (without
+any opening) in behind him at <i>D</i>
+and moving it gently from <i>D</i> to <i>A</i> and
+then place, say slide <i>I</i>, across the
+aquarium at 1, we shall have a chance
+to observe the animal’s behavior to
+good purpose.</p>
+
+<div class="figcenter illowp100" id="figure24" style="max-width: 18.75em;">
+  <img class="w100" src="images/figure24.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 24.</span></p>
+</div>
+
+<div class="figcenter illowp50" id="figure25" style="max-width: 12.5em;">
+  <img class="w100" src="images/figure25.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 25.</span></p>
+</div>
+
+<p>This fish dislikes the sunlight and
+tries to get back to <i>D</i>. He reacts to
+the situation in which he finds himself
+by swimming against the screen, bumping against it here
+and there along the bottom. He may stop and remain
+still for a while. He will occasionally rise up toward the
+top of the water, especially while swimming up and down
+the length of the screen. When he happens to rise up to the
+top at the right-hand end, he has a clear path in front of him
+and swims to <i>D</i> and feels more comfortable.</p>
+
+<p>If, after he has enjoyed the shade fifteen minutes or more,
+you again confine him in <i>A</i>, and keep on doing so six or eight
+times a day for a day or so, you will find that he swims<span class="pagenum"><a id="Page_171"></a>[171]</span>
+against the screen less and less, swims up and down along it
+fewer and fewer times, stays still less and less, until finally
+his only act is to go to the right-hand side, rise up, and
+swim out. In correspondence with this change in behavior
+you will find a very marked decrease in the time he takes to
+escape. The fish has clearly profited by his experience and
+modified his conduct to suit a situation for which his innate
+nervous equipment did not definitely provide. He has, in
+common language, <i>learned</i> to get out.</p>
+
+<p>This particular experiment was repeated with a number of
+individuals. Another experiment was made, using three
+slides, <i>II</i>, <i>III</i>, and another, requiring the fish to find his way
+from <i>A</i> to <i>B</i>, <i>B</i> to <i>C</i>, and from <i>C</i> to <i>D</i>. The results of these
+and still others show exactly the same general mental
+process as does the one described—a process which I have
+discussed at length elsewhere.</p>
+
+<p>Whatever interest there is in the demonstration in the case
+of the bony fishes of the same process which accounts for so
+much of the behavior of the higher vertebrates may be left to
+the neurologists. The value of the experiment, if any, to
+most students will perhaps be the extreme simplicity of the
+method, the ease of administering it, and its possibilities.
+By using long aquaria, one can study the formation of very
+complex series of acts and see to what extent any fish can
+carry the formation of such series. By proper arrangements
+the delicacy of discrimination of the fish in any respect
+may be tested. The artificiality of the surroundings
+may, of course, be avoided when desirable.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_172"></a>[172]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_V">CHAPTER V<br>
+<span class="smcap">The Mental Life of the Monkeys; an Experimental Study</span><a id="FNanchor_22" href="#Footnote_22" class="fnanchor">[22]</a></h2>
+
+</div>
+
+<p>The literary form of this monograph is not at all satisfactory
+to its author. Compelled by practical considerations
+to present the facts in a limited space, he has found it
+necessary to omit explanation, illustration and many rhetorical
+aids to clearness and emphasis. For the same reason
+detailed accounts of the administration of the experiments
+have not always been given. In many places theoretical
+matters are discussed with a curtness that savors of dogmatism.
+In general when a theoretical point has appeared
+justified by the evidence given, I have, to economize space,
+withheld further evidence.</p>
+
+<p>There is, however, to some extent a real fitness in the lack
+of clearness, completeness and finish in the monograph. For
+the behavior of the monkeys, by virtue of their inconstant
+attention, decided variability of performance, and generally
+aimless, unforetellable conduct would be falsely represented
+in any clean-cut, unambiguous, emphatic exposition. The
+most striking testimony to the mental advance of the monkeys
+over the dogs and cats is given by the difficulty of making
+clear emphatic statements about them.</p>
+
+<p><span class="pagenum"><a id="Page_173"></a>[173]</span></p>
+
+<h3><span class="smcap">Introduction</span></h3>
+
+<p>The work to be described in this paper is a direct continuation
+of the work done by the author in 1897-1898 and
+described in Monograph Supplement No. 8 of the <i>Psychological
+Review</i> under the heading, ‘Animal Intelligence;
+an Experimental Study of the Associative Processes in
+Animals.’<a id="FNanchor_23" href="#Footnote_23" class="fnanchor">[23]</a> This monograph affords by far the best introduction
+to the present discussion, and I shall therefore
+assume an acquaintance with it on the part of my readers.</p>
+
+<p>It will be remembered that evidence was there given that
+ordinary mammals, barring the primates, did not infer or
+compare, did not imitate in the sense of ‘learning to do an
+act from seeing it done,’ did not learn various simple acts
+from being put through them, showed no signs of having in
+connection with the bulk of their performances any mental
+images. Their method of learning seemed to be the gradual
+selection of certain acts in certain situations by reason
+of the satisfaction they brought. Quantitative estimates
+of this gradualness were given for a number of dogs and
+cats. Nothing has appeared since the ‘Experimental Study’
+to negate any of these conclusions in the author’s mind.
+The work of Kline and Small<a id="FNanchor_24" href="#Footnote_24" class="fnanchor">[24]</a> on rodents shows the same
+general aspect of mammalian mentality.</p>
+
+<p>Adult human beings who are not notably deficient in
+mental functions, at least all such as psychologists have
+observed, possess a large stock of images and memories.
+The sight of a chair, for example, may call up in their minds
+a picture of the person who usually sits in it, or the sound
+of his name. The sound of a bell may call up the idea of<span class="pagenum"><a id="Page_174"></a>[174]</span>
+dinner. The outside world also is to them in large part a
+multitude of definite percepts. They feel the environment
+as trees, sticks, stones, chairs, tables, letters, words, etc.
+I have called such definite presentations ‘free ideas’ to
+distinguish them from the vague presentations such as
+atmospheric pressure, the feeling of malaise, of the position
+of one’s body when falling, etc. It is such ‘free ideas’
+which compose the substance of thought and which
+lead us to perhaps the majority of the different acts we
+perform, though we do, of course, react to the vaguer sort
+as well. I saw definitely in writing the last sentence the
+words ‘majority of the different acts’ and thought ‘we
+perform’ and so wrote it. I see a bill and so take check
+book and pen and write. I think of the cold outside and
+so put on an overcoat. This mental function ‘having free
+ideas,’ gives the possibility of learning to meet situations
+properly by thinking about them, by being reminded of
+some property of the fact before us or some element therein.</p>
+
+<p>We can divide all learning into (1) <i>learning by trial and
+accidental success</i>, by the strengthening of the connections
+between the sense-impressions representing the situation
+and the acts—or impulses and acts—representing our
+successful response to it and by the inhibition of similar
+connections with unsuccessful responses; (2) <i>learning by
+imitation</i>, where the mere performance by another of a
+certain act in a certain situation leads us to do the same;
+and (3) <i>learning by ideas</i>, where the situation calls up some
+idea (or ideas) which then arouses the act or in some way
+modifies it.</p>
+
+<p>The last method of learning has obviously been the means
+of practically all the advances in civilization. The evidence
+quoted a paragraph or so back from the Experimental
+Study shows the typical mammalian mind to be one which<span class="pagenum"><a id="Page_175"></a>[175]</span>
+rarely or never learns in this fashion. The present study
+of the primates has been a comparative study with two
+main questions in view: (1) How do the monkeys vary
+from the other mammals in the general mental functions
+revealed by their methods of learning? (2) How do they,
+on the other hand, vary from adult civilized human beings?</p>
+
+<p>The experiments to be described seem, however, to be of
+value apart from the possibility of settling crucial questions
+by means of the evidence they give. To obtain exact
+accounts of what animals can learn by their own unaided
+efforts, by the example of their fellows or by the tuition
+of a trainer, and of how and how fast they learn in each
+case, seems highly desirable. I shall present the results
+in the manner which fits their consideration as arguments
+for or against some general hypotheses, but the naturalist
+or psychologist lacking the genetic interest may find an
+interest in them at their face value. I shall confine myself
+mainly to questions concerning the method of learning of
+the primates, and will discuss their sense-powers and unlearned
+reactions or instincts only in so far as is necessary
+to its comprehension.</p>
+
+<p>It has been impossible for the author to make helpful
+use of the anecdotes and observations of naturalists and
+miscellaneous writers concerning monkey intelligence.
+The objections to such data pointed out in Chapter II,
+<a href="#Page_22">pp. 22-26</a>, hold here. Moreover it is not practicable
+to sift out the true from the false or to interpret these
+random instances of animal behavior even if assuredly true.
+In the study of animal life the part is only clear in the
+light of the whole, and it is wiser to limit conclusions to
+such as are drawn from the constant and systematic study
+of a number of animals during a fairly long time. After
+a large enough body of such evidence has been accumulated
+we may be able to interpret random observations.</p>
+
+<p><span class="pagenum"><a id="Page_176"></a>[176]</span></p>
+
+<p>The subjects of the experiments were three South American
+monkeys of the genus <i>Cebus</i>. At the time of beginning
+the experiment No. 1 was about half grown, No. 2 was about
+one fourth full size and No. 3 was about half grown. No. 1
+was under observation from November, 1899, to February,
+1900; No. 2 and No. 3 from October, 1900, to February,
+1901. No. 1 was during the period of experimentation
+decidedly tame, showing no fear whatever of my presence
+and little fear at being handled. He would handle and
+climb over me with no hesitation. No. 2 was timid, did
+not allow handling, but showed no fear of my presence and
+no phenomena that would differentiate his behavior in
+the experiments discussed from that of No. 1, save much
+greater caution in all respects. No. 3 also showed no fear
+at my presence. Any special individual traits that are of
+importance in connection with any of the observations will
+be mentioned in their proper places. No. 1 was kept until
+June, 1900, in my study in a cage 3 by 6 by 6 feet, and was
+left in the country till October, 1900. From October, 1900,
+all three were kept in a room 8 by 9 feet, in cages 6 feet tall
+by 3 long by 2.6 wide for Nos. 1 and 2, 3 feet by 3 feet by 20
+inches for No. 3. I studied their behavior in learning to
+get into boxes, the doors to which could be opened by
+operating some mechanical contrivance, in learning to
+obtain food by other simple acts, in learning to discriminate
+between two signals, that is, to respond to each by a different
+act, and in their general life.</p>
+
+<p>Following the order of the ‘Animal Intelligence,’ I shall
+first recount the observations of the way the monkeys
+learned, solely by their own unaided efforts, to operate
+simple mechanical contrivances.</p>
+
+<p>Besides a number of boxes such as were used with the
+dogs and cats (see <a href="#figure01">illustration on p. 30</a>), I tried a variety<span class="pagenum"><a id="Page_177"></a>[177]</span>
+of arrangements which could be set up beside a cage, and
+which would, when some simple mechanism was set in
+action, throw a bit of food into the cage. <a href="#figure26">Figure 26</a>
+shows one of these. See description of QQ (ff) on <a href="#Page_182">page 182</a>.</p>
+
+<div class="figcenter illowp95" id="figure26" style="max-width: 43.75em;">
+  <img class="w100" src="images/figure26.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 26.</span> <i>A</i>, loop; <i>BB</i>, lever,
+pivoted at <i>M</i>. A bit of food put in front of <i>C</i>
+would be thrown down the chute <i>DDD</i> when <i>A</i> was released.</p>
+</div>
+
+<h3><span class="smcap">Apparatus</span></h3>
+
+<p>The different mechanisms which I used were the following:—</p>
+
+<p>Box BB (O at back) was about 20 by 14 by 12 inches with
+a door in the front which was held by a bolt to which was
+tied a string. This string ran up the front of the box outside,
+over a pulley, across the top, and over another pulley
+down into the box, where it ended in a loop of wire.</p>
+
+<p>Box MM (bolt) was the same as BB but with no string
+and loop attachment to the bolt.</p>
+
+<p>Box CC (single bar) was a box of the same size as BB.<span class="pagenum"><a id="Page_178"></a>[178]</span>
+The door was held by a bar about 3 by 1 by 5 inches which
+swung on a nail at the left side.</p>
+
+<p>Box CCC (double bar) was CC with a second similar
+bar on the right side of the door.</p>
+
+<p>Box NN (hook) was a box about the size of BB with its
+door held by an ordinary hook on the left side which hooked
+through an eyelet screwed into the door.</p>
+
+<p>Box NNN was NN with the hook on the right instead
+of the left side.</p>
+
+<p>Box NNNN was box NN with two hooks, one on each
+side.</p>
+
+<p>Apparatus OO (string box) consisted of a square box tied
+to a string, which formed a loop running over a pulley by
+the cage and a pulley outside, so that pulling on the under
+string would bring the box to the cage. In each experiment
+the box was first pulled back to a distance of 2 feet 3 inches
+from the cage, and a piece of banana put in it. The monkey
+could, of course, secure the banana by pulling the box
+near enough.</p>
+
+<p>Apparatus OOO was the same as OO, with the box tied
+to the upper string, so that the upper string had to be pulled
+instead of the lower.</p>
+
+<p>Box PP was about the size of BB. Its door was held by
+a large string securely fastened at the right, passing across
+the front of the door and ending in a loop which was put
+over a nail on the box at the left of the door. By pulling
+the string off the nail the door could be opened.</p>
+
+<p>Box RR (wood plug) was a box about the size of BB.
+The door was held by a string at its top, which passed up
+over the front and top to the rear, where it was fastened
+to a wooden plug which was inserted in a hole in the top of
+the box. When the plug was pulled out of the hole, the
+door would fall open.</p>
+
+<p><span class="pagenum"><a id="Page_179"></a>[179]</span></p>
+
+<p>Box SS (triple; wood-plug, hook and bar) was a box
+about the size of BB. To open the door, a bar had to be
+pushed around, a hook unhooked and a plug removed from
+a hole in the top of the box.</p>
+
+<p>Box TT (nail plug) was 14 by 10 by 10 inches with a door
+5.5 by 10 on the right side of the front, the rest of the front
+being barred up. The door was hinged at the bottom and
+fastened at its top to a wire which was fastened to a nail
+2.5 inches long, which, when inserted in a hole 0.25 inches
+in diameter at the back of the top of the box, held the door
+closed. By drawing out this nail and pulling the door
+the animal could open the door.</p>
+
+<p>Box VV (plug at side) was a box about 18 by 10 by 10,
+the door held by a plug passing through a hole in the side
+of the box. When the plug was pulled out, the door could
+be pushed inward.</p>
+
+<p>Box W (loop) was 17 by 10 by 10 inches with a door 5 by 9
+at the left side of its front hinged at the bottom. The door
+was prevented from falling inward by a wire stretched
+behind it. It was prevented from falling outward by a
+wire firmly fastened at the right side and held by a loop over
+a nail at the left. By pulling the loop outward and to the
+left it could be freed from the nail. The door could then
+be pulled open.</p>
+
+<p>Box WW (bar inside) was 16 by 14 by 10 inches with a
+door 4 by 11 at the left of its front hinged at the bottom.
+The door could be pushed in or pulled out when a bar on
+its inside was lifted out of a latch. The bar was accessible
+from the outside through an opening in the front of the
+box. It had to be lifted to a height of 1.5 inches (an angle
+of about 30°).</p>
+
+<p>Box XX (bar outside) was about 13 by 11 by 10 inches
+with a door 7 by 8 on the left side of the front. The door<span class="pagenum"><a id="Page_180"></a>[180]</span>
+was held in place by a bar swinging on a nail at the top,
+with its other end resting in a latch at the left side of the
+box. By pushing this up through an angle of 45° the door
+could be opened.</p>
+
+<p>Box YY (push bar) was a box 16 by 8 by 12 inches with
+a door at the left of its front. The door was held by a brass
+bar which swung down in front of an L-shaped piece of
+steel fastened to the inside of the door. This brass bar
+was hung on a pivot at its center and the other end attached
+to a bar of wood; the other end of this bar projected
+through a hole at the right side of the box. By pushing
+this bar in about an inch the door could be opened.</p>
+
+<p>Box LL (triple; nail plug, hook and bar) was a box 10 by
+10 by 13 with a door 3 by 8.5 at the left side. The door
+could be opened only after (1) a nail plug had been removed
+from a hole in the back of the top of the box as in TT, (2) a
+hook in the door had been unhooked, and (3) a bar on the
+left side had been turned from a horizontal to a vertical
+position.</p>
+
+<p>Box Alpha (catch at back) was 11 by 10 by 15 with the
+door (4 by 4) in the left side of its front. The door was held
+by a bolt, which, when let down, held in a catch on the inside
+of the door. A string fastened to the bolt ran across to
+the back of the box and through a hole to the outside.
+There it ended in a piece of wood 2.5 by 1 by .25 inches.
+When this piece of wood was pulled, the bolt went up and
+the door fell open.</p>
+
+<p>Box Beta was the same as NN except in size. It was
+10 by 10 by 13 inches.</p>
+
+<p>Box KK (triple; bolt, side plug, and knob) was a box 16
+by 9 by 11 with a door at the left side of the front. The
+door was held by a bolt on the right side, a wooden plug
+stuck through a hole in the box on its left side and a nail<span class="pagenum"><a id="Page_181"></a>[181]</span>
+which held in a catch at its top. This nail was fastened
+to a wooden knob (1 by 5 by .375) which lay in a depression
+at the top of the box. Only when the bolt had been
+drawn and the plug and knob pulled, could the door be
+opened.</p>
+
+<p>Box Gamma (wind) was 10 by 10 by 13 inches with its
+door held by a wire fastened at the top and wound three
+times about a screw eye in the top of the box. By unwinding
+the wire the door could be opened.</p>
+
+<p>Box Delta (push back) was 12 by 11 by 10 inches. Its
+door was held by a wooden bar projecting from the right
+two inches in front of it. This bar was so arranged that
+it could be pushed or pulled toward the right, allowing the
+door to fall open. It could not be swung up or down.</p>
+
+<p>Box Epsilon (lever or push down) was 12 by 9 by 5 inches.
+At the right side of its front was a hole ½ inch broad by 1½
+inches up and down. Across this hole on the inside of the
+box was a strip of brass, the end of one bar of a lever. If
+this strip was depressed ⅛ of an inch, the door at the extreme
+left would be opened by a spring.</p>
+
+<p>Box Zeta (side plug) was 12 by 11 by 10 inches. Its door
+was held by a round bar of wood put through a hoop of
+steel at the left side of the box. This bar was loose and
+could easily be pulled out, allowing the door to be opened.</p>
+
+<p>Box Theta was the same as KK except that the door
+could be opened as soon as the bolt alone was pulled or
+pushed up.</p>
+
+<p>Box Eta was like Alpha save that the object at the back
+of the box to be pulled was a brass ring.</p>
+
+<p>Apparatus QQ (chute) consisted of a lever mechanism so
+arranged that by pushing in a bar of wood ¼ to ½ an inch,
+a piece of banana would be thrown down a chute into the
+cage. The apparatus was placed outside the cage in such a<span class="pagenum"><a id="Page_182"></a>[182]</span>
+way that it could be easily reached by the monkey’s arm
+through the wire netting.</p>
+
+<p>QQ (a) was of the same general plan. By turning a
+handle through 270° food could be obtained.</p>
+
+<p>QQ (b) was like QQ (a) except that 2½ full revolutions
+of the handle in one direction were necessary to cause the
+food to drop down.</p>
+
+<p>QQ (c) was a chute apparatus so arranged as to work when
+a nail was pulled out of a hole.</p>
+
+<p>QQ (d) was arranged to work at a sharp pull upon a brass
+ring hanging to it.</p>
+
+<p>QQ (e) was arranged to work when a hook was unhooked.</p>
+
+<p>QQ (f) was arranged to work when a loop at the end of a
+string was pulled off from a nail.</p>
+
+<p>QQ (ff) was QQ (f) with a stiff wire loop instead of a loop
+of string.</p>
+
+<h3><span class="smcap">Experiments on the Abilities of the Monkeys to Learn Without Tuition</span></h3>
+
+<p>I will describe a few of the experiments with No. 1 as
+samples and then present the rest in the form of a table.
+No. 1 was tried first in BB (O at back) on January 17, 1900,
+being <i>put inside</i>. He opened the box by pulling up the
+string just above the bolt. His times were .05, 1.38, 6.00,
+1.00, .10, .05, .05. He was not easily handled at this time,
+so I changed the experiment to the form adopted in future
+experiments. I put the food inside and left the animal to
+open the door from the outside. He pulled the string up
+within 10 seconds each time out of 10 trials.</p>
+
+<p>I then tried him in MM (bolt). He failed in 15. I then
+(January 18th) tried him in CC (single bar outside). He
+got in in 36.00 minutes; he did not succeed a second time<span class="pagenum"><a id="Page_183"></a>[183]</span>
+that night, but in the morning the box was open. His
+times thenceforth were 20, 10, 16, 25 and on January 19th,
+40, 5, 12, 8, 5, 5, 5 seconds.</p>
+
+<p>I then tried him (January 21, 1900) in CCC (double bar).
+He did it at first by pushing the old bar and then pulling
+at the door until he worked the second bar gradually
+around. Later he at times pushed the second bar. The
+times taken are shown in the time-curve. I then (January
+25th) tried him in NN (hook). See time-curves on
+<a href="#Page_185">page 185</a>. I then (January 27th) tried him in NNN (hook
+on other side). He opened it in 6, 12 and 4 seconds in the
+first three trials. I then (20 minutes later) tried him with
+NNNN (double hook). He opened the door in 12, 10, 6
+and 6 seconds. I then (January 27th) tried him with PP
+(string across). He failed in 10. I then (February 21st)
+tried him with apparatus OO (string box). For his progress
+as shown by the times taken see the time-curve. His
+progress is also shown in the decrease of the useless pullings
+at the wrong string. There were none in the 9th trial,
+14th, 15th, 16th, 18th, 24th, and following trials.</p>
+
+<p>No. 1 was then (February 24th) tried with OOO (string
+box with box on upper string). No. 1 succeeded in 2.20,
+then failed in 10.00. The rest of the experiment will be
+described under imitation.</p>
+
+<p>He was next tried (March 24th) with apparatus QQ
+(chute). He failed in 10.00, though he played with the apparatus
+much of the time. Other experiments were with
+box RR (wood-plug) (April 5th). He failed in 10.00.
+After he had, in a manner to be described later, come to
+succeed with RR, he was tried in box SS (triple; wood-plug,
+hook and bar) (April 18th); see time-curve. No more
+experiments of this nature were tried until October, 1900.</p>
+
+<p>The rest of the experiments with No. 1 and all those with<span class="pagenum"><a id="Page_184"></a>[184]</span>
+No. 2 and No. 3 may best be enumerated in the form of a
+table. (See Table 9 on <a href="#Page_187">page 187</a>.) It will show briefly the
+range of performances which the unaided efforts of the
+animals can cope with. It will also give the order in which
+each animal experienced them. F means that the animal
+failed to succeed. The figures are minutes and seconds,
+and represent the time taken in the first trial or the
+total time taken without success where there is an F. In
+cases where the animal failed in say 10 minutes, but in a
+later trial succeeded, say in 2.40, the record will be 2.40
+after 10 F. There are separate columns for all three animals,
+headed No. 1, No. 2 and No. 3. Im. stands for a practically
+immediate success.</p>
+
+<p>The curves on pages 185 and 186 (<a href="#figure27">Figs. 27 and 28</a>) show the
+progress of the formation of the associations in those cases
+where the animal was given repeated trials, with, however,
+nothing to guide him but his own unaided efforts. Each
+millimeter on the abscissa represents one trial and each
+millimeter on the ordinate represents 10 seconds, the ordinates
+representing the time taken by the animal to open
+the box. A break in the curve, or an absence of the curve
+at the beginning of the base-line represents cases where the
+animal failed in 10 minutes or took a very long time to get
+out.</p>
+
+<p><span class="pagenum"><a id="Page_185"></a>[185]</span></p>
+
+<div class="figcenter illowp48" id="figure27" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure27.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 27.</span></p>
+</div>
+
+<div class="figcenter illowp48" id="figure28" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure28.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 28.</span></p>
+</div>
+
+<p>In discussing these facts we may first of all clear our way
+of one popular explanation, that this learning was due to
+‘reasoning.’ If we use the word reasoning in its technical
+psychological meaning as the function of reaching conclusions
+by the perception of relations, comparison and inference,
+if we think of the mental content involved as feelings
+of relation, perceptions of similarity, general and abstract
+notions and judgments, we find no evidence of reasoning<span class="pagenum"><a id="Page_186"></a>[186]</span>
+in the behavior of the monkeys toward the mechanisms
+used. And this fact nullifies the arguments for reasoning in
+their case as it did in the case of the dogs and cats. The
+argument that successful dealings with mechanical contrivances
+imply that the animals reasoned out the properties
+of the mechanisms, is destroyed when we find mere selection
+from their general instinctive activities sufficient to cause
+success with bars, hooks, loops, etc. There is also in the
+case of the monkeys, as in that of the other mammals, positive
+evidence of the absence of any general function of reasoning.
+We shall find that at least very many simple acts were
+not learned by the monkeys in spite of their having seen me
+perform them again and again; that the same holds true
+of many simple acts which they saw other monkeys do,
+or were put through by me. We shall find that after having
+abundant opportunity to realize that one signal meant
+food at the bottom of the cage and another none, a monkey
+would not act from the obvious inference and consistently
+stay up or go down as the case might be, but would make
+errors such as would be natural if he acted under the growing
+influence of an association between sense-impression and
+impulse or sense-impression and idea, but quite incomprehensible
+if he had compared the two signals and made a
+definite inference. We shall find that, after experience
+with several pairs of signals, the monkeys yet failed, when
+a new pair was used, to do the obvious thing to a rational
+mind; viz., to compare the two, think which meant food,
+and act on the knowledge directly.</p>
+
+<p><span class="pagenum"><a id="Page_187"></a>[187]</span></p>
+
+<h4><span class="smcap">Table 9</span></h4>
+
+<table class="borders max60">
+  <tr>
+    <th rowspan="2" class="br"></th>
+    <th colspan="3">No. 1.</th>
+    <th colspan="3">No. 2.</th>
+    <th colspan="3">No. 3.</th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>Min. Sec.</th>
+    <th></th>
+    <th></th>
+    <th>Min. Sec.</th>
+    <th></th>
+    <th></th>
+    <th>Min. Sec.</th>
+    <th></th>
+  </tr>
+  <tr class="new">
+    <td>Box TT (nail plug)</td>
+    <td>Oct. 19, 1900</td>
+    <td class="tdr">0.40</td>
+    <td class="tdr"></td>
+    <td>Oct. 21, 1900</td>
+    <td class="tdr">14.10</td>
+    <td class="tdr"></td>
+    <td>Oct. 21, 1900</td>
+    <td class="tdr">36.00</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box UU (old plug at side)</td>
+    <td>Oct. 19, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 60.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3">Box VV (wire loop)</td>
+    <td rowspan="3" class="nw br">Oct. 20, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr nw">{F 10.00</td>
+    <td class="nw">Oct. 24, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr nw">F 10.00</td>
+    <td rowspan="3" class="nw">Oct. 22, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr nw">{F 10.00</td>
+  </tr>
+  <tr>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+    <td>Oct. 25, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+  </tr>
+  <tr>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">Box WW (bar inside)</td>
+    <td rowspan="4" class="br">Oct. 20, 1900</td>
+    <td rowspan="4" class="br"></td>
+    <td rowspan="4" class="tdr br">F 10.00</td>
+    <td rowspan="4" class="br">Oct. 21, 1900</td>
+    <td rowspan="4" class="tdr br">5.00</td>
+    <td rowspan="4" class="tdr br">after<br>F 30.00</td>
+    <td>Oct. 22, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+  </tr>
+  <tr>
+    <td rowspan="3" class="br">Oct. 24, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">{F&#160;&#160;&#160;5.00</td>
+  </tr>
+  <tr>
+    <td class="tdr"></td>
+    <td class="tdr">{F 10.00</td>
+  </tr>
+  <tr>
+    <td class="tdr"></td>
+    <td class="tdr">{F 15.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box XX (bar outside)</td>
+    <td>Oct. 23, 1900</td>
+    <td class="tdr">im.</td>
+    <td class="tdr">after <a id="FNanchor_25" href="#Footnote_25" class="fnanchor">[25]</a><br>F 10.00</td>
+    <td>Oct. 24, 1900</td>
+    <td class="tdr">3.40</td>
+    <td class="tdr"></td>
+    <td>Oct. 23, 1900</td>
+    <td class="tdr">.30</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box YY (push bar)</td>
+    <td>Oct. 30, 1900</td>
+    <td class="tdr">2.00<a id="FNanchor_26" href="#Footnote_26" class="fnanchor">[26]</a></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box Beta (single hook)</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Oct. 30, 1900</td>
+    <td class="tdr">9.00</td>
+    <td class="tdr">after F 10.00 and 10.00</td>
+    <td>Oct. 24, 1900</td>
+    <td class="tdr">im.</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box LL (triple; nail plug, hook and bar outside)</td>
+    <td>Nov. 4, 1900</td>
+    <td class="tdr">16.00<a id="FNanchor_27" href="#Footnote_27" class="fnanchor">[27]</a></td>
+    <td class="tdr"></td>
+    <td>Oct. 3, 1900</td>
+    <td class="tdr">2.00</td>
+    <td class="tdr"></td>
+    <td>Nov. 3, 1900</td>
+    <td class="tdr">1.45</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box Alpha (catch at back)</td>
+    <td>Nov. 5, 1900</td>
+    <td class="tdr">.35</td>
+    <td class="tdr"></td>
+    <td>Oct. 5, 1900</td>
+    <td class="tdr">6.00</td>
+    <td class="tdr"></td>
+    <td>Nov. 5, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>Box KK (triple; bolt, side-plug and knob)</td>
+    <td>Nov. 7, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00<br>F 10.00</td>
+    <td>Oct. 7, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 60.00</td>
+    <td>Nov. 7, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Theta (bolt at top)</td>
+    <td>Nov. 19, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 8, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Eta (ring at back)</td>
+    <td class="nw">Dec. 17, 1900</td>
+    <td class="tdr">im.</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="nw">Dec. 17, 1900</td>
+    <td class="tdr">4.20</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (push chute)</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Dec. 17, 1900</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 60.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Gamma (wind)</td>
+    <td>Jan. 3, 1901</td>
+    <td class="tdr">.20</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 4, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Delta (push back)</td>
+    <td>Jan. 4, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F&#160;&#160;&#160;5.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 4, 1901</td>
+    <td class="tdr">2.10</td>
+    <td class="tdr">after<a id="FNanchor_28" href="#Footnote_28" class="fnanchor">[28]</a><br>F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (a) (bar chute)</td>
+    <td>Jan. 6, 1901</td>
+    <td class="tdr">8.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 7, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Zeta (new side plug)</td>
+    <td>Jan. 7, 1901</td>
+    <td class="tdr">1.10</td>
+    <td class="tdr">after F&#160;&#160;&#160;5.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 8, 1901</td>
+    <td class="tdr">.50</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (b) (2½ revolution chute)</td>
+    <td>Jan. 9, 1901</td>
+    <td class="tdr">3.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 8, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (c) (nail-plug chute)</td>
+    <td>Jan. 11, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F&#160;&#160;&#160;5.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 11, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F&#160;&#160;&#160;5.00</td>
+  </tr>
+  <tr class="new">
+    <td>Box Epsilon (push down)</td>
+    <td>Jan. 12, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F 10.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 12, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F 10.00</td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (d) (ring chute)</td>
+    <td>Jan. 16, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F&#160;&#160;&#160;5.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 16, 1901</td>
+    <td class="tdr">im.</td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (e) (hook chute)</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 16, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00</td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (f) (string chute)</td>
+    <td>Jan. 17, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+  </tr>
+  <tr class="new">
+    <td>App. QQ (ff) (string-wire chute)</td>
+    <td>Jan. 17, 1901</td>
+    <td class="tdr">.20</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td>Jan. 19, 1901</td>
+    <td class="tdr"></td>
+    <td class="tdr">F&#160;&#160;&#160;5.00<br>F&#160;&#160;&#160;5.00</td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_188"></a>[188]</span></p>
+
+<p>The methods one has to take to get them to do anything,
+their general conduct in becoming tame and in the experiments
+throughout, confirm these conclusions. The
+following particular phenomena are samples of the many
+which are inconsistent with the presence of reasoning as
+a general function. No. 1 had learned to open a door by
+pushing a bar around from a horizontal to a vertical position.
