The general bearing of these facts is obvious. Play, as a means of animal education, is varied, and has for its end all-round training of the animal mind in its sphere of operation. Although there are some specific propensities, certain observable trends of behaviour, as in hunting-play, courtship-play, and the like, we must not expect, nor do we find, anything like stereotyped definiteness of conative activity. We find that freedom and elasticity in animal education which is, perhaps, more often advocated than carried into practice in human education.
The second point arising out of the examination analogy is, that its range determines the level of preparation therefor. It is, for animals, a practical examination, not a theoretical. Not a single question is set demanding an explanation. The problems are such as can be solved by intelligence, not such as require the exercise of reason, as we have used the term in foregoing pages. These higher problems are only set when the sixth form is reached, and there is no conclusive evidence that any animals get into the sixth. This, however, is entirely a question of evidence, and many of us will be glad to welcome them there, if proved ability to deal reflectively with ideational questions justifies their promotion.
If any of them do belong to this form, they have probably got there through play. For in the stress of the actual examination there is not much time for reflection. Or perhaps we may rather say that, not in actual struggle, and not in active preparation for it in play-time, but in intervals of leisure between both, when the animal lies quietly turning over in his mind we know not what, will experience be reviewed, and generalizations drawn as to the why of events in this strange world. Probably the animal accepts things as they are, and does not trouble about their explanation. But it may not be so. At any rate, if animals lack the means of descriptive inter-communication, and have no words as concrete pegs on which to hang abstract ideas, their explanations cannot be carried far. Theories without the power of disputation would be a poor solace in leisure moments.
One more point may be noticed with regard to the psychological aspect of the evolution of behaviour--the reciprocal action of intelligence. It is the intelligence of others that introduces so much variety and complexity into the environment. Hunters and hunted, combatants, rivals, mate and mate, enemies or companions in their varied aspects, introduce through their intelligence complications which only intelligence can meet. And, as intelligence begets intelligence, so do emotional attitudes beget answering emotional states. Psychological evolution translated into practical behaviour gives rise to situations of reciprocal complexity. This point of view is, however, so familiar, that nothing need be said in its further elucidation. The behaviour of any given animal does not stand alone, but is closely related with the behaviour of others. Among social animals the relationships are peculiarly close, and it is among them that the psychological aspect of behaviour reaches its highest expression.