Many animals show that they possess a rudimentary sense of humour by the pranks and tricks which they play on each other and on human beings. The monkey is the prince of nonhuman jokers, but dogs, cats, horses, elephants, and other animals have enough of this sense to have books written about it. A monkey has been observed to slyly pass his hand back of a second monkey and tweak the tail of a third one, and then composedly enjoy himself while the resentment of the injured monkey expended itself on the innocent middle one. Many monkeys enjoy entertaining their friends with grimaces, by carrying a cane, putting a tin dish on their heads, or other droll antics. These intelligent animals have a sufficiently high appreciation of the ludicrous to dislike ridicule. Like human beings, they can’t endure being laughed at, and get mad if they are made the victims of a joke. Romanes’ monkey was one day asked to crack a nut for the amusement of a visitor. The nut turned out to be a bad one, and the melancholy look of disappointment on the monkey’s face caused the visitor to laugh. The insulted monkey flew into a rage, and hurled the nut at the offending scoffer, then the hammer, and finally the coffee-pot which simmered on the grate fire.[1c] Darwin tells of a baboon in the Zoological Gardens of London who always became infuriated every time his keeper took out a letter or book and read aloud to him. On one occasion when Darwin was present the baboon became so furious that he bit his own leg until it bled.[4b]
The emotion variously known as shame, regret, repentance, and remorse, is not common among the non-human races. It is found sometimes in dogs and monkeys, and especially in educated anthropoids. But this emotion is exceedingly rare among savages, and is not at all universal even among civilised societies of men. Some animals manifest self-restraint, which is an exceedingly elite quality of mind, and one not so common as it might be even among the higher breeds of mankind. By restraint is meant the inhibition of a desire or instinct in the presence of circumstances tending to render the desire or instinct active—and this is obedience, and the beginning of morality. A dog that will not chase a hare in the presence of his master may do so in his absence. I taught my guinea-pigs to abstain from certain food in their presence which they wanted very much, and which they would have eaten if they had not been educated to let it alone. Sympathy is the most beautiful of all terrestrial emotions. It is manifested, sometimes to an exceedingly touching degree, by all the highest races of animals. No other instances than those already given can be mentioned here. It is sufficient to say that the difference between the savage—whose sympathies are so feeble that he has been known to knock his own child’s brains out for dropping a basket, and who puts his aged parents to death in order to avoid the burden of maintaining them, and whose sympathies seldom extend beyond his family or tribe—and civilised men and women, who feel actual pain when in the presence of those who suffer, and whose sympathies sometimes include all sentient creation, is much greater than that between the savage and many nonhuman animals. The frail, narrow, fantastic character of human sympathy is the most mournful fact in human nature. ‘Man’s inhumanity to man makes countless thousands mourn,’ and his inhumanity to not-men makes the planet a ball of pain and terror.
Volition is the power of the mind to act executively. Or, perhaps, it is the resultant of the impulses actuating a mind at any particular instant. Whatever volition is, it is the same thing in the insect as in the man. Non-human beings have been observed to pause and deliberate and to make wise and momentous decisions in the twinkling of an eye. A chased hare will decide to squat, to go straight ahead, or to do something else which the emergency demands, just as unmistakably as a human fugitive. In the sense of being the power to act differently from the manner in which a being actually does act, there is no such thing as freewill. The will of the worm is just as free as the will of the judge—not in the sense that it is as varied in the directions of its activity, but in the sense that the character of its activities is determined inevitably by the character of its antecedents. All will, whether human or non-human, invariably acts in the direction of the strongest motive, just as a stone or a river invariably moves, if it moves at all, in the direction of the strongest tendency or force. It is impossible that this should be otherwise. For, if the will in any case elects to overthrow this fact by arbitrarily discarding a stronger motive for a feebler, in the very motive of the election are concealed elements which transform the feebler motive into the stronger. All motion, voluntary and involuntary—the motion of bullets, beings, societies, and suns—takes place along the lines of least arrest. Every being is compelled to decide as he does decide and to act as he does act by the inherited tendencies of his own nature and the tendencies of the environment in which he exists. And if any being, after having passed through life, were again placed back at the beginning of life and endowed with the same nature as before, and were acted upon through life by surroundings identical with those he had previously met, he would act—that is, he would exercise his will—in precisely the same way in every particular as he had previously done. To deny these things is to assert that the conduct of living beings is without law, and that psychology and sociology are not sciences.
Non-human beings, all of the higher ones, have the same brain and nervous apparatus as man, and in their involuntary phenomena they closely resemble human beings. Aim a pretended blow near the eyes of a dog or a horse and it will wink involuntarily, just as a human being does. Sever the spinal cord of a man or a frog, and irritate the feet of each, and they will each manifest the same phenomena of reflex action, drawing their feet away each time from the stimulus.
Instinct and reason are forms of intelligence. Intelligence is the adaptation of acts to ends. Intelligence is manifested by all organisms, both plants and animals, and may be either conscious or unconscious. Plant intelligence and reflex action are forms of unconscious intelligence. Plant intelligence, or the adaptation of acts to ends by plants, is manifested by plants in the shifting of their positions when in need of light in order to obtain as large a supply as possible of the essential sunshine; in devices, such as traps and flowers, for utilising the juices and services of insects; in germinating and growing away from, instead of toward, the centre of the earth; in discriminating between this and that kind of food; and in a thousand other ways. Plant intelligence is all explicable in terms of chemistry and physics, and is, so far as is known, unaccompanied by consciousness. Reflex action is chemical affinity aided by the co-ordinating powers of nerve tissue. The vital processes of all animals, from the lowest to the highest, and many other highly habitual and highly essential operations, are carried on by reflex action. Reflex action in animals, like plant intelligence, is unconscious.