+The same box was then fitted with two bars. He
+turned the first bar round thirteen times before attempting
+to push the other bar around. In box LL all three monkeys
+would in the early trials do one or two of the acts over and
+over after they had once done them. No. 1, who had
+learned to pull a loop of wire off from a nail, failed thereafter
+to pull off a similar loop made of string. No. 1 and No. 3
+had learned to poke their left hands through the cage for
+me to take and operate a chute with. It was extremely
+difficult to get either of them to put his right hand through
+or even to let me take it and pull it through.</p>
+
+<p>A negative answer to the question “Do the monkeys
+reason?” thus seems inevitable, but I do not attach to<span class="pagenum"><a id="Page_189"></a>[189]</span>
+the question an importance commensurate with the part
+it has played historically in animal psychology. For I
+think it can be shown, and I hope in a later monograph
+to show, that reasoning is probably but one secondary
+result of the general function of having free ideas in great
+numbers, one product of a type of brain which works in
+great detail, not in gross associations. The denial of reasoning
+need not mean, and does not to my mind, any denial
+of continuity between animal and human mentality or any
+denial that the monkeys are mentally nearer relatives to
+man than are the other mammals.</p>
+
+<p>So much for supererogatory explanation. Let us now
+turn to a more definite and fruitful treatment of these
+records.</p>
+
+<p>The difference between these records and those of the
+chicks, cats and dogs given on <a href="#Page_39">pages 39-65</a> <i>passim</i> is undeniable.
+Whereas the latter were practically unanimous,
+save in the cases of the very easiest performances,
+in showing a process of gradual learning by a gradual
+elimination of unsuccessful movements, and a gradual
+reënforcement of the successful one, these are unanimous,
+save in the very hardest, in showing a process of sudden
+acquisition by a rapid, often apparently instantaneous,
+abandonment of the unsuccessful movements and a selection
+of the appropriate one which rivals in suddenness the
+selections made by human beings in similar performances.
+It is natural to infer that the monkeys who suddenly replace
+much general pulling and clawing by a single definite
+pull at a hook or bar have an idea of the hook or bar and
+of the movement they make. The rate of their progress
+is so different from that of the cats and dogs that we cannot
+help imagining as the cause of it a totally different mental
+function, namely, free ideas instead of vague sense-impressions<span class="pagenum"><a id="Page_190"></a>[190]</span>
+and impulses. But our interpretation of these results
+should not be too hasty. We must first consider several
+other possible explanations of the rapidity of learning
+by the monkeys before jumping to the conclusion that the
+forces which bring about the sudden formation of associations
+in human beings are present.</p>
+
+<p>First of all it might be that the difference was due to the
+superiority of the monkeys in clear detailed vision. It
+might be that in given situations where associations were
+to be formed on the basis of smells, the cats and dogs
+would show similar rapid learning. There might be, that is,
+no general difference in type of mental functioning, but
+only a special difference in the field in which the function
+worked. This question can be answered by an investigation
+of the process of forming associations in connection with
+smells by dogs and cats. Such an investigation will, I
+hope, soon be carried on in the Columbia Laboratory by
+Mr. Davis.<a id="FNanchor_29" href="#Footnote_29" class="fnanchor">[29]</a></p>
+
+<p>Secondly, it might be that the superior mobility and more
+detailed and definite movements of the monkeys’ hands
+might have caused the difference. The slowness in the
+case of the dogs and cats might be at least in part the result
+of difficulty in executing movements, not in intending them.
+This difficulty in execution is a matter that cannot be readily
+estimated, but the movements made by the cats and dogs
+would not on their face value seem to be hard. They were
+mostly common to the animals’ ordinary life. At the same
+time there were certain movements (<i>e.g.</i> depressing the
+lever) which were much more quickly associated with their
+respective situations by the cats than others were, and if
+we could suppose that all the movements learned by the
+monkeys were comparable to these few, it would detract<span class="pagenum"><a id="Page_191"></a>[191]</span>
+from the necessity of seeking some general mental difference
+as the explanation of the difference in the results.</p>
+
+<p>In the third place it may be said by some that no comparison
+of the monkeys with dogs and cats is valid, since
+the former animals got out of boxes while the latter got in.
+It may be supposed that the instinctive response to confinement
+includes an agitation which precludes anything save
+vague unregulated behavior. Professor Wesley Mills has
+made such a suggestion in referring to the ‘Animal Intelligence’
+in the <i>Psychological Review</i>, May, 1899. In the
+July number of the same journal I tried to show that
+there was no solid evidence of such a harmful agitation.
+Nor can we be at all sure that agitation when present does
+not rather quicken the wits of animals. It often seems to.
+However I should, of course, allow that for purposes of
+comparison it would be better to have the circumstances
+identical. And I should welcome any antagonist who should,
+by making experiments with kittens after the fashion of
+these with the monkeys, show that they did learn as suddenly
+as the latter.</p>
+
+<p>Again we know that, whereas the times taken by a cat
+in a box to get out are inversely proportional to the strength
+of the association, inasmuch as they represent fairly the
+amount of its efforts, on the other hand, the times taken by a
+monkey to get in represent the amounts of his efforts <i>plus
+the amount of time in which he is not trying to get in</i>. It may
+be said therefore that the time records of the monkeys prove
+nothing,—that a record of four minutes may mean thirty
+seconds of effort and three minutes thirty seconds of sleep,—that
+one minute may really represent twice as much effort.
+As a matter of fact this objection would occasionally hold
+against some single record. The earliest times and the
+occasional long times amongst very short ones are likely<span class="pagenum"><a id="Page_192"></a>[192]</span>
+to be too long. The first fact makes the curves have too
+great a drop at the start, making them seem cases of too
+sudden learning, but the second fact makes the learning
+seem indefinite when it really is not. And in the long run
+the times taken do represent fairly well the amount of
+effort. I carefully recorded the amount of actual effort
+in a number of cases and the story it tells concerning the
+mental processes involved is the same as that told by the
+time-curves.</p>
+
+<p>Still another explanation is this: The monkeys learn
+quickly, it is true, but not quickly enough for us to suppose
+the presence of ideas, or the formation of associations among
+them. For if there were such ideas, they should in the complex
+acts do even better than they did. The explanation
+then is a high degree of facility in the formation of associations
+of just the same kind as we found in the chicks, dogs
+and cats.</p>
+
+<p>Such an explanation we could hardly disapprove in any
+case. No one can from objective evidence set up a standard
+of speed of learning below which all shall be learning without
+ideas and above which all shall be learning by ideas.
+We should not expect any hard and fast demarcation.</p>
+
+<p>This whole matter of the rate of learning should be studied
+in the light of other facts of behavior. My own judgment,
+if I had nothing but these time-curves to rely on, would be
+that there was in them an appearance of learning by ideas
+which, while possibly explicable by the finer vision and
+freer movements of the monkey in connection with ordinary
+mammalian mentality, made it worth while to look farther
+into their behavior. This we may now do.</p>
+
+<p>What leads the lay mind to attribute superior mental
+gifts to an animal is not so much the rate of learning as
+the amount learned. The monkeys obviously form more<span class="pagenum"><a id="Page_193"></a>[193]</span>
+associations and associations in a greater variety than do the
+other mammals. The improved rate assists, but another
+cause of this greater number of associations is the general
+physical activity of the monkeys, their constant movements
+of the hands, their instinctive curiosity or tendency to fool
+with all sorts of objects, to enjoy having sense-impressions,
+to form associations because of the resulting sound or sight.
+These mental characteristics are of a high degree of importance
+from the comparative point of view, but they cannot
+be used to prove that the monkeys have free ideas, for a
+large number of associations may be acquired after the
+purely animal fashion.</p>
+
+<p>What is of more importance is the actual behavior of the
+animals in connection with the boxes. First of all, as has
+been stated, all the monkey’s movements are more definite,
+he seems not merely to pull, but to pull at, not merely to poke,
+but to push at. He seems, even in his general random play,
+to go here and there, pick up this, examine the other, etc.,
+more from having the idea strike him than from feeling like
+doing it. He seems more like a man at the breakfast table
+than like a man in a fight. Still this appearance may be
+quite specious, and I think it is likely to lead us to read
+ideational life into his behavior if we are not cautious.
+It may be simply general activity of the same sort as the
+narrower activities of the cat or dog.</p>
+
+<p>In the second place the monkeys often make special
+movements with a directness which reminds one unavoidably
+of human actions guided by ideas. For instance, No. 1
+escaped from his cage one day and went directly across the
+room to a table where lay a half of a banana which was in a
+very inconspicuous place. It seemed as if he had observed
+the banana and acted with the idea of its position fully in
+mind. Again, on failing to pull a hook out, No. 1 immediately<span class="pagenum"><a id="Page_194"></a>[194]</span>
+applied his teeth, though he had before always
+pulled it out with his hand. So again with a plug. It may
+be that there is a special inborn tendency to bite at objects
+pulled unsuccessfully. If not, the act would seem to show
+the presence of the idea ‘get thing out’ or ‘thing come out’
+and associated with it the impulse to use the teeth. We
+shall see later, however, that in certain other circumstances
+where we should expect ideas to be present and result in
+acts they do not.</p>
+
+<p>The fact is that those features in the behavior of the
+monkeys in forming associations between the sight of a box
+and the act needed to open it which remind us of learning
+by ideas may also be possibly explained by general activity
+and curiosity, the free use of the hand, and superior quickness
+in forming associations of the animal sort. We must
+have recourse to more crucial tests or at least seek evidence
+from a number of different kinds of mental performances.
+The first of these will naturally be their behavior toward
+these same mechanisms after a long time-interval.</p>
+
+<h4><span class="smcap">The Permanence of Associations in the Case of Mechanisms</span></h4>
+
+<p>My records are too few and in all but one case after too
+short an interval to be decisive on the point of abrupt
+transition from failure to success such as would characterize
+an animal in whose mind arose the idea of a certain part of
+the mechanism as the thing to be attacked or of a certain
+movement as the fit one. The animals are all under observation
+in the Columbia Laboratory, however, and I
+trust that later satisfactory tests may be made. No. 2
+was not included in the tests because he was either unwell
+or had become very shy of the boxes, entering them even<span class="pagenum"><a id="Page_195"></a>[195]</span>
+when the door was left open only after great delay. The
+time-curves for the experiments performed will be found
+on <a href="#Page_186">page 186</a> among the others. The figures beside each pair
+represent the number of days without practice.</p>
+
+<p>The records show a decided superiority to those of the
+cats and dogs. Although the number of trials in the original
+tests were in general fewer in the case of the monkeys, the
+retention of the association is complete in 6 cases out of 8
+and is practically so in one case where the interval was
+8 months.</p>
+
+<h4><span class="smcap">Experiments on the Discrimination of Signals</span></h4>
+
+<p>My experiments on discrimination were of the following
+general type: I got the animal into the habit of reacting
+to a certain signal (a sound, movement, posture, visual
+presentation or what not) by some well-defined act. In
+the cases to be described this act was to come down from
+his customary positions about the top of the cage, to a place
+at the bottom. I then would give him a bit of food. When
+this habit was wholly or partly formed, I would begin to
+mix with that signal another signal enough like it so that
+the animal would respond in the same manner. In the
+cases where I gave this signal I would not feed him. I could
+then determine whether the animal did discriminate or not,
+and his progress toward perfect discrimination in case he did.
+If an animal responds indiscriminately to both signals (that
+is, does not learn to disregard the ‘no food’ signal) it is
+well to test him by using two somewhat similar signals,
+after one of which you feed him at one place and after the
+other of which you feed him at a different place.</p>
+
+<p>If the animal profits by his training by acquiring ideas of<span class="pagenum"><a id="Page_196"></a>[196]</span>
+the two signals and associates with them ideas of ‘food’
+and ‘no food,’ ‘go down’ and ‘stay still,’ and uses these
+ideas to control his conduct, he will, we have a right to
+expect, change suddenly from total failure to differentiate
+the signals to total success. He will or won’t have the ideas,
+and will behave accordingly. The same result could, of
+course, be brought about by very rapid association of the
+new signal with the act of keeping still, a very rapid inhibition
+of the act of going down in response to it by virtue
+of the lack of any pleasure from doing so.</p>
+
+<p>For convenience I shall call the signals after which food
+was given <i>yes</i> signals and those after which food was not
+given <i>no</i> signals. Signals not described in the text are
+shown in <a href="#figure29">Fig. 29</a>, below. The progress of the monkeys in
+discriminating is shown by <a href="#figure30">Figs. 30 and 31, on pages 199
+and 201</a>. In <a href="#figure30">Figs. 30 and 31</a> every millimeter along the
+horizontal or base line represents 10 trials with the signal.
+The heights of the black surface represent the percentages
+of <i>wrong</i> responses, 10 mm. meaning 100 per cent of<span class="pagenum"><a id="Page_197"></a>[197]</span>
+incorrect responses. Thus the first figure of the set, Left
+hand, <i>a</i>, presents the following record: First 10 trials, all
+wrong; of next 10, 7 wrong; of next 10, 6 wrong; of next
+10, 7; of the next, 9; of the next, 9; of the next, 4; of
+the next, none; of the next, 3; of the next, 2, and then
+70 trials without an error.</p>
+
+<div class="figcenter illowp100" id="figure29" style="max-width: 31.25em;">
+  <img class="w100" src="images/figure29.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 29.</span></p>
+</div>
+
+<p>I will describe some of the experiments in detail and then
+discuss the graphic presentation of them all.</p>
+
+<h4><span class="smcap">Experiments with No. 1</span></h4>
+
+<p>Having developed in No. 1 the habit of coming down
+to the bottom of his cage to get a bit of food when he saw
+me reach out and take such a bit from my desk, I tested
+his ability to discriminate by beginning to use now one hand,
+now the other, feeding him only when I used the left. I
+also used different sets of words, namely, ‘I will give some
+food’ and ‘They shall not have any.’ It will be seen later
+that he probably reacted only to the difference of the hands.
+The experiment is similar to that described on <a href="#Page_129">pages 129
+and 130</a> of Chapter II. At the beginning, it should be
+remembered, No. 1 would come down whichever hand was
+used, no matter what was said, except in the occasional
+cases where he was so occupied with some other pursuit
+as to be evidently inattentive. He did come to associate
+the act of going down with the one signal and the act of
+staying still or continuing his ordinary movements with
+the other signal. His progress in learning to do so is best
+seen in the curves of his errors. To the ‘yes’ signal he responded
+correctly, except for the occasional lapses which I
+just mentioned, from the start and throughout. With
+the ‘no’ signal his errors were as shown in <a href="#figure30">Fig. 30</a>, <i>a</i>. The
+break in the curve at 110 and 120 is probably not significant<span class="pagenum"><a id="Page_198"></a>[198]</span>
+of an actual retrograde as the trials concerned followed an
+eight days’ cessation of the experiments.</p>
+
+<p>I next tried No. 1 with an apparatus exposing sometimes
+a card with a diamond-shaped piece of buff-colored paper
+on it and sometimes a card with a similar black piece.
+The black piece was three fourths of an inch farther behind
+the opening than the other. The light color was the ‘yes’
+signal. The error curves for both signals are given, as No. 1
+at the beginning of the experiment did not go down always
+(<a href="#figure30">Fig. 30</a>, <i>b</i> and <i>b₁</i>).</p>
+
+<p>I next tried No. 1 with the same apparatus but exposing
+cards with YES and N in place of the buff and black diamonds.
+The record of the errors is given in <a href="#figure30">Fig. 30</a>, <i>c</i> and <i>c₁</i>.
+At the start he came down halfway very often. This I
+arbitrarily scored as an error no matter which signal it
+was in response to. It should not be supposed that these
+curves represent two totally new associations. It seems
+likely that the monkey reacted to the <i>position</i> of the N
+card in the apparatus (the same as that of the black diamond
+card) rather than to the shape of the letters. On
+putting the black diamond in front he was much confused.</p>
+
+<p>I next gave No. 1 the chance to form the habits of coming
+down when I rapped my pencil against the table twice and
+of staying where he was when I rapped with it once. He
+had 90 trials of each signal but failed to give evidence of
+any different associations in the two cases.</p>
+
+<p>Experiments of this sort were discontinued in the summer.
+In October I tried No. 1 with the right and left hand experiment,
+he being in a new room and cage, and I being
+seated in a different situation. He came down at both signals
+and failed to make any ascertainable progress with the
+no signal in 80 trials. (October 20-24.)</p>
+
+<p><span class="pagenum"><a id="Page_199"></a>[199]</span></p>
+
+<div class="figcenter illowp48" id="figure30" style="max-width: 28.125em;">
+  <img class="w100" src="images/figure30.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 30.</span></p>
+</div>
+
+<p><span class="pagenum"><a id="Page_200"></a>[200]</span></p>
+
+<p>I then tried him with the black and buff diamonds, the
+black being in front (October 25-29). The reaction to the
+‘yes’ signal was perfect from the start. The progress with
+the ‘no’ signal is shown in <a href="#figure30">Fig. 30</a>, <i>d</i>.</p>
+
+<p>I then tried him with an apparatus externally of different
+size, shape and color from that so far used, showing as the
+‘yes’ signal a brown card and as the ‘no’ signal a white
+and gold card one half inch farther back in the apparatus.
+The ‘yes’ signal was practically perfect from the start. His
+progress with the ‘no’ signal is shown in <a href="#figure30">Fig. 30</a>, <i>e</i>.</p>
+
+<p>I then tried a still different arrangement for exposure, to
+which, however, he did not give uniform attention.</p>
+
+<p>I then tried cards 1 and 101, 101 being in front and 1 in
+back. 1 was the ‘yes’ signal. ‘Yes’ responses were perfect
+from the start. For ‘no’ responses see <a href="#figure30">Fig. 30</a>, <i>f</i>. I then put
+the ‘yes’ signal in front and the ‘no’ signal behind. ‘Yes’
+responses perfect; for ‘no’ responses see <a href="#figure30">Fig. 30</a>, <i>f</i>, <i>a</i>.</p>
+
+<p>From now on I arranged the exposures in such a way that
+there was no difference between the ‘yes’ and ‘no’ signals
+in distance or surroundings.</p>
+
+<p>The following list shows the dates, signals used, and the
+figures on <a href="#Page_199">page 199</a> presenting the results. Where there is
+only one figure drawn, it refers to progress with the ‘no’
+signal, the ‘yes’ signal being practically perfect from the start.</p>
+
+<h5><span class="smcap">Table 10</span></h5>
+
+<table class="borders">
+  <tr>
+    <th></th>
+    <th><span class="smcap">‘Yes’ Signal</span></th>
+    <th><span class="smcap">‘No’ Signal</span></th>
+    <th><span class="smcap">Figure</span></th>
+  </tr>
+  <tr>
+    <td>Nov. 13-15, 1900.</td>
+    <td class="tdr">2</td>
+    <td class="tdr">102</td>
+    <td><i>g g₁</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 14-16, 1900.</td>
+    <td class="tdr">3</td>
+    <td class="tdr">103</td>
+    <td><i>i i₁</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 16-19, 1900.</td>
+    <td class="tdr">4</td>
+    <td class="tdr">104</td>
+    <td><i>h</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 19, 1900.</td>
+    <td class="tdr">5</td>
+    <td class="tdr">105</td>
+    <td><i>j</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 20, 1900.</td>
+    <td class="tdr">6</td>
+    <td class="tdr">106</td>
+    <td><i>k</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 21, 1900.</td>
+    <td class="tdr">7</td>
+    <td class="tdr">107</td>
+    <td><i>l</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 23(?), 1900.</td>
+    <td class="tdr">8</td>
+    <td class="tdr">108</td>
+    <td><i>m</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 27-29, 1900.</td>
+    <td class="tdr">9</td>
+    <td class="tdr">109</td>
+    <td><i>n</i></td>
+  </tr>
+  <tr>
+    <td>Nov. 30, 1900.</td>
+    <td class="tdr">10</td>
+    <td class="tdr">110</td>
+    <td><i>o</i></td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_201"></a>[201]</span></p>
+
+<p><a href="#figure29">Fig. 29</a> gives facsimiles of the different signals reduced to
+one sixth their actual size. The drawing of 101 is not accurate,
+the outer ring being too thick.</p>
+
+<h4><span class="smcap">Experiments with No. 2</span></h4>
+
+<div class="figcenter illowp75" id="figure31" style="max-width: 25em;">
+  <img class="w100" src="images/figure31.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 31.</span></p>
+</div>
+
+<p>I first secured the partial formation of the habit of coming
+down when I took a bit of food in my hand. I then used the
+apparatus for exposing cards, YES in front being the ‘yes’
+signal and a circle at the back being the ‘no’ signal. I gave
+No. 2 25 trials with the ‘yes’ signal and then began a regular
+experiment similar to those described. After about 90 trials
+(November 9-12, 1900) there was no progress toward differentiation
+of response, and it was evident from No. 2’s behavior
+that he was reacting solely to the movements of my
+hand. So I abandoned the exposing apparatus and used
+(November 11-13, 1900) as the ‘yes’ signal the act of taking
+the food with my left hand from a pile on the front of the box
+and for the ‘no’ signal the act of taking food with my right
+hand from a pile 4 inches behind that just mentioned.<span class="pagenum"><a id="Page_202"></a>[202]</span>
+No. 2 did come to differentiate these two signals. The record
+of his progress is given in <a href="#figure31">Fig. 31</a> by <i>A</i> and <i>A₁</i>.</p>
+
+<p>I then made a second attempt with the exposing apparatus,
+using cards 2 and 102 (November 6, 14-21). No. 2
+did react to my movements in pulling the string but in over
+100 trials made no progress in the direction of a differential
+reaction to the ‘no’ signal. I then tried feeding him at each
+signal, feeding him at the bottom of the cage as usual when
+I gave the ‘yes’ signal and at the top when I gave the ‘no’
+signal. After a hundred trials with the ‘no’ signal there
+was no progress.</p>
+
+<p>I then abandoned again the exposing apparatus and used
+as signals the ordinary act of taking food with my left hand
+(yes) and the act of moving my left arm from my right side
+round diagonally (swinging it on my elbow as a center) and
+holding the hand, after taking the food, <i>palm up</i> (no) (November
+26, 27, 1900). No. 2 did come to differentiate these
+signals. His progress is given in the diagram in <a href="#figure31">Fig. 31</a> entitled
+‘Palm up’ (<i>B</i>).</p>
+
+<p>I next used (November 27, 1900) as the ‘yes’ signal the
+same act as before and for the ‘no’ signal the act of holding
+the food just in front of the box about four inches below
+the edge. No. 2’s progress is shown in <a href="#figure31">Fig. 31</a> in the diagram
+entitled ‘low front’ (<i>C</i> and <i>C₁</i>).</p>
+
+<p>I next used (November 27-30) the same movement for
+both ‘yes’ and ‘no’ signals save that as the ‘yes’ signal I took
+the food from a brown pasteboard box 3 by 3 by 0.5, and as
+the ‘no’ signal I took it from a white crockery cover two
+inches in diameter and three eighths of an inch high which
+was beside the box but three inches nearer me. No. 2’s
+progress is shown in <a href="#figure31">Fig. 31</a> in the diagram entitled ‘Box
+near’ (<i>D</i>).</p>
+
+<p>I next used for the ‘yes’ signal the familiar act and for the<span class="pagenum"><a id="Page_203"></a>[203]</span>
+‘no’ signal the act of holding the food six inches above the
+box instead of a quarter or a half an inch. The progress is
+shown in <a href="#figure31">Fig. 31</a>, <i>E</i> and <i>E₁</i>. I then tried taking the food
+from a saucer off the front of the box for the ‘yes’ signal and
+from a small box at the back for the ‘no’ signal. ‘Yes’ was
+perfect from the start (10 trials given). ‘No’ was right
+once, then wrong once, then right for the remaining eight.</p>
+
+<h4><span class="smcap">Experiments with No. 3</span></h4>
+
+<p>No. 3 was kept in a cage not half so big as those of 1 and 2.
+Perhaps because of the hindrance this fact offered to forming
+the habit of reacting in some definite way to ‘yes’ signals,
+perhaps because of the fact that I did not try hand movements
+as signals, there was no successful discrimination by
+No. 3 of the yellow from the black diamond or of a card with
+YES from a card with a circle on it. I tried climbing up to
+a particular spot as the response to the ‘yes’ signal and staying
+still as the response to the ‘no’ signal. I also tried instead
+of the latter a different act, in which case the animal
+was fed after both signals but in different places. In the
+latter case No. 3 made some progress, but for practical
+reasons I postponed experiments with him. Circumstances
+have made it necessary to postpone such experiments indefinitely.</p>
+
+<h4><span class="smcap">Permanence of the Ability to Discriminate</span></h4>
+
+<p>No. 1 and No. 2 were tried again after intervals of 33 to 48
+days. The results of these trials are shown in <a href="#figure32">Fig. 32</a>. Here
+every millimeter along the base line represents <i>one</i> trial with
+the ‘no’ signal (the ‘yes’ signals were practically perfect),
+and failure is represented by a column 10 mm. high while<span class="pagenum"><a id="Page_204"></a>[204]</span>
+success is represented by the absence of any column. Thus
+the first record reads, “No. 1 with signal 104 after 40 days
+made 5 failures, then 2
+successes, then 1 failure,
+then 1 success,
+then 3 failures, then 1
+success, then 1 failure,
+then 3 successes, then
+1 failure, then 10 successes.”
+The third
+record (106; 40 days)
+reads, “perfect success
+in ten trials.”</p>
+
+<div class="figcenter illowp48" id="figure32" style="max-width: 18.75em;">
+  <img class="w100" src="images/figure32.jpg" alt="">
+  <p class="caption"><span class="smcap">Fig. 32.</span></p>
+</div>
+
+<h4><span class="smcap">Discussion of Results</span></h4>
+
+<p>The results of all
+these discrimination
+experiments emphasize
+the rapidity of formation
+of associations
+amongst the monkeys,
+which appeared in their
+behavior toward the
+mechanisms. The suddenness of the change in many cases
+is immediately suggestive of human performances. If all
+the records were like c, f, h, i, j, k, l, m, B, E, and memory
+trials 103, A, B, and C, one would have to credit the animals
+with either marvelous rapidity in forming associations of
+the purely animal sort or concede that from all the objective
+evidence at hand they were shown to learn as human beings
+would. One would have to suppose that they had clear<span class="pagenum"><a id="Page_205"></a>[205]</span>
+ideas of the signals and clean-cut associations with those
+ideas. The other records check such a conclusion.</p>
+
+<p>In studying the figures we should remember that occasional
+mistakes, say 1 in 10 trials, are probably not significant
+of incomplete learning but of inattention or of precipitate
+action before the shutter had fairly exposed the card. We
+must not expect that a monkey who totally fails to discriminate
+will <i>always</i> respond wrongly to the ‘no’ signal, or that
+a monkey who has come to discriminate perfectly will <i>always</i>
+respond rightly. A sudden drop from an average high level
+of error to an average low level will signify sudden learning.
+Where the failure was on the first trial of a series a few hours
+or a day removed from the last series, I have generally represented
+the fact not by a column 1 mm. high and 1 mm.
+broad, but by a single 10 mm. perpendicular. See i and A.
+Such cases represent probably the failure of the animal to
+keep his learning permanent rather than any general inability
+to discriminate.</p>
+
+<p>K was to some extent a memory trial of d (after over half
+a year).</p>
+
+<p>The experiment with 10 and 110 is noteworthy. Although,
+as can be seen from the figures, the difference is obvious
+to one looking at the white part of the figure, it is not
+so to one looking at the black part. No. 1 failed to improve
+appreciably in fifty trials, probably because his previous
+experience had gotten him into the habit of attending to the
+black lines.</p>
+
+<p>Before arguing from the suddenness of the change from
+failure to success we have to consider one possibility that I
+have not mentioned, and in fact for the sake of clearness in
+presentation have rather concealed. It is that the sudden
+change in the records, which report only whether the animal
+did or did not go down, may represent a more gradual<span class="pagenum"><a id="Page_206"></a>[206]</span>
+change in the animal’s mind, a gradual weakening of the
+impulse to go down which makes him feel less and less inclined
+to go down, though still doing so, until this weakening
+reaches a sort of saturation point and stops the action.
+There were in their behavior some phenomena which might
+witness to such a process, but their interpretation is so dependent
+on the subjective attitude and prepossessions of the
+observer that I prefer not to draw any conclusions from
+them. On the other hand, records c, g, n, A and D seem
+to show that gradual changes can be paralleled by changes
+in the percentage of failures.</p>
+
+<p>In the statement of conclusions I shall represent what
+would be the effect on our theory of the matter in both cases,
+(1) taking the records to be fairly perfect parallels of the
+process, and (2) taking them to be the records of the summation
+points of a process not shown with surety in any measurable
+objective facts. But I shall leave to future workers
+the task of determining which case is the true one.</p>
+
+<p>If we judge by the objective records themselves, we may
+still choose between two views. (1) We may say that the
+monkeys did come to have ideas of the acts of going down to
+the bottom of the cage and of staying still, and that their
+learning represented the association of the sense-impressions
+of the two signals, one with each of these ideas, or possibly
+their association with two other ideas (of being fed
+and of not being fed), and through them with the acts. Or
+(2) we may say that the monkeys had no such ideas, but
+merely by the common animal sort of association came to
+react in the profitable way to each signal.</p>
+
+<p>If we take the first view, we must explain the failure of the
+animals to change suddenly in some of the experiments,
+must explain why, for instance, No. 1 in g should, after he had
+responded correctly to the ‘no’ signal for 27 trials out of 30,<span class="pagenum"><a id="Page_207"></a>[207]</span>
+fail in one trial out of four for a hundred or more trials. If
+the 27 successes were due to ideas, why was there regression?
