Popular Science Monthly/Volume 30/March 1887/Comparative Psychology: Its Objects and Problems
| COMPARATIVE PSYCHOLOGY: ITS OBJECTS AND PROBLEMS.[1] |
By T. WESLEY MILLS, M. A., M. D.,
PROFESSOR OF PHYSIOLOGY IN McGILL UNIVERSITY, MONTREAL.
THE term comparative psychology, in its modern sense, gives us the widest desirable scope as including all that pertains to the mind or soul of the animal kingdom. It may have been at one time considered as highly impertinent to ask whether the lower animals possess mind, and to substitute the term soul would have been dangerously suggestive of heterodoxy of a type rapidly to be extinguished. However, few persons of any degree of culture will now be found prepared to deny that the inferior animals have minds. The questions now to be settled are: What kind of minds? In how far do they resemble, and in how far differ from, our own? Few, it is true, have considered that they sufficiently resemble the human mind to make it worth while to investigate the subject at all. Probably the great mass of persons have been led to believe that man does and always has occupied a distinctive and wholly isolated position in the universe of life—a center around whom and for whom all other forms exist. This view seems to me totally unwarranted by the state of our scientific knowledge at the present day. Further, it is a view not only without scientific foundation, but calculated to lead to pernicious practical results.
By experiments on the lower animals, and by this means almost wholly, has the science of physiology been built up. We argue from the case in animals to the case in man, and consider the inferences thus derived valuable, even final—possibly too much so; but we are apt to ignore the psychological similarity. From experiments on the brains of the lower animals we argue as to the nature of the brain of man. Why not pursue the comparative method for the soul?
This condition of things can be traced to the influence of views still surviving, unscientific, as we believe, as to man's origin and place in the universe. At all events, such views exist and influence practically our treatment of the lower animals. Where man is concerned, their rights are very seldom considered. The question is not raised as to whose rights are paramount, but it is tacitly assumed that when man is involved the brutes have none. That such views have been up to the present time operative to the neglect, and often the positive annoyance, if not the actual persecution and death of unoffending creatures, will be perfectly plain to any one who will take the pains to examine into the case.
If there is to be order in the universe, it must be conceded that where respective interests clash in certain cases, that interest, and that creature of less importance must give way to the one of greater importance; but man can never act righteously to his fellow-creatures lower in the animal scale, till he recognizes that he is of them not only in his body but in his mind; in other words, that they are truly fellows, or, as some one has expressed it, "poor relations." But let this not be said in any pitying sense, for it can be most clearly shown that in not a few respects not only are these "poor relations" equal but superior to man.
Physiologists have long been familiar with the higher development of the senses in animals below man. There is not a single sense that man possesses in which he is not excelled by some one animal, often immeasurably.
Many of the performances of the lower animals, if accomplished by men, would be regarded as indications of the possession of marvelous genius. In the brutes they are regarded ae the outcome of "mere instinct," by which is meant an endowment acting blindly and incapable either of philosophic explanation or of modification. While the fact seems to be that instincts, as they exist, are the result of inherited experiences accumulated through considerable periods of time; that they may be modified, and are constantly being modified by new experiences; that they may be lost or replaced; and much more that we have still to learn. Many of the instincts of animals are so far removed from any knowledge or faculty we possess that they are at present inexplicable. Rut man must learn to say, "I don't know," about a great many things still, instead of assuming the validity of explanations which are not true solutions at all, but mere assumptions.
