This theory has much to commend it. It certainly meets the objection to the reflex theory which was stated just above--the objection that some of the instincts could not have arisen by gradual reflex adaptations. It also accounts for the extremely intelligent appearance which many instincts have.

But this view in turn is liable to a criticism which has grown in force with the progress of biological knowledge in recent years. This criticism is based on the fact that the theory of lapsed intelligence demands that the actions which the animals of one generation have acquired by their intelligence should be handed down through heredity to the next generation, and so on. It is evident that unless this be true it does no good to the species for one generation to do things intelligently, seeing that if the effects on the nervous system are not transmitted to their children, then the next and later generations will have to start exactly where their fathers did, and the actions in question will never become ingrained in the nervous system at all.

Now, the force of this criticism is overwhelming to those who believe--as the great majority of biologists now do[1]--that none of the modifications or so-called "characters" acquired by the parents, none of the effects of use or disuse of their limbs, none of the tendencies or habits of action, in short, none of the changes wrought in body or mind of the parents during their lifetime, are inherited by their children. The only sorts of modification which show themselves in subsequent generations are the deep-seated effects of disease, poison, starvation, and other causes which concern the system as a whole, but which show no tendency to reproduce by heredity any of the special actions or functions which the fathers and mothers may have learned and practised. If this difficulty could be met, the theory that intelligence has been at work in the origination of the complex instincts would be altogether the preferable one of the two; but if not, then the "lapsed intelligence" view must be thrown overboard.

[Footnote 1: The matter is still under discussion, however, and I do not mean in any way to deny the authority of those who still accept the "inheritance of acquired characters."]

Recent discussion of evolution has brought out a point of view under the name of Organic Selection which has a very fruitful application to this controversy over the origin of instincts. This point of view is one which in a measure reconciles the two theories. It claims that it is possible for the intelligent adaptations, or any sort of "accommodations," made by the individuals of one generation, to set the direction of subsequent evolution, even though there be no direct inheritance of acquired characters from father to son. It proceeds in the case of instinct somewhat thus:

Suppose we say, with the first theory given above, that the organism has certain reflexes which show some degree of adaptation to the environment; then suppose we admit the point, urged by the advocates of the lapsed intelligence theory, that the gradual improvement of these reflexes by variations in the endowment of successive generations would not suffice for the origin of instinct, seeing that partial instincts would not be useful; and, further, suppose we agree that many of the complex instincts really involved intelligent adaptation in their acquisition. These points carefully understood, then one new and further principle will enable us to complete a theory which will avoid the objections to both the others. This principle is nothing else than what we have seen already--namely, that the intelligence supplements the partial instincts in each generation and makes them useful in the respects in which they are inadequate, and so keeps the young alive in successive generations as long as the instinct is imperfect. This gives the species time gradually to supplement its instinctive endowment, in the course of many generations each of which uses its intelligence in the same way: time to acc.u.mulate, by the occurrence of variations among the offspring, the changes in the nervous system which the perfect instinct requires.

Thus as time goes on the dependence of each generation upon the aid of intelligence is less and less, until the nervous system becomes capable of performing the function quite alone. The result then will be the same as if the acquisitions made by each generation had been inherited, while in reality they have not. All that this theory requires in addition to what is admitted by both the historical views is that the species be kept alive long enough by the aid of its intelligence, which supplements imperfect instincts, to give it time to produce sufficient variations in the right direction. The instinct then achieves its independence, and intelligent supervision of it is no longer necessary (see Fig. 1).

[Ill.u.s.tration: FIG. 1,--Origin of instinct by Organic Selection: _A n_, perfect instinct. 1, 2 ... _n_, successive generations. Solid lines, nervous equipment in the direction of the instinct. Dotted lines, intelligence supplementing the nervous equipment. The intelligence is relied upon to keep the species alive until by congenital variations the nervous equipment becomes "perfect."]

This theory is directly confirmed by the facts, already spoken of, which show that many instincts are imperfect, but are pieced out and made effective by the intelligent imitations and acquisitions of the young creatures. The little chick, for example, does not know the value of water when he sees it, as essential as water is to his life; but he depends upon imitation of his mother's drinking, or upon the mere accident of wetting his bill, to stimulate his partial instinct of drinking in the peculiar fashion characteristic of fowls, by throwing back the head. So in other functions which are peculiar to a species and upon which their very lives depend, we find the delicate adjustment between intelligent adaptation by conscious action and the partially formed instincts which the creatures possess.