+If the animal came to respond by staying still on seeing the
+K (card 104), because that sight was associated with the idea
+of no food or the idea of staying still, why did he, in his
+memory trial, act sometimes rightly, sometimes wrongly, for
+eleven trials after his acting rightly twice. If he stayed still
+because the idea was aroused, why did he not stay still as
+soon as he had a few trials to remind him of the idea? It is
+easy, one may say, to see why, with a capacity to select
+movements and associate them with sense-presentations
+very quickly, in cases where habit provides only two movements
+for selection and where the sense-presentation is very
+clear and simple, an animal should practically at once be
+confirmed in the one act on an occasion when he does it
+with the sense-impression in the focus of attention. It is
+easy, therefore, to explain the sudden change in i, l, m, B, C
+and E. But our critic may add, “It is very hard to suppose
+that an animal that learned by connecting the sight of a card
+with the idea ‘stay still’ or the idea ‘no food,’ should be so
+long in making the connection as was the case in some of
+these experiments, should take 10, 20 or 40 trials to change
+from a high percentage of wrong to a high percentage of
+right reactions.”</p>
+
+<p>If we take the second view, we have to face the fact that
+many of the records are nothing like the single one we have
+for comparison, that of the kitten shown in <a href="#figure30">Fig. 30</a>, and that
+the appeal to a capacity to form animal associations very
+quickly seems like a far-fetched refuge from the other view
+rather than a natural interpretation. If we take the records
+to be summation points in a more gradual process, this
+difficulty is relieved.</p>
+
+<p>If further investigation upheld the first view, we should<span class="pagenum"><a id="Page_208"></a>[208]</span>
+still not have a demonstration that the monkeys habitually
+did learn by getting percepts and images associated with
+sense-impressions, by having free ideas of the acts they performed;
+we should only have proved that they could under
+certain circumstances.</p>
+
+<p>The circumstances in these experiments on discrimination
+were such as to form a most favorable case. The act of
+going down had been performed in all sorts of different connections
+and was likely to gain representation in ideational
+life; the experience ‘bit of banana’ had again been attended
+to as a part of very many different associations and so would
+be likely to develop into a definite idea.</p>
+
+<p>These results then do not settle the choice between three
+theories: (1 <i>a</i>) that they were due to a general capacity for
+having ideas, (1 <i>b</i>) that they were due to ideas acquired by
+specially favoring circumstances, (2) that they were due to
+the common form of association, the association of an impulse
+to an act with a sense-impression rather roughly felt.</p>
+
+<p>It would be of the utmost interest to duplicate these experiments
+with dogs, cats and other mammals and compare
+the records. Moreover, since we shall find (1 <i>a</i>) barred out
+by other experiments, it will be of great interest to test the
+monkeys with some other type of act than discrimination
+to see if, by giving the animal experience of the act and result
+involved in many different connections, we can get a rate
+of speed in the formation of a new association comparable to
+the rates in some of these cases.</p>
+
+<p>Of course here, as in our previous section, the differences
+in the sense-powers of the monkeys from those of the kitten
+which I have tested with a similar experiment may have
+caused the difference in behavior. Focalized vision lends
+itself to delicate associations. Perhaps if one used the sense
+of smell, or if the dogs and cats could, preserving their same<span class="pagenum"><a id="Page_209"></a>[209]</span>
+mental faculties in general, add the capacity for focalized
+vision, they would do as well as the monkeys.</p>
+
+<h3><span class="smcap">Experiments on the Influence of Tuition</span></h3>
+
+<p>The general aim of these experiments was to ascertain
+whether the monkeys’ actions were at all determined by the
+presence of free ideas and if so, to what extent. The question
+is, “Are the associations which experience leads them to
+form, associations between (1) the idea of an object and (2)
+the idea of an act or result and (3) the impulses and act itself,
+or are they merely associations between the sense-impression
+of the object and the impulse and act?” Can a monkey
+learn and does he commonly learn to do things, not by
+the mere selection of the act from amongst the acts done by
+him, but by getting some idea and then himself providing
+the act because it is associated in his mind with that idea.
+If a monkey feels an impulse to get into a box, sees his arm
+push a bar and sees a door fall open immediately thereafter
+and goes into the box enough times, he has every chance to
+form the association between the impulse to get into the
+box and the idea ‘arm push bar,’ provided he can have such
+an idea. If his general behavior is due to having ideas
+connected with and so causing his acts, he has had chance
+enough to form the association between the idea ‘push at’
+and the act of pushing. If then a monkey forms an association
+leading to an act by being put through the act, we
+may expect that he has free ideas. And if he has free ideas
+in general in connection with his actions, we may expect him
+to so form associations. So also if a monkey shows a general
+capability to learn from seeing another monkey or a
+human being do a thing. A few isolated cases of imitation,
+however, might witness not to any general mental quality,<span class="pagenum"><a id="Page_210"></a>[210]</span>
+but only to certain instincts or habits differing from others
+only in that the situation calling forth the act was the same
+act performed by another.</p>
+
+<p>If the monkeys do not learn in these ways, we must, until
+other evidence appears, suppose them to be in general destitute
+of a life of free ideas, must regard their somewhat ambiguous
+behavior in learning by their own unaided efforts
+as of the same type as that of the dogs and cats, differing
+only in the respects mentioned on <a href="#Page_190">pages 190 and 191</a>.</p>
+
+<p>The general method of experimentation was to give monkeys
+who had failed of their own efforts to operate some
+simple mechanism, a chance to see me do it or see another
+monkey do it or to see and feel themselves do it, and then
+note any change in their behavior. The chief question is
+whether they succeed after such tuition when they have
+failed before it, but the presence of ideas would also be
+indicated if they attacked, though without success, the
+vital point in the mechanism when they had not done so
+before. On the other hand, mere success would not prove
+that the tuition had influenced them, for if they made a different
+movement or attacked a different spot, we could not
+attribute their behavior to getting ideas of the necessary act.</p>
+
+<p>The results of the experiments as a whole are on their face
+value a trifle ambiguous, but they surely show that the monkeys
+in question had no considerable stock of ideas of the
+objects they dealt with or of the movements they made and
+were not in general capable of acquiring, from seeing me or
+one of their comrades attack a certain part of a mechanism
+and make a certain movement, any ideas that were at all
+efficacious in guiding their conduct. They do not acquire
+or use ideas in anything that approaches the way human
+adults do. Whether the monkeys may not have some few
+ideas corresponding to habitual classes of objects and acts<span class="pagenum"><a id="Page_211"></a>[211]</span>
+is a different question. Such may be present and function
+as the excitants of acts.</p>
+
+<p>It is likely that this question could have been definitely
+solved if it had been possible for me to work with a larger
+number of animals. With enough subjects one could use
+the method mentioned on <a href="#Page_105">page 105</a> of Chapter II, of
+giving the animals tuition in acts which they would
+eventually do themselves without it, and then leaving them
+to their efforts, noting any differences in the way they
+learned from that in which other subjects who had no tuition
+learned the same acts. The chief of such differences to
+note would be differences in the time of their first trial, in the
+slope of the time-curve and in the number of useless acts.</p>
+
+<p>It would also be possible to extend experiments of the
+type of the (on chair) experiment, where a subject is given
+first a certain time (calculated by the experimenter to be
+somewhat less than would be needed for the animal to hit
+upon the act) and if he does fail is then given certain tuition
+and then a second trial. The influence of the tuition is estimated
+by the presence or absence of cases where after tuition
+the act is done within the time.</p>
+
+<p>There is nothing necessarily insoluble in the problem.
+Given ten or twenty monkeys that can be handled without
+any difficulty and it could be settled in a month.</p>
+
+<p>With this general preface we may turn to the more special
+questions connected with the experiments on imitation of
+human acts and of the acts of other monkeys and on the formation
+of associations apart from the selection of impulses.</p>
+
+<h4><span class="smcap">Imitation of Human Beings</span></h4>
+
+<p>It has been a common opinion that monkeys learned
+to do things from seeing them done by human beings.<span class="pagenum"><a id="Page_212"></a>[212]</span>
+We find anecdotes to that effect in fairly reputable
+authors.</p>
+
+<p>Of course, such anecdotes might be true and still not prove
+that the animals learned to do things because they saw them
+done. The animal may have been taught in other ways to
+respond to the particular sights in question by the particular
+acts. Or it may have been in each case a coincidence.</p>
+
+<p>If a monkey did actually form an association between a
+given situation and act by seeing some one respond to that
+situation by that act, it would be evidence of considerable
+importance concerning his general mental status, for it
+would go to show that he could and often did form associations
+between sense-impressions and ideas and between
+ideas and acts. Seeing some one turn a key in a lock might
+thus give him the idea of turning or moving the key, and this
+idea might arouse the act. However, the mere fact that a
+monkey does something which you have just done in his
+presence need not demonstrate or even render a bit more
+probable such a general mental condition. For he perhaps
+would have acted in just the same manner if you had offered
+him no model. If you put two toothpicks on a dish, take
+one and put it in your mouth, a monkey will do the same, not
+because he profits by your example, but because he instinctively
+puts nearly all small objects in his mouth. Because
+of their general activity, their instinctive impulses to
+grab, drop, bite, rub, carry, move about, turn over, etc., any
+novel object within their reach, their constant movement
+and assumption of all sorts of postures, the monkeys perform
+many acts like our own and simulate imitation to a far
+greater extent than other mammals.</p>
+
+<p>Even if a monkey which has failed of itself to do a certain
+thing does it after you have shown him the act, there need
+be no reason to suppose that he is learning by imitation,<span class="pagenum"><a id="Page_213"></a>[213]</span>
+forming an association between the sight of the object and
+the act towards it through an idea gained from watching
+you. You may have caused his act simply by attracting his
+attention to the object. Perhaps if you had pointed at it or
+held it passively in your hand, you would have brought to
+pass just the same action on his part. There are several
+cases among my records where an act which an animal failed
+totally to do of himself was done after I had so attracted his
+attention to the object concerned.</p>
+
+<p>Throughout all the time that I had my monkeys under observation
+I never noticed in their general behavior any act
+which seemed due to genuine imitation of me or the other
+persons about. I also gave them special opportunities to
+show such by means of a number of experiments of the following
+type: where an animal failed by himself to get into
+some box or operate some mechanism, I would operate it in
+his presence a number of times and then give him a chance to
+profit by the tuition. His failure might be due to (1) the
+absence of instinctive impulses to make the movement in
+that situation, (2) to lack of precision in the movement, (3)
+to lack of force, or (4) to failure to notice and attack some
+special part of the mechanism. An instance of (1) was the
+failure to push away from them a bar which held a door;
+an instance of (2) was the failure to pull a wire loop off a
+nail; an instance of (2) or (3) was the failure to pull up a
+bolt; an instance of (4) was the failure to pull up an inside
+bar. Failures due to (3) occur rarely in the case of such
+mechanisms as were used in my investigations.</p>
+
+<p>The general method of experiment was to make sure that
+the animal would not of itself perform a certain act in a certain
+situation, then to make sure that his failure could not
+be remedied by attracting his attention to the object, then
+to perform the act for him a number of times, letting him get<span class="pagenum"><a id="Page_214"></a>[214]</span>
+each time the food which resulted, and finally to see whether,
+having failed before the tuition, he would succeed after it.
+This sounds very simple, but such experiments are hard to
+carry out satisfactorily. If you try the animal enough times
+by himself to make quite sure that he will not of himself hit
+upon the act, you are likely to form in him the habit of
+meeting the particular situation in question with total disregard.
+His efforts having failed so often may be so inhibited
+that you could hardly expect any tuition to give
+them new life. The matter is worse if you add further
+enough trials to assure you that your attracting his attention
+to it has been unavailing. On the other hand, if you
+take failure in five or ten minutes to mean inability, and
+from subsequent success after imitation argue that imitation
+was efficient, you have to face the numerous cases where
+animals which have failed in ten minutes have succeeded in
+later unaided trials. With dogs and cats this does not much
+matter, because they are steady performers, and their conduct
+in one short trial tells you what to expect with some probability.
+But the monkeys are much more variable and are
+so frequently distracted that one feels much less confidence
+in his predictions. Moreover, you cannot be at all sure of
+having attracted a monkey’s attention to an object unless he
+does touch it. Suppose, for example, a monkey has failed
+to even touch a bar though you have put a bit of food on it
+repeatedly. It is quite possible that he may look at and
+take the food and not notice the bar, and the fact that after
+such tuition he still fails to push or pull the bar may mean
+simply that it has not caught his notice. I have, therefore,
+preferred in most cases to give the animals only a brief
+period of trial to test their ability by their own unaided
+efforts and to omit the attempts to test the efficacy of attracting
+their attention to the vital point in the mechanism.<span class="pagenum"><a id="Page_215"></a>[215]</span>
+This makes the results appear less elegant and definitive but
+really increases their value for purposes of interpretation.</p>
+
+<p>The thoughtful reader will not expect from my experiments
+any perfectly rigorous demonstration of either the
+presence or the absence of imitation of human acts as a
+means of learning. The general trend of the evidence, it
+seems to me, is decidedly towards justifying the hypothesis
+that the monkeys did not learn acts from seeing me do
+them.</p>
+
+<p>I will first describe a sample experiment and then present
+a summary of all those made.</p>
+
+<p>On January 12th I put box Epsilon (push down) in No.
+3’s cage, the door of the box being open. I put a bit of food
+in the box. No. 3 reached in and took it. This was repeated
+three times. I then put in a bit of food and closed the
+door. No. 3 pulled and bit the box, turned it over, fingered
+and bit at the hole where the lever was, but did not succeed
+in getting the door open. After ten minutes I took the box
+out. Later I took No. 3 out and let him sit on my knees (I
+sitting on the floor with the box in front of us). I would
+then put my hand out toward the box and when he was
+looking at it would insert my finger and depress the lever
+with as evident a movement as I could. The door, of
+course, opened, and No. 3 put his arm in and took the
+bit of food. I then put in another, closed the door and depressed
+the lever as before. No. 3 watched my hand pretty
+constantly, as all his experiences with me had made such
+watching profitable. After ten such trials he was put back
+in the cage and the box put in with a large piece of food in it
+and its door closed. No. 3 failed in five minutes and the
+box was taken out. He was shown fifteen times more and
+then left to try himself. I tried him for a couple of minutes
+under just the same circumstances as existed during the<span class="pagenum"><a id="Page_216"></a>[216]</span>
+tuition, <i>i.e.</i> he on the floor by me, the box in front. In this
+trial and in a five-minute trial inside his cage he failed to
+open the door or to differ in any essential respect from his
+behavior before tuition.</p>
+
+<p>No. 1 saw me do 9 different acts and No. 3, 7, which they
+had failed of themselves to do.<a id="FNanchor_30" href="#Footnote_30" class="fnanchor">[30]</a> After from 1 to 40 chances
+to imitate me they still failed to operate at all 11 of these
+mechanisms. In the case of 3 out of 5 that were worked
+the act was not the same as that taught. No. 1, who saw
+me pull a nail out by taking the end of it and pulling the nail
+away from the box, himself put his hand round the nail and
+wriggled it out by pulling his hand back and forth. No. 3,
+who saw me pull a bolt up with my fingers, succeeded by
+jerking and yanking the door until he shook the bolt up.
+He saw me pull a hook out of an eye, but he succeeded by
+pulling at a bar to which it was attached. In the case of
+one of the two remaining acts (No. 3 with <i>nail chute</i>) the act
+was done once and never again, though ample opportunity
+was given and tuition continued. It could, therefore,
+hardly have been due to an idea instilled by the tuition.
+The remaining case, No. 1, with loop, must, I think, be attributed
+to accident, especially since No. 3 failed to profit<span class="pagenum"><a id="Page_217"></a>[217]</span>
+by precisely the same sort of tuition with precisely the same
+act.</p>
+
+<p>Nor is there any evidence to show that although tuition
+failed to cause successes where unaided effort failed, it yet
+caused attempts which would not otherwise have occurred.
+Out of fifteen cases where such might have appeared, there
+were only three where it is possible to claim that they did.
+No one of these three is a sure case. With RR (wood plug)
+No. 1 did seem to pull the plug more definitely after seeing
+me than before. With QQ (c) (nail chute) and MM (bolt
+at top) he may possibly have done so.</p>
+
+<p>In 5 cases I tried the influence of seeing me make the
+movement on animals who had done the act of themselves,
+the aim being to see whether there would be a marked shortening
+of the time, a change in their way of operating the
+mechanism or an attempt at such change. I will give the
+essential facts from the general table on <a href="#Page_226">pages 226-229</a>.</p>
+
+<p>(<i>a</i>) No. 1 had succeeded in pulling in the box by the upper
+string in OOO (upper string box) in 2.20 and then failed in
+3.00. I showed him 4 times. He failed in 10. I showed
+him 4 more times. He failed in 10. I showed him 4 more
+times. He succeeded in .20. No change in manner of act or
+objects attacked, though my manner was different from his.</p>
+
+<p>(<i>b</i>) No. 1 had succeeded in QQ (a) (chute bar) in 8.00. I
+showed him 20 times. He failed in 10. I showed him 10
+more times. He succeeded in 2.00. I showed him 10 more
+times. He succeeded in 50 seconds. No change in his
+manner of performance or in the object attacked, though my
+manner was different from his.</p>
+
+<p>(<i>c</i>) No. 1 had succeeded in 3.00, .25, .07, .25, .20, .06 and
+.09 with QQ (b) (chute bar double) and then failed in 5.00.
+I showed him 10 times. He then failed in 5 twice, succeeded
+in 3.00, and failed in 5 again. No change in manner of performance<span class="pagenum"><a id="Page_218"></a>[218]</span>
+or in the object attacked, though my manner was
+different from his.</p>
+
+<p>(<i>d</i>) No. 3 had the following record in box Delta:—</p>
+
+<table>
+  <tr>
+    <td class="tdr">2.00</td>
+    <td>(pushed with head)</td>
+  </tr>
+  <tr>
+    <td class="tdr">3.20</td>
+    <td>(pushed with head)</td>
+  </tr>
+  <tr>
+    <td class="tdr">30</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td class="tdr">10</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td class="tdr">10</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td class="tdr">2.10</td>
+    <td>(pulled wire and door).</td>
+  </tr>
+</table>
+
+<p>I showed him 20 times by pushing the bar to the right with
+my finger. He succeeded in 8.00 and 8.00 by pulling the
+wire and the door. No change in object attacked.</p>
+
+<p>(<i>e</i>) No. 2 had failed twice in 5 with chute QQ (ff) (chute
+string wire) and succeeded once in 2.00 by a strong pull on
+the wire itself, not the loop. I showed him 5 times, pulling
+the loop off the nail. He then failed in 5. There was no
+change in the objects attacked.</p>
+
+<p>These records show no signs of any influence of the tuition
+that are not more probably signs of something else. We
+cannot attribute the rapid decrease in time taken in (<i>b</i>) to
+the tuition until we know the time-curve for the same
+process without tuition.</p>
+
+<p>The systematic experiments designed to detect the presence
+of ability to learn from human beings are thus practically
+unanimous against it. So, too, was the general behavior
+of the monkeys, though I do not consider the failure of the
+animals to imitate common human acts as of much importance
+save as a rebuke to the story-tellers and casual observers.
+The following facts are samples: The door of No.
+1’s cage was closed by an iron hoop with a slit in it through
+which a staple passed, the door being held by a stick of wood
+thrust through the staple. No. 1 saw me open the door of<span class="pagenum"><a id="Page_219"></a>[219]</span>
+his and other cages by taking out sticks hundreds of times,
+but though he escaped from his cage a dozen times in other
+ways, he never took the stick out and to my knowledge never
+tried to. I myself and visitors smoked a good deal in the
+monkeys’ presence, but a cigar or cigarette given to them
+was always treated like anything else.</p>
+
+<h4><span class="smcap">Imitation of Other Monkeys</span></h4>
+
+<p>It would theoretically seem far more likely that the monkeys
+should learn from watching each other than from watching
+human beings, and experimental determinations of such
+ability are more important than those described in the last
+section as contributions both to genetic psychology and to
+natural history. I regret that the work I have been able to
+do in the study of this phase of the mental life of the monkeys
+has been very limited and in many ways unsatisfactory.</p>
+
+<p>We should expect to find the tendency to imitation more
+obvious in the case of young and parents than elsewhere. I
+have had no chance to observe such cases. We should expect
+closely associated animals, such as members of a common
+troop or animals on friendly terms, to manifest it more
+than others. Unfortunately, two of my monkeys, by the
+time I was ready to make definite experiments, were on terms
+of war. The other had then become so shy that I could not
+confidently infer inability to do a thing from actual failure
+to do it. He showed no evidence of learning from his
+mates. I have, therefore, little evidence of a quantitative
+objective nature to present and shall have in the end to ask
+the reader to take some opinions without verifiable proofs.</p>
+
+<p>My reliable experiments, five in number, were of the following
+nature. A monkey who had failed of himself (and
+often also after a chance to learn from me or from being put<span class="pagenum"><a id="Page_220"></a>[220]</span>
+through the act) would be put where he could see another
+do the act and get a reward (food) for it. He would then be
+given a chance to do it himself, and note would be taken of
+his success or failure, and of whether his act was the same
+as that of his model in case he succeeded, and of whether he
+tried that act more than before the tuition in case he tried
+it and failed. The results are given in Table 11.</p>
+
+<p>In the fourth experiment No. 1 showed further that the
+tuition did not cause his successes in that after some successes
+further tuition did not improve him.</p>
+
+<p>There is clearly no evidence here of any imitation of No. 1
+by No. 3. There was also apparently nothing like purposive
+watching on the part of No. 3. He seemed often to see No.
+1 open the box or work the chute mechanism, but without
+special interest.</p>
+
+<p>This lack of any special curiosity about the doings of their
+own species characterized the general behavior of all three of
+my monkeys and in itself lessens the probability that they
+learn much from one another. Nor did there appear, in the
+course of the three months and more the animals were together,
+any signs of imitation. There were indeed certain
+notable instances of the lack of it in circumstances which
+one would suppose would be favorable cases for it.</p>
+
+<p>For instance: No. 2 was very timid. No. 1 was perfectly
+tame from the first day No. 2 was with me, and No. 3 became
+tame shortly after. No. 2 saw Nos. 1 and 3 come to me,
+be played with, fed and put through experiments, yet he
+never did the same nor did he abate a jot or tittle from his
+timidity save in so far as I sedulously rewarded any chance
+advances of his. Conversely No. 1 and No. 3 seemed uninfluenced
+by the fear and shyness of No. 2. No. 2’s cage
+was between No. 1’s and No. 3’s, and they were for three
+weeks incessantly making hostile demonstrations toward
+each other, jumping, chattering, scowling, etc. No. 2
+never did anything of the sort. Again, seeing No. 3 eat
+meat did not lead No. 1 to take it; nor did seeing No. 1
+retreat in fright from a bit of absorbent cotton lead No. 3
+to avoid it.</p>
+
+<p><span class="pagenum"><a id="Page_221"></a>[221]</span></p>
+
+<h5><span class="smcap">Table 11</span></h5>
+
+<table class="borders max60">
+  <tr>
+    <th><span class="smcap">Subject, Date, Act</span></th>
+    <th><span class="smcap">Time tried alone, with result</span></th>
+    <th><span class="smcap">No. of times imitatee did</span></th>
+    <th><span class="smcap">Result after chance for imitation</span></th>
+    <th><span class="smcap">Similarity or dissimilarity of act</span></th>
+    <th><span class="smcap">Similar act attempted, though unsuccessfully in
+    cases where it had not been before training</span></th>
+    <th><span class="smcap">General judgment as to influence of training</span></th>
+  </tr>
+  <tr>
+    <td>No. 3. Dec. 17, 1900. VV (wire loop)</td>
+    <td class="tdr">50 F</td>
+    <td class="tdr">43</td>
+    <td class="tdr">55 F</td>
+    <td></td>
+    <td>No.</td>
+    <td>None.</td>
+  </tr>
+  <tr>
+    <td class="nw">No. 3. Jan. 15, 1901. QQ (c) (nail chute)</td>
+    <td class="tdr">91 F</td>
+    <td class="tdr">75</td>
+    <td class="tdr">35 F</td>
+    <td></td>
+    <td>No.</td>
+    <td>None.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">1.30</td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>No. 3. Jan. 21, 1901. Gamma (wind)</td>
+    <td class="tdr">63 F</td>
+    <td class="tdr">43</td>
+    <td class="tdr">5 F</td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td>None.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">9.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">6.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>No. 3. Jan. 21, 1901. QQ (ff) (string chute with wire)</td>
+    <td class="tdr">20 F</td>
+    <td class="tdr">30</td>
+    <td class="tdr">1.30</td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td>None.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr">2.00</td>
+    <td class="tdr"></td>
+    <td class="tdr">.40</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">.35</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td class="tdr"></td>
+    <td class="tdr"></td>
+    <td class="tdr">5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>No. 3. Jan. 23, 1901. QQ (chute)</td>
+    <td class="tdr">1.15 F</td>
+    <td class="tdr">40</td>
+    <td class="tdr">10 F</td>
+    <td></td>
+    <td>No.</td>
+    <td>None.</td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_222"></a>[222]</span></p>
+
+<p>Nothing in my experience with these animals, then, favors
+the hypothesis that they have any general ability to learn to
+do things from seeing others do them. The question is still
+an open one, however, and a much more extensive study of it
+should be made, especially of the possible influence of imitation
+in the case of acts already familiar either as wholes or
+in their elements.</p>
+
+<h4><span class="smcap">Learning apart from Motor Impulses</span></h4>
+
+<p>The reader of my monograph, ‘Animal Intelligence,’ will
+recall that the experiments there reported seemed to show
+that the chicks, cats and dogs had only slight and sporadic,
+if any, ability to form associations except such as contained
+some actual motor impulse. They failed to form such associations
+between the sense-impressions and ideas of movements
+as would lead them to make the movements without
+having themselves previously in those situations given
+the motor impulses to the movements. They could not,
+for instance, learn to do a thing from having been put
+through it by me.</p>
+
+<p>The monkeys Nos. 1 and 3 were tested in a similar way
+with a number of different acts. The general conclusion
+from the experiments, the details of which will be given
+presently, is that the monkeys are not proved to have the
+power of forming associations of ideas to any greater extent
+than the other mammals, that they do not demonstrably
+learn to do things from seeing or feeling themselves make<span class="pagenum"><a id="Page_223"></a>[223]</span>
+the movement. An adult human being whose hand was
+taken and made to push in a bar or pull back a bolt would
+thereby learn to do it for himself. Cats and dogs would
+not, and the monkeys are not proved to do so. On the
+other hand, it is impossible for me to say, as of the dogs and
+cats, that the monkeys are proved not to do so. In a few
+cases the animals did perform acts after having been put
+through them which they had failed to perform when left
+to their own trial and success method. In the majority of
+cases they did not. And in some of these latter cases failure
+seemed so improbable in case the animal really had the
+power of getting an idea of the act and proceeding from idea
+to execution, that one is inevitably led to some explanation
+for the few successes other than the presence of ‘ideas.’</p>
+
+<p>The general manner of making these experiments was like
+that in the case of the cats and dogs, save that the monkey’s
+paw was used to open the box from the outside instead of
+from the inside, and that the monkeys were also put through
+the acts necessary to operate some of the chute mechanisms.
+Tests parallel to that of comparing the behavior of kittens
+who had themselves gone into boxes with those who were
+dropped in by me were made in the following manner. I
+would carry a monkey from his cage and put him in some
+conspicuous place (<i>e.g.</i> on the top of a chair) and then give
+him a bit of food. This I would repeat a number of times.
+Then I would turn him loose in the room to see whether he
+had acquired an idea of being on the chair which would lead
+him to himself go to the chair. I would, in order to tell
+whether his act, in case he did so, was the result of random
+activities or was really due to his tuition, leave him alone for
+5 or 10 minutes before the tuition. If he got on the chair
+afterwards when he had not before, or got on it much
+sooner, it would tend to show that the idea of getting food<span class="pagenum"><a id="Page_224"></a>[224]</span>
+on that chair was present and effective. We may call these
+last the ‘on chair’ type of experiments.</p>
+
+<p>A sample experiment with a box is the following:—</p>
+
+<p>On January 4, 1901, box Delta (push back) was put in No.
+1’s cage. He failed in 5, though he was active in trying to
+get in for about 4 minutes of the time and pulled and pushed
+the bar a great deal, though up and down and out instead of
+back. In his aimless pushings and pullings he nearly succeeded.
+He failed in 5 in a second trial also. I then opened
+the door of the cage, sat down beside it, held out my hand,
+and when he came to me took his right paw and with it (he
+being held in front of the box) pushed the bar back (and
+pulled the door open in those cases when it did not fall open
+of itself). He reached in and took the food and went back
+to the top of his cage and ate it. (No. 1 generally did this,
+while No. 3 generally stayed by me.) I then tried him alone;
+result 10 F; no activity at all. On January 5th I put the
+box in; result 10 F. He was fairly active. He pulled at
+the bar but mostly from a position on the top of the box
+and with his left hand; no attempts like the one I had tried
+to teach him. Being left alone he failed in 5. Being tried
+again with the door of the cage open and me sitting as I had
+done while putting him through the act, he succeeded in 7.00
+by pushing the bar with his head in the course of efforts to
+poke his head in at the door. I then put him through the
+act 10 times and left him to himself. He failed in 5.00;
+no activity. I then sat down by the cage as when teaching
+him. He failed in 5; little activity. Later in the day I put
+him through the act 10 times and then left him to himself.
+He failed in 5; little activity. I sat down as before. He
+failed in five; little activity. On January 6th I put him
+through the act 10 times and then left him. He failed in
+10. This was repeated later in the day with the same result.<span class="pagenum"><a id="Page_225"></a>[225]</span>
+Record:—By himself, 10 F. Put through 80 times. F 65
+(a) [the (a) refers to a note of his unrepeated chance success
+with his head]. No similar act unsuccessfully attempted.
