Animals not only vary in their mental qualities, but they also inherit these variations, just as they do physical properties and peculiarities. Evidence of this is furnished by every new being that comes into the world. Insanity runs in families, and so does genius and criminality. Even the most trifling idiosyncrasies are often transmitted, not only by men, but also by dogs, horses, and other animals. Such qualities of mind as courage, fidelity, good and bad temper, intelligence, timidity, special tastes and aptitudes, are certainly transmitted in all the higher orders of animal life.
Animals are also selected, are enabled to survive in the struggle for life quite as much through the possession by them of certain mental qualities as on account of their physical characters. Whether the selections are made by nature or by man, they are not determined by the physical facts of size, strength, speed, and the like, more than by cunning, courage, sagacity, skill, industry, devotion, ferocity, tractability, and other mental properties. The fittest survive, and the fittest may be the most timid or analytic as well as the most powerful. No better illustration of this truth can be found than that furnished by man himself. Man is by nature a comparatively feeble animal. He is neither large nor powerful. Yet he has been selected to prosper over all other animals because of his ingenuity, sympathy, and art. The great feeling and civilisation of higher men have been built up by slow accretion due to the operation of the law of survival extending over vast measures of time. Creeds and instincts, governments and impulses, forms of thought and forms of expression, have struggled and survived just as have cells and species. A struggle for existence is constantly going on, as Max Müller has pointed out, even among the words and grammatical forms of every language. The better, shorter, easier forms are constantly gaining the ascendancy, and the longer and more cumbrous expressions grow obsolete.
If, therefore, the higher types of mind have not come into existence as have the higher types of structure, through evolution from simpler and more generalised forms, it has not been due to the absence of the factors necessary for bringing about this evolution.
5. The presumption created by the existence of the factors of psychic evolution is strengthened by the facts of artificial selection. We know mind can evolve, for it has done so in many cases. The races of domesticated animals, the races whom man has exploited and preyed upon during the past several thousand years, have, many of them, been completely changed in character and intelligence through human selection. Old instincts have been wiped out and new ones implanted. In many instances the psychology has been not only revolutionised, but remade.
Take, for instance, the dog. The dog is a reformed bandit. It is a revised wolf or jackal. It has been completely transformed by human selection; indeed, it may be said that the dog in the last ten or fifteen thousand years has made greater advances in sagacity and civilisation than any other animal, scarcely even excepting man. Man has made wonderful strides along purely intellectual lines, but in the improvement of his emotions he has not been so successful. The rapid development of the dog in feeling and intelligence has no doubt been due to the fact that his utility to man has always depended largely on his good sense and fidelity, and man has persistently emphasised these qualities in his selection. Fierceness and distrust—two of the most prominent traits in the psychology of the primitive dog—have been entirely eradicated in the higher races of dogs. There is not anywhere on the face of the earth a more trustful, affectionate, and docile being than this one-time cut-throat. Whether the dog has been derived from the wolf or from some wild canine race now extinct, or from several distinct ancestors, he must have had originally a fierce, distrustful, and barbaric nature, for all of the undomesticated members of the dog family wolves, foxes, jackals, etc.—have natures of this sort.
There are about 175 different races of domestic dogs. They represent almost as great a range of development as do the races of men. Some of them are exceedingly primitive, while others are highly intelligent and civilised. The Eskimo dogs are really nothing but wolves that have been trained to the service of man. They look like wolves, and have the wolf psychology. They are not able to bark, like ordinary dogs; they howl like wolves, and their ears stand up straight, like the ears of all wild Canidae. Some of the more advanced of the canine races—like the sheep-dogs, pointers, and St. Bernards—are animals of great sympathy and sensibility. When educated, these dogs are almost human in their impulses and in their powers of discernment. In patience, vigilance, and devotion to duty, they are superior to many men. At a word, or even a look, from its master, the loyal collie will gather the sheep scattered for miles around to the place designated, and do it with such tact and expedition as to command admiration. It has been said that if it were not for this faithful and competent canine the highlands of Scotland would be almost useless for sheep-raising purposes, because of the greater expense that would be entailed if men were employed. One collie will do the work of several men, and will do it better, and the generous-hearted creature pours out its services like water. It requires no compensation except table refuse and a straw bed. In South America sheep-dogs are trained to act as shepherds and assume the whole responsibility of tending the flock. ‘It is a common thing,’ says Darwin, ‘to meet a large flock of sheep guarded by one or two dogs, at a distance of some miles from any house or man.’ When the dogs get hungry, they come home for food, but immediately return to the flock on being fed. ‘It is amusing,’ remarks this writer, ‘to observe, when approaching a flock, how the dog immediately advances barking, while the sheep all close in his rear as around the oldest ram.’ Romanes relates an incident which well illustrates the high character and intelligence of the dog and its wonderful devotion to a trust. ‘It was a Scotch collie. Her master was in the habit of consigning sheep to her charge without supervision. On this particular occasion he remained behind or proceeded by another road. On arriving at home late in the evening, he was astonished to learn that his faithful animal had not made her appearance with the drove. He immediately set out in search of her. But on going out into the streets, there she was coming with the drove, not one missing, and, marvellous to relate, she was carrying a young puppy in her mouth. She had been taken in travail on the hills, and how the poor creature had contrived to manage her drove in her condition is beyond human calculation, for her road lay through sheep all the way. Her master’s heart smote him when he saw what she had suffered and effected. But she was nothing daunted, and after depositing her young one in a place of safety she again set out full speed for the hills, and brought another and another, till she brought the whole litter, one by one; but the last one was dead’.[1a]
What a wonderful transformation in canine character! The very beings whose blood the dog once drank with ravenous thirst it now protects with courage and fidelity. And this transformation in character is not due to education simply. It is innate. Young dogs brought from Tierra del Fuego or Australia, where the natives do not keep such domestic animals as sheep, pigs, and poultry, invariably have an incurable propensity for attacking these animals.
The feeling of ownership possessed by so many dogs is an entirely new element in canine character, a trait implanted wholly by human selection. Bold and confident on his own premises, the dog immediately becomes weak and apologetic when placed in circumstances in which he feels he has no rights.
The pointers and setters have been developed as distinct breeds by human selection during the past 150 or 200 years.
What is true of the dog is true also, to a large extent, of the cat, cow, horse, sheep, goat, fowl, and other domestic animals. Serene and peaceful puss is the tranquillised descendant of the wild cat of Egypt, one of the most untamable of all animals. The migratory instinct, so strong in wild water-fowl, is almost absent from our geese and ducks, as is the fighting propensity (prominent in the Indian jungle-bird) from most varieties of the domesticated chicken. There are now as many as a hundred different kinds of domesticated animals, and there is scarcely one of these animals that has not been profoundly changed in character during the period of its domestication. There are much greater changes in some races than in others. Some races have been much longer in captivity than others. And then, too, there is great difference in the degree of plasticity in different races, the races of ancient origin being much more fixed in their psychology than those of more recent beginnings. In some races, too—as in the sheep—the selections made by man have been made primarily with reference to certain physical qualities, and in these cases the mental qualities have been only incidentally affected. In Polynesia, where it is selected for its flavour instead of for its fleetness or intelligence, the dog is said to be a very stupid animal. But in most cases of domestication the changes wrought by selection in the mental make-up of the race have been fully as great as the changes in body, and in some instances much greater. And the process by which these great changes in psychology have been effected is in principle identically the same as that by which mental evolution in general is assumed to have been brought about.