In the theory of Organic Selection, therefore, we seem to have a positive solution of the question of the origin of instinct. It is capable of a similar application in other cases where evolution has taken certain definite directions, seemingly guided by intelligence.

It shows us that mind has had a positive place in the evolution of organic nature.

_Animal Intelligence._--Coming to consider what further equipment the animals have, we light upon the fact just spoken of when we found it necessary to appeal in some measure to the animal's Intelligence to supplement his instincts. What is meant by Intelligence?

This word may be used in the broad sense of denoting all use of consciousness, or mind, considered as a thing in some way additional to the reflexes of the nervous system. In the life of the animal, as in that of man, wherever we find the individual doing anything with reference to a mental picture, using knowledge or experience in any form, then he is said to be acting intelligently.

The simplest form of intelligent action in the animal world and that from which most of the higher forms have arisen is ill.u.s.trated in the following example: a chick will peck at a strange worm, and, finding it unpalatable, will then in the future refuse to peck at worms of that sort. This refusal to do a second time what has once had a disagreeable result is intelligent. We now say that the chick "knows"

that the worm is not good to eat. The instinctive action of pecking at all worms is replaced by a refusal to peck at certain worms. Again, taking the reverse case, we find that the chick which did not respond to the sight of drinking water instinctively, but had to see the mother drink first, acted intelligently, or through a state of consciousness, when it imitated the old hen, and afterward drank of its own accord. It now "knows" that water is the thing to drink.

The further question which comes upon us here concerns the animal's acquisition of the action appropriate to carry out his knowledge. How does he learn the muscular combinations which supplement or replace the earlier instinctive ways of acting?

This question appears very clearly when we ask about the child's acquisition of new acts of skill. We find him constantly learning, modifying his habits, refining his ways of doing things, becoming possessed of quite new and complex functions, such as speech, handwriting, etc. All these are intelligent activities; they are learned very gradually and with much effort and pains. It is one of the most important and interesting questions of all psychology to ask how he manages to bring the nervous and muscular systems under greater and greater control by his mind. How can he modify and gradually improve his "reactions"--as we call his responses to the things and situations about him--so as to act more and more intelligently?

The answer seems to be that he proceeds by what has been called Experimenting. He does not simply do things because he has intelligence,--simply that is, because he sees how to do them without first learning how; that is the older and probably quite erroneous view of intelligence. The mind can not move the body simply by its fiat. No man can do that. Man, like the little animal, has to try things and keep on trying things, in order to find out the way they work and what their possibilities are. And each animal, man, beast, or bird has to do it for himself. Apart from the instinctive actions which the child does without knowing their value at all, and apart from the equally instinctive imitative way of doing them without aiming at learning more by the imitations, he proceeds in all cases to make experiments. Generally his experiments work through acts of imitation. He imitates what he sees some other creature do; or he imitates his own instinctive actions by setting up before him in his mind the memories of the earlier performance; or, yet again, after he has struck a fortunate combination, he repeats that imitatively. Thus, by the principle already spoken of, he stores up a great ma.s.s of Kinaesthetic Equivalents, which linger in memory, and enable him to act appropriately when the proper circ.u.mstances come in his way. He also gets what we have called a.s.sociations established between the acts and the pleasure or pain which they give, and so avoids the painful and repeats the pleasurable ones.

The most fruitful field of this sort of imitative learning is in connection with the "try-try-again" struggles of the young, especially children. This is called Persistent Imitation. The child sees before him some action to imitate--some complex act of manipulation with the hand, let us say. He tries to perform it in an experimental way, using the muscles of the hand and arm. With this he strains himself all over, twisting his tongue, bending his body, and grimacing from head to foot, so to speak. Thus he gets a certain way toward the correct result, but very crudely and inexactly. Then he tries again, proceeding now on the knowledge which the first effort gave him; and his trial is less uncouth because he now suppresses some of the hindering grimacing movements and retains the ones which he sees to be most nearly correct. Again he tries, and again, persistently but gradually reducing the blundering movements to the pattern of the copy, and so learning to perform the act of skill.

The ma.s.sive and diffused movements which he makes by wriggling and fussing are also of direct use to him. They increase remarkably the chances that among them all there will be some movements which will hit the mark, and so contribute to his stock of correct Equivalents.

Dogs and monkeys learn to unlock doors, let down fence rails, and perform relatively complex actions by experimenting; persistently with many varied movements until the successful ones are finally struck.