And at this point allow me to indicate a danger that should make us cautious and modest in attempting to explain the behavior of animals. We infer from our fellow-man's behavior similarity of motive and mental processes to our own under like circumstances. We find, the more experience we have, that we are often at fault as to both. And when we are more free from the thralldom of so-called systems and methods in education, we may learn that the activities of the human mind can not be reduced in all persons to precisely the one plan, like so much clock-work. This may mar somewhat the completeness and beauty of our philosophy of education, but it may also in the end conduce to human progress by providing the greater freedom, and end in insuring an individuality of character which seems to be now rapidly disappearing. Now, if individual men so differ in psychic behavior, how much more is it likely that still greater differences hold for the lower animals! An objection may be based, however, on this to the whole study of comparative psychology. The objection holds to some extent even for human psychology; but, as we infer, similarity of behavior in men to denote similarity of inner processes, so are we justified in the same as regards the lower animals, though it must be conceded somewhat less so. We must always be prepared to admit that there may be psychic paths unknown and possibly unknowable to us in the realm of their inner life. But if we regard man as the outcome of development through lower forms, according to variation with natural selection—in a word, if a man is the final link in a long chain binding the whole animal creation together, we have the greater reason for inferring that comparative psychology and human psychology have common roots. We must, in fact, believe in a mental or psychic evolution as well as in a physical (morphological) one.
It is not inconceivable that special faculties which do not exist in the lower animals have been implanted in man; but the trend of investigation thus far goes to show that at least the germ of every human faculty does exist in some species of animal. Nor does such a view at all derogate from the dignity of superior man, while it links the animal creation together in a way that no other can. It opens up the subject for genuine scientific study; it tends to beget a respect for the lower creation, which, while it fosters modesty in man, also furnishes a foundation for broader sympathy with those lower in the scale. The opposite view may lead to our pitying the brute, but can scarcely yield as good moral fruit. Let but an individual man assume that by virtue of something he possesses he is radically different from his fellows, and what is the result? Your genuine aristocrat (in feeling) is a sad stranger to humanity in general.
But where shall we draw the line? Formerly the line was drawn at reason. It was said the brutes can not reason. Only persons who do not themselves reason about the subject with the facts before them can any longer occupy such a position. The evidence of reasoning power is overwhelming for the upper ranks of animals, and yearly the downward limits are being extended the more the inferior tribes are studied. Perhaps the highest faculty man possesses is that by which he generalizes and forms conceptions of the abstract. That animals have imagination or the power to frame mental pictures of absent objects, the grief of the dog at the absence or loss of his master amply proves, as does also the capacity of animals to dream. If, as some assume, abstraction is a necessary part of reasoning, then it must of course be conceded that animals have the power of framing abstract conceptions. There is a certain amount of evidence that some animals can count within narrow limits. It is scarcely possible to account for the conduct of the horse, dog, elephant, and ape, under certain circumstances, without believing that they have the power to generalize upon details. Once concede the power to form abstract ideas, and there is then the basis for any other faculty man possesses that is considered usually as peculiarly his.
Have animals a moral nature, or are they capable of forming a conception of right and wrong? The answer to this introduces the question as to method of comparison. Should the highest of the inferior animals be compared with the most civilized races of men, or with man in his most degraded condition? That neither of these comparisons is just, can be shown. As capacity for education is one of the best evidences of mental ability in both man and inferior animals, and as man's civilization is the outcome of his own intellect, he must be credited with this as evidence of his superiority.
It is to be remembered, however, that each marked advance in progress has been made by the few great intellects that have appeared, and only accepted, not originated, by the many; that but for permanent records in language, much of man's civilization would have been lost as rapidly as acquired; that man's civilization is the growth of thousands of years, beginning with a condition of things scarcely if at all higher than that now known to some tribes of animals; that what any child becomes is really largely dependent upon the training it receives; the child of the savage, and that of the civilized man, can not be compared any more than the latter and the inferior animals. Now, the reverse of all this holds for the lower animals. So far as any systematic training from man is concerned, they are very much as they were thousands of years ago. Before it were possible absolutely to compare the highest man and the highest animal, it would be necessary that for ages the effect of culture should be tried on the lower animals. The astonishing results achieved in the lifetime of a single animal, and the results attained by the creation of hereditary specialists as among dogs, put the whole matter in a light that shows our usual comparisons to be somewhat unfair. If the highest among dogs, apes, and elephants be compared with the lowest among savage tribes, the balance, whether mental or moral, will not be very largely in man's favor—indeed, in many cases the reverse.
