Animal Behaviour

by C. Lloyd Morgan

IV.—The Conscious Aspect of Instinctive Behaviour

In our definition of instinctive behaviour all positive reference to the presence of conscious states was omitted. By some writers, however, the fact that it is accompanied by consciousness is regarded as a distinguishing feature of instinct. Romanes introduced his definition with the words:[38] “Instinct is reflex action into which there is imported the element of consciousness.” And he emphasized the conscious aspect when he said: “The term comprises all those faculties of mind which are concerned with conscious and adaptive action, antecedent to individual experience.” Professor Wundt also lays some stress on the conscious accompaniments of instinctive activities which, he says,[39] “differ from the reflexes proper in this, that they are accompanied by emotions in the mind, and that their performance is regulated by these emotions.” The definitions of other writers express or imply the presence of consciousness in differing modes and degrees, culminating in the hypothesis of inherited knowledge. Douglas Spalding, for example, said[40] that “animals can forget the instinctive knowledge which they never learned!”

Now, the exclusion from our definition of direct reference to the conscious aspect must not be taken to imply that instinctive behaviour is a mere matter of unconscious automatism; nor even that it is unprofitable to discuss how much consciousness there may be, of what sort, and how distributed. All that it does imply is, that the amount, nature, and distribution of consciousness cannot well be introduced into a definition the object of which is to help us to distinguish certain observable types of behaviour from others. In a word, the definition given is biological and objective, and is to be accepted or rejected without prejudice to such psychological considerations as those upon which we have now briefly to enter.

The first thing we have to decide is how much we are to include, from the psychological standpoint, under instinct. For we may take either a broader or a narrower view of the matter; and which of these we adopt will make much difference in our conclusions. Let us first deal with the narrower. We have said above that what is hereditary in instinctive behaviour is the co-ordination. Now, such co-ordination of movements into a finished and appropriate act is due to a nicely graded distribution of efferent nerve-waves to the several muscles concerned, so that these muscles may be caused to contract in due order, and each to just the right extent. But efferent nerve-waves as such, and their mode of distribution by the nerve-centres, are in all probability unconscious, while the contraction of the muscles is a purely organic matter. If, therefore, we narrow our conception of instinct so as to include only the co-ordinated act by itself, excluding all reference both to the stimuli which are its antecedents, and to the effects in consciousness which its performance may produce; and if the data for consciousness are in all cases supplied through afferent channels; then there seems to be no escape from the conclusion that instinctive behaviour as such may be, and probably is, altogether outside the individual consciousness. It should be noted, however, that on this view only the instinctive co-ordination in itself can be fairly regarded as independent of the stream of experience.

Now, in the first place it is convenient so far to broaden our conception as to include under the head of instinctive behaviour, in its conscious aspect, not only the co-ordinated act but the data which its performance affords to consciousness. It may indeed seem that we are here trying to draw a distinction where no real difference exists. The physiological distinction is, however, not only clear and undeniable, but quite easily understood. For the sake of illustration let us take the case of an intentional action, such as glancing up from the words we are reading to the clock. Efferent waves course along several motor nerves to the six muscles by which each eye is moved, and to the muscles of accommodation within the eye. These muscles are called into duly co-ordinated activity, by which our vision is focussed upon the clock-face. This is one part of the physiological procedure—that by which the intended result is attained. But there is a second part readily distinguishable from the former. As the eyes move, afferent messages course inwards from the muscles or the eye-sockets and their neighbourhood; and it is these incoming waves which afford data to consciousness, telling us that the movements are in progress or have been effected. The nerves involved in the latter part are quite different from those concerned in the former part, and they proceed to areas of the brain differently situated from those whence the efferent waves issued. Thus it is in all cases of movement; the efferent nerves call the muscles into play; the afferent nerves bring information that the movements are carried out. It is through the latter that data are unquestionably afforded to consciousness.

But in the case of any complex action—and, as we have seen, instinctive behaviour is often remarkably complex—the information that the action has begun comes in before the behaviour is completed. Practically we may say that any given stage of performance and the consciousness it evokes are simultaneous; for though in strictness the one lags just a little behind the other, yet they are so nearly coincident in time that we may disregard the interval between them. Such being the case, therefore, we may fairly regard the felt performance of the instinctive act as capable of introducing important elements into the conscious situation.

