VI

FOOLING, APING, IMITATING

Definite experimental study of Congo's sensory and perceptual equipment was not attempted, but nevertheless a great many of the observations in connection with experimental situations or incidental to them and to my care and handling of Congo, threw valuable light on receptivity and perceptual status. My .descriptive statements must be made with extreme reserve, however, for they are generalizations from a short acquaintance with Congo and are rather in the nature of impressions tentatively advanced than of scientifically accurate assertions.

With this sweeping apology I should say that the visual receptivity of Congo seems to be comparable with our own. Lacking measures of acuity I may not venture on further comparison. Her use of vision seems to be highly effective. I have no indications whatever of the nature and development of color vision, but I gained the very definite impression that vision is the dominant sense in Congo's life.

As my work progressed it became clear that the animal's visual configurations are more or less radically different from our own. This appeared, for example, in her manipulation of such objects as the stick and the box. But always in such instances my knowledge remained inadequate because I failed to analyze the factors of motor adjustment or motor coördination. Perhaps Congo's failure to use the stick definitely and appropriately as a tool was due more largely to lack of the necessary visual-motor coördination than to the nature of visual perception. This idea, however, would not seem to apply to the same extent when the animal placed a rectangular box on the corner of one edge in order to achieve the nearest approach to suspended food; or when instead she lifted the box toward the food and holding it in mid-air tried to climb

upon it. Such instances of peculiarity of visual configuration might be multiplied indefinitely.

It is the careful, detailed, analytic study of just such performances on the part of our animal subjects that may be expected to qualify us properly as experimenters and enable us increasingly to devise and create experimental situations suitable to their sensory-perceptual equipment, and calculated to exhibit on the one hand the animal's capacity for adaptation and on the other the modifiability or transformability of sensory configurations. It is increasingly clear to the writer, from his study of Congo, that the results of a considerable proportion of the presumably important studies of methods of learning, adaptive capacity, habit-formation, etc., in animals are determined in the main by the intellectual equipment, experience, pre-suppositions, and prejudices, and above all, the types of perceptual configuration of the experimenter. The experiment may be a human masterpiece, but as likely as not it is so contrived as to give the animal meager opportunity to utilize its peculiar adaptive or expressive capacities. We need, in my opinion, general familiarity with our animal subjects and a sympathetic understanding of them, before we even attempt to design crucial experiments to test their abilities.

Of hearing and auditory perception in Congo I can say little. She seemed to be as keenly aware of the sounds in our common environment as was I; at least as alert in detecting novel or unexpected sounds, and in general interested in the world of sounds and continuously ready to utilize them to her advantage. No experiments on acuity or range of hearing or any aspects of auditory perception were made, but I took considerable pains to record the various forms of vocal expression of the young gorilla, and my natural inference from the nature and variety of these sounds is that Congo has a sense. of hearing which is comparable in its development with her sense of sight.

The senses of taste and smell were commonly called into service by new or novel objects whose possible food value was

to be tested. Visual inspection seldom convinced Congo that an unfamiliar object might not be eaten. If accessible, it was promptly carried to the nose or mouth, usually both. The few tests of olfactory sensitivity which I carried out had slight value. I discovered that Congo quickly noticed unusual odors, but that the familiar odors of foods, as for example a banana, would cause her to ignore any strange odor which was not positively disagreeable. On the other hand she was quick to detect disagreeable, penetrating, or irritating odors and to form associations which enabled her to avoid them. One demonstration of this was in connection with tear gas which quite evidently irritated her nose even at a distance of several feet. We are accustomed to think of the primates, especially in early life, as peculiarly and wantonly destructive. Is this impression in accord with the facts? In experimental as well as other types of situation I have worked over considerable periods with six widely differing primates: marmoset, cebus monkey, orang-utan, chimpanzee, gorilla, and man, and I have observed that they exhibit extreme differences in degree of natural destructiveness. Perhaps in proportion to its strength the monkey deserves first place, but certainly the chimpanzee and the human infant and child compete closely, if not for first then certainly for second place. It has seemed in my experience that destructiveness ordinarily is more or less incidental to the sensory examination and the sensory-perceptual testing or manipulation of objects which in the long run acquaint the organism with the qualities of its environment and give it measured control thereof.