+Influence of tuition, none.</p>
+
+<p>With the chute mechanisms the record would be of the
+same nature. With them I put the animal through generally
+by taking his paw, held out through the wire netting of
+the cage, and making the movement with it. In one experiment
+(No. 3 with QQ chute) the first 58 trials were made
+by taking the monkey outside the cage and holding him instead
+of having him put his paw through the netting for me
+to take.</p>
+
+<p>Many of the experiments were with mechanisms which
+had previously been used in experiments concerning the
+ability to learn from seeing me operate them. And the
+following Table (12) includes the results of experiments of
+both sorts. The results of experiments of the ‘on chair’
+type are in Table 13. In cases where the same apparatus
+was used for both purposes, the sort of training which was
+given first is that where an A is placed.</p>
+
+<p>In the first four experiments with No. 1 there was some
+struggling and agitation on his part while being held and put
+through the act. After that there was none in his case except
+occasional playfulness, and there was never any with
+No. 3 after the first third of the first experiment. The
+monkeys soon formed the habit of keeping still, because it
+was only when still that I put them through the act and that
+food resulted. After you once get them so that they can
+be held and their arms taken without their clinging to you,
+they quickly learn to adapt themselves to the experiments.</p>
+
+<p>With No. 1, out of 8 cases where he had of himself failed
+(in five of the cases he had also failed after being shown by
+me), he succeeded after being put through (13, 21, 51, 10, 7,
+80, and 10 times) in two cases (QQ (chute) and RR (wood
+plug). The act was unlike the one taught him in the former
+case.</p>
+
+<p><span class="pagenum"><a id="Page_226"></a>[226]</span></p>
+
+<h5><span class="smcap">Table 12</span></h5>
+
+<table class="borders max60">
+  <tr>
+    <th><span class="smcap">Subject. Date. Act</span></th>
+    <th><span class="smcap">Times tried alone, with result</span></th>
+    <th><span class="smcap">Number of times attention attracted</span></th>
+    <th><span class="smcap">Result</span></th>
+    <th><span class="smcap">Number of times shown by me</span></th>
+    <th><span class="smcap">Result in trials after being shown by me</span></th>
+    <th><span class="smcap">Number of times put through the act</span></th>
+    <th><span class="smcap">Result in trials after being put through the act</span></th>
+    <th><span class="smcap">Comparison of act used with act taught</span></th>
+    <th><span class="smcap">Similar act attempted though unsuccessfully</span></th>
+    <th><span class="smcap">Act done once or more, but not repeated in spite of repeated tuition</span></th>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 7, 1900, PP (string across)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>13</td>
+    <td>10 F</td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 17, 1900, MM (bolt at top)</td>
+    <td>15 F</td>
+    <td></td>
+    <td></td>
+    <td>21 A</td>
+    <td>150 F</td>
+    <td>21</td>
+    <td>10 F</td>
+    <td></td>
+    <td>(?)</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 1, Feb. 24, 1900, OOO (upper string)</td>
+    <td>2.20</td>
+    <td></td>
+    <td></td>
+    <td>4}</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>Partly similar.</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>3 F</td>
+    <td></td>
+    <td></td>
+    <td>4} 12</td>
+    <td>.20</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>4}</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>4</td>
+    <td>.22</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td>No. 1, Mar. 24, 1900, QQ (chute)</td>
+    <td>120 F</td>
+    <td></td>
+    <td></td>
+    <td>10 A</td>
+    <td>60 F</td>
+    <td>10</td>
+    <td>30.00</td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 1, Apr. 5, 1900, RR (wood plug)</td>
+    <td>10 F</td>
+    <td>2</td>
+    <td>5 F</td>
+    <td>1 A</td>
+    <td>2 F</td>
+    <td>7</td>
+    <td>2.20</td>
+    <td>Similar.</td>
+    <td>Yes(?)</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1</td>
+    <td>2 F</td>
+    <td>2</td>
+    <td>2.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1</td>
+    <td>2 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 1, Oct. 20, 1900, VV (loop)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>4</td>
+    <td>.22</td>
+    <td></td>
+    <td></td>
+    <td>Similar.</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td>No. 1, Nov. 19, 1900, Theta (new bolt)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>5</td>
+    <td>10 F</td>
+    <td>51 A</td>
+    <td>132 F</td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 4, 1901, Delta (push back)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>15</td>
+    <td>10 F</td>
+    <td>80 A</td>
+    <td>65 F<a id="FNanchor_31" href="#Footnote_31" class="fnanchor">[31]</a></td>
+    <td></td>
+    <td>No.</td>
+    <td><span class="pagenum"><a id="Page_227"></a>[227]</span></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 1, Jan. 6, 1901, QQ (a) (single wind chute)</td>
+    <td>8.00</td>
+    <td></td>
+    <td></td>
+    <td>40</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>Dissimilar.</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>2.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>.50</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 1, Jan. 7, 1901, Zeta (side plug new)</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>20</td>
+    <td>im.</td>
+    <td>?</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>1.10</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>im.</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 1, Jan. 9, 1901, QQ (b) (2½ wind chute)</td>
+    <td>3.00 to .06</td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td>Yes.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>3.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 11, 1901, QQ (c) (nail chute)</td>
+    <td>5 F</td>
+    <td>5</td>
+    <td>5 F</td>
+    <td>1<a id="FNanchor_32" href="#Footnote_32" class="fnanchor">[32]</a></td>
+    <td>2.20</td>
+    <td></td>
+    <td></td>
+    <td>Dissimilar.</td>
+    <td></td>
+    <td>Yes.<a id="FNanchor_33" href="#Footnote_33" class="fnanchor">[33]</a></td>
+  </tr>
+  <tr>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 1, Jan. 12, 1901, Epsilon (push down)</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td>25 A</td>
+    <td>10 F</td>
+    <td>10</td>
+    <td>5 F</td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10 F</td>
+    <td>10</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>15</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 16, 1901, QQ (d) (pull chute)</td>
+    <td>5 F</td>
+    <td>5</td>
+    <td>3.30</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>5 F</td>
+    <td></td>
+    <td>.10</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 17, 1901, QQ (f) (string chute)</td>
+    <td>5 F</td>
+    <td>5</td>
+    <td>5 F</td>
+    <td>15 A</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 1, Jan. 18, 1901, QQ (e) (hook chute)</td>
+    <td>5 F</td>
+    <td>3</td>
+    <td>im.</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td><span class="pagenum"><a id="Page_228"></a>[228]</span></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 3, Dec. 17, 1900, QQ (chute)</td>
+    <td>60 F</td>
+    <td>3</td>
+    <td>60 F</td>
+    <td>10 A</td>
+    <td>5 F</td>
+    <td>113</td>
+    <td>90 F</td>
+    <td></td>
+    <td>(?)</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>30</td>
+    <td>30 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 3, Dec. 17, 1900, VV (loop)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>23</td>
+    <td>20 F</td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>20 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 3, Jan. 4, 1901, Delta (push back)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>20</td>
+    <td>8.00<a id="FNanchor_34" href="#Footnote_34" class="fnanchor">[34]</a></td>
+    <td>5 A</td>
+    <td>2.00<a id="FNanchor_35" href="#Footnote_35" class="fnanchor">[35]</a></td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>2.10 (by pulling string)</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>8.00<a href="#Footnote_34" class="fnanchor">[34]</a></td>
+    <td>5</td>
+    <td>3.20</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>15</td>
+    <td>30 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="2" class="br">No. 3, Jan. 4, 1901, Gamma (wind)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>30</td>
+    <td>10 F</td>
+    <td>20 A</td>
+    <td>5 F</td>
+    <td></td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10 F</td>
+    <td></td>
+    <td>8 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td>No. 3, Jan. 8, 1901, Theta (bolt at top)</td>
+    <td>10 F<a id="FNanchor_36" href="#Footnote_36" class="fnanchor">[36]</a></td>
+    <td></td>
+    <td></td>
+    <td>25</td>
+    <td>6 F</td>
+    <td></td>
+    <td></td>
+    <td>Dissimilar.</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 3, Jan. 9, 1901, QQ (a) (chute bar)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>3.00<a id="FNanchor_37" href="#Footnote_37" class="fnanchor">[37]</a></td>
+    <td>10</td>
+    <td></td>
+    <td></td>
+    <td>No complete circle.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>.40</td>
+    <td>?</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>1.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>1.00</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 3, Jan. 9, 1901, QQ (b) (2½ wind chute)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>20</td>
+    <td>8 F</td>
+    <td></td>
+    <td>5 F</td>
+    <td>Dissimilar.</td>
+    <td></td>
+    <td>Yes.</td>
+  </tr>
+  <tr>
+    <td><span class="pagenum"><a id="Page_229"></a>[229]</span></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>8 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="5" class="br">No. 3, Jan. 11, 1901, QQ (c) (nail chute)</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>5 F</td>
+    <td>25 A</td>
+    <td>5 F</td>
+    <td>45</td>
+    <td>38 F</td>
+    <td></td>
+    <td>No.</td>
+    <td>Yes.</td>
+  </tr>
+  <tr>
+    <td>5 F</td>
+    <td></td>
+    <td>12 F<a id="FNanchor_38" href="#Footnote_38" class="fnanchor">[38]</a></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1.30</td>
+    <td>10</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 3, Jan. 15, 1901, Epsilon (push down)</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td>25 A</td>
+    <td>5 F</td>
+    <td>20</td>
+    <td>11.00</td>
+    <td></td>
+    <td>No.</td>
+    <td>Yes.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td>30 F</td>
+    <td>?</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>15</td>
+    <td>10 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 3, Jan. 16, 1901, QQ (e) (hook chute)</td>
+    <td>5 F</td>
+    <td>5</td>
+    <td>5 F</td>
+    <td>5 A</td>
+    <td>2.00</td>
+    <td>10</td>
+    <td>.10</td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1.25</td>
+    <td></td>
+    <td>.10</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>1.20</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="4" class="br">No. 3, Jan. 19, 1901, QQ (ff) (string chute with wire)</td>
+    <td>5 F</td>
+    <td></td>
+    <td>5</td>
+    <td>5 A</td>
+    <td>5 F</td>
+    <td>7</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>8</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>2.00<a id="FNanchor_39" href="#Footnote_39" class="fnanchor">[39]</a></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>12</td>
+    <td>3.00</td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr class="new">
+    <td rowspan="3" class="br">No. 3, Jan. 22, 1901, WW (bar inside)</td>
+    <td>5 F previously some 40.00 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>6.00<a id="FNanchor_40" href="#Footnote_40" class="fnanchor">[40]</a></td>
+    <td></td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>7.00<a href="#Footnote_40" class="fnanchor">[40]</a></td>
+    <td>Dissimilar.</td>
+    <td>No.</td>
+    <td></td>
+  </tr>
+</table>
+
+<p><span class="pagenum"><a id="Page_230"></a>[230]</span></p>
+
+<p>In only one case (bolt at top) out of eight was there possibly
+any attempt at the act after he had been put through
+which had not been made before. The ‘yes or?’ in the
+table with RR was a case occurring after the imitation of me
+but before the putting No. 1 through.</p>
+
+<p>Out of 6 cases where he had himself failed, No. 3 succeeded
+(after being put through 113, 23, 20, 10, 10, 20 and 10
+times) in 3 cases (chute bar, push down and bar inside).
+The act was dissimilar in all three cases, bearing absolutely
+no resemblance in one case. There was no unsuccessful
+attempt at the act taught him in any of the cases. With
+the chute he did finger the bar after tuition where he had
+not done so before, but it was probably an accidental result
+of his holding his hand out toward it for me to take as he had
+formed the habit of doing. In the case of box Epsilon
+(push down), with which he succeeded by pushing his hand
+in above the lever (an act which though unlike that taught
+him might be by some considered to be due to an idea
+gained from the tuition), he failed entirely after further
+tuition (15 times).</p>
+
+<p>Like the dogs and cats, then, the monkeys seemed unable
+to learn to do things from being put through them. We
+may now examine those which they did do of themselves before
+tuition and ask whether they learned the more rapidly
+thereby or modified their behavior in ways which might be
+due to the tuition. There are too few cases and no chance
+for comparison on the first point; on the second the records
+are unanimous in showing no change in the method of operating
+the mechanisms due to the tuition.</p>
+
+<p>As in Table 9, figures followed by F mean that in that<span class="pagenum"><a id="Page_231"></a>[231]</span>
+length of time the animal failed. Figures without an F denote
+the time taken by the animal to operate the mechanism.</p>
+
+<p>As a supplement to Table 12 I have made a summary of
+the cases where the animals did succeed after tuition, that
+shows the nature of the act shown them as compared with
+the act they made use of.</p>
+
+<h5><span class="smcap">Supplement to Table 12</span></h5>
+
+<table class="borders align-top">
+  <tr>
+    <th><span class="smcap">Apparatus</span></th>
+    <th><span class="smcap">Model given or act put through</span></th>
+    <th><span class="smcap">Act of No. 1</span></th>
+    <th><span class="smcap">Act of No. 3</span></th>
+  </tr>
+  <tr>
+    <td>OOO</td>
+    <td>To pull upper string.</td>
+    <td>Pulled both strings alternately, but upper enough more to succeed.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>QQ</td>
+    <td>To push bar in.</td>
+    <td>Inserted fingers between bar and its slot and pulled and pushed vaguely.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>RR</td>
+    <td>To pull plug out with right hand.</td>
+    <td>Pulled and bit.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>VV</td>
+    <td>To pull loop off nail with right hand.</td>
+    <td><i>Similar.</i></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>QQ (a)</td>
+    <td>To pull bar around toward him.</td>
+    <td>Pulled back and forth indiscriminately.</td>
+    <td>Pulled back and forth indiscriminately.</td>
+  </tr>
+  <tr>
+    <td>QQ (b)</td>
+    <td>To pull bar around toward him in 2½ continuous revolutions.</td>
+    <td>Pulled back and forth indiscriminately.</td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>QQ (c)</td>
+    <td>To take nail and pull directly outward.</td>
+    <td>Pulled back and forth.</td>
+    <td><i>Similar</i> or nearly so.</td>
+  </tr>
+  <tr>
+    <td>Delta</td>
+    <td>To push bar to right with right hand.</td>
+    <td></td>
+    <td>Did before tuition by pulling wire; after tuition by chance movement of head.</td>
+  </tr>
+  <tr>
+    <td>Theta</td>
+    <td>To pull bolt up with right hand.</td>
+    <td></td>
+    <td>Pulled door and worked bolt loose.</td>
+  </tr>
+  <tr>
+    <td><span class="pagenum"><a id="Page_232"></a>[232]</span>Epsilon</td>
+    <td>To stand in front, insert fingers of right hand and press lever down.</td>
+    <td></td>
+    <td>Inserted arm in general activity while on top of the box.</td>
+  </tr>
+  <tr>
+    <td>QQ (e)</td>
+    <td>To pull hook down.</td>
+    <td></td>
+    <td>Pulled at the lever and hook in a general attack on the apparatus.</td>
+  </tr>
+  <tr>
+    <td>QQ (ff)</td>
+    <td>To pull wire loop off nail with right hand.</td>
+    <td></td>
+    <td>Pulled outward on the lever which pushed the banana down the chute so hard as to pull it off its pivot.</td>
+  </tr>
+  <tr>
+    <td>WW</td>
+    <td>To stand on top of box, reach right hand down and pull bar up.</td>
+    <td></td>
+    <td>Pulled at door until bar worked out of its catch.</td>
+  </tr>
+</table>
+
+<p>I have kept the results of the tests of the ‘on chair’ type
+separate from the others because they may be tests of a different
+thing and surely are subject to different conditions.</p>
+
+<p>They were tests of the animals’ ability to form the habit of
+going to a certain place by reason of having been <i>carried</i>
+there and securing food thereby. I would leave the animal
+loose in the room, and if he failed in 5 or 10 minutes to go to
+the place of his own accord, would put him back in his cage;
+if he did go of his own accord, I would note the time. Then
+I would take him, carry him to the place, and feed him.
+After doing this 10 times I would turn him loose again and
+see whether the idea of being fed in such and such a place was
+present and active in making him go to the place. In such
+tests we are absolutely sure that the animal can without any
+difficulty perform the necessary movements and would in<span class="pagenum"><a id="Page_233"></a>[233]</span>
+case the proper stimulus to set them off appeared, if, for
+instance, a bit of food on one of the places to which he was to
+go caught his eye. In so far forth the tests were favorable
+cases for learning. On the other hand, the situation associated
+with getting food may have been in these cases not
+the mere ‘being on box’ but the whole previous experience
+‘being carried while clinging and being put or let jump on a
+box.’ In this respect the tests may have been less favorable
+than the acts where getting food was always the direct
+sequent of the act of going into the box.</p>
+
+<p>The experiments were:—</p>
+
+<p>A. Carrying the animal and putting him on a chair.</p>
+
+<p>B. Carrying the animal and putting him on a pile of boxes.</p>
+
+<p>C. Carrying the animal and putting him on the top of a
+sewing machine.</p>
+
+<p>D. Carrying the animal and putting him on the middle of
+a board 6 feet long, stretched horizontally across the room,
+3 feet from the floor.</p>
+
+<p>E. Carrying the animal and putting him on the side of the
+cage, head down.</p>
+
+<p>The results are given in Table 13.</p>
+
+<p>The size of the room in which I worked and other practical
+difficulties prevented me from extending these experiments.
+As they stand, no stable judgments can be inferred from
+them. It should be noted that in the successful cases there
+were no other signs of the presence of the idea ‘food when
+there’ than the mere going to a certain place. The animal
+did not wait at the place more than a second or two, did not
+look at me or show any signs of expecting anything.</p>
+
+<p><span class="pagenum"><a id="Page_234"></a>[234]</span></p>
+
+<h5><span class="smcap">Table 13</span></h5>
+
+<table class="borders">
+  <tr>
+    <th><span class="smcap">Experiment and date</span></th>
+    <th><span class="smcap">Animal</span></th>
+    <th><span class="smcap">Results before training</span></th>
+    <th><span class="smcap">Number of times put through</span></th>
+    <th><span class="smcap">Results after training</span></th>
+  </tr>
+  <tr>
+    <td>A. Jan. 22, 1901</td>
+    <td>No. 1.</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>1.00</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>3.00</td>
+  </tr>
+  <tr>
+    <td>&#160;&#160;&#160;&#160;Jan. 22, 1901</td>
+    <td>No. 1.</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>im.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>3.30</td>
+  </tr>
+  <tr>
+    <td>&#160;&#160;&#160;&#160;Jan. 23, 1901</td>
+    <td>No. 3.</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>3.30</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td>5 F</td>
+    <td></td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>B. Jan. 26, 1901</td>
+    <td>No. 1.</td>
+    <td>10 F</td>
+    <td>10 and 5</td>
+    <td>10 F 5 F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>No. 3.</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>5 F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td></td>
+    <td></td>
+    <td>10</td>
+    <td>5 F</td>
+  </tr>
+  <tr>
+    <td>C. Jan. 27, 1901</td>
+    <td>No. 1.</td>
+    <td>5 F</td>
+    <td>10</td>
+    <td>3.00</td>
+  </tr>
+  <tr>
+    <td>D. Jan. 27, 1901</td>
+    <td>No. 1.</td>
+    <td>3.20</td>
+    <td>10</td>
+    <td>5 F</td>
+  </tr>
+  <tr>
+    <td>E. Jan. 26, 1901</td>
+    <td>No. 3.</td>
+    <td>5 F</td>
+    <td>5</td>
+    <td>5 F</td>
+  </tr>
+</table>
+
+<p>Although, as I noted in the early part of this monograph,
+there were occasionally phenomena in the general behavior
+of the monkeys which of themselves impressed one as being
+suggestive of an ideational life, the general run of their
+learning apart from the specific experiments described was
+certainly confined to the association of impulses of their
+own with certain situations. The following examples will
+suffice:—</p>
+
+<p>In getting them so that they would let themselves be handled
+it was of almost no service to <i>take</i> them and feed them
+while holding them or otherwise make that state pleasant
+for them. By far the best way is to wait patiently till they
+do come near, then feed them; wait patiently till they do
+take hold of your arm, then feed them. If you do take them
+and hold them partly by force, you must feed them only
+when they are comparatively still. In short, in taming
+them one comes unconsciously to adopt the method of rewarding
+certain of their impulses rather than certain <i>conditions</i>
+which might be associated in their minds with ideas,
+had they such.</p>
+
+<p>After No. 1 and No. 3 had both reached a point where
+both could hardly be gotten to leave me and go back into<span class="pagenum"><a id="Page_235"></a>[235]</span>
+their cages or down to the floor of the room, where they evidently
+enjoyed being held by me, they still did not climb
+upon me. The idea of clinging to me was either absent or
+impotent to cause them to act. What they did do was, in
+the case of No. 1, to jump about, pawing around in the
+air, until I caught an arm or leg, to which stimulus he had
+by dint of the typical sort of animal association learned to
+react by jumping to my arm and clinging there; in the case
+of No. 3, to stand still until I held my arm right in front of
+him (if he were in his cage) or to come and stand on his
+hind legs in front of me (if he were out on the floor). In
+both cases No. 3’s act was one which had been learned by
+my rewarding his impulses. I often tried, at this period of
+their intimacy with me, this instructive experiment. The
+monkey would be clinging to me so that I could hardly
+tear him away. I would do so, and he would, if dropped
+loose from me, make no efforts to get back.</p>
+
+<p>I have already mentioned my failure to get the animals to
+put out their right hands through the netting after they had
+long done so with their left hands. With No. 3 I tried putting
+my fingers through and poking the arm out and then
+making the movement with it. He profited little if any by
+this tuition. Had I somehow induced him to do it himself,
+a few trials would have been sufficient to get the habit well
+under way.</p>
+
+<p>Monkey No. 1 apparently enjoyed scratching himself.
+Among the stimuli which served to set off this act of scratching
+was the irritation from tobacco smoke. If any one
+would blow smoke in No. 1’s face, he would blink his eyes
+and scratch himself, principally in the back. After a time
+he got in the habit of coming to the front of his cage when
+any one was smoking and making such movements and
+sounds as in his experience had attracted attention and<span class="pagenum"><a id="Page_236"></a>[236]</span>
+caused the smoker to blow in his face. He was often given
+a lighted cigar or cigarette to test him for imitation. He
+formed the habit of rubbing it on his back. After doing so
+he would scratch himself with great vigor and zest. He
+came to do this always when the proper object was given
+him. I have recounted all this to show that the monkey
+enjoyed scratching himself. <i>Yet he apparently never
+scratched himself except in response to some sensory stimulus.</i>
+He was apparently incapable of thinking ‘scratch’ and so
+doing. Yet the act was quite capable of association with
+circumstances with which as a matter of hereditary organization
+it had no connection. For by taking a certain well-defined
+position in front of his cage and feeding him whenever
+he did scratch himself I got him to always scratch
+within a few seconds after I took that position.</p>
+
+<h3><span class="smcap">General Mental Development of the Monkeys</span></h3>
+
+<p>It is to be hoped that the growing recognition of the worth
+of comparative and genetic studies will lead to investigations
+of the mental make-up of other species of monkeys, and
+to the careful overhauling of the work done so far, including
+these rather fragmentary studies of mine. Work with three
+monkeys of one species, especially when no general body of
+phenomena, such as one has at hand in the case of domestic
+animals, can be used as a means of comparison, must necessarily
+be of limited application in all its details and of insecure
+application even in its general features. What I shall
+say concerning the advance in the mental development
+of the monkeys over that of other mammals may then be
+in strictness true of only my three subjects, and it may be
+left to the judgment of individuals to extend my conclusions<span class="pagenum"><a id="Page_237"></a>[237]</span>
+as far as seems to them likely. To me it seems fairly likely
+that the very general mental traits which the research has
+demonstrated hold true with little variation in the monkeys
+in general.</p>
+
+<p>The monkeys represent progress in mental development
+from the generalized mammalian type toward man:—</p>
+
+<p>1. In their sensory equipment, in the presence of focalized
+vision.</p>
+
+<p>2. In their motor equipment, in the coördinated movements
+of the hand and the eye.</p>
+
+<p>3. In their instincts or inherited nervous connections, in
+their general physical and mental activity.</p>
+
+<p>4. In their method of learning or associative processes;
+in—</p>
+
+<ul>
+<li><i>a.</i> Quicker formation of associations,</li>
+<li><i>b.</i> Greater number of associations,</li>
+<li><i>c.</i> Greater delicacy of associations,</li>
+<li><i>d.</i> Greater complexity of associations,</li>
+<li><i>e.</i> Greater permanence of associations.</li>
+</ul>
+
+<p>The fact of (1) is well known to comparative anatomists.
+Its importance in mental development is perhaps not realized,
+but appears constantly to a systematic student.</p>
+
+<p>(2) is what accounts for much of the specious appearance
+of human ways of thinking in the monkeys and becomes in
+its human extension the handy tool for much of our intellectual
+life. It is in great measure the prerequisite of 4 <i>c</i>.</p>
+
+<p>(3) accounts for the rest of such specious appearances, is
+at the basis of much of 4 <i>b</i>, presages the similar though
+extended instincts of the human being, which I believe are
+the leading efficient causes of human mental capacity, and
+is thus the great mental bond which would justify the inclusion
+of monkeys and man in a common group if we were
+to classify animals on the basis of mental characteristics.</p>
+
+<p><span class="pagenum"><a id="Page_238"></a>[238]</span></p>
+
+<p>Even the casual observer, if he has any psychological insight,
+will be struck by the general, aimless, intrinsically
+valuable (to the animal’s feelings) physical activities of a
+monkey compared with the specialized, definitely aroused,
+utilitarian activities of a dog or cat. Watch the latter and
+he does but few things, does them in response to obvious
+sense presentations, does them with practical consequences
+of food, sex-indulgence, preparation for adult battles, etc.
+If nothing that appeals to his special organization comes
+up, he does nothing. Watch a monkey and you cannot
+enumerate the things he does, cannot discover the stimuli
+to which he reacts, cannot conceive the <i>raison d’être</i> of
+his pursuits. Everything appeals to him. He likes to be
+active for the sake of activity.</p>
+
+<p>The observer who has proper opportunities and takes
+proper pains will find this intrinsic interest to hold of mental
+activity as well. No. 1 happened to hit a projecting
+wire so as to make it vibrate. He repeated this act hundreds
+of times in the few days following. He did not, could
+not, eat, make love to, or get preliminary practice for the
+serious battles of life out of, that sound. But it did give
+him mental food, mental exercise. Monkeys seem to enjoy
+strange places; they revel, if I may be permitted an anthropomorphism,
+in novel objects. They like to have
+feelings as they do to make movements. The fact of mental
+life is to them its own reward.</p>
+
+<p>It is beyond question rash for any one to venture hypotheses
+concerning the brain parallel of mental conditions,
+most of all for the ignoramus in the comparative histology
+of the nervous system, but one cannot help thinking that
+the behavior of the monkeys points to a cerebrum that is no
+longer a conservative machine for making a few well-defined
+sorts of connections between sense-impressions and acts,<span class="pagenum"><a id="Page_239"></a>[239]</span>
+that is not only fitted to do more delicate work in parts,
+but is also alive, tender all over, functioning throughout,
+set off in action by anything and everything. And if one
+adds coördinations allowing a freedom and a differentiation
+of action of the muscles used in speech comparable to that
+already present in connection with the monkey’s hand, he
+may well ask, “What more of a nervous mechanism do
+you need to parallel the behavior of the year-old child?”
+However, this is not the place to speculate upon the importance
+to human development of our instinctive aimless
+activity, physical and mental, or to describe further its
+similarity and evident phylogenetic relationship to the instinctive
+behavior of the monkeys. Elsewhere I shall undertake
+that task.</p>
+
+<p>4. In their method of learning, the monkeys do not advance
+far beyond the generalized mammalian type, but in
+their proficiency in that method they do. They seem at
+least to form associations very much faster, and they form
+very many more. They also seem superior in the delicacy
+and in the complexity of the associations formed and the
+connections seem to be more permanent.</p>
+
+<p>This progress may seem, and doubtless will to the thinker
+who looks upon the human intellect as a collection of functions
+of which ideation, judgment and reasoning are chief,
+to be slight. To my mind it is not so in reality. For it
+seems to me highly probable that the so-called ‘higher’ intellectual
+processes of human beings are but secondary results
+of the general function of having free ideas and that
+this general function is the result of the formation after the
+fashion of the animals of a very great number of associations.
+I should therefore say, “Let us not wonder at the comparative
+absence of free ideas in the monkeys, much less at
+the absence of inferences or concepts. Let us not wonder<span class="pagenum"><a id="Page_240"></a>[240]</span>
+that the only demonstrable intellectual advance of the monkeys
+over the mammals in general is the change from a few,
+narrowly confined, practical associations to a multitude of
+all sorts, for that may turn out to be at the bottom the
+only <i>demonstrable advance of man</i>, an advance which in connection
+with a brain acting with increased delicacy and
+irritability, brings in its train the functions which mark off
+human mental faculty from that of all other animals.”</p>
+
+<p>The typical process of association described in Chapter II
+has since been found to exist among reptiles (by Mr. R.
+M. Yerkes) and among fishes (by myself). It seems fairly
+likely that not much more characterizes the primates. If
+such work as that of Lubbock and the Peckhams holds its
+own against the critical studies of Bethe, this same process
+exists in the insects. Yerkes and Bosworth think they
+have demonstrated its presence in the crayfish. Even if
+we regard the learning of the invertebrates as problematic,
+still this process is the most comprehensive and important
+thing in mental life. I have already hinted that we ought
+to turn our views of human psychology upside down and
+study what is now casually referred to in a chapter on habit
+or on the development of the will, as the general psychological
+law, of which the commonly named processes are
+derivatives. When this is done, we shall not only relieve
+human mentality from its isolation and see its real relationships
+with other forms; we may also come to know more
+about it, may even elevate our psychologies to the explanatory
+level and connect mental processes with nervous activities
+without arousing a sneer from the logician or a grin
+from the neurologist.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_241"></a>[241]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_VI">CHAPTER VI<br>
+<span class="smcap">Laws and Hypotheses for Behavior</span></h2>
+
+</div>
+
+<h3><span class="smcap">Laws of Behavior in General</span></h3>
+
+<p><i>Behavior is predictable.</i> The first law of behavior, one
+fraction of the general law of the uniformity of nature, is
+that with life and mind, as with mass and motion, the same
+cause will produce the same effect,—that <i>the same situation
+will, in the same animal, produce the same response</i>,—and
+that <i>if the same situation produces on two occasions two
+different responses, the animal must have changed</i>.</p>
+
+<p>Scientific students of behavior will, with few exceptions,
+accept this law in theory, but in practice we have not fully
+used it. We have too often been content to say that a man
+may respond in any one of several ways to the same situation,
+or may attend to one rather than another feature of
+the same object, without insisting that the man must in each
+case be different, and without searching for the differences
+in him which cause the different reactions.</p>
+
+<p>The changes in an organism which make it respond differently
+on different occasions to the same situation range from
+temporary to permanent changes. Hunger, fatigue, sleep,
+and certain diseases on the one hand, and learning, immunity,
+growth and senility on the other, illustrate this range.</p>
+
+<p>Behavior is predictable <i>without recourse to magical agencies</i>.
+It is, of course, the case that any given difference
+between the responses of an animal to the same situation<span class="pagenum"><a id="Page_242"></a>[242]</span>
+depends upon some <i>particular</i> difference in the animal. Each
+immunity, for example, has its detailed representation in an
+altered condition of the blood or other bodily tissue. In
+general the changes in an animal which cause changes in its
+behavior to the same situation are fully enumerated in a
+list of the bodily changes concerned. That is, whatever
+changes may be supposed to have taken place in the animal’s
+vital force, spiritual essence, or other magical bases for life
+and thought, are useless for scientific explanation and control
+of behavior.</p>
+
+<p>No competent thinker probably doubts this in the case of
+such changes as are referred to by hunger, sleep, fatigue, so-called
+‘functional’ diseases and immunity, and those who do
+doubt it in the case of mental growth and learning seem to
+represent an incomplete evolution from supernatural, or
+rather infrascientific, thinking. There may be in behavior
+a surplus beyond what would be predictable if the entire
+history of every atom in the body was known—a surplus
+necessarily attributable to changes in the animal’s incorporeal
+structure. But scientific thinkers properly refuse
+to deliberately count upon such a surplus.</p>
+
+<p><i>Every response or change in response of an animal is then
+the result of the interaction of its original knowable nature and
+the environment.</i> This may seem too self-evident a corollary
+for mention. It should be so, but, unfortunately, it is not.
+Two popular psychological doctrines exist in defiance of it.
+One is the doctrine that the movements of early infancy are
+random, the original nature of the animal being entirely
+indifferent as to what movement shall be made upon a given
+stimulus. But no animal can have an original nature that
+does not absolutely prescribe just what the response shall
+be to every stimulus. If the movements are really random,
+they occur by virtue of some force that works at random.<span class="pagenum"><a id="Page_243"></a>[243]</span>
+If the movements are really the result of the action of the environment
+on the animal’s nature, they are never random.