This is the type of all those acts of experimenting by which new complex movements are acquired. In children it proceeds largely without interference from others; the child persists of himself. He has greater ability than the animals to see the meaning of the completed act and to really desire to acquire it. With the animals the acquisitions do not extend very far, on account of their limitation in intelligent endowment; but in the training of the domestic animals and in the education of show-animals the trainer aids them and urges them on by making use of the a.s.sociations of pleasure and pain spoken of above. He supplements the animal's feelings of pain and pleasure with the whip and with rewards of food, etc., so that each step of the animal's success or failure has acute a.s.sociations with pain or pleasure. Thus the animal gradually gets a number of a.s.sociations formed, avoids the actions with which pain is a.s.sociated, repeats those which call up memories of pleasure all the way through an extended performance in regular steps; and in the result the performance so closely counterfeits the operations of high intelligence--such as counting, drawing cards, etc.--that the audience is excited to admiration.

This first glimpse of the animal's limitations when compared with man may suggest the general question, how far the brutes go in their intelligent endowment. The proper treatment of this much-debated point requires certain further explanations.

In the child we find a tendency to act in certain ways toward all objects, events, etc., which are in any respect alike. After learning to use the hands, for example, for a certain act, the same hand movements are afterward used for other similar acts which the child finds it well to perform. He thus tends, as psychologists say, to "generalize," that is, to take up certain general att.i.tudes which will answer for a great many details of experience. On the side of the reception of his items of knowledge this was called a.s.similation, as will be remembered. This saves him enormous trouble and risk; for as soon as an object or situation presents itself before him with certain general aspects, he can at once take up the att.i.tude appropriate to these general aspects without waiting to learn the particular features of the new. The ability to do this shows itself in two rather different ways which seem respectively to characterize man on the one hand and the lower animals on the other.

With the animals this tendency to generalize, to treat objects in cla.s.ses rather than as individuals, takes the form of a sort of composition or direct union of brain pathways. Different experiences are had, and then because they are alike they tend to issue in the same channels of action. The animal is tied down strictly to his experience; he does not antic.i.p.ate to any extent what is going to happen. He does not use one experience as a symbol and apply it beforehand to other things and events. He is in a sense pa.s.sive; stimulations rain down upon him, and force him into certain att.i.tudes and ways of action. As far as his knowledge is "general" it is called a Recept. A dog has a Recept of the whip; so far as whips are not too different from one another, the dog will act in the same way toward all of them. In man, on the other hand, the development of mind has gone a decided step further. The child very quickly begins to use symbols, words being the symbols of first importance to him. He does not have, like the brute, to wait for successive experiences of like objects to impress themselves upon him; but he goes out toward the new, expecting it to be like the old, and so acting as to antic.i.p.ate it. He thus falls naturally into general ways of acting which it is the function of experience to refine and distinguish. He seems to have more of the higher sort of what was called above Apperception, as opposed to the more concrete and accidental a.s.sociations of Ideas. He gets Concepts, as opposed to the Recepts of the animals. With this goes the development of speech, which some psychologists consider the source of all the man's superiority over the animals. Words become symbols of a highly abstract sort for certain cla.s.ses of experiences; and, moreover, through speech a means of social communication is afforded by which the development of the individual is enormously advanced.

It is probable, in fact, that this difference--that between the Generalization which uses symbols, and mere a.s.sociation--is the root of all the differences that follow later on, and give man the magnificent advantage over the animals which he has. From it is developed the faculty of thinking, reasoning, etc., in which man stands practically alone. On the brain side, it requires special developments both through the preparation of certain brain centres given over to the speech function, and also through the greater organization of the gray matter of the cerebral cortex, to which we revert again in a later chapter. Indeed, looked at from the side of the development of the brain, we see that there is no break between man and the animals in the laws of organization, but that the difference is one of evolution.

Later on in the life of the child we find another contrast connected with the difference of social life and organization as between the animals and man. The animals probably do not have a highly organized sense of Self as man does; and the reason doubtless is that such a Self-consciousness is the outcome of life and experience in the very complex social relations in which the human child is brought up, and which he alone is fitted by his inherited gifts to sustain.

_The Play of Animals._--Another of the most interesting questions of animal life is that which concerns their plays. Most animals are given to play. Indeed that they indulge in a remarkable variety of sports is well known even to the novice in the study of their habits. Beginning when very young, they gambol, tussle, leap, and run together, chase one another, play with inanimate objects, as the kitten with the ball, join in the games of children and adults, as the dog which plays hide and seek with his little master, and all with a knowingness and zest which makes them the best of companions. The volumes devoted to the subject give full accounts of these plays of animals, and we need not repeat them; the psychologist is interested, however, mainly in the general function of play in the life of the individual animal and child, and in the psychological states and motives which it reveals.