Between a typical chimpanzee of the same age and the gorilla Congo there is an amazing difference in natural destructiveness. Whereas the chimpanzee pounces eagerly upon new things, examines them with every available sense, tests them, manipulates them, and usually in short order demolishes them if this can be done, Congo mostly confined herself to a rather demure and ladylike examination of unfamiliar objects. The scrutiny is primarily visual, tactual, olfactory, and gusta

tory. If this examination indicates edibility, the appropriate reaction immediately ensues; otherwise the object, unless capable of some peculiar sort of manipulation, tends to be neglected. Never did I see Congo wantonly destroy an object. Yet in her cage at various times, and partly for the express purpose of testing destructiveness, I placed wooden and paper boxes, carpenter's tools, pieces of experimental apparatus, and even a corncob pipe. So much did her lack of destructiveness impress me that I one day recorded in my notes my willingness to trust my best hat in her cage. I should feel fairly confident that if it were left there overnight I should be able to reclaim it the next day, somewhat crumpled and soiled but still a hat. With a monkey or chimpanzee at hand I should feel equally certain that the hat would not be identifiable as such a few hours after its commitment to the cage.

I am coming to suspect that destructiveness is importantly related on the one hand to curiosity and perhaps on the other to mode of learning and to the functioning of different learning processes in specific situations. It therefore is particularly in point to consider Congo's display of curiosity.

From my first meeting with Congo I was impressed by the relative infrequency of indications of curiosity about unusual objects or events. I continue uncertain whether the animal represses or inhibits the usual primate expressions of curiosity or instead lacks the experience. In addition to the observations which I made in the course of our daily contacts, I planned many simple experimental situations with intent to elicit gorilla curiosity. The evidences are so abundant that I must limit description to typical examples, whereas I base my impressions and generalizations upon the totality of my observations.

In the several stick problems it will be recalled that Congo initially paid little or no attention to sticks placed on the floor of her cage, put in front of her, or even handed to her. At first she completely ignored these objects; later she sometimes pushed or brushed them aside as if in irritation, and still later

she occasionally picked them up, smelled them, and either laid them down or for a few seconds carried them about with her. Even though the stick was of unusual color, texture, or shape, she ordinarily displayed little or no interest in it or concern about it.

It would be difficult for me to forget my genuine surprise in the following experience. One day as I was working on the roof of the cage I accidentally dropped my two-foot rule through the wire netting and it fell to the floor of the cage where Congo could readily see and get it. Assuming, from my previous contacts with monkeys and apes that it would be ruined by Congo before I could get there, I made all haste down the ladder, around the cage, and hastily opened the door and rushed in. The rule lay undisturbed where it had fallen and Congo sat placid and unconcerned on the porch of her nest-room. In the course of weeks of continuous experimental work many similar happenings commanded my attention.

Problem 13. Hammer and nail imitation. An intentional test of curiosity and desire to manipulate things I made one day as I was constructing apparatus. With hammer, wooden block, wire, and boards at hand I was doing certain simple mechanical things which involved frequent use of the hammer. Congo was chained nearby. I called her to me to let her watch or, if she desired, help. She came, but giving almost no attention to what I was doing promptly climbed on my back and wished to remain there. Neither the noise nor my manipulation of the objects seemed to have interest for her. This further stirred my wonder and I became increasingly eager to find something which would really command her attention and examination.

One morning when conditions seemed favorable, I handed her through the netting of her cage a wooden door stop and a two by four inch sheet of red rubber. Each was tested by smell and taste and then, despite their varied qualities and possible uses as amusing objects, she put them to one side and ignored them. The same response was given to a corncob