+A baby twiddles his thumbs or waves his legs for exactly the
+same sort of reason that a chick pecks at a worm or preens
+its wing.</p>
+
+<p>The other doctrine which witnesses to neglect of the
+axiom that behavior is the creation of the environment, acting
+on the animal’s nature, is the doctrine that the need
+for a certain behavior helps to create it, that being in a
+difficulty tends in and of itself to make an animal respond so
+as to end the difficulty.</p>
+
+<p>The truth is that to a difficulty the animal responds by
+whatever its inherited and acquired nature has connected
+with the special form of difficulty and that in many animals
+the one response of those thus provided which relieves the
+difficulty is selected and connected more firmly with that
+difficulty’s next appearance. The difficulty acts only as a
+stimulus to the animal’s nature and its relief acts only as a
+premium to the connection whereby it was relieved. The
+law of original behavior, or the law of instinct, is then that
+<i>to any situation an animal will, apart from learning, respond
+by virtue of the inherited nature of its reception-, connection-
+and action-systems</i>.</p>
+
+<p>The inquiry into the laws of learning to be made in this
+essay is limited to those aspects of behavior which the term
+has come historically to signify, that is, to intellect, skill,
+morals and the like.</p>
+
+<p>For the purposes of this essay it is not necessary to decide
+just what features of an animal’s behavior to include under
+intellect, skill, morals and the like. The statements to be
+made will fit any reasonable dividing line between behavior
+on the one side and mere circulation, digestion, excretion
+and the like on the other. There should in fact be no clear<span class="pagenum"><a id="Page_244"></a>[244]</span>
+dividing line, since there is no clear gap between those
+activities which naturalists have come to call behavior and
+the others.</p>
+
+<p>The discussion will include: First, a description of two
+laws of learning; second, an argument to prove that no additional
+forces are needed—that these two laws explain all
+learning; and third, an investigation of whether these two
+laws are reducible to more fundamental laws. I shall also
+note briefly the consequences of the acceptance of these laws
+in one sample case, that of the study of mental evolution.</p>
+
+<h3><span class="smcap">Provisional Laws of Acquired Behavior or Learning</span></h3>
+
+<p>The Law of Effect is that: <i>Of several responses made to
+the same situation, those which are accompanied or closely
+followed by satisfaction to the animal will, other things being
+equal, be more firmly connected with the situation, so that,
+when it recurs, they will be more likely to recur; those which
+are accompanied or closely followed by discomfort to the animal
+will, other things being equal, have their connections with
+that situation weakened, so that, when it recurs, they will be
+less likely to occur. The greater the satisfaction or discomfort,
+the greater the strengthening or weakening of the bond.</i></p>
+
+<p>The Law of Exercise is that: <i>Any response to a situation
+will, other things being equal, be more strongly connected with
+the situation in proportion to the number of times it has been
+connected with that situation and to the average vigor and duration
+of the connections.</i></p>
+
+<p>These two laws stand out clearly in every series of experiments
+on animal learning and in the entire history of the
+management of human affairs. They give an account of
+learning that is satisfactory over a wide range of experience,<span class="pagenum"><a id="Page_245"></a>[245]</span>
+so long as all that is demanded is a rough and general means
+of prophecy. We can, as a rule, get an animal to learn a
+given accomplishment by getting him to accomplish it,
+rewarding him when he does, and punishing him when he
+does not; or, if reward or punishment are kept indifferent,
+by getting him to accomplish it much oftener than he does
+any other response to the situation in question.</p>
+
+<p>For more detailed and perfect prophecy, the phrases
+‘result in satisfaction’ and ‘result in discomfort’ need further
+definition, and the other things that are to be equal need
+comment.</p>
+
+<p>By a satisfying state of affairs is meant one which the
+animal does nothing to avoid, often doing such things as
+attain and preserve it. By a discomforting or annoying
+state of affairs is meant one which the animal commonly
+avoids and abandons.</p>
+
+<p>The satisfiers for any animal in any given condition cannot
+be determined with precision and surety save by observation.
+Food when hungry, society when lonesome, sleep
+when fatigued, relief from pain, are samples of the common
+occurrence that what favors the life of the species satisfies
+its individual members. But this does not furnish a completely
+valid rule.</p>
+
+<p>The satisfying and annoying are not synonymous with
+favorable and unfavorable to the life of either the individual
+or the species. Many animals are satisfied by deleterious
+conditions. Excitement, overeating, and alcoholic intoxication
+are, for instance, three very common and very potent
+satisfiers of man. Conditions useful to the life of the species
+in moderation are often satisfying far beyond their useful
+point: many conditions of great utility to the life of the
+species do not satisfy and may even annoy its members.</p>
+
+<p>The annoyers for any animal follow the rough rule that<span class="pagenum"><a id="Page_246"></a>[246]</span>
+alterations of the animal’s ‘natural’ or ‘normal’ structure—as
+by cuts, bruises, blows, and the like,—and deprivations
+of or interference with its ‘natural’ or ‘normal’ activities,—as
+by capture, starvation, solitude, or indigestion,—are intolerable.
+But interference with the structure and functions
+by which the species is perpetuated is not a sufficient
+criterion for discomfort. Nature’s adaptations are too
+crude.</p>
+
+<p>Upon examination it appears that the pernicious states of
+affairs which an animal welcomes are not pernicious <i>at the
+time, to the neurones</i>. We learn many bad habits, such as
+morphinism, because there is incomplete adaptation of all
+the interests of the body-state to the temporary interest of
+its ruling class, the neurones. So also the unsatisfying
+goods are not goods to the neurones at the time. We neglect
+many benefits because the neurones choose their immediate
+advantage. The neurones must be tricked into permitting
+the animal to take exercise when freezing or quinine when
+in a fever, or to free the stomach from certain poisons.</p>
+
+<p>Satisfaction and discomfort, welcoming and avoiding, thus
+seem to be related to the maintenance and hindrance of the
+life processes of the neurones rather than of the animal as a
+whole, and to temporary rather than permanent maintenance
+and hindrance.</p>
+
+<p>The chief life processes of a neurone concerned in learning
+are absorption of food, excretion of waste, reception and
+conduction of the nerve impulse, and modifiability or change
+of connections. Of these only the latter demands comment.</p>
+
+<p>The connections formed between situation and response
+are represented by connections between neurones and neurones,
+whereby the disturbance or neural current arising in
+the former is conducted to the latter across their synapses.
+The strength or weakness of a connection means the greater<span class="pagenum"><a id="Page_247"></a>[247]</span>
+or less likelihood that the same current will be conducted
+from the former to the latter rather than to some other place.
+The strength or weakness of the connection is a condition
+of the synapse. What condition of the synapse it is remains
+a matter for hypothesis. Close connection might mean protoplasmic
+union, or proximity of the neurones in space, or a
+greater permeability of a membrane, or a lowered electrical
+resistance, or a favorable chemical condition of some other
+sort. Let us call this undefined condition which parallels
+the strength of a connection between situation and response
+the intimacy of the synapse. Then the modifiability or
+connection changing of a neurone equals its power to alter
+the intimacy of its synapses.</p>
+
+<p>As a provisional hypothesis to account for what satisfies
+and what annoys an animal, I suggest the following:—</p>
+
+<p>A neurone modifies the intimacy of its synapses so as to
+keep intimate those by whose intimacy its other life processes
+are favored and to weaken the intimacy of those
+whereby its other life processes are hindered. The animal’s
+action-system as a whole consequently does nothing to avoid
+that response whereby the life processes of the neurones
+other than connection-changing are maintained, but does
+cease those responses whereby such life processes of the
+neurones are hindered.</p>
+
+<p>This hypothesis has two important consequences. First:
+Learning by the law of effect is then more fully adaptive for
+the neurones in the changing intimacy of whose synapses
+learning consists, than for the animal as a whole. It is
+adaptive for the animal as a whole only in so far as his organization
+makes the neurones concerned in the learning
+welcome states of affairs that are favorable to his life and
+that of his species and reject those that are harmful.</p>
+
+<p>Second: A mechanism in the neurones gives results in<span class="pagenum"><a id="Page_248"></a>[248]</span>
+the behavior of the animal as a whole that seem beyond
+mechanism. By their unmodifiable abandonment of certain
+specific conditions and retention of others, the animal as a
+whole can modify its behavior. Their one rule of conduct
+causes in him a countless complexity of habits. The learning
+of an animal is an instinct of its neurones.</p>
+
+<p>I have limited the discussion to animals in whom the connection-system
+is a differentiated organ, the neurones. In
+so far as the law of effect operates in an animal whose connection-system
+is not anatomically distinguishable and is
+favored and hindered in its life by the same conditions that
+favor and hinder the life of the animal as a whole, the satisfying
+and annoying will be those states of affairs which the
+connection-system, whatever it be, maintains and abandons.</p>
+
+<p>The other things that have to be equal in the case of the
+law of effect are: First, the frequency, energy and duration
+of the connection,—that is, the action of the law of exercise;
+second, the closeness with which the satisfaction is
+associated with the response; and, third, the readiness of the
+response to be connected with the situation.</p>
+
+<p>The first of these accessory conditions requires no comment.
+A slightly satisfying or indifferent response made
+often may win a closer connection than a more satisfying
+response made only rarely.</p>
+
+<p>The second is most clearly seen in the effect of increasing
+the interval between the response and the satisfaction
+or discomfort. Such an increase diminishes the rate of
+learning. If, for example, four boxes were arranged so that
+turning a button caused a door to open (and permit a cat
+to get freedom and food) in one, five, fifty and five hundred
+seconds, respectively, a cat would form the habit of prompt
+escape from the first box most rapidly and would almost
+certainly never form that habit in the case of the fourth.<span class="pagenum"><a id="Page_249"></a>[249]</span>
+The electric shock administered just as an animal starts on
+the wrong path or touches the wrong mechanism, is potent,
+but the same punishment administered ten or twenty
+seconds after an act will have little or no effect upon that
+act.</p>
+
+<p>Close temporal sequence is not the only means of insuring
+the connection of the satisfaction with the response producing
+it. What is called attention to the response counts also.
+If a cat pushes a button around with its nose, while its main
+occupation, the act to which its general ‘set’ impels it, to
+which, we say, it is chiefly attentive, is that of clawing at
+an opening, it will be less aided in the formation of the habit
+than if it had been chiefly concerned in what its nose was
+doing. The successful response is as a rule only a part of all
+that the animal is doing at the time. In proportion as it
+is an eminent, emphatic part of it, learning is aided. Similarly
+discomfort eliminates most the eminent, emphatic
+features of the total response which it accompanies or
+shortly follows.</p>
+
+<p>The third factor, the susceptibility of the response and
+situation to connection, is harder to illustrate. But, apparently,
+of those responses which are equally strongly connected
+with a situation by nature and equally attended to,
+some are more susceptible than others to a more intimate
+connection.</p>
+
+<p>The things which have to be equal in the case of the law
+of exercise are the force of satisfyingness; that is, the
+action of the law of effect, and again the readiness of
+the response to be connected with the situation.</p>
+
+<p>The operation of the laws of instinct, exercise and effect
+is conditioned further by (1) what may be called the law
+of assimilation or analogy,—that a situation, especially
+one to which no particular response is connected by original<span class="pagenum"><a id="Page_250"></a>[250]</span>
+nature or previous experience, may connect with whatever
+response is bound to some situation <i>much like it</i>,—and (2)
+by the law of partial activity—that more or less of the
+total situation may be specially active in determining the
+response.</p>
+
+<p>The first of these laws is a result of the facts that conduction
+in the neurones follows the line of least resistance or
+closest connection, that the action-system is so organized
+that certain responses tend to be made in their totality if
+at all, and that slightly different situations may, therefore,
+produce some one response, the effects of their differences
+being in the accessories of that response.</p>
+
+<p>The second law is a result of the facts that the situation,
+itself a compound, produces a compound action in the neurones,
+and that by reason of inner conditions, the relative
+intensities of different parts of the compound may vary.
+The commonest response will be that due to the modal
+condition of the neural compound, but every condition
+of the compound will have its response.</p>
+
+<h3><span class="smcap">The Adequacy of the Laws of Exercise and Effect</span></h3>
+
+<p>Behavior has been supposed to be modified in accordance
+with three other principles or laws besides the law of exercise
+and the law of effect. Imitation is often used as a name
+for the supposed law that the perception of a certain response
+to a situation by another animal tends in and of itself
+to connect that response to that situation. Common
+acceptance has been given to more or less of the law that
+the idea of an act, or of the result of an act, or of the immediate
+or remote sensations produced by the act, tends
+in and of itself to produce the act. Such a law of ‘suggestion’<span class="pagenum"><a id="Page_251"></a>[251]</span>
+or ‘ideo-motor’ action may be phrased differently,
+but in whatever form, it insists that the bond between a
+situation and some conscious representation of a response
+or of its consequences can do the work of the bond between
+the situation and the response itself. In acts of reasoning
+man has been supposed to connect with a given situation a
+response that could never have been predicted merely from
+knowledge of what responses were connected with that
+situation by his original nature or had been connected with
+it by the laws of exercise and effect. Inference has been
+supposed to create bonds in and of itself and to be above
+the mere laws of habit.</p>
+
+<p>Various forms of statement, most of them vague, have
+been and would be used in describing the potency of a perceived
+response, a thought-of response, or a train of inference,
+to produce a response and bind it to the given total
+situation. Any forms will do for the present argument,
+since all forms mean to assert that responses can be and
+often are bound to situations otherwise than by original
+bodily nature, satisfaction, discomfort, disuse and use. I
+shall try to show that they cannot; that, on the contrary,
+the laws of exercise and effect account for all learning.</p>
+
+<p><i>The facts of imitation in human and animal behavior are
+explainable by the laws of instinct, exercise and effect.</i></p>
+
+<p>Some cases of imitation are undoubtedly mere instincts
+in which the situation responded to is an act by another of
+the same species. If the baby smiles at a smile, it is because
+of a special, inborn connection between that sight
+and that act,—he smiles at a smile for just the same reason
+that he draws down his mouth and wails at harsh
+words. At that stage of his life he does not imitate other
+simple acts. A man runs <i>with</i> a crowd for the same reason
+that he runs <i>from</i> a tiger. Returning a blow is no more due
+to a general tendency to imitate than warding it off is.</p>
+
+<p><span class="pagenum"><a id="Page_252"></a>[252]</span></p>
+
+<p>Other cases of imitation are mere adjuncts to the ordinary
+process of habit-formation. In the first place, the act of another,
+or its result, may serve as a model by which the satisfyingness
+of one’s own responses are determined. Just as
+the touch and taste of food tells a baby that he has got it
+safely into his mouth, so the sound of a word spoken by another
+or the sight of another performing some act of skill
+tells us whether our pronunciation or technique is right or
+wrong.</p>
+
+<p>In the second place, the perception of another’s act may
+serve as a stimulus to a response whereby the situation is
+altered into one to which the animal responds from habit by
+an act like the one perceived. For example, the perception
+of another making a certain response (<i>A</i>) to a situation (<i>B</i>)
+may lead in me by the laws of habit to a response (<i>C</i>)
+which puts me in a situation (<i>D</i>) such that the response (<i>A</i>)
+is made by me by the laws of habit. Suppose that by previous
+training the act of taking off my hat (<i>A</i>) has become
+connected as response to the situation (<i>D</i>), ‘thought of hat
+off,’ and suppose that with the sight of others uncovering
+their heads (<i>A</i>) in church (<i>B</i>) there has, again by previous
+habituation, been connected, as response (<i>C</i>), ‘thought of
+hat off.’ Then the sight of others uncovering their heads
+would by virtue of the laws of habit lead me to uncover.
+Imitation of this sort, where the perception of the act or
+condition in another gives rise to the idea of performing the
+act or attaining the condition, the idea in turn giving rise
+to the appropriate act, is certainly very common.</p>
+
+<p>There may be cases of imitation which cannot be thus
+accounted for as special instinctive responses to the perception
+of certain acts by the same acts, as habits formed under
+the condition that the satisfyingness of a response is its
+likeness to the perceived act of another, or as the connection<span class="pagenum"><a id="Page_253"></a>[253]</span>
+of two habits, one of getting, from the perceived act of another,
+a certain inner condition, the other of getting, from
+this inner condition, the act in question. There may be,
+that is, cases where the perceived act of another in and of
+itself creates a connection.</p>
+
+<p>It is apparently taken for granted by a majority of writers
+on human behavior that cases of such direct mental infection,
+as it were, not only exist, but are the rule. I am
+unable to find proof of such cases, however. Those commonly
+quoted are far from clear. Learning to talk in the
+human infant, for example, the stock case of imitation as a
+direct means of learning, offers only very weak and dubious
+evidence. Since what is true of it holds substantially
+for the other favored cases for learning by imitation, I
+shall examine it at some length.</p>
+
+<p>Let us first be clear as to the alternative explanations of
+linguistic imitation. The first is that seeing the movements
+of another’s mouth-parts or hearing a series of word-sounds
+in and of itself produces the response of making that series
+of sounds or one like it.</p>
+
+<p>The other is that the laws of instinct and habit are adequate
+to explain the fact in the following manner: A
+child instinctively produces a great variety of sounds and
+sound-series. Some of these, accepted as equal to words by
+the child’s companions, are rewarded, so that the child
+learns by the law of effect to use them in certain situations to
+attain certain results. It is possible also that a child instinctively
+feels a special satisfaction at babbling when
+spoken to and a special satisfaction at finding the sound he
+makes like one that rings in the ears of memory and has
+meaning. The latter would be like the instinctive satisfaction
+apparently felt in constructing an object which is like
+some real object whose appearance and meaning he knows.</p>
+
+<p><span class="pagenum"><a id="Page_254"></a>[254]</span></p>
+
+<p>A child also meets frequently the situations ‘say dada,’
+‘say mama,’ ‘say good night’ and the like,<a id="FNanchor_41" href="#Footnote_41" class="fnanchor">[41]</a> and is rewarded
+when his general babble produces something like the word
+spoken to him. He thus, by the law of effect, learns to respond
+to any ‘say’ situation by making <i>some</i> sound and to
+each of many ‘say’ situations by making an appropriate
+sound, and to feel satisfaction at duplicating these words
+when heard. According to the amount of such training,
+the tendency to respond to words spoken to him by making
+some sound may become very strong, and the number
+of successful duplications very large. Satisfaction may be
+so connected with saying words that the child practices
+them by himself orally and even in inner speech. The second
+alternative relies upon the instinct of babbling, and the
+satisfaction of getting desirable effects from speech, either
+the effect which the word has by its meaning as a request
+(‘water,’ ‘milk,’ ‘take me outdoors’ and the like) or the
+effect which it has by its mere sound upon companions
+who notice, pet or otherwise reward a child for linguistic
+progress.</p>
+
+<p>There are many difficulties in the way of accepting the
+first alternative. First of all, no one can believe that <i>all</i>
+of a child’s speech is acquired by direct imitation. On
+many occasions the process is undoubtedly one of the production
+of many sounds, irrespective of the model given, and
+the selection of the best one by parental reward. Any student
+who will try to get a child who is just beginning to
+speak, to say cat, dog and mouse and will record the
+sounds actually made by the child in the three cases, will
+find them very much alike. There will in fact be little<span class="pagenum"><a id="Page_255"></a>[255]</span>
+that even <i>looks</i> like direct imitation until the child has
+‘learned’ at least forty or fifty words.</p>
+
+<p>The second difficulty lies in the fact that different children,
+in even the clearest cases of the imitation of one
+sound, vary from it in so many directions. A list of all the
+sounds made in response to one sound heard is more suggestive
+of random babble as modified by various habits of
+duplicating sounds, than of a direct potency of the model.
+Ten children of the same age may, in response to ‘Christmas,’
+say, kiss, kissus, krismus, mus, kim, kimus, kiruss,
+i-us and even totally unlike vocables such as hi-yi or ya-ya.</p>
+
+<p>The third difficulty is that in those features of word-sounds
+which are hard to acquire, such as the ‘th’ sound,
+direct imitation is inadequate. The teacher has recourse to
+trial and chance success, the spoken word serving as a model
+to guide satisfaction and discomfort. In general no sound
+not included in the instinctive babble of children seems to be
+acquired by merely hearing and seeing it made.</p>
+
+<p>A fourth difficulty is that by the doctrine of direct imitation
+it should not be very much more than two or three
+times as hard to repeat a two- or three-syllable series as to
+repeat a single syllable. It is, in fact, enormously harder.
+This is, of course, just what is to be expected if learning a
+sound means the selection from random babbling plus previous
+habits. If, for instance, a child makes thirty monosyllabic
+sounds like pa, ga, ta, ma, pi, gi, li, mi, etc., there
+is, by chance, one chance in thirty that in response to a
+word or phrase he will make that one-syllable sound of his
+repertory which is most like it, but there is only one chance
+in nine hundred that he will make that <i>two-syllable</i> combination
+of his repertory which is most like it.</p>
+
+<p>On the other hand, two objections will be made to the opposite
+view that the word spoken acts only as a model to<span class="pagenum"><a id="Page_256"></a>[256]</span>
+select from responses otherwise caused, or as a stimulus to
+habits already existing. First it will be said that clear, indubitable
+repetitions of words never practiced by the child,
+either as totals or in their syllables separately, <i>do</i> occur,—that
+children do respond by repeating a word in cases where
+full knowledge of all their previous habits would give no
+reason to expect them to make such a connection. To this
+the only retort is that such observations should be based on
+a very delicate and very elaborate record of a child’s linguistic
+history, and that until they are so made, it is wise to
+withhold acceptance.</p>
+
+<p>The second objection is that the rapid acquisition of a
+vocabulary such as occurs in the second and third year is
+too great a task to be accomplished by the laws of exercise
+and effect alone. This objection is based on an overestimation
+of the variety of sounds which children of the ages in
+question make. For example, a child who says 250 words,
+including say 400 syllables, comprising say 300 syllables
+which, when properly pronounced, are distinguishable, may
+actually use less than 50 distinguishable syllables. <i>Ba</i>, may
+stand for the first syllable of father, water, barn, park and
+the like. <i>Ki</i> may stand for cry, climb, and even carry.
+For a child to say a word commonly means that he makes
+a sound which his intimate companions can recognize as his
+version of that word. A child who can produce something
+like each one of a thousand words upon hearing them, may
+do so from actual control over less than a hundred syllables.
+If we suppose him to have acquired the habits,
+first, of saying <i>something</i> in such a case, second, of responding
+to a certain hundred sounds when perceived or remembered
+by making, in each case, a similar sound, and,
+third, of responding to any other sound when perceived or
+remembered, by making that sound of his own repertory<span class="pagenum"><a id="Page_257"></a>[257]</span>
+which is most like it,<a id="FNanchor_42" href="#Footnote_42" class="fnanchor">[42]</a> we can account for a thousand ‘imitations,’
+and still not have made a large demand upon childish
+powers of learning.</p>
+
+<p>No one should pretend to have disproved direct imitation
+in the case of learning to talk until he has subjected all these
+and other matters to crucial experiments. But the burden
+of proof does seem to belong upon those who deny the adequacy
+of the laws of exercise and effect. In so far as the
+choice is between accepting or rejecting a general law that,
+other things being equal, the perception of a response in
+another produces that response, we surely must reject it.
+Some of the cases of imitation may be unexplained by the
+laws of exercise and effect. But for others no law of imitation
+is required. And of what should happen by such a law
+not over a trivial fraction at most does happen.</p>
+
+<div class="blockquote">
+
+<p class="center"><i>The idea of a response is in and of itself unable to produce
+that response.</i></p>
+
+</div>
+
+<p>The early students of behavior, considering human behavior
+and emphasizing behavior that was thought about
+and purposive, agreed that the sure way to connect a response
+with a situation was to choose, or will, or consent to,
+that response. Later students still agreed that to think
+about the response in some way, to have an image of it or of
+the sensations caused in you by previous performances of it,
+was a strong provocative to it. To get a response, get some
+sort of conscious representative of it, has been an acceptable
+maxim. Medicine, education and even advertising have
+based their practice upon the theory that ideas tended to
+issue in the particular sort of acts that they were ideas of.</p>
+
+<p>The laws of exercise and effect, on the contrary, if they<span class="pagenum"><a id="Page_258"></a>[258]</span>
+are the sole laws of modifiability, insist that the thought of
+an act will produce that act only if the act has been connected
+with that thought (and without resulting discomfort)
+in the animal’s past.</p>
+
+<p>It seems plausible that there should be a peculiar bond
+between the thought of a response and the response. The
+plausibility is due to two reasons, one of which is sound but
+inadequate, the other being, in my opinion, entirely unsound.
+The first reason is that, as a mere matter of fact,
+the thought of a response does so often produce it. The
+second is that an idea of a response seems a natural and
+sufficient cause for it to appear. The first reason is inadequate
+to justify any law of the production of a response by
+its image or other representative, since evidence can be
+found to show that when a response is produced by an idea
+of it, it has been already bound to that idea by repetition or
+satisfaction. The second reason is unsound because, even
+if responses are brought to pass occasionally by their
+images, that is surely an extremely rare and unnatural
+method.</p>
+
+<p>It is certain that in at least nine cases out of ten a response
+is produced, not by an image or other representation
+of it, but by a situation nowise like it or any of its accessories.
+Hunger and the perception of edible objects, far outweigh
+ideas of grasping, biting and swallowing, as causes
+of the eating done in the world. Objects sensed, not images
+of eye-movements, cause a similar overwhelming majority
+of the eye’s responses. We walk, reach and grasp
+on most occasions, not because of anticipatory images of
+how it will feel to do so or verbal descriptions to ourselves
+of what we are to do, but because we are stimulated by the
+perception of some object.</p>
+
+<p>It is also certain that the idea of a response may be impotent<span class="pagenum"><a id="Page_259"></a>[259]</span>
+to produce it. I cannot produce a sneeze by thinking
+of sneezing. A child may have, in the case of some
+simple bodily act, which he has done in response to certain
+situations thousands of times, as adequate ideas of it as are
+possessed by others, and yet be utterly unable to make himself
+do it; many adults show this same phenomenon, for
+instance, in the case of swallowing a pill. And, of course,
+one can have ideas of running a mile in two minutes, jumping
+a fence eight feet high, or drawing a line exactly equal
+to a hundred millimeter line, just as easily as of running the
+mile in ten minutes, or jumping four feet.</p>
+
+<p>It is further certain that the thought of doing one thing
+very often results in the man’s doing something quite different.
+The thought of moving the eyes smoothly without
+stops along a line of print has occurred to many people, who
+nevertheless actually did as a result move the eyes in a series
+of jumps with long stops.</p>
+
+<p>It is further certain that in many cases where an animal
+does connect a given response with the image or thought of
+that response, the connection has been built up by the laws
+of exercise and effect. Such cases as appropriate responses
+to, ‘I will go to bed,’ ‘I will get up,’ ‘I will eat,’ ‘I will write
+a letter,’ ‘I will read,’ or to the corresponding commands,
+requests or suggestions, are observably built up by training.
+The appropriate response follows the idea only if it has,
+by repetition or reward, been connected with it or something
+like it. If the only requirement in moral education were to
+have the idea of the right act at the right time, the lives of
+teachers and parents would be greatly alleviated. But the
+decision to get up, or the idea of getting up or of being up,
+is futile until the child has connected therewith the actual
+act of getting up.</p>
+
+<p>The defender of the direct potency of conscious representatives<span class="pagenum"><a id="Page_260"></a>[260]</span>
+of a response to produce it may be tempted to complain
+at this point that what the laws of exercise and effect
+do is to reduce the strength of competing ideas, and leave the
+idea, say of getting up, free to exercise its direct potency.
+The complaint shows a weak sense for fact. The ordinary
+child is not a Hamlet, nor is he beguiled by the imagined
+delights of staying in bed, nor repelled by the image of getting
+up out of it. On the contrary, he may be entirely willing
+to <i>think of</i> getting up. It is the actual delights that
+hold him, the actual discomforts that check him, and the
+only way to be sure that he will get up is so to arrange matters
+that it is more satisfactory to him to get up than not to
+when the situation, whatever it be, that is to suggest that
+response, makes its appearance.</p>
+
+<p>The experience of every schoolroom shows that it is not
+enough to get the idea of an act. The act must have gone
+with that idea or be now put with it. The bond must be
+created. Responses to the suggestions of language, whether
+addressed to us by others or by ourselves in inner speech,
+in a very large majority of cases owe their bonds to the laws
+of exercise and effect. We learn to do what we are told,
+or what we tell ourselves, by doing <i>something</i> and rejecting
+or retaining what we do by virtue of its effects. So also in
+the case of a majority of responses to the suggestions of other
+than verbal imagery.</p>
+
+<p>The idea of a response, like the perception of a response
+by another, acts often as a guide to response <i>ex post facto</i> by
+deciding what shall be satisfying. Where superficial inspection
+leaves the impression that the idea creates the act, a
+little care often shows it to have only selected from the acts
+produced by instinct and habit. For example, let the reader
+think of some act never performed hitherto, such as putting
+his left middle finger upon the upper right hand corner of<span class="pagenum"><a id="Page_261"></a>[261]</span>
+this page, and make the movement. It may seem at first
+sight that having the idea entirely unopposed was the sufficient
+cause of the act. But careful experiment, including,
+for instance, the closure of the eyes and anesthesia of the
+fingers will reveal that the original propulsion of the idea is
+not to just that act, but to many possibilities, and that its
+chief potency lies in the fact that not to get the finger to
+that point is annoying, and that consequently the organism
+is at peace only when the act is done.</p>
+
+<p>So far it has been shown that: The majority of responses
+are not produced by ideas of them. The idea of a response
+may be impotent to produce it. The idea of one act may
+produce a different, even an opposite act. When an idea
+seems to produce a response in and of itself, it may really act
+by determining the satisfyingness of responses otherwise
+made. These facts are sufficient to destroy the pretensions
+of any general law that the image of an act will, other things
+being equal, produce it. But the possibility that such an
+image may occasionally exercise this peculiar potency remains.</p>
+
+<p>I despair of convincing the reader that it does not. Man
+is the only animal possessing a large fund of ideas of acts,
+and man’s connection-system is so complex and his ideas of
+acts are so intricately bound to situations that have by
+use and effect produced those acts, that the proof of this
+negative is a practical impossibility. But it is possible to
+show that even the most favored cases for the production
+of a response by securing an ideal representation of it may
+be explainable by use and effect alone.</p>
+
+<p>The extreme apparent potency of ideas representing acts
+to produce them regardless of bonds of use or effect is, of
+course, witnessed in the phenomena of suggestion in hypnosis
+and allied states. To try to reduce these phenomena<span class="pagenum"><a id="Page_262"></a>[262]</span>
+to consequences of the laws of habit may seem fanatical.
