If, then, we agree to exclude from the category of imitative behaviour in animals, on the one hand, any “circular process” which may occur in the same individual, and on the other hand any reflective imitation, such as is so important a factor in human education, it remains to be seen what may be fairly included in this category.
It is probable that in animals imitation has its foundations in instinctive behaviour, of which it may be regarded as the characteristically social type. If one of a group of chicks learn by casual experience to drink from a tin of water, others will run up and peck at the water, and thus learn to drink. A hen teaches her little ones to pick up grain or other food by pecking on the ground and dropping suitable materials before them, while they seemingly imitate her action in seizing the grain. One may make chicks and pheasants peck by simulating the action of a hen with a pencil point or pair of fine forceps. According to Mr. Peal, the Assamese find that young jungle pheasants will perish if their pecking responses are not thus stimulated; and Professor Claypole tells me that this is also the case with young ostriches hatched in an incubator. A little pheasant and guinea-fowl followed two older ducklings, one wild, the other tame, and seemed to wait upon their bills, to peck when they pecked, and to be guided by their actions. It is certainly much easier to bring up young birds if older birds are setting an example of eating and drinking; and instinctive acts, such as scratching the ground, are performed earlier if imitation be not excluded. If a group of chicks have learnt to avoid cinnabar caterpillars, and if then two or three from another group are introduced and begin to pick up the caterpillars, the others will sometimes again seize them, though they would otherwise have left them untouched. One of my chicks, coming upon a dead bee, gave the danger or alarm note; another at some little distance at once made the same sound. A number of similar cases might be given; but what impresses the observer as he watches the early development of a brood of young birds, is the presence of an imitative tendency which is exemplified in many little ways not easy to describe in detail. It is probable, however, that these imitative tendencies or propensities are not wholly indefinite. The young birds do not imitate any actions, but behaviour of certain specific types, the imitation of which has been engrained through the action of natural selection.
What generalization, then, can be drawn from this somewhat indefinite group of facts, to which many others of like import could be added from observations on the young of mammals? What is their relation to instinctive procedure in general? It would seem that they are characterized by a special relation of the external stimulus to the response. When this stimulus is afforded by the behaviour of another animal, and the responsive behaviour it initiates is similar to that which affords the stimulus, such behaviour may be termed imitative. A chick sounds the danger note; this is the stimulus under which another chick sounds a similar note, and we say that the one imitates the other. Such an action may be described as imitative in its effects, but not imitative in its purpose. Only from the observer’s standpoint does such instinctive behaviour differ from other modes of congenital procedure. It may be termed biological, but not psychological, imitation. And if it be held that the essence of imitation lies in the purpose so to imitate, we must find some other term under which to describe the facts. This does not seem necessary, however, if we are careful to qualify the term “imitation” by the adjective “instinctive” or “biological.” And the retention of the term serves to indicate that this is the stock on which deliberate imitation is eventually grafted.
The fact that instinctive imitation leads, under natural conditions, to behaviour which is already familiar to us in the species concerned, prevents us from recognizing the influence of this social factor so easily as might otherwise be the case. The abnormal arrests our attention more readily than the normal, and hence the cases commonly cited are generally those which strike us as unusual, such as the imitation of human sounds by the parrot. But if the young inherit a tendency to imitate certain actions of their parents, and if there is among the members of a gregarious species such instinctive imitation as shall tend to keep them gregarious, we have here a social factor in animal life of no slight importance. Just as the higher type of reflective imitation is of great value in bringing the human child to the level of the adults who form the family and social environment, so, too, does the sub-conscious instinctive imitation of the lower animals bring the young bird or other creature into line with the members of its own species. In broods of chicks brought up under experimental conditions, there are often one or two more active, vigorous, intelligent, and mischievous birds. These are the leaders of the brood; the others are their imitators. Their presence raises the general level of intelligent activity. Remove them, and the others show a less active, less inquisitive, less adventurous life. They seem to lack initiative. From which one may infer that imitation affords to some extent a means of levelling up the less intelligent to the standard of the more intelligent; and of supplying a stimulus to the development of habits which would otherwise be lacking. When a mongrel pup, whose development Dr. Wesley Mills watched and has described, was introduced to the society of other dogs, its progress was, he tells us, “extraordinarily rapid.”