Play, whether in animals or in man, shows certain general characteristics which we may briefly consider.

1. The plays of animals are very largely instinctive, being indulged in for the most part without instruction. The kitten leaps impulsively to the game. Little dogs romp untaught, and fall, as do other animals also, when they are strong enough, into all the playful att.i.tudes which mark their kind. This is seen strikingly among adult animals in what are called the courtship plays. The birds, for example, indulge in elaborate and beautiful evolutions of a playful sort at the mating season.

2. It follows from their instinctive character that animal plays are peculiar to the species which perform them. We find series of sports peculiar to dogs, others to cats, and so on through all the species of the zoological garden, whether the creatures be wild or tame. Each shows its species as clearly by its sportive habits as by its shape, cry, or any other of what are called its "specific" habits. This is important not only to the zoologist, as indicating differences of evolution and scale of attainment, environment, etc., but also to the psychologist, as indicating differences of what we may call animal temperament. Animals show not only the individual differences which human beings do, one liking this game and another that, one being leader in the sport and another the follower, but also the greater differences which characterize races. The Spaniards love the bull fight; other nations consider it repulsive, and take their fun in less brutal forms, although, perchance, they tolerate Rugby football! So the animals vary in their tastes, some playing incessantly at fighting, and so zealously as to injure one another, while others like the milder romp, and the game with flying leaves, rolling stones, or the incoming waves on the sh.o.r.e.

3. Psychologically, the most interesting characteristic of animal, as of human, play is what is called the "make-believe" state of mind which enters into it. If we consider our own sports we find that, in the midst of the game, we are in a condition of divided consciousness.

We indulge in the scheme of play, whatever it be, as if it were a real situation, at the same time preserving our sense that it is not real.

That is, we distinguish through it all the actual realities, but make the convention with our companions that for the time we will act together as if the playful situation were real. With it there is a sense that it is a matter of voluntary indulgence that can stop at anytime; that the whole temporary illusion to which we submit is strictly our own doing, a job which we have "put up" on ourselves.

That is what is meant by make-believe.

Now it is clear that the animals have this sense of make-believe in their games both with other animals and with man. The dog plays at biting the hand of his master, and actually takes the member between his teeth and mumbles it; but all the while he stops short of painful pressure, and goes through a series of characteristic att.i.tudes which show that he distinguishes very clearly between this play biting and the real. If perchance the master shows signs of being hurt, the dog falls into att.i.tudes of sorrow, and apologizes fulsomely. So also when the animals play together, a vigorous squeal from a companion who is "under" generally brings him his release.

The princ.i.p.al interest of this make-believe consciousness is that it is considered by many to be an essential ingredient of aesthetic feeling. A work of art is said to have its effect through its tendency to arouse in us a make-believe acceptance of the scene or motive presented, while it nevertheless remains contrasted with the realities of our lives. If this be true, the interesting question arises how far the animals also have the germs of aesthetic feeling in their make-believe situations. Does the female pea-fowl consider the male bird, with all his display of colour and movement, a beautiful object?

And does the animal companion say: How beautiful! when his friend in the sport makes a fine feint, and comes up serene with the knowing look, which the human on-looker can not fail to understand?

In some cases, at any rate, we should have to reply to this question affirmatively, if we considered make-believe the essential thing in aesthetic enjoyment.

_Theories of Animal Play._--The question of the meaning and value of play to the animals has had very enlightening discussion of late.

There are two princ.i.p.al theories now advocated.

I. The older theory considered play simply the discharge of surplus nerve force in the animal's organism. He was supposed to play when he felt fresh and vigorous. The horse is "skittish" and playful in the morning, not so much so at night. The dogs lie down and rest when they are tired, having used up their surplus energies. This is called the Surplus-Energy Theory of play.

The difficulty with this theory is that it is not adequate to explain any of the characteristics of play which have been given above. Why should play be instinctive in its forms, showing certain complex and ingrained channels of expression, if it were merely the discharge of surplus force? We are more lively in the morning, but that does not explain our liking and indulging in certain sorts of complex games at all hours. Moreover, animals and children will continue to play when greatly fatigued. A dog, for example, which seems absolutely "used up," can not resist the renewed solicitations of his friends to continue the chase. Furthermore, why is it that plays are characteristic of species, different kinds of animals having plays quite peculiar to themselves? It is difficult to see how this could have come about unless there had been some deeper-going reason in accordance with which each species has learned the particular forms of sport in which it indulges.