+Here, it will be said, are the crucial cases where the idea of
+an act, if freed from all effects of opposing ideas, does inevitably
+produce the act so far as it is a possibility for the
+animal’s action-system.</p>
+
+<p>That is precisely what I cannot find proof of.</p>
+
+<p>Efficient suggestions to hypnotized subjects, on the contrary,
+are often ambiguous in the sense that they seem as
+likely to arouse a situation <i>to which the act has been bound
+by the law of habit</i> as to arouse an idea of the act. Often
+they are far better suited to the former purpose. Direct
+commands—Walk, Dance, Get up, Sit down—obviously
+will operate by the law of habit provided the situations
+connected with disobedience are excluded. This is also
+the case with such indirect suggestions as ‘This is a knife
+(stick).’ ‘This is your sword (broom).’ ‘Have a cigar
+(a pen).’</p>
+
+<p>The release of a suggestion from inhibitions may as well
+be the release from <i>ideas connected as antecedents with</i> not
+performing the act as the release from <i>ideas of</i> not performing
+it. It is a question of fact whether, to get an act done
+by the subject, one must arouse in him an idea to which or
+to a part of which or to something like which the act has been
+bound by use or effect, or may arouse simply an idea of the
+act.</p>
+
+<p>Finally, if an idea has a tendency to connect with a certain
+response, over and above the bonds due to exercise and
+effect, it should <i>always</i> manifest that tendency. If the
+connection is not made, it must be due to the action of some
+contrary force. It is less my duty to show that the laws of
+habit can account for hypnotic suggestibility, obsessions,
+and the like, than it is my opponents’ duty to explain why a
+man can spend a half day in hospitably welcoming a hundred<span class="pagenum"><a id="Page_263"></a>[263]</span>
+ideas of acts and yet perform no one of them, save those in
+the case of which he has learned to do the thing when he
+thinks of doing it. Again, how can the mere addition of
+the idea of a future date to the idea of an act so utterly
+deprive it of present potency.</p>
+
+<p>In view of all these facts it seems probable that ideas of
+responses act in connection just as do any other situations,
+and that the phenomena of suggestion and ideo-motor
+action really mean that any idea will, except for competing
+ideas, produce the response, not that <i>is like it</i>, but that <i>has
+gone with it</i>, or with some idea like it.</p>
+
+<div class="blockquote">
+
+<p class="center"><i>Rational connections are, in their causation, like any
+others, the difference being in what is connected.</i></p>
+
+</div>
+
+<p>It remains to ask whether situation and response are
+bound together in the case of reasoning by any other forces
+than the forces of repetition, energy and satisfaction? Do
+the laws of inferential thinking transcend the laws of exercise
+and effect? Or does the mind, even in these novel and
+constructive responses, do only what it is forced to do by
+original nature or has done without discomfort?</p>
+
+<p>To defend the second alternative involves the reduction
+of the processes of abstraction, association by similarity and
+selective thinking to mere secondary consequences of the
+laws of exercise and effect. This I shall try to do.</p>
+
+<p>The gist of the fact of abstraction is that response may be
+made to some elements or aspects of a situation which have
+never been experienced in isolation, and may be made to the
+element in question regardless of the gross total situation in
+which it inheres. A baby thus learns to respond to its
+mother’s face regardless of what total visual field it is a part
+of. A child thus learns to respond by picking out any red
+object, regardless of whether the redness be in an apple, a<span class="pagenum"><a id="Page_264"></a>[264]</span>
+block, a pencil, a ribbon or a ball. A student thus learns to
+respond to any plane surface inclosed by three straight lines
+regardless of its size, shape, color or other than geometrical
+meaning.</p>
+
+<p>What happens in such cases is that the response, by being
+connected with many situations alike in the presence of the
+element in question and different in other respects, is bound
+firmly to that element and loosely to each of its concomitants.
+Conversely any element is bound firmly to any one response
+that is made to all situations containing it and very, very
+loosely to each of those responses that are made to only a
+few of the situations containing it. The element of triangularity,
+for example, is bound firmly to the response of saying
+or thinking ‘triangle’ but only very loosely to the response
+of saying or thinking white, red, blue, large, small, iron, steel,
+wood, paper and the like. A situation thus acquires bonds
+not only with some response to it as a gross total, but also
+with responses to each of its elements that has appeared in
+any other gross totals.</p>
+
+<p>Appropriate response to an element regardless of its concomitants
+is a necessary consequence of the laws of exercise
+and effect if an animal learns to make that response to the
+gross total situations that contain the element and not to
+make it to those that do not. Such prepotent determination
+of the response by one or another element of the situation
+is no transcendental mystery, but, given the circumstances,
+a general rule of all learning. The dog who responds appropriately
+to ‘beg’ no matter when, where, or by whom
+spoken, manifests the same laws of behavior. There is no
+difficulty in understanding how each element of a situation
+may come to tend to produce a response peculiar to it as
+well as to play its part in determining the response to the
+situation as a total. There may be some difficulty in understanding<span class="pagenum"><a id="Page_265"></a>[265]</span>
+how each element of a situation comes to be <i>felt</i>
+whereas before only the gross total was felt. The change in
+consciousness from the ‘big, blooming, buzzing confusion’
+to an aggregate of well-defined percepts and images, which
+accompanies the change in behavior from response to totals
+to response to parts or elements, may be mysterious. With
+the change in consciousness, however, we are not now concerned.
+The <i>behavior</i> of man and other animals toward the
+abstract elements of color, size, number, form, time or value
+is explained by the laws of instinct, exercise and effect.</p>
+
+<p>When the perception or thought of a fact arouses the
+thought of some other fact identical in part with the former
+fact, we have so-called association by similarity. An
+element of the neurone-action is prepotent in determining
+the succeeding neurone-action. The particular way in
+which it determines it is by itself continuing and making
+connection with other associates. These it possesses by
+virtue of the law of exercise and effect.</p>
+
+<p class="tb">The changes in behavior classified under intellect and
+morality seem then to be all explainable by the two laws
+of exercise and effect. The facts of imitation really refer
+to certain specific original connections or to the efficiency
+of a model in determining what shall satisfy or to the provision
+of certain instructive situations in the form of the
+behavior of other animals. The facts variously referred to
+as suggestion, ideo-motor action or the motor power of ideas,
+really refer to the fact, common in the human animal only,
+that to those ideas that represent acts in thought the acts
+are often bound as responses. The bonds are due to the
+primary laws of effect and exercise. The facts of reasoning
+really refer to the fact of prepotency of one or another
+element in a situation in determining the response.</p>
+
+<p><span class="pagenum"><a id="Page_266"></a>[266]</span></p>
+
+<p>The reduction of all learning to making and rewarding
+or avoiding and punishing connections between situation
+and response allows changes in intellect and character to
+be explained by changes in the neurones that are known
+either to be or to be possible. I have elsewhere sketched
+one such possible neural mechanism for the law of effect.<a id="FNanchor_43" href="#Footnote_43" class="fnanchor">[43]</a></p>
+
+<p>On the contrary, imitation, suggestion and reasoning,
+as commonly described, put an intolerable burden upon
+the neurones. To any one who has tried to imagine a
+possible action in the neurones to parallel the traditional
+power of the mere perception of an act in another or of
+the mere representation of an act as done by oneself to
+produce that act, this is a great merit. For the only
+adequate psychological parallel of traditional imitation
+and suggestion would be the original existence or the gratuitous
+formation of a connection between (1) each neurone-action
+corresponding to a percept of an act done by another
+or to the idea of an act done by oneself and (2) the neurone-action
+arousing that act. It is incredible that the neurone-action
+corresponding to the perception of a response in
+another, or to the idea of a response in oneself, or to the first
+term in an association by similarity, should have, in and
+of itself, a special power to determine that the next neurone-action
+should be that paralleling the response in question.
+And there is no possible physiological parallel of a power
+to jump from premise to conclusion for no other reason
+than the ideal fitness of the sequence.</p>
+
+<h3><span class="smcap">Simplifications of the Laws of Exercise and Effect</span></h3>
+
+<p>There has been one notable attempt to explain the facts
+of learning by an even simpler theory than that represented<span class="pagenum"><a id="Page_267"></a>[267]</span>
+in the laws of exercise and effect. Jennings has formulated
+as an adequate account of learning the law that: “When
+a certain physiological state has been resolved, through
+the continued action of an external agent, or otherwise,
+into a second physiological state, this resolution becomes
+easier, so that in course of time it takes place quickly and
+spontaneously” (‘Behavior of the Lower Organisms,’ p. 289).
+“The law may be expressed briefly as follows:—<i>The
+resolution of one physiological state into another becomes
+easier and more rapid after it has taken place a number of
+times.</i> Hence the behavior primarily characteristic for
+the second state comes to follow immediately upon the first
+state. The operations of this law are, of course, seen on
+a vast scale in higher organisms in the phenomena which
+we commonly call memory, association, habit formation
+and learning” (<i>ibid.</i>, p. 291). This law may be expressed
+conveniently as a tendency of a series of states</p>
+
+<p class="center">A -> B -> C -> D</p>
+
+<p class="noindent">to become</p>
+
+<p class="center">A -> D</p>
+
+<p class="noindent">or</p>
+
+<p class="center">A -> B¹ -> C¹ -> D</p>
+
+<p class="noindent">B¹ and C¹ being states B and C passed rapidly and in a
+modified way so that they do not result in a reaction but
+are resolved directly into D.</p>
+
+<p>If Professor Jennings had applied to this law the same
+rigorous analysis which he has so successfully employed
+elsewhere, he would have found that it could be potent
+to cause learning only if supplemented by the law of effect
+and then only for a fraction of learning.</p>
+
+<p>For, the situations being the same, the state A cannot
+produce, at one time, now B and, at another time, abbreviated,
+rudimentary B¹ instead of B. If A with S produces B
+once, it must always. If D or a rudimentary B¹ is produced,
+there must be something other than A; A must itself have<span class="pagenum"><a id="Page_268"></a>[268]</span>
+changed. Something must have been added to or subtracted
+from it. In Professor Jennings’ own words, “Since
+the external conditions have not changed, the animal itself
+must have changed” (<i>ibid.</i>, p. 286). And in adaptive
+learning something related to the results of the S A connection
+must have changed it.</p>
+
+<p>The series A—B—C—D does not become the series
+A—D or A—B¹—C¹—D by magic. If B and C are
+weakened and D is strengthened as sequents of A in response
+to S, it is because something other than repetition
+acts upon them. Repetition alone could not blow hot
+for D and cold for B.</p>
+
+<p>Moreover, as a mere matter of fact, “the resolution of one
+physiological state into another” through intermediate
+states does not with enough repetition “become easier so
+that in course of time it takes place quickly and spontaneously.”</p>
+
+<p>Paramecium does not change its response to, say, an obstacle
+in the water, from swimming backward, turning to
+one side and swimming forward by abbreviating and eventually
+omitting the turn and the backward movement.
+The schoolboy does not tend to count 1, 2, 10 or to say
+a, b, z, or give ablative plurals after nominative singulars.</p>
+
+<p>Repetition of a series of physiological states in and of itself
+on the contrary makes an animal increasingly <i>more</i>
+likely to <i>maintain</i> the series <i>in toto</i>. It is hard to give the
+first and then the last word of an oft repeated passage like
+Hamlet’s soliloquy or the Lord’s Prayer, or to make readily
+the first and then the last movement of writing a name or
+address. Repetition never eliminates absolutely and eliminates
+relatively the <i>less</i> often or <i>less</i> emphatically connected.</p>
+
+<p>Even if supplemented by the law of effect, so that some
+force is at hand to change the effect of S upon the animal<span class="pagenum"><a id="Page_269"></a>[269]</span>
+to A D instead of the original A B C D, the law of the
+resolution of physiological states would be relevant to only a
+fraction of learning. For example, let a cat or dog be given
+an ordinary discrimination experiment, but so modified
+that whether the animal responds by the ‘right’ or the
+‘wrong’ act <i>he is removed immediately after the reward or
+punishment</i>. That is, the event is either S R1 or S R2,
+never S R1 R2. Let the experiment be repeated at intervals
+so long that the physiological state, St. R1, or St. R2,
+leading to the response R1 or R2 in the last trial, has
+ceased before the next. The animal will come to respond to
+S by R2 only, though R2 has never been reached by the
+‘resolution’ of S R1 R2.</p>
+
+<p>Cats in jumping for birds or mice, men in playing
+billiards, tennis or golf, and many other animals in many
+other kinds of behavior, often learn as the dog must in
+this experiment. The situation on different occasions is
+followed by different responses, but by only one per
+occasion. Professor Jennings was misled by treating as
+general the special case where the situation itself includes a
+condition of discomfort terminable only by a ‘successful’
+response or by the animal’s exhaustion or death.</p>
+
+<p>Assuming as typical this same limited case of response
+to an annoying situation, so that success consists simply
+in replacing the situation by another, Stevenson Smith
+reduces the learning-process to the law of exercise alone.
+He argues that,—</p>
+
+<p>“For instance, let an organism at birth be capable of
+giving N reactions (a, b, c, ... N) to a definite stimulus
+S and let only one of these reactions be appropriate. If
+only one reaction can be given at a time and if the one
+given is determined by the state of the organism at the
+time S is received, there is one chance in N that it is the<span class="pagenum"><a id="Page_270"></a>[270]</span>
+appropriate reaction. When the appropriate reaction is
+finally given, the other reactions are not called into play,
+S may cease to act, but until the appropriate reaction is
+given let the organism be such that it runs through the
+gamut of the others until the appropriate reaction is brought
+about. As there are N possible reactions, the chances are
+that the appropriate reaction will be given before all N
+are performed. At the next appearance of the stimulus,
+which we may call S₂, those reactions which were in the
+last case performed, are, through habit, more likely to be
+again brought about than those which were not performed.
+Let <i>u</i> stand for the unperformed reactions. Then we have
+N - <i>u</i> probable reactions to S₂. Habit rendering the
+previously most performed reactions the most probable
+throughout we should expect to find the appropriate reaction
+in response to</p>
+
+<ul>
+<li>S₁ contained in N.</li>
+<li>S₂ contained in N - <i>u₁</i>.</li>
+<li>S₃ contained in N - <i>u₁</i> - <i>u₂</i>.</li>
+<li>...</li>
+<li>S<i>ₙ</i> contained in N - <i>nu</i>, which approaches <i>one</i> as a limit.</li>
+</ul>
+
+<p>Thus the appropriate reaction would be fixed through the
+laws of chance and habit. This law of habit is that when
+any action is performed a number of times under certain
+conditions, it becomes under those conditions more and
+more easily performed” (<i>Journal of Comparative Neurology
+and Psychology</i>, 1908, Vol. XVIII, pp. 503-504).</p>
+
+<p>This hypothesis is, like Professor Jennings’, adequate to
+account for only the one special case, and is adequate to
+account for that only upon a further limitation of the number
+of times that the animal may repeat any one of his varied
+responses to the situation before he has gone through them<span class="pagenum"><a id="Page_271"></a>[271]</span>
+all once, or reached the one that puts an end to the situation.</p>
+
+<p>The second limitation may be illustrated in the simple
+hypothetical case of three responses, 1, 2 and 3, of which
+No. 2 is successful. Suppose the animal always to go
+through his repertory with <i>no</i> repetitions until he reaches 2
+and so closes the series.</p>
+
+<p>Only the following can happen:—</p>
+
+<ul>
+<li>1 2</li>
+<li>1 3 2</li>
+<li>2</li>
+<li>2</li>
+<li>3 1 2</li>
+<li>3 2</li>
+</ul>
+
+<p class="noindent">and, in the long run, 2 will happen twice as often as 1 or 3
+happens.</p>
+
+<p>Suppose the animal to repeat each response of his repertory
+six times before changing to another, the remaining
+conditions being as above. Then only the following can
+happen:—</p>
+
+<ul>
+<li>1 1 1 1 1 1 2</li>
+<li>1 1 1 1 1 1 3 3 3 3 3 3 2</li>
+<li>2</li>
+<li>2</li>
+<li>3 3 3 3 3 3 1 1 1 1 1 1 2</li>
+<li>3 3 3 3 3 3 2,</li>
+</ul>
+
+<p class="noindent">and in the long run 2 will happen one third as often as 1 or 3
+and, though always successful, must, by Smith’s theory,
+appear later and later, so that if the animal meets the
+situation often enough, he will eventually fail utterly in it!</p>
+
+<p>Animals do, as a matter of fact, commonly repeat responses
+many times before changing them,<a id="FNanchor_44" href="#Footnote_44" class="fnanchor">[44]</a> so that if only the law<span class="pagenum"><a id="Page_272"></a>[272]</span>
+of exercise operated, learning would not be adaptive. It is
+the <i>effect</i> of 2 that gives it the advantage over 1 and 3. Of
+two responses to the same annoying situation, one continuing
+and the other relieving it, an animal could never learn
+to adopt the latter as a result of the law of exercise alone,
+if the former was, originally, twice as likely to occur. 1 1 2
+would occur as often as 2 and exercise would be equal for
+both. The convincing cases are, of course, those where
+learning equals the strengthening to supremacy of an
+originally very weak connection and the weakening of
+originally strong bonds. An animal’s original nature may
+lead it to behave as shown below:—</p>
+
+<ul>
+<li>1 1 1 3 1 1 4 1 1 2</li>
+<li>1 1 1 1 3 1 1 1 3 1 1 4 2</li>
+<li>4 1 1 3 3 1 1 4 4 1 1 1 1 1 2, etc.,</li>
+</ul>
+
+<p class="noindent">and yet the animal’s eventual behavior may be to react to
+the situation always by 2. The law of effect is primary,
+irreducible to the law of exercise.</p>
+
+<h3><span class="smcap">The Evolution of Behavior</span></h3>
+
+<p>The acceptance of the laws of exercise and effect as adequate
+accounts of learning would make notable differences
+in the treatment of all problems that concern learning. I
+shall take, to illustrate this, the problem of the development
+of intellect and character in the animal series, the phylogenesis
+of intellectual and moral behavior.</p>
+
+<p>The difficulties in the way of understanding the evolution
+of intellectual and moral behavior have been that neither
+what had been evolved nor that from which it had been
+evolved was understood.</p>
+
+<p>The behavior of the higher animals, especially man, was
+thought to be a product of impulses and ideas which got<span class="pagenum"><a id="Page_273"></a>[273]</span>
+into the mind in various ways and had power to arouse
+certain acts and other ideas more or less mysteriously, in the
+manner described by the laws of ideo-motor action, attention,
+association by contiguity, association by similarity,
+suggestion, imitation, dynamo-genesis and the like, with
+possibly a surplus of acts and ideas due to ‘free will.’ The
+mind was treated as a crucible in which a multifarious solution
+of ideas, impulses and automatisms boiled away,
+giving off, as a consequence of a subtle chemistry, an
+abundance of thoughts and movements. Human behavior
+was rarely viewed from without as a series of responses
+bound in various ways to a series of situations. The student
+of animal behavior passed as quickly as might be from
+such mere externals to the inner life of the creature, making
+it his chief interest to decide whether it had percepts,
+memories, concepts, abstractions, ideas of right and wrong,
+choices, a self, a conscience, a sense of beauty. The facts
+in intellect and character that are due to learning, that are
+not the inherited property of the species and that consequently
+are beyond the scope of evolution in the race,
+were not separated off from the facts of original nature.
+The comparative psychologist misspent his energy on such
+problems as the phylogenesis of the idea of self, moral
+judgments, or the sentiment of filial affection.</p>
+
+<p>At the other extreme, the behavior of the protozoa was
+either contemplated in the light of futile analogies,—for
+instance, between discriminative reactions and conscious
+choice, and between inherited instincts and memory,—or
+studied crudely in its results without observation of what
+the animals really did. The protozoa were regarded either
+as potential ‘conscious selves’ or as drifting lumps turned
+hither and thither by the direct effects of light, heat, gravity
+and chemical forces upon their tissues.</p>
+
+<p><span class="pagenum"><a id="Page_274"></a>[274]</span></p>
+
+<p>The evolution of the intellectual and moral nature which
+a higher animal really possesses from the sort of a nature
+which the real activities of the protozoa manifest, is far
+less difficult to explain.</p>
+
+<p>In so far as the higher animal is a collection of original
+tendencies to respond to physical events without and within
+the body, subject to modification by the laws of exercise
+and effect and by these alone, and in so far as the protozoan
+is already possessed of a well-defined repertory of responses
+connected with physical events without and within the
+body in substantially the manner of the higher animal’s
+original tendencies, the problems of the evolution of behavior
+are definite and in the way of solution.</p>
+
+<p>The previous sections gave reason for the belief that the
+higher animals, including man, manifest no behavior
+beyond expectation from the laws of instinct, exercise and
+effect. The human mind was seen to do no more than
+connect in accord with original bonds, use and disuse, and
+the satisfaction and discomfort resulting to the neurones.
+The work of Jennings has shown that the protozoa already
+possess full-fledged instincts, homologous with the instincts
+of man. They too may have specialized receptors, an
+action-system with a well-defined repertory and a connecting
+system or means of influencing the bonds between the
+stimuli received and the motor reactions made. The difficulties
+of tracing the possible development of a super-man
+from an infra-animal thus disappear.</p>
+
+<p>There is, of course, an abundance of <i>bona fide</i> difficulty
+in discovering the unlearned behavior of each group of
+animals and in tracing, throughout the animal series,
+changes in the physical events to which animals are sensitive
+so that to each a different response may be attached,
+changes in the movements of which animals are capable,<span class="pagenum"><a id="Page_275"></a>[275]</span>
+and changes in the bonds by which particular movements
+follow particular physical events. To find when and how
+animals whose natures remained nearly or quite unchanged
+by the satisfying and annoying effects of their behavior,
+gave birth to animals that could learn, is perhaps a still
+harder task. But these tasks concern problems that are
+intelligible matters of fact. They do not require a student
+to get out of matter something defined as beyond matter,
+or to get volition out of tropisms, or to get ideas of space
+and time out of swimming and sleeping.</p>
+
+<p>The evolution of the sensitivities and of the action-systems
+of animals has already been subjected to matter-of-fact
+study by naturalists. The evolution of the connection-system
+will soon be. Each reflex, instinct or capacity,
+each bond between a given situation presented to a given
+physiological state and a given response, has its ancestral
+tree. Scratching at an irritated spot on the skin
+is older than arms. Following an object that is moving
+slowly does not have to be explained separately, as a
+‘chance’ variation in dogs, sheep and babies. The mechanical
+trades of man are related to the miscellaneous
+manipulations of the apes. Little as we know of the connection-systems
+possessed by animals, we know enough
+to be sure that a bond between situation and response
+has ancestors and children as truly as does any bodily
+organ. Professor Whitman a decade ago showed the possibility
+of phylogenetic investigation of instinctive connections
+in a study which should be a stimulus and model
+for many others. In place of any further general account
+of the study of the phylogeny of the connection-system,
+I shall quote from his account of the concrete phylogeny
+of the instinct of incubation.</p>
+
+<p><span class="pagenum"><a id="Page_276"></a>[276]</span></p>
+
+<div class="blockquote">
+
+<p class="center">“<i>b. The Incubation Instinct</i></p>
+
+<p>1. <i>Meaning to be Sought in Phyletic Roots.</i>—It seems
+quite natural to think of incubation merely as a means of
+providing the heat needed for the development of the egg,
+and to assume that the need was felt before the means
+was found to meet it. Birds and eggs are thus presupposed,
+and as the birds could not have foreseen the need, they
+could not have hit upon the means except by accident.
+Then, what an infinite amount of chancing must have
+followed before the first ‘cuddling’ became a habit, and
+the habit a perfect instinct! We are driven to such preposterous
+extremities as the result of taking a purely casual
+feature to start with. Incubation supplies the needed heat,
+but that is an incidental utility that has nothing to do with
+the nature and origin of the instinct. It enables us to see
+how natural selection has added some minor adjustments,
+but explains nothing more. For the real meaning of the
+instinct we must look to its phyletic roots.</p>
+
+<p>If we go back to animals standing near the remote ancestors
+of birds, to the amphibia and fishes, we find the same
+instinct stripped of its later disguises. Here one or both
+parents simply remain over or near the eggs and keep a
+watchful guard against enemies. Sometimes the movements
+of the parent serve to keep the eggs supplied with
+fresh water, but aëration is not the purpose for which the
+instinct exists.</p>
+
+<p>2. <i>Means Rest and Incidental Protection to Offspring.</i>—The
+instinct is a part of the reproductive cycle of activities,
+and always holds the same relation in all forms that exhibit
+it, whether high or low. It follows the production of eggs,
+or young, and means primarily, as I believe, rest, with<span class="pagenum"><a id="Page_277"></a>[277]</span>
+incidental protection to offspring. That meaning is always
+manifest, no less in worms, molluscs, crustacea, spiders
+and insects, than in fishes, amphibia, reptiles and birds.
+The instinct makes no distinction between eggs and young,
+and that is true all along the line up to birds, which extend
+the same blind instinct to one as to the other.</p>
+
+<p>3. <i>Essential Elements of the Instinct.</i>—Every essential
+element in the instinct of incubation was present long
+before the birds and eggs arrived. These elements are:
+(1) the disposition to remain with or over the eggs; (2) the
+disposition to resist and drive away enemies; and (3) periodicity.
+The birds brought all these elements along in
+their congenital equipment, and added a few minor adaptations,
+such as cutting the period of incubation to the
+need of normal development, and thus avoiding indefinite
+waste of time in case of sterile or abortive eggs.</p>
+
+<p>(1) <i>Disposition to Remain over the Eggs.</i>—The disposition
+to remain over the eggs is certainly very old, and is
+probably bound up with the physiological necessity for rest
+after a series of activities tending to exhaust the whole system.
+If this suggestion seems far-fetched, when thinking
+of birds, it will seem less so as we go back to simpler conditions,
+as we find them among some of the lower invertebrate
+forms, which are relatively very inactive and predisposed
+to remain quiet until impelled by hunger to move.
+Here we find animals remaining over their eggs, and thus
+shielding them from harm, from sheer inability or indisposition
+to move. That is the case with certain molluscs
+(<i>Crepidula</i>), the habits and development of which have been
+recently studied by Professor Conklin. Here full protection
+to offspring is afforded without any exertion on the part
+of the parent, in a strictly passive way that excludes even
+any instinctive care. In <i>Clepsine</i> there is a manifest<span class="pagenum"><a id="Page_278"></a>[278]</span>
+unwillingness to leave the eggs, showing that the disposition
+to remain over them is instinctive. If we start with forms
+of similar sedentary mode of life, it is easy to see that remaining
+over the eggs would be the most likely thing to
+happen, even if no instinctive regard for them existed.
+The protection afforded would, however, be quite sufficient
+to insure the development of the instinct, natural selection
+favoring those individuals which kept their position unchanged
+long enough for the eggs to hatch.”<a id="FNanchor_45" href="#Footnote_45" class="fnanchor">[45]</a></p>
+
+<p>Professor Whitman proceeds to study the ‘Disposition
+to Resist Enemies’ and the ‘Periodicity’ in the same genetic
+way.</p>
+
+</div>
+
+<p>The most important of all original abilities is the ability
+to learn. It, like other capacities, has evolved. The
+animal series shows a development from animals whose
+connection-system suffers little or no permanent modification
+by experience to animals whose connections are in
+large measure created by use and disuse, satisfaction and
+discomfort.</p>
+
+<p>Some of this development can be explained without recourse
+to differences in mere power to learn, by the fact
+that the latter animals are given greater stimuli to or rewards
+for learning. But part of it is due to differences in
+sheer ability to learn, that is, in the power of equally
+satisfying conditions to strengthen or of equally annoying
+conditions to weaken bonds in the animals’ connection-systems.
+This may be seen from the following simple and
+partial case:—</p>
+
+<p>Call 1 and 2 two animals.</p>
+
+<p>Call C₁ and C₂ the internal conditions of the two animals<span class="pagenum"><a id="Page_279"></a>[279]</span>
+except for their connection-systems, each being the average
+condition of the animal in question.</p>
+
+<p>Call S₁ and S₂ two external states of affairs, each being
+near the indifference point for the animal in question,—that
+is, being one which the animal does little to either
+avoid or secure.</p>
+
+<p>Call G₁ and G₂ two responses which result in O₁ and O₂ the
+<i>optima</i> or most satisfying state of affairs for 1 and 2.</p>
+
+<p>Call I₁ and I₂ two responses which result in the continuation
+of S₁ and S₂.</p>
+
+<p>The only responses possible for 1 are G₁ and I₁.</p>
+
+<p>The only responses possible for 2 are G₂ and I₂.</p>
+
+<p>Animal 1 upon the recurrence of S₁ and C₁ is little or no
+more likely to respond by G₁ than he was before.</p>
+
+<p>Animal 2 upon the recurrence of S₂ and C₂ is far more
+likely to respond by G₂ than he was before.</p>
+
+<p>The fact thus outlined might conceivably be due to an
+intrinsic inequality between O₁ and O₂, the power of equally
+satisfying <i>optima</i> to influence, their antecedents being identical.
+This is not the case in the evolution of learning,
+however. For even if, instead of O₂, we had only a moderately
+satisfying state of affairs, such as the company of
+other chicks to (2) a 15-day-old chick, while O₁ was the
+optimum of darkness, dampness, coolness, etc., for (1) an
+earthworm, 2 would learn far, far more rapidly than 1.</p>
+
+<p>The fact is due, of course, to the unequal power of equally
+satisfying conditions to influence their antecedents. The
+same argument holds good for the influence of discomfort.</p>
+
+<p>The ability to learn,—that is, the possession of a connection-system
+subject to the laws of exercise and effect,—has
+been found in animals as ‘low’ as the starfish and
+perhaps in the protozoa. It is hard to tell whether the
+changed responses observed in Stentor by Jennings and in<span class="pagenum"><a id="Page_280"></a>[280]</span>
+Paramecium by Stevenson Smith are easily forgotten learnings
+or long retained excitabilities. Sooner or later clear
+learning appears, and then, from crabs to fish and turtle,
+from these to various birds and mammals, from these to
+monkeys, and from these to man, a fairly certain increase
+in sheer ability to learn, in the potency of a supposedly
+constant degree of satisfyingness or annoyingness to influence
+the connection preceding it, can be assumed. We
+cannot, of course, define just what we mean by equal satisfyingness
+to a mouse and a man, but the argument is substantially
+the same as that whereby we assume that the
+gifted boy has more sheer ability to learn than the idiot, so
+that if the two made the same response to the same situation
+and were equally satisfied thereby, the former would
+form the habit more firmly.</p>
+
+<p>We may, therefore, expect that when knowledge of the
+structure and behavior of the neurones comprising the connection-systems
+of animals (or of the neurones’ predecessors
+in this function) progresses far enough to inform us of just
+what happens when a connection is made stronger or weaker
+and of just what effects satisfying and annoying states of
+affairs exert upon the connection-system (and in particular
+upon the connections most recently in activity) the ability
+to learn will show as true an evolution as the ability to sneeze,
+oppose the thumb, or clasp an object touched by the hand.</p>
+
+<p>If my analysis is true, the evolution of behavior is a rather
+simple matter. Formally the crab, fish, turtle, dog, cat,
+monkey and baby have very similar intellects and characters.
+All are systems of connections subject to change by
+the law of exercise and effect. The differences are: first, in
+the concrete particular connections, in <i>what</i> stimulates the
+animal to response, <i>what</i> responses it makes, <i>which</i> stimulus
+connects with <i>which</i> response, and second, in the degree of<span class="pagenum"><a id="Page_281"></a>[281]</span>
+ability to learn—in the amount of influence of a given degree
+of satisfyingness or annoyingness upon the connection
+that produced it.</p>
+
+<p>The peculiarly human features of intellect and character,
+responses to elements and symbols, are the results of:
+first, a receiving system that is easily stimulated by the
+external world bit by bit (as by focalized vision and touch
+with the moving hand) as well as in totals composed of various
+aggregates of these bits; second, of an action-system of
+great versatility (as in facial expression, articulation, and
+the hands’ movements); and third, of a connection-system
+that includes the connections roughly denoted by babbling,
+manipulation, curiosity, and satisfaction at activity, bodily
+or mental, for its own sake; that is capable of working in
+great detail, singling out elements of situations and parts
+of responses; and that allows satisfying and annoying states
+of affairs to exert great influence on their antecedent connections.
