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 illustrated 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 mass of Kinæsthetic Equivalents, which linger in memory, and enable him to act appropriately when the proper circumstances come in his way. He also gets what we have called Associations established between the acts and the pleasure or pain which they give, and so avoids the painful and repeats the pleasurable ones.