We are not contending for the equality of man and the rest of the animal kingdom; even assuming that the child and the dog have equal advantages, the child will still be in many respects superior to the dog; but we are desirous of pointing out how much has been overlooked in all these comparisons between man and the lower animals. It will be noticed that all those species of animals which have for ages been in contact with man, have made great advances over their wild progenitors, evidencing a capacity for education—mental and moral—which is one of the best demonstrations of superiority.
The assumption that man is only accidentally the superior of the brute would but lead to confusion, for it must be admitted that there is a scale, and that man ranks first. We are simply desirous of doing the lower creation that justice which we feel assured has not yet been allowed them, and of seeing the human family interested in those that we think scientific investigation is proving constantly are much more our fellow-creatures than has generally been supposed.
If we compare the intelligence and general rectitude of behavior of our best races of dogs with the same in any of their wild carnivorous allies, we are astonished at the great difference in favor of the dog. To what is this due? Largely to what he has become by virtue of association with man for hundreds if not thousands of years—that is, to education, after a fashion. Nor is such influence confined to the dog. Any observing person, of moderate experience in travel, can call to mind numerous instances of members of different classes of animals trained to the performance of many feats demanding intelligence. But, while in an irregular way dogs have been trained to certain duties for the benefit of man for a considerable period, it can not be said that any one of the tribes of the lower animals has ever been subjected to any such mental or moral discipline as man receives and has received for long ages. We have ample evidence, in the condition not only of savage man, but in the neglected classes of large cities, as to what man would be without such culture. Sufficient has been said, it is believed, to show that we are not yet in possession of enough facts to enable us to determine exactly the limit of mental and moral capacity in the lower animals. As yet, we neither know adequately what they are or of what they are capable. Both these subjects are worthy of human investigation. Their elucidation must tend to give man a better knowledge of himself, if only by contrast.
To return to the question of the moral nature of animals. The study of the dog alone, both in the light of observations accumulated in the literature which are often true of special individuals in a degree not of the average animal (a fact which does not, however, at all invalidate their force), the study of any dog we may ourselves own, can not but convince us that a sense of right and wrong is possessed by that animal. It may be that the dog does not rise to these conceptions as understood by the learned divine discoursing from the pulpit; but neither does a large proportion of the congregation when transacting the business of the week. It may be, and perhaps is, largely true that the right with the dog means what is in accord with his master's will; that is, the dog may end at the stage in which every child, even the most highly endowed, is found at some period of his development. It is a condition unquestionably in advance, by far, of that of scores of tribes. Moreover, as in the child and the less endowed morally of men, even such ideas of the right are powerfully operative in producing courses of useful conduct. They lead to action on the one hand, and to restraint on the other, instances of which, in the case of the dog, are abundant, and some of them of a most touching, we might almost say ennobling, character. To affirm that the idea of right and wrong of the lower animals does not rise above the hope of reward and the fear of punishment is not to keep to the facts, unless we include as the only reward, in many cases, the master's approbation, and the only punishment his displeasure. When a child arrives at such a stage of feeling, most persons would not be inclined to deny it a moral nature and a very good one, too. We might almost speak of a dog having a religion, with man as his deity. But as a whole host of qualities—some of them difficult to classify—go to make up the character of the human individual so developed and balanced as to deserve the epithet "gentleman," so there are many qualities in the best specimens of the canine race that we can practically appreciate better than define.
In all such discussions it must be borne in mind that if we adopt the theory of organic evolution we are almost bound, of necessity, to a belief in the origin and gradual development of mind from the faintest glimmerings of consciousness, in the simplest protoplasmic creatures; and that system will be most philosophical and complete which can fill up the gaps between the lowest manifestation of any quality and the highest. Hence, many are inclined to believe that the great distinction between man's faculties and those of animals lower in the scale is difference in degree and not in kind, certainly in so far as they run parallel. Such a view does not prevent our conceiving of additional forms of psychic activity not represented in man as the possession of the brutes. That such seems probable will appear when we discuss some of the problems still demanding solution. Nor does such a view imply that there may not be avenues of knowledge of a special kind open to man which are closed to those lower in the scale, such as a special revelation from a higher source. So far as we see, indeed, there are no theological difficulties any more than with evolution as ordinarily applied to animal and plant forms.