+Because he learns fast and learns much, in the
+animal way, man seems to learn by intuitions of his own.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_282"></a>[282]</span></p>
+
+<h2 class="nobreak" id="CHAPTER_VII">CHAPTER VII<br>
+<span class="smcap">The Evolution of the Human Intellect</span><a id="FNanchor_46" href="#Footnote_46" class="fnanchor">[46]</a></h2>
+
+</div>
+
+<p>To the intelligent man with an interest in human nature
+it must often appear strange that so much of the energy of
+the scientific world has been spent on the study of the body
+and so little on the study of the mind. ‘The greatest thing
+in man is mind,’ he might say, ‘yet the least studied.’ Especially
+remarkable seems the rarity of efforts to trace the
+evolution of the human intellect from that of the lower animals.
+Since Darwin’s discovery, the beasts of the field,
+the fowl of the air and the fish of the sea have been examined
+with infinite pains by hundreds of workers in the
+effort to trace our physical genealogy, and with consummate
+success; yet few and far between have been the efforts to
+find the origins of intellect and trace its progress up to human
+faculty. And none of them has achieved any secure
+success.</p>
+
+<p>It may be premature to try again, but a somewhat extended
+series of studies of the intelligent behavior of fishes,
+reptiles, birds and mammals, including the monkeys, which
+it has been my lot to carry out during the last five years, has
+brought results which seem to throw light on the problem
+and to suggest its solution.</p>
+
+<p>Experiments have been made on fishes, reptiles, birds and
+various mammals, notably dogs, cats, mice and monkeys,
+to see how they learned to do certain simple things in order<span class="pagenum"><a id="Page_283"></a>[283]</span>
+to get food. All these animals manifest fundamentally the
+same sort of intellectual life. Their learning is after the
+same general type. What that type is can be seen best from
+a concrete instance. A monkey was kept in a large cage.
+Into the cage was put a box, the door of which was held
+closed by a wire fastened to a nail which was inserted in a
+hole in the top of the box. If the nail was pulled up out of
+the hole, the door could be pulled open. In this box was a
+piece of banana. The monkey, attracted by the new object,
+came down from the top of the cage and fussed over the box.
+He pulled at the wire, at the door, and at the bars in the
+front of the box. He pushed the box about and tipped it up
+and down. He played with the nail and finally pulled it out.
+When he happened to pull the door again, of course it opened.
+He reached in and got the food inside. It had taken him
+36 minutes to get in. Another piece of food being put in
+and the door closed, the occurrences of the first trial were
+repeated, but there was less of the profitless pulling and tipping.
+He got in this time in 2 minutes and 20 seconds.
+With repeated trials the animal finally came to drop entirely
+the profitless acts and to take the nail out and open
+the door as soon as the box was put in his cage. He had,
+we should say, learned to get in.</p>
+
+<p>The process involved in the learning was evidently a
+process of selection. The animal is confronted by a state
+of affairs or, as we may call it, a ‘situation.’ He reacts in
+the way that he is moved by his innate nature or previous
+training to do, by a number of acts. These acts include
+the particular act that is appropriate and he succeeds. In
+later trials the impulse to this one act is more and more
+stamped in, this one act is more and more associated with
+that situation, is selected from amongst the others by reason
+of the pleasure it brings the animal. The profitless acts<span class="pagenum"><a id="Page_284"></a>[284]</span>
+are stamped out; the impulses to perform them in that
+situation are weakened by reason of the positive discomfort
+or the absence of pleasure resulting from them. So the
+animal finally performs in that situation only the fitting act.</p>
+
+<p>Here we have the simplest and at the same time the most
+widespread sort of intellect or learning in the world. There
+is no reasoning, no process of inference or comparison;
+there is no thinking about things, no putting two and two
+together; there are no ideas—the animal does not think
+of the box or of the food or of the act he is to perform. He
+simply comes after the learning to feel like doing a certain
+thing under certain circumstances which before the learning
+he did not feel like doing. Human beings are accustomed
+to think of intellect as the power of having and controlling
+ideas and of ability to learn as synonymous with ability to
+have ideas. But learning by having ideas is really one of
+the rare and isolated events in nature. There may be a
+few scattered ideas possessed by the higher animals, but the
+common form of intelligence with them, their habitual
+method of learning, is not by the acquisition of ideas, but
+by the selection of impulses.</p>
+
+<p>Indeed this same type of learning is found in man. When
+we learn to drive a golf ball or play tennis or billiards, when
+we learn to tell the price of tea by tasting it or to strike a
+certain note exactly with the voice, we do not learn in the
+main by virtue of any ideas that are explained to us, by
+any inferences that we reason out. We learn by the gradual
+selection of the appropriate act or judgment, by its
+association with the circumstances or situation requiring
+it, in just the way that the animals do.</p>
+
+<p>From the lowest animals of which we can affirm intelligence
+up to man this type of intellect is found. With
+it there are in the mammals obscure traces of the ideas<span class="pagenum"><a id="Page_285"></a>[285]</span>
+which come in the mental life of man to outweigh and hide it.
+But it is the basal fact. As we follow the development
+of animals in time, we find the capacity to select impulses
+growing. We find the associations thus made between
+situation and act growing in number, being formed more
+quickly, lasting longer and becoming more complex and
+more delicate. The fish can learn to go to certain places, to
+take certain paths, to bite at certain things and refuse others,
+but not much more. It is an arduous proceeding for him
+to learn to get out of a small pen by swimming up through
+a hole in a screen. The monkey can learn to do all sorts
+of things. It is a comparatively short and easy task for
+him to learn to get into a box by unhooking a hook, pushing
+a bar around and pulling out a plug. He learns quickly
+to climb down to a certain place when he sees a letter T
+on a card and to stay still when he sees a K. He performs
+the proper acts nearly as well after 50 days as he did when
+they were fresh in his mind.</p>
+
+<p>This growth in the number, speed of formation, permanence,
+delicacy and complexity of associations possible for
+an animal reaches its acme in the case of man. Even if we
+leave out of question the power of reasoning, the possession
+of a multitude of ideas and abstractions and the power of
+control over impulses, purposive action, man is still the
+intellectual leader of the animal kingdom by virtue of the
+superior development in him of the power of forming associations
+between situations or sense-impressions and acts,
+by virtue of the degree to which the mere learning by
+selection possessed by all intelligent animals has advanced.
+In man the type of intellect common to the animal kingdom
+finds its fullest development, and with it is combined the
+hitherto nonexistent power of thinking about things and
+rationally directing action in accord with thought.</p>
+
+<p><span class="pagenum"><a id="Page_286"></a>[286]</span></p>
+
+<p>Indeed it may be that this very reason, self-consciousness
+and self-control which seem to sever human intellect so
+sharply from that of all other animals are really but secondary
+results of the tremendous increase in the number, delicacy
+and complexity of associations which the human animal
+can form. It may be that the evolution of intellect
+has no breaks, that its progress is continuous from its
+first appearance to its present condition in adult civilized
+human beings. If we could prove that what we call ideational
+life and reasoning were not new and unexplainable
+species of intellectual life but only the natural consequences
+of an increase in the number, delicacy, and complexity of
+associations of the general animal sort, we should have
+made out an evolution of mind comparable to the evolution
+of living forms.</p>
+
+<p>In 1890 William James wrote, “The more sincerely one
+seeks to trace the actual course of psychogenesis, the
+steps by which as a race we may have come by the peculiar
+mental attributes which we possess, the more clearly one
+perceives ‘the slowly gathering twilight close in utter
+dark.’” Can we perhaps prove him a false prophet? Let
+us first see if there be any evidence that makes it probable
+that in some way or another the mere extension of the
+animal type of intellect has produced the human sort. If
+we do, let us proceed to seek a possible account of <i>how</i> this
+might have happened, and finally to examine any evidence
+that shows this possible ‘how’ to have been the real way
+in which human reason has evolved.</p>
+
+<p>It has already been shown that in the animal kingdom
+there is, as we pass from the early vertebrates down to man,
+a progress in the evolution of the general associative process
+which practically equals animal intellect, that this progress
+continues as we pass from the monkeys to man. Such a<span class="pagenum"><a id="Page_287"></a>[287]</span>
+progress is a real fact; it does exist as a possible <i>vera causa</i>;
+it is thus at all events better than some imaginary cause
+of the origin of human intellect, the very existence of
+which is in doubt. In a similar manner we know that the
+neurones, which compose the brain and the connections
+between which are the physiological parallels of the habits
+that animals form, show, as we pass down through the
+vertebrate series, an evolution along lines of increased delicacy
+and complexity. That an animal associates a certain
+act with a certain felt situation means that he forms or
+strengthens connections between certain cells. The increase
+in number, delicacy and complexity of cell structures
+is thus the basis for an increase in the number, delicacy
+and complexity of associations. Now the evolution noted
+in cell structures affects man as well as the other vertebrates.
+He stands at the head of the scale in that respect as well.
+May not this obvious supremacy in the animal type of intellect
+and in the adaption of his brain to it be at the bottom
+of his supremacy in being the sole possessor of reasoning?</p>
+
+<p>This question becomes more pressing if we realize that
+we must have some sort of brain correlate for ideational
+life and reasoning. Some sort of difference in processes in
+the brain must be at the basis of the mental differences between
+man and the lower animals, we should all admit. And
+it would seem wise to look for that difference amongst differences
+which really do or at least may exist. Now the most
+likely brain difference between man and the lower animals for
+our purpose, to my mind indeed the only likely one, is just this
+difference in the fineness of organization of the cell structures.
+If we could show with any degree of probability
+how it might account for the presence of ideas and of reasoning,
+we should at least have the satisfaction of dealing with
+a cause actually known to exist.</p>
+
+<p><span class="pagenum"><a id="Page_288"></a>[288]</span></p>
+
+<p>The next important fact is that the intellect of the infant
+six months to a year old is of the animal sort, that ideational
+and reasoning life are not present in his case, that the only
+obvious intellectual difference between him and a monkey is
+in the quantity and quality of the associations formed.
+In the evolution of the infant’s mind to its adult condition
+we have the actual transition within an individual from the
+animal to the human type of intellect. If we look at the
+infant and ask what is in him to make in the future a thinker
+and reasoner, we must answer either by invoking some mysterious
+capacity, the presence of which we cannot demonstrate,
+or by taking the difference we actually do find. That is
+the difference in the quality and quantity of associations of
+the animal sort. Even if we could never see how it came to
+cause the future intellectual life, it would seem wiser to believe
+that it did than to resort to faith in mysteries. Surely there
+is enough evidence to make it worth while to ask our second
+question, “How might this difference cause the life of ideas
+and reasoning?”</p>
+
+<p>To answer this question fully would involve a most intricate
+treatment of the whole intellectual life of man, a
+treatment which cannot be attempted without reliance on
+technical terms and psychological formulas. A fairly
+comprehensible account of the general features of such an
+answer can, however, be given. The essential thing about
+the thinking of the animals is that they feel things in gross.
+The kitten who learned to respond differently to the signals,
+“I must feed those cats” and “I will not feed them,” felt
+each signal as a vague total, including the tone, the movements
+of my head, etc. It did not have an idea of the sound
+of <i>I</i>, another of the sound of <i>must</i>, another of the sound
+<i>feed</i>, etc. It did not turn the complex impression into a set
+of elements, but felt it, as I have said, in gross. The dog<span class="pagenum"><a id="Page_289"></a>[289]</span>
+that learned to get out of a box by pulling a loop of wire
+did not feel the parts of the box separately, the bolt as a
+definite circle of a certain size, did not feel his act as a sum
+of certain particular movements. The monkey who learned
+to know the letter K from the letter Y did not feel the separate
+lines of the letter, have definite ideas of the parts.
+He just felt one way when he saw one total impression and
+another way when he saw another.</p>
+
+<p>Strictly human thinking, on the contrary, has as its essential
+characteristic the breaking up of gross total situations
+into feelings of particular facts. When in the presence
+of ten jumping tigers we not only feel like running, but also
+feel the number of tigers, their color, their size, etc. When,
+instead of merely associating some act with some situation
+in the animal way, we think the situation out, we have a
+set of particular feelings of its elements. In some cases, it
+is true, we remain restricted to the animal sort of feelings.
+The sense impressions of suffocation, of the feeling of a
+new style of clothes, of the pressure of 10 feet of water above
+us, of malaise, of nausea and such like remain for most of us
+vague total feelings to which we react and which we feel
+most acutely but which do not take the form of definite
+ideas that we can isolate or combine or compare. Such
+feelings we say are not parts of our real intellectual life.
+They <i>are</i> parts of our intellectual life if we mean by it the
+mental life concerned in learning, but they are not if we
+mean by it the life of reasoning.</p>
+
+<p>Can we now see how the vague gross feelings of the animal
+sort might turn into the well-defined particular ideas of the
+human sort, by the aid of a multitude of delicate associations?</p>
+
+<p>It seems to be a general law of mind that any mental
+element which occurs with a number of different mental
+elements, appears, that is, in a number of different combinations,<span class="pagenum"><a id="Page_290"></a>[290]</span>
+tends to thereby acquire an independent life
+of its own. We show children six lines, six dots, six peas,
+six pieces of paper, etc., and thus create the definite feeling
+of sixness. Out of the gross feelings of a certain number of
+lines, of dots, etc., we evolve the definite elementary feeling
+of sixness by making the ‘six’ aspect of the situations
+appear in a number of different connections. We learn to
+feel whiteness as a definite idea by seeing white paper, white
+cloth, white eggs, white plates, etc. We learn to feel
+the meaning of <i>but</i> or <i>in</i> or <i>notwithstanding</i> by feeling the
+meanings of many total phrases containing each of them.
+Now in this general law by which different associates for the
+same elementary process elevate it out of its position as
+an undifferentiated fragment of a gross total feeling, we
+have, I think, the manner in which the vague feelings of
+the nine-months-old infant become the definite ideas of
+the five-year-old boy, the manner in which in the race
+the animal mind has evolved into the human, and the explanation
+of the service performed by the increase in the
+delicacy of structure of the human brain and the consequent
+increase in the number of associations.</p>
+
+<p>The bottle to the six-months-old infant is a vague sense-impression
+which the infant does not think about or indeed
+in the common meanings of the words perceive or remember
+or imagine. Its presence does not arouse ideas, but
+action. It is not to him a thing so big, or so shaped, or
+so heavy, but is just a vaguely sizable thing to be reached
+for, grabbed and sucked. Like the lower animals, with the
+exception that as he grows a little older he reacts in very
+many more ways, the child feels things in gross in a way
+to lead to direct reactions. Vague sense-impressions and
+impulses make up his mental life. The bottle, which to a
+dog would be a thing to smell at and paw, to a kitten a<span class="pagenum"><a id="Page_291"></a>[291]</span>
+thing to smell at and perhaps worry, is to the child a little
+later a thing to grab and suck and turn over and drop and
+pick up and pull at and finger and rub against its toes and
+so on. The sight of the bottle thus becomes associated
+with many different reactions, and thus by our general law
+tends to gain a position independent of any of them, to
+evolve from the condition of being a portion of the cycles
+see-grab, see-drop, see-turn over, etc., to the condition of
+being a definite idea.</p>
+
+<p>The increased delicacy and complexity of the cell
+structures in the human brain give the possibility of very
+small parts of the brain-processes forming different connections,
+allow the brain to work in very great detail, provide
+processes ready to be turned into definite ideas. The great
+number of associations which the human being forms
+furnish the means by which this last event is consummated.
+The infant’s vague feelings of total situations are by virtue
+of the detailed working of his brain all ready to split up
+into parts, and his general activity and curiosity provide
+the multitude of different connections which allow them to
+do so. The dog, on the other hand, has few or no ideas
+because his brain acts in coarse fashion and because there
+are few connections with each single process.</p>
+
+<p>When once the mind begins to function by having definite
+ideas, all the phenomena of reasoning soon appear.
+The transition from one idea to another is the feeling of
+their relationship, of similarity or difference or whatever
+it may be. As soon as we find any words or other symbols
+to express such a feeling, or to express our idea of an action
+or condition, we have explicit judgments. Observation
+of any child will show us that the mind cannot rest in a condition
+where it has a large body of ideas without comparing
+them and thinking about them. The ideas carry within<span class="pagenum"><a id="Page_292"></a>[292]</span>
+them the forces that make abstractions, feelings of similarity,
+judgments and other characteristics of reasoning.</p>
+
+<p>In children two and three years of age we find all these
+elements of reasoning present and functioning. The product
+of children’s reasoning is often irrational, but the processes
+are all there. The following instances from a collection
+of children’s sayings by Mr. H. W. Brown show children
+making inductions and deductions after the same general
+fashion as adults:—</p>
+
+<div class="blockquote">
+
+<p>(2 yrs.) T. pulled the hairs on his father’s wrist. Father.
+“Don’t, T., you hurt papa!” T. “It didn’t hurt grandpa.”</p>
+
+<p>(2 yrs. 5 mos.) M. said, “Gracie can’t walk, she wears little
+bits of shoes; if she had mine, she could walk. When I get some
+new ones, I’m going to give her these, so she can walk.”</p>
+
+<p>(2 yrs. 9 mos.) He usually has a nap in the forenoon, but
+Friday he did not seem sleepy, so his mother did not put him to
+bed. Before long he began to say, “Bolly’s sleepy; mamma put
+him in the crib!” This he said very pleasantly at first; but, as
+she paid no attention to him, he said, “Bolly cry, then mamma
+will.” And he sat down on the floor and roared.</p>
+
+<p>(3 yrs.) It was between five and six in the afternoon; the
+mother was getting the baby asleep. J. had no one to play with.
+He kept saying, “I wish R. would come home; mamma, put
+baby to bed, so R. will come home.” I usually get home about
+six, and as the baby is put to bed about half-past five, he had
+associated the one with the other.</p>
+
+<p>(3 yrs.) W. likes to play with oil paints. Two days ago
+my father told W. he must not touch the paints any more, for
+he was too small. This morning W. said, “When my papa is a
+very old man, and when I am a big man and don’t need any
+papa, then I can paint, can’t I, mamma?”</p>
+
+<p>(3 yrs.) G.’s aunt gave him ten cents. G. went out, but soon
+came back saying, “Mamma, we will be rich now.” “Why so,<span class="pagenum"><a id="Page_293"></a>[293]</span>
+G.?” “Because I planted my ten cents, and we will have lots of
+ten cents growing.”</p>
+
+<p>(3 yrs.) B. climbed up into a large express wagon, and would
+not get out. I helped him out, and it was not a minute before
+he was back in the wagon. I said, “B., how are you going to get
+out of there now?” He replied, “I can stay here till it gets little,
+and then I can get out my own self.”</p>
+
+<p>(3 yrs.) F. is not allowed to go to the table to eat unless she
+has her face and hands washed and her hair combed. The other
+day she went to a lady visiting at her house and said, “Please
+wash my face and hands and comb my hair; I am very hungry.”</p>
+
+<p>(3 yrs.) If C. is told not to touch a certain thing, that it will
+bite him, he always asks if it has a mouth. The other day he
+was examining a plant, to see if it had a mouth. He was told
+not to break it, and he said, “Oh, it won’t bite, because I can’t
+find any mouth.”</p>
+
+</div>
+
+<p>Nowhere in the animal kingdom do we find the psychological
+elements of reasoning save where there is a mental
+life made up of the definite feelings which I have called
+‘ideas,’ but they spring up like magic as soon as we get in a
+child a body of such ideas. If we have traced satisfactorily
+the evolution of a life of ideas from the animal life of vague
+sense-impressions and impulses, we may be reasonably sure
+that no difficulty awaits us in following the life of ideas
+in its course from the chaotic dream of early childhood to
+the logical world-view of the adult scientist.</p>
+
+<p>In a very short time we have come a long way, from the
+simple learning of the minnow or chick to the science and
+logic of man. The general frame of mind which one acquires
+from the study of animal behavior and of the mental development
+of young children makes our hypothesis seem
+vital and probable. If the facts did eventually corroborate
+it, we should have an eminently simple genesis of human<span class="pagenum"><a id="Page_294"></a>[294]</span>
+faculty, for we could put together the gist of our contention
+in a few words. We should say:—</p>
+
+<p>“The function of intellect is to provide a means of modifying
+our reactions to the circumstances of life, so that we
+may secure pleasure, the symptom of welfare. Its general
+law is that when in a certain situation an animal acts so
+that pleasure results, that act is selected from all those performed
+and associated with that situation, so that, when
+the situation recurs, the act will be more likely to follow than
+it was before; that on the contrary the acts which, when
+performed in a certain situation, have brought discomfort,
+tend to be dissociated from that situation. The intellectual
+evolution of the race consists in an increase in the number,
+delicacy, complexity, permanence and speed of formation
+of such associations. In man this increase reaches such a
+point that an apparently new type of mind results, which
+conceals the real continuity of the process. This mental
+evolution parallels the evolution of the cell structures of
+the brain from few and simple and gross to many and
+complex and delicate.”</p>
+
+<p>Nowhere more truly than in his mental capacities is man
+a part of nature. His instincts, that is, his inborn tendencies
+to feel and act in certain ways, show throughout marks of
+kinship with the lower animals, especially with our nearest
+relatives physically, the monkeys. His sense-powers show
+no new creation. His intellect we have seen to be a
+simple though extended variation from the general animal
+sort. This again is presaged by the similar variation
+in the case of the monkeys. Amongst the minds of animals
+that of man leads, not as a demigod from another planet,
+but as a king from the same race.</p>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="footnotes">
+
+<div class="chapter">
+
+<h2 class="nobreak" id="FOOTNOTES">FOOTNOTES</h2>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_1" href="#FNanchor_1" class="label">[1]</a> ‘Animal Intelligence: An Experimental Study of the Associative Processes
+in Animals’ (’98), ‘The Instinctive Reactions of Young Chicks’ (’99),
+‘A Note on the Psychology of Fishes’ (’99), and ‘The Mental Life of the
+Monkeys’ (’01). I have added a theoretical paper, ‘The Evolution of the
+Human Intellect,’ which appeared in the <i>Popular Science Monthly</i> in 1901,
+and which was a direct outgrowth of the experimental work. I am indebted
+to the management of the <i>Psychological Review</i>, and that of the <i>American
+Naturalist</i> and <i>Popular Science Monthly</i>, for permission to reprint the three
+shorter papers.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_2" href="#FNanchor_2" class="label">[2]</a> Unless one assumes telepathic influences.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_3" href="#FNanchor_3" class="label">[3]</a> Reason in Common Sense, p. 154 ff.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_4" href="#FNanchor_4" class="label">[4]</a> This chapter originally appeared as Monograph Supplement No. 8 of
+the Psychological Review.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_5" href="#FNanchor_5" class="label">[5]</a> I do not mean that scientists have been too credulous with regard to
+spiritualism, but am referring to the cases where ten or twenty scientists
+have been sent to observe some trick-performance by a spiritualistic ‘medium,’
+and have all been absolutely confident that they understood the secret
+of its performance, <i>each of them giving a totally different explanation</i>.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_6" href="#FNanchor_6" class="label">[6]</a> The phrase ‘practically utter hunger’ has given rise to misunderstandings.
+I have been accused of experimenting with starving or half-starved
+animals, with animals brought to a state of fear and panic by hunger, and
+the like!</p>
+
+<p>The desideratum is, of course, to have the motive as nearly as possible of
+equal strength in each experiment with any one animal with any one act.
+That is, the animal should be as hungry at the tenth or twentieth trial as at
+the first. To attain this, the animal was given after each ‘success’ only
+a very small bit of food as a reward (say, for a young cat, one quarter of a
+cubic centimeter of fish or meat) and tested not too many times on any one
+day. ‘Utter hunger’ means that no diminution in his appetite was noted
+and that at the close of the experiment for the day he would still eat a hearty
+meal. After the experiments for the day were done, the cats received
+abundant food to maintain health, growth and spirits, but commonly somewhat
+less than they would of their own accord have taken. No one of the
+many visitors to the room mentioned anything extraordinary or distressful
+in the animals’ condition. There were no signs of fear or panic.</p>
+
+<p>Possibly I was wrong in choosing the term ‘utter hunger’ to denote the
+hunger of an animal in good, but not pampered, condition and without food
+for fourteen hours. It is not sure, however, that the term ‘utter hunger’
+is inappropriate. The few reports made of experiments in going without
+food seem to show that, in health, the feeling of hunger reaches its maximum
+intensity very early. It is of course not at all the same thing as the complex
+of discomforts produced by long-continued insufficiency of food. Hunger
+is not at all a synonym for starvation.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_7" href="#FNanchor_7" class="label">[7]</a> The experiments now to be described were for the most part made in the
+Psychological Laboratory of Columbia University during the year ’97-’98,
+but a few of them were made in connection with a general preliminary
+investigation of animal psychology undertaken at Harvard University in
+the previous year.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_8" href="#FNanchor_8" class="label">[8]</a> No. 7 hit the string in his general struggling, apparently utterly without
+design. He did not realize that the door was open till, two seconds after it
+had fallen, he happened to look that way.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_9" href="#FNanchor_9" class="label">[9]</a> No. 6, in trying to crawl out at the top of the box, put its paw in above
+the string. It fell down and thus pulled the string. It did not claw at it,
+and it was 16 seconds before it noticed that the door was open. In all
+the other times that it escaped the movement was made in the course of
+promiscuous scrambling, never in anything like the same way that No. 2
+made it.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_10" href="#FNanchor_10" class="label">[10]</a> No. 3 did not go out until 12 seconds had elapsed after it had pulled the
+string.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_11" href="#FNanchor_11" class="label">[11]</a> The back of the pen adjoined the elevator shaft, being separated from it
+by a partition 33 inches high. No. 2 heard the elevator coming up and put
+his paws up on the top of this partition so as to look over. In so doing he
+knocked the fastening of the cord at that end and opened the door. He
+did not turn to come out, and I shut the door again.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_12" href="#FNanchor_12" class="label">[12]</a> FF was a box 40 × 21 × 24 inches, the door of which could be opened
+by putting the paw out between the bars to its right and pulling a loop which
+hung 16 inches above the floor, 4 inches out from the box and 6 inches to
+the right of the door.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_13" href="#FNanchor_13" class="label">[13]</a> KKK was box K with both bolts removed. All that had to be done
+was to poke the paw out at one side of the door and press down a little bar of
+wood.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_14" href="#FNanchor_14" class="label">[14]</a> The cats and chick were left in for two minutes at each trial, the dogs
+for from one to one and a half minutes.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_15" href="#FNanchor_15" class="label">[15]</a> One result of the application of experimental method to the study of
+the intellect of animals was the distinction of learning by the selection of
+impulses or acts from learning by the selection of ideas. The usual method
+of learning in the case of animals other than man was shown by the studies
+reprinted in this volume to be the direct selection, in a certain situation, of
+a desirable response and its association with that situation, not the indirect
+selection of such a response by the selection of some <i>idea</i> which then of
+itself produced the response. The animals did not usually behave as if they
+<i>thought of</i> getting freedom or food in a certain way and were thereby moved
+to do so, but as if the stimulus in question made immediate connection with
+the response itself or an intimately associated impulse.</p>
+
+<p>The experiments had in this respect both a negative or destructive and a
+positive or constructive meaning. On the one hand, they showed that animal
+learning was not homologous with human association of ideas; that animal
+learning was not human learning <i>minus</i> abstract and conceptual thought,
+but was on a still ‘lower’ level. On the other hand, the first positive evidence
+that animals could, under certain circumstances, learn, as man so
+commonly does, by the indirect connection of a response with a situation
+through some non-sensory relic or representative of the latter, came from my
+experiments.</p>
+
+<p>It was perhaps natural that the more exciting denial of habitual learning
+by ideas should have attracted more attention than the somewhat tedious
+experiments to prove that under certain conditions they could so learn.
+At all events, a perverse tradition seems to have grown up to the effect that
+I denied the possibility of animals having images or learning in any case by
+representative thinking.</p>
+
+<p>There is some excuse for this tradition in the fact that whereas the proof
+that the habitual learning of these dogs and cats did not require ‘ideas’
+is clear and emphatic, my evidence that certain features of their behavior
+<i>did</i> require ‘ideas’ is complicated and imperfect.</p>
+
+<p>The fact seems to be that a ‘free idea’ comes in the animals or in man
+only as a result of a somewhat elaborate process of analysis or extraction from
+a gross total sensory process. The primary level or grade of experience,
+common to animals and little babies, comprises states of mind such as an
+adult man gets if lost in anger, fear, suffocation, dyspepsia, looking at a
+panorama of unknown objects with head upside down, smelling the mixture
+of odors of a soap factory, driving a golf ball, dashing to the net in a game of
+tennis, warding off a blow, or swimming under water. For a man to get a
+distinct controllable percept of approaching asthma, of a carpet loom seen
+upside down, or of a successful ‘carry through,’ or ‘smash’ or ‘lob,’
+so that one knows just what one is experiencing or doing, and can recall
+just what one experienced or did, requires further experience of the element
+in question—contemplation of it in isolation or dealings with it in many varied
+connections. So for a cat to get a distinct controllable percept of a loop,
+or of its own clawing or nosing or pulling, it must have the capacity to analyze
+such elements out of the total gross complexes in which they inhere,
+and also certain means or stimuli to such analysis.</p>
+
+<p>This capacity or tendency the cats and dogs do, in my opinion, possess,
+though in a far less degree than the average child. They also suffer from
+lack of stimuli to the exercise of the capacity. Their confinement, for the
+most part, to the direct sensory experience of things and acts, is due in part
+to the weakness of the capacity or tendency of their neurones to act in great
+detail, and in part to the lack of such stimuli as visual exploration of things
+in detail, manual manipulation of the same thing in many ways, and the identification
+of elements of objects and acts by language. They get few free
+ideas because they are less ready than man to get them under the same conditions
+and because their instinctive behavior and social environment offer
+conditions that are less favorable. The task of getting an animal to have
+some free ideational representative of a red loop or of pushing up a button
+with the nose may be compared with that of getting a very stupid boy to
+have a free ideational representative of acceleration, or of the act of sounding
+<i>th</i>. The difference between them and man which is so emphasized in
+the text, though real and of enormous practical importance, is thus not at
+all a mysterious gap or trackless desert. We can see our way from animal
+to human learning.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_16" href="#FNanchor_16" class="label">[16]</a> A man may learn to swim from the general feeling, “I want to be able to
+swim.” While learning, he may think of this desire, of the difficulties of the
+motion, of the instruction given him, or of anything which may turn up in
+his mind. This is all extraneous and is not concerned in the acquisition of
+the association. Nothing like it, of course, goes on in the animal’s mind.