But not only does instinctive behaviour thus introduce important elements into the conscious situation, it is also called forth by stimuli which themselves afford not less important elements. To exclude these from any consideration of instinct, in its conscious aspect, would render the treatment of the problem so incomplete as to be wholly unsatisfactory from a psychological point of view. Can we believe that when the moor-hen dived, as it never had dived before, at the sight of the rough-haired pup, the vivid experience of that strange and disquieting intruder did not enter into, and form a prominent feature in, the conscious situation? If we are to consider the conscious aspect at all, we must try and grasp the situation as a whole. And on these grounds we may yet further broaden our conception so as to include, from the psychological point of view, not only the behaviour itself, and its effects in consciousness, but also the stimulating conditions under which it is called into play. If, then, we accept this position, and agree to use the term “instinct” for our present purpose in a comprehensive sense, we may now proceed to consider very briefly the nature of the elements which enter into the instinctive situation.

First, there are the external stimuli affecting one or more of the sense organs, and thus evoking consciousness; and secondly, there are internal factors, having their source in the condition of the body, or its parts and organs. It is convenient to take these two together, so that we may see what relationship they bear to each other. Both seem to be present, and to co-operate in a great number of instinctive acts. In the behaviour connected with feeding, for example, an internal element of hunger co-operates with the external presentation of the appropriate food or prey. So, too, with the instincts concerned in the propagation of the race. Looking at the matter generally, we may regard the internal factors of the kind with which we are now dealing, as giving rise to a want or need, passing in some cases into a state of craving. In themselves such conscious states are in their inception exceedingly indefinite; for a want can only be rendered definite in experience by its appropriate satisfaction. In many cases of instinctive behaviour the indefinite want and the particular and duly related stimulus seem to lead, without prevision and by a blind impulse, to the performance of those acts which will afford the unforeseen satisfaction. And when once this satisfaction has been attained, subsequent wants or needs of like character will no longer be indefinite; nor will future behaviour of the same kind be thereafter wholly instinctive, for it can never again be prior to, or independent of, experience.

Granted, however, that a felt need of some kind, indefinite at first but none the less real, is present in many cases as a spur to instinctive behaviour; is it in all cases a necessary factor? May we say that this distinguishes instinctive from merely reflex action? The question is, from the nature of the case, exceedingly difficult to answer. But without going so far as to say that reflex action may be unerringly distinguished from instinctive behaviour by the absence of any such internal factors, we may perhaps, at any rate, go so far as to give provisional acceptance to the view that in instinct these wants and felt needs enter into the conscious situation in a manner and to a degree that are so far distinctive—which seems to be the position adopted by Professor Wundt.

There is, however, a further relation between the external stimulus and these internal factors which is presumably of no little importance. The stimulus intensifies the want, or may in some cases call it into existence. Just as a whiff from the kitchen may lead us to realize that we need the satisfaction that will erelong be presented at table, so may the sight of his mate in the spring evoke in the breast of the yearling sparrow a need, having its source in morphological and physiological changes, that spurs him on to the courtship that shall lead to its due satisfaction. Popular attention has, indeed, been so naturally drawn to the internal needs or wants with which we are now dealing, as to give them an almost exclusive monopoly of the term “instinct,” which thus often comes to be regarded as a connecting link between the stimulus and the act. The sight of a mouse, for example, is said to call forth the instinct of the cat, which is satisfied by her pouncing upon it. And so it comes about that, while the biologist fixes upon the instinctive act as the essential feature, the psychologist is apt to regard the impulse[41] which prompts to action as the more central and characteristic element. We are here endeavouring to combine both these points of view.

To come to closer quarters with the relationship which holds good between the external and internal elements, it appears that, when the stimulus evokes or intensifies the want or need, this is probably effected by efferent waves which call the organs or parts into tonic action, of which the animal becomes conscious through the afferent messages which come in from them to the sensory centres; in much the same way as the whiff from the kitchen takes effect on the salivary and other glands, and throws the organs of digestion into a felt preparedness for the fulfilment of their functions. But it may have other and more indirect consequences. When the moor-hen dived to escape from the obtrusive puppy, his heart-beat was probably affected; he had, perhaps, an uncomfortable sinking in his gizzard; his breathing was short and laboured; and he experienced creepy sensations in the skin and around the feather-roots. Such we may suppose were the accompaniments or sources of the emotional state of fear or alarm. And they presumably entered with no little vividness into the conscious situation at the moment of instinctive action. In all those cases in which the behaviour is associated with such an emotional state as anger or fear, the external stimulus seems to produce widely-spread effects on the glands, respiratory organs, heart and blood-vessels, skin and other parts, as well as the more direct response in productive action. And all this must enter into the conscious situation, contributing largely, as we shall hereafter see, to the emotions in their instinctive origin.