Man's present superiority over the lower animals is traceable in large part to his eminently social tendencies, resulting in the division of labor, with its consequent development of special aptitudes and its outcome in the enormous amount of force which he can, on occasion, bring to bear against the various tendencies making for his destruction. Indeed, the isolated individual man is scarcely as well prepared in the struggle for existence as most other animals. But the extent to which animals do continue, it may be in pairs or in larger numbers, to defend themselves against enemies; hunt down prey; rear young; elude enemies; overcome difficulties in travel; work in concert in the preparation of dwellings, and in many other instances, has been but inadequately considered. And in many such cases it is quite impossible to explain these things by that refuge of the unthinking or prejudiced, "instinct." The limits of an address of this kind do not, of course, permit of detailed evidence being adduced for the views maintained. Such evidence is, however, within the observation of all to some extent, and is, so far as the literature is concerned, found in elaborate form in the admirable writings of Romanes and Lindsay more especially. Thus much by way of clearing the ground, of preparing the mind for a careful and earnest study of our fellow-creatures of the lower grades, without prejudice and without fear of any loss of self-respect by the concessions we may be obliged to make.
As to how, so far as the study of comparative psychology itself is concerned, the objects of this society may be best advanced, let me now endeavor to indicate briefly. A great part of the material available is found in literature of very varying reliability. In many cases there is so obvious a prejudice in favor of the particular animals whose performances are described, that very large deductions must be made. We shall do well to be more than cautious in what we accept. At the same time much that can not be regarded as wholly reliable may prove suggestive and serve as the starting-point of investigations. But there is no reason why many points now bearing the character of uncertainty and indefiniteness might not be submitted to the test of experiment. Doubtless not a few supposed facts would vanish into thin air if subjected to such examination. However, I must at the same time state that a careful perusal of the accounts of the experiments of even the most skillful investigators by this method, with its clearly defined but artificially arranged conditions, has convinced me that such do not wholly meet the case. They bear with them the danger of fallacy against which one must constantly be on the watch. It must always be considered that the great question is, not how an animal's mind may act, valuable as that may be, but how it normally does act; that is to say, what are the natural psychic processes of the class of animals under investigation? The same cautions, in drawing conclusions, must be observed in the allied science of physiology, one in which the conditions can be much more accurately regulated. Plainly, it will be desirable to keep our facts very sharply apart from our explanations. The science of psychology is a very youthful one, that of comparative psychology still more so; and, at the present stage of the science, any one who contributes a single fact will be a real friend to their progress. We must endeavor to secure a large number of correspondents who will furnish accurate accounts of phenomena in this realm, of which they have been themselves the observers. We must place all material coming at second-hand by itself, not as worthless, but as calling for special scrutiny. But so long as we have facts only, we have no science; such, indeed, are as the wood and stone for the building, and, unless worked up into scientific form, may prove an incumbrance. Let me, then, briefly indicate some of the problems that have seemed to myself and others as most urgently demanding solution.
One of the questions still far from clear is that which we had under discussion last year, viz.: In how far can the lower animals understand man's various forms of expression, especially his spoken words? A priori, we should not expect that creatures unable to invent words should have the capacity to understand them in the sense in which man himself does. I am inclined to think that more has been claimed for the inferior races of animals in this direction than an exact examination of the subject will warrant. On the other hand, we have probably very much underrated their capacity to comprehend our various forms of unspoken language. The subject calls for close observation. A kindred problem is the degree to which various kinds of animals can communicate with one another. This is a much more difficult subject, and it may prove that the creatures we despise as so very much inferior may have modes of subtile communication which we are, possibly, incapable even of comprehending.
The whole subject of the senses of the lower animals is a field for investigation both by the psychologist and the physiologist; all the more important, as it is scarcely possible to understand one form or degree of sensation adequately, except by comparison with its lower and higher forms. The field is as yet but little tilled, but enough has been done to suggest this very important question: Do the senses of the lower animals and those of man differ only in degree, or also in kind? Is the sense of smell, e. g., in the dog, merely more acute, or is it not also characteristically different? The latter seems the more probable, when we consider how different the hearing of man is in some respects (music) from that of other animals, even the dog.