Instinctive imitation thus introduces into the conscious situation certain modes of behaviour, and if the development of the situation as a whole is pleasurable, there will be a tendency to its redevelopment, under the guidance of intelligence, on subsequent occasions. As in the case of other instincts and propensities, there is given through inheritance a more or less definite outline sketch of social procedure, which intelligence further defines, and refines, and shapes to more delicate issues. As a rule, however, intelligence does not tend to make the imitation as such more perfect. It may perfect the behaviour, but not necessarily on imitative lines. In the case, however, of the song and call-notes of birds, and not improbably the sounds of other animals, there does seem a predisposition to render the imitation as such more perfect. The facts, as afforded by such birds as the magpie, jay, starling, marsh-warbler, and mocking-bird, are familiar; and I have elsewhere[81] given some account of them. It may be specially noted that we have in this case that circular mode of activity on which, as we have seen, Professor Mark Baldwin lays so much stress. Professor Thorndike seems to regard the phenomena presented by imitative birds as somewhat of a mystery, and as the result of a specialization removed from the general course of mental development. And he says that, until we know whether there is in birds which repeat sounds any tendency to imitate in other lines, we cannot 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. Upon the view, however, that such imitation is primarily instinctive and only secondarily intelligent, there seems no reason why we should expect to find imitation in birds running along any other lines than those which the hereditary instinct has marked out. And so far from being unable to use the phenomena to advantage in a discussion of animal imitation as a forerunner of human, we may perhaps see in them the best examples, other than those afforded by apes, of that intelligent imitation which is the precursor of the rational and reflective imitation of the boy or girl.
In the case of the human child we may see the three stages in the development of vocal imitation. First, the instinctive stage, where the sound which falls upon the ear is a stimulus to the motor-mechanism of sound production. Secondly, the intelligent stage of the profiting by experience. Intelligence, as we have seen, aims at the reinstatement of pleasurable situations, and the suppression of those which are the reverse. The sound-stimulus, the motor effects in behaviour, and the resulting sound-production coalesce into a conscious situation, which appears to be pleasurable or the reverse, according as the sound produced resembles or not the initiating sound-stimulus. If we assume that the resemblance of the sounds he utters to the sounds he hears is itself a source of pleasurable satisfaction (and this certainly seems to be the case), intelligence, without the aid of any higher faculty, will secure accommodation and render imitation more and more perfect. And this appears to be the stage reached by the mocking-bird or the parrot. But the child soon goes further. He reflects upon the results he has reached; he at first dimly, and then more clearly realizes that they are imitative; and his later efforts at imitation are no longer subject to the chance occurrence of happy results, but are based on a scheme of behaviour which is taking form in his mind, are deliberate and intentional, and are directed to a special end more or less clearly perceived as such. He no longer imitates like a parrot; he begins to imitate like a man, and may, by the study of good models and the maintenance of a high ideal, acquire the moving cadences of an orator.
According to our interpretation, instinctive imitation is a factor of wide importance in animal behaviour, intelligent imitation, arising in close connection with interest in the doings of others, is a co-operating factor, but of intentional and reflective imitation there is at present no satisfactory evidence in any animal below man.
II.—Intercommunication
The foundations of intercommunication, like those of imitation, are laid in certain instinctive modes of response, which are stimulated by the acts of other animals of the same social group. These have been fostered by natural selection as a means of social linkage furthering the preservation, both of the individual and of the group.
Some account has already been given of the sounds made by young birds, which seem to be instinctive and to afford an index of the emotional state at the time of utterance. That in many cases they serve to evoke a like emotional state and correlated expressive behaviour in other birds of the same brood cannot be questioned. The alarm note of a chick will place its companions on the alert; and the harsh “krek” of a young moor-hen, uttered in a peculiar crouching attitude, will often throw others into this attitude, though the maker of the warning sound may be invisible. That the cries of her brood influence the conduct of the hen is a matter of familiar observation; and that her danger signal causes them at once to crouch or run to her for protection is not less familiar. No one who has watched a cat with her kittens, or a sheep with her lambs, can doubt that such “dumb animals” are influenced in their behaviour by suggestive sounds. The important questions are, how they originate, what is their value, and how far such intercommunication—if such we may call it—extends.