Enough has now been said to indicate with sufficient clearness the kind of co-operation and mutual relationship which subsists between the external and the internal factors in the conscious situation which leads to instinctive behaviour. We have seen that, not improbably, some organic prompting is always present in greater or less degree. But the question still remains whether anything like a definite and particular external stimulus is in all cases a necessary factor.

When the predaceous larva of the water-beetle, Dytiscus, ceases to feed, and, creeping into the moist earth near the pond’s edge, makes a hollow cell in which to enter upon its pupal sleep, there does not seem to be any well-defined stimulus from the outer world which can be said to initiate the behaviour of whose purport the larva can have no idea. Some inner need seems to impel the creature to this necessary but as yet unknown course of action; and this appears to constitute, if not the sole, at least the preponderant element in the conscious situation. In healthy young birds and other animals there is after the rest of sleep a certain exhilaration and exuberance of spirits which seemingly leads to characteristic action; dancing, flapping of the wings, running hither and thither in short quick spurts, and so forth. No doubt in such cases external stimuli are present, and contribute in some degree to the effects produced; but they do not seem to be particularized so that one can say that just this or that well-defined stimulus is necessary to give rise to the observed behaviour. In the case of migration, too, an internal factor—the nature of which we do not know—is probably as strong as if not stronger than any influence from without. While, therefore, we may say that some external factors are frequently, not improbably always, contributory, we must add that observation does not enable us in all cases to define them with any approach to accuracy; and, further, that promptings from within seem in some instinctive acts to be the most important elements in the conscious situation.

It now only remains to draw attention to the fact that the effects of the behaviour, as the animal becomes conscious of the performance of the acts concerned, serve to complete and render definite the conscious situation. Consciousness, however, probably receives information of the net results of the progress of behaviour, and not of the minute and separate details of muscular contraction. These net results, having thus entered presentatively into the situation, are subsequently susceptible of re-presentative recall, when the recurrence of certain salient elements serve to reproduce the essential features of the situation of which experience has been gained on a former occasion. Hence, as has already been noted, it is only the first performance of an instinctive action which can be described as prior to experience. The second time the deed is done it is done by an animal which has had opportunity of gaining experience on the foregoing occasion. And then it may be done with a difference, with some acquired modification of performance. By the repetition of the slightly modified behaviour the effects of habit are introduced, and thus acquired peculiarities of action are established as individual traits. We must not forget that, in a large number of cases, so-called instinctive behaviour, as presented to observation, has lost through modified repetition its original purity of type. The acts we see are often the joint products of heredity and individual acquisition, the inherited co-ordination having been supplemented or otherwise altered through experience.

Even in the case of the very first exhibition of such a deferred instinct as the moor-hen’s dive, although that organized sequence of acts which constituted the behaviour as a whole had never before occurred, although there was no gradual learning how to dip beneath the surface, and to swim under water, still many of the constituent acts had been often repeated; experience had already been gained of much of the detail then for the first time combined in an instinctive sequence. So that if we distinguish between instinct as congenital and habit as acquired, we must not lose sight of the fact that there is continual interaction, in a great number of cases, between instinct and habit, and that the first performance of a deferred instinct may be carried out in close and inextricable association with the habits which, at the period of life in question, have already been acquired. Instinct supplies an outline sketch of behaviour, to which experience adds colour and shading. Which predominates in the finished picture depends on the status of the animal. In the lower and less intelligent types the outline stands out clearly, there being but little shading to divert our attention from the clear firm lines inscribed by heredity; but in the higher and more intelligent animals, the deft pencil of experience has added so much detail and has interwoven with the fainter outline so many new and skilfully introduced touches, that the original sketch is scarcely distinguishable unless we have carefully watched from the beginning the gradual development of the picture.