Among wholly unsolved problems ranks the nature of the mental processes by which many different tribes of animals find their way back to the place from which they have been removed when the distances involved are great, and often when they have never traveled, so much as once the way by which they return.
Akin to this, possibly, though perhaps quite different, is the question as to the nature of the faculties by which animals are enabled to migrate. "How a small and tender bird coming from Africa or Spain, after traversing the sea, finds the very same hedge-row in the middle of England, where it made its nest last season, is truly marvelous" (Darwin). "We are much in need of more facts in regard to the migrations of animals; and it is hoped that the systematic work recently inaugurated by the American Ornithological Association may lead to useful results in this field. With regard to the so-called "homing instinct," it has been noticed that savage or semi-savage man possesses a power of finding his way in the trackless forest by more accurate observation than that of which the civilized man seems capable. While this throws light upon the case of the lower animals, it does but very inadequately explain it. It may turn out that both of these puzzles are susceptible of simple explanation; but at present they strike me as rather belonging to that class of psychic phenomena the meaning of which can be but inadequately understood by man, owing to his not possessing the requisite faculties or those faculties in sufficiently powerful or acute development. The performances of a Shakespeare and Scott in literature, or a Beethoven in music, to the mass of men, must be but imperfectly understood in any proper sense of realisation. Probably these sons of genius could have given little account of the "manner of it" themselves. We might hesitate to call such faculties as the above in the lower animals genius, or to acknowledge any kinship; but genius among men is often as limited and as disassociated with general mental power as are certain marvelous faculties in the lower animals. It may be that migration is accomplished by means of some forms of acute sensation, according to "which the animal acts more or less blindly. Plainly, no mere restless impulse can account for the performance, though it may initiate it. These and many other problems are before us; and, like most recondite problems, they will require the labors of many, each bringing his little for their solution. But is it not worth while? Man can not live by bread alone. We hunger for completeness in our knowledge and harmony in our philosophy. But, apart from this philosophical satisfaction, it can not but prove for the interests both of man and the lower animals that the latter should be better understood.
Belonging, as most of you do, to the veterinary profession, or, as I should prefer to call it, the profession of comparative medicine, either as students or as practitioners and teachers, the more you comprehend the mental workings and modes of expression of your patients, the more successfully must you arrive at an accurate knowledge of their symptoms, and so be the better prepared to relieve the suffering among them, and in so doing also advance man's material interests. To you, at the present time, must we especially look for diffusing more enlightened and humane views, views worthy of this renowned school of comparative medicine, which many of you have come so far to attend. It will be for you to intervene in cases of public panic like that witnessed in connection with the recent hydrophobia scare; reassure the public mind, and protect our fellow-creatures of the lower ranks from needless molestation. There is probably no class of men whose daily life-work gives them so large an opportunity for at the same time acquiring and diffusing truer views in regard to the lower animals. Your enthusiasm and success during the first year of our existence as a society, have been a matter of equal surprise and delight to me, especially considering how fully you are occupied with the ordinary duties of your profession. We hope to enlist the interest of others and bring them into our ranks, to accumulate a library of books bearing on this subject, secure a large number of correspondents from widely separated parts of the continent, and in various other ways stimulate the study which we feel calls for and is worthy of man's earnest attention.[2] I can not close this address without making grateful reference on behalf of this society to the kind manner in which, in many ways. Principal McEachran, and the professors of the Veterinary College, have lent their support to our projects.
- ↑ A presidential address delivered before the Society for the Study of Comparative Psychology.
- ↑ This young society, so far as known, the only one in America for the study of comparative psychology, is composed at present almost entirely of the students and teachers of the School of Comparative (Veterinary) Medicine in Montreal, though its membership is open to all eligible persons. On behalf of the society, the president takes this opportunity of soliciting written accounts of accurate personal observations bearing on the subject, especially on any of the obscure problems treated in this paper.