Instinct and reason are conscious. Instinct is inherited intelligence—intelligence manifested independently of, and prior to, experience and instruction. ‘Instinct,’ says Romanes, ‘is reflex action into which has been imported the element of consciousness’.[5a] It is exhibited by the babe when it nurses the mother’s breast; by the chick when it pecks its way out through the shell of the egg; by animals generally, including man, in their solicitude for their young; by the parent bird in incubation; and by all beings when they seek food in obedience to the impulse of hunger. Our conception of the mental processes of non-humans is as yet very primitive, owing to our limited means of information and the erroneous influence on our judgments of traditional ways of thinking; and much that is attributed by us to instinct is not instinct at all, but is acquired by the young through education imparted by the elders. Parent birds have often been seen teaching their young ones to fly, and no doubt a good deal of the migratory acumen manifested by birds is nothing but custom and tradition handed down to each younger generation by the old and experienced. A large part of the knowledge of mankind (or what passes for knowledge) consists of habits and hobbies, customs and traditions, impressed upon each new generation by the generation which produced it. Each generation of men seems to feel that whenever it creates a new generation it has got to pile on to this new generation all of the fool notions which have been acquired from the past, amplified by its own inventions. And when we come to know other animals better, there is practically no doubt that we shall find that a large part of what we now call instinct and look upon as congenital will, on closer and more rational examination, be found to be nothing but the pedagogical effects of early environment. Professor Poulton, of Oxford, who has made many experiments on just-born birds, says that young chicks learn to fear the hawk and to interpret the oral warnings of the mother. Cats teach their young to play with their prey in that cruel manner so characteristic of all the Felidae, as I have myself observed more than once. A mother cat will carry a live mouse into the presence of her kittens and lie down and play with it, tossing it playfully into the air, poking it with her paw when it does not move, and arresting it when it starts to run away, the kittens all the time looking on, but never once attempting to take the mouse. After awhile the mother hands the captive over to the kittens, who go through the same performance one after another. After they have practised on it until the unfortunate creature is almost dead, the old cat will probably walk over to where the mouse is and eat it up. The whole thing is a school. The mouse is obviously not intended as food for the young, but to be used simply to impart instruction to them.
‘In popular writings and lectures some or all of the following activities of ant-life are commonly ascribed to instinct: The recognition of members of the same nest; powers of communication; keeping aphides for the sake of their sweet secretions; collection of aphid eggs in October, hatching them out in the nest, and taking them in the spring to the daisies on which they feed, for pasture; slave-making and slave-keeping, which, in some cases, is so ancient a habit that the enslavers are unable even to feed themselves; keeping insects as beasts of burden—e.g. a kind of plant-bug to carry leaves; keeping beetles, etc., as domestic pets; habits of personal cleanliness—one ant giving another a brush-up, and being, brushed up in return; habits of play and recreation; habits of burying their dead; the storage of grain and nipping the budding rootlet to prevent further germination; the habit of Texan ants of preparing a clearing around their nest, and, six months later, harvesting the ant-rice—a kind of grass of which they are particularly fond—even seeking and sowing the grain which shall yield the harvest; the collection by other ants of grass to manure the soil, on which there grows a species of fungus upon which they feed; the military organisation of the ecitons of Central America; and so forth. But to class all of these activities of the ant as illustrations of instinct is a survival of an old-fashioned method of treatment.
‘Suppose that the intelligent ant were to make observations on human behaviour as displayed in one of our great cities or in an agricultural district. Seeing so great an amount of routine work going on around him, might he not be in danger of regarding all this as evidence of hereditary instinct? Might he not find it difficult to obtain satisfactory evidence of the fact that this routine work has to some extent to be learned? Might he not say (perhaps not wholly without truth), “I can see nothing whatever in the training of these beings to fit them for their life-work. The training of their children has no more apparent bearing upon the activities of their after-life than the feeding of our grubs has on the duties of ant-life. They seem to fall into the routine of life with little or no preparatory training as the periods for the manifestation of the various instincts arrive. If learning thereof there be, it has so far escaped our observation. And such intelligence as their activities evince (and many of them do show remarkable adaptations to uniform conditions of life) would seem to be rather ancestral than of the present time, as is shown by the fact that many of the adaptations are directed rather to past conditions of life than to those which now hold good. In the presence of new emergencies to which their instincts have not fitted them, these poor creatures are often completely at a loss. We cannot but conclude, therefore, that, although acting under somewhat different and less favourable conditions, instinct occupies fully as large a space in the psychology of man as it does in that of the ant, while human intelligence is far less unerring and hence markedly inferior to our own.”
‘Are these views much more absurd than the views of those who, on the evidence which we at present possess, attribute all the activities of ant-life to instinct?’[6]
Reason is the power of adapting means to ends which is acquired from experience or instruction. All animals that profit by experience, therefore, or that learn from instruction—that is, are teachable—exercise reason.