+Imagine a man thrown into the water repeatedly, and gradually floundering
+to the shore in better and better style until finally, when thrown in, he swims
+off perfectly, and deprive the man of all extraneous feelings, and you have
+an approximate homologue of the process in animals. He feels discomfort,
+certain impulses to flounder around, some of which are the right ones to
+move his body to the shore. The pleasure which follows stamps in these,
+and gradually the proper movements are made immediately on feeling the
+sense-impression of surrounding water.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_17" href="#FNanchor_17" class="label">[17]</a> See 10 in A, 3 in A, 10 in D; 10 in C, 4 in C, 3 in C; 6, 2, 5, 4 in E; 4 in
+F; 10 in H, 3 in H; 3, 4, 5, in I; 4 in G, 3 in G; 3 in K; 10 in L; dog 1 in N
+and CC; dog 1 in G and O.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_18" href="#FNanchor_18" class="label">[18]</a> This chapter appeared originally in the <i>Psychological Review</i>, Vol. VI,
+No. 3.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_19" href="#FNanchor_19" class="label">[19]</a> This double rating is necessary because of the fact that the chick often
+gives several distinct pecks in a single reaction. The ‘times reacted to’
+mean the number of different times that the chicks noticed the color.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_20" href="#FNanchor_20" class="label">[20]</a> The crude experiments reported in this and the preceding paragraphs
+were not made to test the presence of color vision proper, that is, of differentiation
+of two colors of the same brightness, but only to ascertain how
+chicks reacted to ordinary colored objects. It was, however, almost certain
+from the relative frequency of the reactions that the intensity factor was not
+the cause of the response. For example, if it had been, black on white and
+yellow on black should have been pecked at oftener.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_21" href="#FNanchor_21" class="label">[21]</a> This chapter appeared originally in the <i>American Naturalist</i>, Vol. XXXIII,
+No. 396.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_22" href="#FNanchor_22" class="label">[22]</a> This chapter appeared originally as Monograph Supplement No. 15 to
+the <i>Psychological Review</i>.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_23" href="#FNanchor_23" class="label">[23]</a> <a href="#Page_20">Pp. 20 to 155</a> of this volume.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_24" href="#FNanchor_24" class="label">[24]</a> <i>American Journal of Psychology</i>, Vol. X, pp. 256-279; Vol. XI, pp. 80-100,
+131-165; Vol. XII, pp. 206-239.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_25" href="#FNanchor_25" class="label">[25]</a> Practically a memory trial of CC, done January 21, 1900.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_26" href="#FNanchor_26" class="label">[26]</a> Did it by pulling door and thus shaking lever.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_27" href="#FNanchor_27" class="label">[27]</a> Practically a memory trial of SS.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_28" href="#FNanchor_28" class="label">[28]</a> Did it by pulling door and biting wire.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_29" href="#FNanchor_29" class="label">[29]</a> This, I regret, was not done [E. L. T., 1911].</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_30" href="#FNanchor_30" class="label">[30]</a> The acts and the number of chances to see me do each and the results
+were as follows; details can be found on the table on <a href="#Page_226">page 226</a>. F = failed
+after tuition.</p>
+
+<table>
+  <tr>
+    <td>No. 1.—</td>
+    <td>MM</td>
+    <td class="tdr">21</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>Theta</td>
+    <td class="tdr">5</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ</td>
+    <td class="tdr">10</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>RR</td>
+    <td class="tdr">4</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>W</td>
+    <td class="tdr">9</td>
+    <td>did in .22</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>Delta</td>
+    <td class="tdr">15</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>Epsilon</td>
+    <td class="tdr">40</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ (f)</td>
+    <td class="tdr">15</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ (c)</td>
+    <td class="tdr">1</td>
+    <td>did in 2.20</td>
+  </tr>
+  <tr>
+    <td>No. 3.—</td>
+    <td>Theta</td>
+    <td class="tdr">25</td>
+    <td>did in 3.00.</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ</td>
+    <td class="tdr">40</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>Gamma</td>
+    <td class="tdr">30</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>Epsilon</td>
+    <td class="tdr">25</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ (ff)</td>
+    <td class="tdr">5</td>
+    <td>F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ (c)</td>
+    <td class="tdr">20</td>
+    <td>F, did in 1.30, F, 5 F, 5 F</td>
+  </tr>
+  <tr>
+    <td></td>
+    <td>QQ (e)</td>
+    <td class="tdr">5</td>
+    <td>F, did in 2.00</td>
+  </tr>
+</table>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_31" href="#FNanchor_31" class="label">[31]</a> He did push it once with his nose.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_32" href="#FNanchor_32" class="label">[32]</a> I inadvertently pulled the nail out in one of five cases when I was fingering it to see if attracting his attention to it would lead to the act.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_33" href="#FNanchor_33" class="label">[33]</a> Not significant. Due to inattention. Was temporary.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_34" href="#FNanchor_34" class="label">[34]</a> Pulled wire and door.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_35" href="#FNanchor_35" class="label">[35]</a> Pushed with head by chance.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_36" href="#FNanchor_36" class="label">[36]</a> Reached in at 9:30 and took out the banana, which I replaced.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_37" href="#FNanchor_37" class="label">[37]</a> Did by constant pulling at the door.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_38" href="#FNanchor_38" class="label">[38]</a> Did touch nail four times.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_39" href="#FNanchor_39" class="label">[39]</a> Did by pulling hard on wire (not loop); the loop got loose from nail.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_40" href="#FNanchor_40" class="label">[40]</a> Did by pulling at the door till the bar was worked around.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_41" href="#FNanchor_41" class="label">[41]</a> The ‘say,’ may be replaced by some bodily attitude, facial expression,
+or other verbal formula that identifies the situation as one to be responded
+to by speech.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_42" href="#FNanchor_42" class="label">[42]</a> This would, of course, result from a well-known corollary of the laws of
+habit.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_43" href="#FNanchor_43" class="label">[43]</a> In <i>Essays Philosophical and Psychological in Honor of William James</i>,
+pp. 591-599.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_44" href="#FNanchor_44" class="label">[44]</a> Professor Smith’s own experiments illustrate this.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_45" href="#FNanchor_45" class="label">[45]</a> Biological Lectures from the Marine Biological Laboratory of Woods
+Holl, 1898, p. 323 ff.</p>
+
+</div>
+
+<div class="footnote">
+
+<p><a id="Footnote_46" href="#FNanchor_46" class="label">[46]</a> This chapter appeared originally in the <i>Popular Science Monthly</i>, Nov.,
+1901.</p>
+
+</div>
+
+</div>
+
+<hr class="chap x-ebookmaker-drop">
+
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_295"></a>[295]</span></p>
+
+<h2 class="nobreak" id="INDEX">INDEX</h2>
+
+</div>
+
+<ul>
+
+<li class="ifrst">Abstraction, <a href="#Page_120">120</a>.</li>
+<li class="isub1"><i>See also</i> <a href="#Reasoning">Reasoning</a>.</li>
+
+<li class="indx">Action-system, importance of the study of the, <a href="#Page_15">15 f.</a>;</li>
+<li class="isub1">of monkeys, <a href="#Page_190">190 f.</a>, <a href="#Page_237">237</a>.</li>
+
+<li class="indx">Anecdotal school in animal psychology, <a href="#Page_23">23 ff.</a>, <a href="#Page_151">151 f.</a></li>
+
+<li class="indx">Apparatus, descriptions of, <a href="#Page_29">29 ff.</a>, <a href="#Page_56">56 ff.</a>, <a href="#Page_61">61 f.</a>, <a href="#Page_169">169 f.</a>, <a href="#Page_177">177 ff.</a>, <a href="#Page_196">196 ff.</a></li>
+
+<li class="indx">Assimilation, <a href="#Page_249">249 f.</a></li>
+
+<li class="indx" id="Association">Association, as a problem in animal psychology, <a href="#Page_20">20 ff.</a>;</li>
+<li class="isub1">by similarity, <a href="#Page_116">116 ff.</a>;</li>
+<li class="isub1">complexity of, <a href="#Page_132">132 ff.</a>;</li>
+<li class="isub1">conditions of, <a href="#Page_43">43 ff.</a>;</li>
+<li class="isub1">delicacy of, <a href="#Page_128">128 ff.</a>, <a href="#Page_195">195 ff.</a>;</li>
+<li class="isub1">development of, in the animal kingdom, <a href="#Page_285">285 ff.</a>;</li>
+<li class="isub1">in cats, <a href="#Page_38">38 ff.</a>;</li>
+<li class="isub1">in chicks, <a href="#Page_63">63 f.</a>;</li>
+<li class="isub1">in dogs, <a href="#Page_56">56 ff.</a>;</li>
+<li class="isub1">in fishes, <a href="#Page_169">169 ff.</a>;</li>
+<li class="isub1">in man, <a href="#Page_123">123 ff.</a>, <a href="#Page_127">127</a>, <a href="#Page_285">285</a>;</li>
+<li class="isub1">in monkeys, <a href="#Page_182">182 ff.</a>, <a href="#Page_194">194 f.</a>, <a href="#Page_209">209 ff.</a>;</li>
+<li class="isub1">in relation to attention, <a href="#Page_44">44 ff.</a>;</li>
+<li class="isub1">to individual differences, <a href="#Page_52">52 ff.</a>;</li>
+<li class="isub1">to inhibition, <a href="#Page_142">142 ff.</a>;</li>
+<li class="isub1">to instincts, <a href="#Page_36">36 f.</a>, <a href="#Page_142">142 ff.</a>;</li>
+<li class="isub1">to previous experience, <a href="#Page_48">48 ff.</a>;</li>
+<li class="isub1">number of connections formed by, <a href="#Page_135">135 ff.</a>;</li>
+<li class="isub1">permanence of connections formed by, <a href="#Page_138">138 ff.</a>, <a href="#Page_194">194 f.</a>, <a href="#Page_203">203 f.</a>;</li>
+<li class="isub1">progress of, measurable by time-curves, <a href="#Page_28">28</a>, <a href="#Page_40">40</a>, <a href="#Page_42">42</a>;</li>
+<li class="isub1">the mental fact in, <a href="#Page_98">98 ff.</a>;</li>
+<li class="isub1">without ideas, <a href="#Page_101">101 f.</a>, <a href="#Page_127">127</a>, <a href="#Page_209">209 ff.</a></li>
+<li class="isub1"><i>See also</i> <a href="#Association">Associations</a> and <a href="#Learning">Learning</a>.</li>
+
+<li class="indx">Associations, complexity, <a href="#Page_132">132 ff.</a>;</li>
+<li class="isub1">delicacy, <a href="#Page_128">128 ff.</a>, <a href="#Page_195">195 ff.</a>;</li>
+<li class="isub1">number, <a href="#Page_121">121</a>, <a href="#Page_135">135 ff.</a>;</li>
+<li class="isub1">permanence, <a href="#Page_138">138 ff.</a>, <a href="#Page_194">194 f.</a>, <a href="#Page_203">203 f.</a></li>
+
+<li class="indx">Associative memory. <i>See</i> <a href="#Association">Association</a>.</li>
+
+<li class="indx">Attention, <a href="#Page_144">144 ff.</a>;</li>
+<li class="isub1">and association, <a href="#Page_44">44 ff.</a>;</li>
+<li class="isub1">to imposed movements, <a href="#Page_103">103 ff.</a></li>
+
+<li class="ifrst" id="Behavior">Behavior, acquired tendencies to, <a href="#Page_244">244 ff.</a> (<i>see also</i> <a href="#Association">Association</a>);</li>
+<li class="isub1">evolution of, <a href="#Page_272">272 ff.</a>;</li>
+<li class="isub1">general laws of, <a href="#Page_241">241 ff.</a>;</li>
+<li class="isub1">indefiniteness of the term, <a href="#Page_5">5</a>;</li>
+<li class="isub1">of cats, <a href="#Page_35">35 ff.</a>, <a href="#Page_88">88 f.</a>, and <i>passim</i>;</li>
+<li class="isub1">of chicks, <a href="#Page_63">63 f.</a>, <a href="#Page_138">138</a>, <a href="#Page_143">143 f.</a>, <a href="#Page_156">156 ff.</a>, and <i>passim</i>;</li>
+<li class="isub1">of dogs, <a href="#Page_59">59 ff.</a>, <a href="#Page_92">92 ff.</a>;</li>
+<li class="isub1">of fishes, <a href="#Page_169">169 ff.</a>;</li>
+<li class="isub1">of monkeys, <a href="#Page_182">182 ff.</a>;</li>
+<li class="isub1">original tendencies to, <a href="#Page_242">242 f.</a> (<i>see also</i> <a href="#Instincts">Instincts</a>);</li>
+<li class="isub1">predictability of, <a href="#Page_241">241 f.</a>;</li>
+<li class="isub1">proposed simplification of the laws of, <a href="#Page_265">265 ff.</a>;</li>
+<li class="isub1"><i>versus</i> consciousness as an object of study, <a href="#Page_1">1 ff.</a></li>
+<li class="isub1"><i>See also</i> <a href="#Association">Association</a>, <a href="#Instincts">Instincts</a>, <a href="#Learning">Learning</a>, <a href="#Memory">Memory</a>, etc.</li>
+
+<li class="indx"><span class="smcap">Bosworth, F. D.</span>, <a href="#Page_240">240</a>.</li>
+
+<li class="ifrst">Cats, associative processes in, <a href="#Page_35">35 ff.</a>;</li>
+<li class="isub1">imitation in, <a href="#Page_85">85 ff.</a>;</li>
+<li class="isub1">the presence of ideas in, <a href="#Page_100">100 ff.</a>;</li>
+<li class="isub1">reasoning in, <a href="#Page_67">67 ff.</a></li>
+
+<li class="indx">Chicks, associative processes in, <a href="#Page_61">61 ff.</a>;</li>
+<li class="isub1">imitation in, <a href="#Page_81">81 ff.</a>;</li>
+<li class="isub1">instincts of, <a href="#Page_156">156 ff.</a></li>
+
+<li class="indx">Complexity, of associations, <a href="#Page_132">132 ff.</a></li>
+
+<li class="indx">Concepts, <a href="#Page_116">116 ff.</a></li>
+
+<li class="indx">Connection-systems, action of, in association, <a href="#Page_246">246 ff.</a>, <a href="#Page_266">266</a>;</li>
+<li class="isub1">importance of the study of, <a href="#Page_16">16 f.</a></li>
+
+<li class="indx">Consciousness, amenability of, to scientific study, <a href="#Page_7">7 ff.</a>;</li>
+<li class="isub1">as pure experience, <a href="#Page_13">13 f.</a>;</li>
+<li class="isub1">as studied by the one who has or is it, <a href="#Page_10">10 ff.</a>;</li>
+<li class="isub1">of animals, <a href="#Page_25">25 f.</a>, <a href="#Page_67">67 ff.</a>, <a href="#Page_98">98 ff.</a>, <a href="#Page_123">123</a>, <a href="#Page_146">146 f.</a>, and <i>passim</i>;</li>
+<li class="isub1">social, <a href="#Page_146">146 f.</a>;</li>
+<li class="isub1">space-relations of, <a href="#Page_14">14</a>;</li>
+<li class="isub1"><i>versus</i> behavior as an object of study, <a href="#Page_1">1 ff.</a></li>
+
+<li class="indx">Coördinations, of chicks, <a href="#Page_160">160 ff.</a></li>
+
+<li class="ifrst"><span class="smcap">Dean, B.</span>, <a href="#Page_161">161</a>.</li>
+
+<li class="indx">Delicacy of association, <a href="#Page_128">128 ff.</a>, <a href="#Page_195">195 ff.</a></li>
+
+<li class="indx"><span class="smcap">Dewey, J.</span>, <a href="#Page_6">6</a>.</li>
+
+<li class="indx">Differences, between species of animals in the associative processes, <a href="#Page_64">64 ff.</a></li>
+
+<li class="indx">Discomfort, as an influence in learning, <a href="#Page_245">245 ff.</a></li>
+
+<li class="indx">Discrimination, in cats and dogs, <a href="#Page_128">128 ff.</a>;</li>
+<li class="isub1">in chicks, <a href="#Page_156">156 ff.</a>;</li>
+<li class="isub1">in monkeys, <a href="#Page_195">195 ff.</a></li>
+
+<li class="indx">Dogs, associative processes in, <a href="#Page_56">56 ff.</a>;</li>
+<li class="isub1">imitation in, <a href="#Page_91">91 ff.</a>;</li>
+<li class="isub1">the presence of ideas in, <a href="#Page_115">115 f.</a>;</li>
+<li class="isub1">reasoning in, <a href="#Page_67">67 ff.</a></li>
+
+<li class="ifrst">Education, applications of animal psychology in, <a href="#Page_149">149 f.</a></li>
+
+<li class="indx">Effect, the law of, <a href="#Page_244">244 f.</a>, <a href="#Page_266">266 ff.</a></li>
+
+<li class="indx">Emotional reactions of chicks, <a href="#Page_162">162 ff.</a></li>
+
+<li class="indx">Evolution, of behavior, <a href="#Page_272">272 ff.</a>;</li>
+<li class="isub1">of human intellect, <a href="#Page_282">282 ff.</a>;</li>
+<li class="isub1">of ideas, <a href="#Page_289">289 ff.</a></li>
+
+<li class="indx">Exercise, the law of, <a href="#Page_244">244 f.</a></li>
+
+<li class="indx"><span class="pagenum"><a id="Page_296"></a>[296]</span>Experience, the influence of previous, <a href="#Page_48">48 ff.</a></li>
+
+<li class="indx">Experiments, need of, in animal psychology, <a href="#Page_26">26</a>;</li>
+<li class="isub1">with cats, <a href="#Page_35">35 ff.</a>, <a href="#Page_85">85 ff.</a>, <a href="#Page_103">103 ff.</a>, <a href="#Page_111">111 f.</a>, <a href="#Page_114">114 f.</a>, <a href="#Page_129">129 ff.</a>, <a href="#Page_138">138 f.</a>;</li>
+<li class="isub1">with chicks, <a href="#Page_61">61 ff.</a>, <a href="#Page_81">81 ff.</a>, <a href="#Page_132">132</a>, <a href="#Page_136">136</a>, <a href="#Page_143">143 f.</a>, <a href="#Page_156">156 ff.</a>;</li>
+<li class="isub1">with dogs, <a href="#Page_56">56 ff.</a>, <a href="#Page_91">91 ff.</a>, <a href="#Page_103">103 ff.</a>, <a href="#Page_115">115 f.</a>;</li>
+<li class="isub1">with fishes, <a href="#Page_169">169 ff.</a>;</li>
+<li class="isub1">with monkeys, <a href="#Page_176">176-235</a>, <i>passim</i>.</li>
+
+<li class="ifrst">Fears, of chicks, <a href="#Page_162">162 ff.</a></li>
+
+<li class="indx">Fishes, experiments with, <a href="#Page_169">169 ff.</a></li>
+
+<li class="ifrst"><span class="smcap">Galton, F.</span>, <a href="#Page_3">3</a>.</li>
+
+<li class="ifrst">Habit. <i>See</i> <a href="#Association">Association</a>.</li>
+
+<li class="indx"><span class="smcap">Hall, G. S.</span>, <a href="#Page_3">3</a>.</li>
+
+<li class="indx">Human. <i>See</i> <a href="#Man">Man</a>.</li>
+
+<li class="indx">Hunger, effect of, on animal learning, <a href="#Page_27">27 f.</a></li>
+
+<li class="indx"><span class="smcap">Hunt, H. E.</span>, <a href="#Page_163">163</a>.</li>
+
+<li class="ifrst" id="Ideas">Ideas, development of, <a href="#Page_121">121 f.</a>, <a href="#Page_289">289 ff.</a>;</li>
+<li class="isub1">existence of, as adjuncts in animal learning, <a href="#Page_108">108 ff.</a>, <a href="#Page_189">189 ff.</a>, <a href="#Page_206">206 ff.</a>, <a href="#Page_222">222 ff.</a>;</li>
+<li class="isub1">impotence of, to create connections, <a href="#Page_257">257 ff.</a></li>
+
+<li class="indx">Ideo-motor action, <a href="#Page_257">257 ff.</a></li>
+
+<li class="indx">Images, <a href="#Page_108">108 f.</a> <i>See also</i> <a href="#Ideas">Ideas</a>.</li>
+
+<li class="indx" id="Imitation">Imitation, analysis of the supposed effects of, <a href="#Page_251">251 ff.</a>;</li>
+<li class="isub1">in cats, <a href="#Page_85">85 ff.</a>;</li>
+<li class="isub1">in chicks, <a href="#Page_81">81 ff.</a>;</li>
+<li class="isub1">in dogs, <a href="#Page_91">91 ff.</a>;</li>
+<li class="isub1">in general, <a href="#Page_76">76 ff.</a>, <a href="#Page_94">94 ff.</a>;</li>
+<li class="isub1">in monkeys, <a href="#Page_96">96</a>, <a href="#Page_211">211 ff.</a>, <a href="#Page_219">219 ff.</a>;</li>
+<li class="isub1">in speech, <a href="#Page_253">253 ff.</a></li>
+
+<li class="indx">Impulses, as features of the associative processes, <a href="#Page_100">100 ff.</a>;</li>
+<li class="isub1">defined, <a href="#Page_37">37</a>.</li>
+
+<li class="indx">Incubation, the instinct of, <a href="#Page_276">276 ff.</a></li>
+
+<li class="indx">Individual differences in association, <a href="#Page_52">52 ff.</a></li>
+
+<li class="indx">Inhibition of instincts by association, <a href="#Page_142">142 ff.</a></li>
+
+<li class="indx" id="Instincts">Instincts, as explanations of some cases of supposed imitation, <a href="#Page_251">251</a>;</li>
+<li class="isub1">inhibition of, <a href="#Page_142">142 ff.</a>;</li>
+<li class="isub1">of chicks, <a href="#Page_156">156 ff.</a>;</li>
+<li class="isub1">of incubation, <a href="#Page_276">276 ff.</a>;</li>
+<li class="isub1">of monkeys, <a href="#Page_237">237</a>;</li>
+<li class="isub1">the starting-point of animal learning, <a href="#Page_36">36 f.</a></li>
+
+<li class="indx">Intellect. <i>See</i> <a href="#Association">Association</a>, <a href="#Ideas">Ideas</a>, <a href="#Imitation">Imitation</a>, <a href="#Memory">Memory</a>, <a href="#Reasoning">Reasoning</a>, etc.</li>
+
+<li class="indx">Interaction, <a href="#Page_147">147 f.</a></li>
+
+<li class="indx">Introspection, the over-emphasis of, <a href="#Page_3">3</a>.</li>
+
+<li class="ifrst"><span class="smcap">James, W.</span>, <a href="#Page_3">3</a>, <a href="#Page_120">120</a>, <a href="#Page_143">143</a>, <a href="#Page_286">286</a>.</li>
+
+<li class="indx"><span class="smcap">Jennings, H. S.</span>, <a href="#Page_267">267</a>, <a href="#Page_268">268</a>, <a href="#Page_269">269</a>, <a href="#Page_270">270</a>, <a href="#Page_274">274</a>, <a href="#Page_279">279</a>.</li>
+
+<li class="ifrst"><span class="smcap">Kline, L. W.</span>, <a href="#Page_173">173</a>.</li>
+
+<li class="ifrst">Language, <a href="#Page_253">253 ff.</a></li>
+
+<li class="indx" id="Learning">Learning, evolution of, <a href="#Page_278">278 ff.</a>;</li>
+<li class="isub1">methods of, <a href="#Page_174">174 f.</a></li>
+<li class="isub1"><i>See</i> <a href="#Association">Association</a>, <a href="#Behavior">Behavior</a>, <a href="#Ideas">Ideas</a>, <a href="#Imitation">Imitation</a>, <a href="#Reasoning">Reasoning</a>.</li>
+
+<li class="indx"><span class="smcap">Lubbock, J.</span>, <a href="#Page_240">240</a>.</li>
+
+<li class="ifrst" id="Man">Man, compared with lower animals in intellect, <a href="#Page_123">123 ff.</a>, <a href="#Page_239">239 f.</a>;</li>
+<li class="isub1">mental evolution of, <a href="#Page_282">282 ff.</a></li>
+
+<li class="indx" id="Memory">Memory, <a href="#Page_108">108 f.</a>, <a href="#Page_138">138 ff.</a>, <a href="#Page_203">203</a>.</li>
+<li class="isub1"><i>See</i> <a href="#Association">Association</a> and <a href="#Permanence">Permanence of associations</a>.</li>
+
+<li class="indx">Methods in animal psychology, <a href="#Page_22">22 ff.</a></li>
+
+<li class="indx"><span class="smcap">Mills, W.</span>, <a href="#Page_191">191</a>.</li>
+
+<li class="indx" id="Monkeys">Monkeys, <a href="#Page_172">172 ff.</a>;</li>
+<li class="isub1">associative processes in, <a href="#Page_182">182 ff.</a>;</li>
+<li class="isub1">differences from lower mammals, <a href="#Page_189">189 ff.</a>, <a href="#Page_204">204 ff.</a>, <a href="#Page_237">237 ff.</a>;</li>
+<li class="isub1">general mental development of, <a href="#Page_236">236 ff.</a>;</li>
+<li class="isub1">imitation of man by, <a href="#Page_211">211 ff.</a>;</li>
+<li class="isub1">imitation of other monkeys by, <a href="#Page_219">219 ff.</a>;</li>
+<li class="isub1">possible mental degeneracy of, <a href="#Page_151">151</a>;</li>
+<li class="isub1">presence of ideas in, <a href="#Page_189">189 ff.</a>, <a href="#Page_206">206 ff.</a>, <a href="#Page_222">222 ff.</a>;</li>
+<li class="isub1">reasoning in, <a href="#Page_184">184 ff.</a></li>
+
+<li class="indx"><span class="smcap">Morgan, C. L.</span>, <a href="#Page_3">3</a>, <a href="#Page_80">80</a>, <a href="#Page_99">99 f.</a>, <a href="#Page_101">101</a>, <a href="#Page_119">119</a>, <a href="#Page_120">120</a>, <a href="#Page_125">125 f.</a>, <a href="#Page_146">146</a>, <a href="#Page_147">147</a>, <a href="#Page_162">162</a>, <a href="#Page_165">165 f.</a></li>
+
+<li class="indx">Motives, used in the experiments, <a href="#Page_26">26 ff.</a>;</li>
+<li class="isub1">defined, <a href="#Page_38">38</a>.</li>
+
+<li class="ifrst">Number of associations, <a href="#Page_135">135 ff.</a>;</li>
+<li class="isub1">as a cause of the development of free ideas, <a href="#Page_121">121 f.</a></li>
+
+<li class="ifrst"><span class="smcap">Peckham, G. W.</span> and E. G., <a href="#Page_240">240</a>.</li>
+
+<li class="indx">Pecking, accuracy of, in chicks, <a href="#Page_159">159 f.</a></li>
+
+<li class="indx">Pedagogy, applications of animal psychology to, <a href="#Page_149">149 f.</a></li>
+
+<li class="indx" id="Permanence">Permanence of associations, <a href="#Page_138">138 ff.</a>, <a href="#Page_203">203</a>.</li>
+
+<li class="indx">Predictability of behavior, <a href="#Page_241">241 f.</a></li>
+
+<li class="indx">Primates. <i>See</i> <a href="#Monkeys">Monkeys</a>.</li>
+
+<li class="ifrst" id="Reasoning">Reasoning, <a href="#Page_118">118 f.</a>;</li>
+<li class="isub1">and free ideas, <a href="#Page_291">291 ff.</a>;</li>
+<li class="isub1">as a consequence of the laws of exercise and effect, <a href="#Page_263">263 ff.</a>;</li>
+<li class="isub1">in cats and dogs, <a href="#Page_67">67 ff.</a>;</li>
+<li class="isub1">in monkeys, <a href="#Page_184">184 ff.</a></li>
+
+<li class="indx">Recepts, <a href="#Page_120">120</a>.</li>
+
+<li class="indx">Resolution, Jennings’ law of, <a href="#Page_267">267 ff.</a></li>
+
+<li class="indx">Responses to situations as the general form of behavior, <a href="#Page_242">242 ff.</a>, <a href="#Page_283">283 f.</a></li>
+
+<li class="indx"><span class="smcap">Romanes, G. J.</span>, <a href="#Page_68">68 f.</a>, <a href="#Page_70">70</a>, <a href="#Page_80">80</a>.</li>
+
+<li class="ifrst"><span class="smcap">Santayana, G.</span>, <a href="#Page_6">6</a>, <a href="#Page_18">18 f.</a></li>
+
+<li class="indx">Satisfaction, the influence of, in learning, <a href="#Page_147">147 f.</a>, <a href="#Page_244">244 f.</a>;</li>
+<li class="isub1">the nature of, <a href="#Page_245">245 f.</a></li>
+
+<li class="indx"><span class="pagenum"><a id="Page_297"></a>[297]</span>Situation and response as the general form of behavior, <a href="#Page_242">242 ff.</a>, <a href="#Page_283">283 ff.</a></li>
+
+<li class="indx"><span class="smcap">Small, W. S.</span>, <a href="#Page_173">173</a>.</li>
+
+<li class="indx"><span class="smcap">Smith, S.</span>, <a href="#Page_269">269 f.</a>, <a href="#Page_280">280</a>.</li>
+
+<li class="indx">Social consciousness of animals, <a href="#Page_146">146 f.</a></li>
+
+<li class="indx"><span class="smcap">Spalding, D. A.</span>, <a href="#Page_162">162</a>, <a href="#Page_163">163</a>, <a href="#Page_165">165</a>.</li>
+
+<li class="indx"><span class="smcap">Stout, G. F.</span>, <a href="#Page_3">3</a>.</li>
+
+<li class="indx">Swimming, by chicks, <a href="#Page_161">161 f.</a></li>
+
+<li class="ifrst">Time of achievement as a measure of the closeness of association, <a href="#Page_28">28</a>, <a href="#Page_40">40</a>, <a href="#Page_42">42</a>, <a href="#Page_54">54</a>.</li>
+
+<li class="indx">Time-curves, <a href="#Page_38">38 ff.</a>, <a href="#Page_57">57 ff.</a>, <a href="#Page_65">65</a>, <a href="#Page_185">185 f.</a>;</li>
+<li class="isub1">as evidence against the existence of reasoning, <a href="#Page_73">73 f.</a></li>
+
+<li class="indx"><span class="smcap">Titchener, E. B.</span>, <a href="#Page_2">2</a>.</li>
+
+<li class="ifrst">Vigor, as a factor in learning, <a href="#Page_46">46</a>.</li>
+
+<li class="ifrst"><span class="smcap">Whitman, C. O.</span>, <a href="#Page_275">275 ff.</a></li>
+
+<li class="ifrst"><span class="smcap">Yerkes, R. M.</span>, <a href="#Page_240">240</a>.</li>
+
+</ul>
+
+<hr class="chap x-ebookmaker-drop">
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+
+<p class="book">A Synoptic Text-book of Zoölogy for Colleges and Schools</p>
+
+<p class="author">By ARTHUR WISSWALD WEYSSE, A.M., Ph.D.
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+element is most meritorious.”—<i>Journal of Education.</i></p>
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+Dial.</i></p>
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+
+<p class="book">The Protozoa</p>
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author	nfenwick <nfenwick@pglaf.org>	2025-01-25 11:32:23 -0800
committer	nfenwick <nfenwick@pglaf.org>	2025-01-25 11:32:23 -0800
commit	5b7011de3ea3a49cf1eb08fd5e20002afbe5da7e (patch)
tree	bc2e22d138098736690f2b0d7478b59f3938cf3e