The advocates of this theory attempt to meet these objections by saying that the imitative instinct accounts for the particular directions in which the discharges of energy occur. A kitten's plays are like those of the cat tribe because the kitten is accustomed to imitate cats; when it falls to playing it is with cats, and so it sheds its superfluous energies in the customary imitative channels. In this way it grows to learn the games of its own species. There is a good deal in this point; most games are imitative in so far as they are learned at all. But it does not save the theory; for many animal plays are not learned by the individual at all, as we have seen above; on the contrary, they are instinctive. In these cases the animal does not wait to learn the games of his tribe by imitation, but starts-right-in on his own account. Besides this there are many forms of animal play which are not imitative at all. In these the animals co-operate, but do not take the same parts. The young perform actions in the game which the mother does not.

All this goes to support another and most serious objection to this theory--in the mind of all those who believe in the doctrine of evolution. The Surplus-Energy Theory considers the play-impulse, which is one of the most widespread characters of animal life, as merely an accidental thing or by-product--a mere using-up of surplus energies.

It is not in any way important to the animals. This makes it impossible to say that play has come to be the very complex thing that it really is by the laws of evolution; for survival by natural selection always supposes that the attribute or character which survives is important enough to keep the animal alive in the struggle for existence; otherwise it would not be continued for successive generations, and gradually perfected on account of its utility.

On the whole, therefore, we find the Surplus-Energy Theory of play quite inadequate.

II. Another theory therefore becomes necessary if we are to meet these difficulties. Such a theory has recently been developed. It holds that the plays of the animals are of the greatest utility to them in this way: they exercise the young animals in the very activities--though in a playful way--in which they must seriously engage later on in life. A survey of the plays of animals with a view to comparing them in each case with the adult activities of the same species, confirms this theory in a remarkably large number of cases. It shows the young antic.i.p.ating, in their play, the struggles, enjoyments, co-operations, defeats, emergencies, etc., of their after lives, and by learning to cope with all these situations, so preparing themselves for the serious onset of adult responsibilities. On this theory each play becomes a beautiful case of adaptation to nature. The kitten plays with the ball as the old cat handles the mouse; the little dogs wrestle together, and so learn to fight with teeth and claws; the deer run from one another, and so test their speed and learn to escape their enemies. If we watch young animals at play we see that not a muscle or nerve escapes this preliminary training and exercise; and the instinctive tendencies which control the play direct the activities into just the performances which the animal's later life-habits are going on to require.

On this view play becomes of the utmost utility. It is not a by-product, but an essential part of the animal's equipment. Just as the infancy period has been lengthened in the higher animals in order to give the young time to learn all that they require to meet the harsh conditions of life, so during this infancy period they have in the play-instinct a means of the first importance for making good use of their time. It is beautiful to see the adults playing with their young, adapting their strength to the little ones, repeating the same exercises without ceasing, drilling them with infinite pains to greater hardihood, endurance, and skill.

On this theory it is also easy to see why it is that the plays are different for the different species. The actual life conditions are different, and the habits of the species are correspondingly different. So it is only another argument for the truth of this theory that we find just those games natural to the young which train them in the habits natural to the old.

This view is now being very generally adopted. Many fine ill.u.s.trations might be cited. A simple case may be seen in so small a thing as the habit of leaping in play; the difference, for example, between the mountain goat and the common fawn. The former, when playing on level ground makes a very ludicrous exhibition by jumping in little up-and-down leaps by which he makes no progress. In contrast with this the fawn, whose adult life is normally in the plains, takes a long graceful spring. The difference becomes clear from the point of view of this theory, when we remember that the goat is to live among the rocks, where the only useful jump is just the up-and-down sort which the little fellow is now practising; while the deer, in his life upon the plains, will always need the running jump.

Finally, on this theory, play becomes a thing for evolution to cultivate for its utility in the progress of animal life, and for that reason we may suppose it has been perfected in the remarkable variety and beauty of form which it shows.

On the psychological side, we find a corresponding state of things.

The mind in the young animal or child gets the main education of early life through its play situations. Games have an extraordinary pedagogical influence. The more so because they are the natural and instinctive way of getting an education in practical things. This again is of supreme utility to the individuals.

Both for body and mind we find that play ill.u.s.trates the principle of Organic Selection explained above. It makes the young animal flexible, plastic, and adaptable; it supplements all his other instincts and imperfect functions; it gives him a new chance to live, and so determines the course of evolution in the direction which the playful animal represents. The quasi-social and gregarious habits of animals probably owe much of their strength to the play-impulse, both through the training of individual animals and through the fixing of these tendencies as instincts in various animal species in the way just mentioned.