But not only does the evolutionary study of the child-mind hint at the parallelism of indi vidual and racial development : it intimates that the child often 'harks back' to experiences of his animal progenitors. Alany of his emotions, as fear and anger, his instinctive and impulsive actions, his vegetarian propensities, habits of scratching, biting, clawing, teasing, hi- cruelty. many of his games and plays, have been instanced as showing atavistic tendencies. In this matter. again. the ria media is the only safe way. Many so-called atavisms arc simply analogies. some of them poor analogies. whose real explanation is to he found within the experience of the indi vidual himself. We grant that the experience of the human young has ninny points in common with the experience of certain of the lower ani mals: but the question is whether the likeness is not usually coincidental. Take, e.g. the cruelty of the child. It is due largely to a failure to appreciate the significance of pain: while in the savage it is the natural result (where it really exists) of a hard struggle for survival.
Reside the evolutionary method, we tind mueli work in child psyehology proceeding from a gen eral interest in ehildhood. This is a part of the child-study movement, which has acquired great momentum within the last few years. Child study embraces many aspects of childhood rsyehologi•al. anatomical. physiological, hygienic. patholo7iral. :esthetic, moral, sociological. Still another incentive to child psychology is given by im•dagogy. Many practical problems which con front educators depend upon psychology for solution. The mental capacity of s•hool-chihlren is determined by psyehological methods. The hygiene of the attention and of memory. the fatigue-effects of various disciplines, the times and seasons of mental aptitude and dullness, the child's power of association, and the most offer tive incentives 0) an awakening of interest. are all psychological necessarily influence methods of teaching and the ment of school curricula. Still. it is evident that psychology is directly concerned with a small number only of the problems of child-study and pedagogy; i.e. the problems which relate immediately to the mind of the child.
Adult psychology forms the logical basis for child psychology; for in passing from the mind of the adult to that of the child, psychology pro ceeds from the known to the less known. Dne's own mental processes may be known at tirst hand; and although no .one can know a fellow mind except through the various avenues of ex pression, language is so flexible, and at the same time so stable, that adults who are trained in introspection can communicate their feeling., ideas, and emotions with little danger of mis understanding. But it is different with the child.
Tven though he hits acquired a language, he is so unskilled in its use that he would not be able to report many of his mental processes were he able to observe them. It follows. then, that the psychologist must approach the'ebild's mind only after analyzing and ela•sifying the contents of the normal adult mind. Although he is obliged to supplement his methods by others more in direct. his study has given him an outline map of every 1111111:111 mind. and, more than this, he has learned to estimate and to criticise his material. Introspection may, then, be replaced very largely by individual observation, reinforced (where pos sible) by experiment. and by statistical inquiries.
We have seen that we can know the conscious ness of the child only by investigating it at dif ferent levels. i.e. at different ages. The mind of the infant is radivally different from the mind of the child of eight, and this again from the mind of adoleseent youth. There is some dif ference of opinion as to where lines of division shall he drawn. Almost every student of child psychology separates childhood into periods, ac to his Own system. Since the transition from one period to another is gradual, it is im possible to make sharp distinctions. Those divi sions are best which mark the decisive and con stant periods in mental development. Perhaps the most simple and time most practical is some such division as the following: 1 I) from the beginning of conseion•ness to the acquire speech; (2) from the acquirement of speech to school-entrance; (31 from school entrance to puberty: and ( t) the period of adolescence. Each period has its peculiar fea problems. In the first, as in fact in all the epochs. a good deal of aid is derived from physiology. At birth and for some time afterwards the nervous system is incomplete. 'unripe.' as Fleehsig has put it. The higher cerebral centres, in particular. are not yet in a condition to fun•tionate. so that con must be extremely meagre. More over. sonic of the sense-organs mature after hi It 11. The ear does not functionate for some there is no eoi;rdination in of the eyes; and even the ynocato fate,/ does not develop until intra-uterine life has ended. The suc cessive beginning of nervous functions furnishes the last key to the nature of the infant's con s•iousness. To this is added the list of move ments. grmlually increasing in number and com plexity, from which more may be leanied of the developing consciousness. The difficulty in in t•rpreting these movements is partly removed by reference to the structure of the adult mind, and by a free use of the law of parsimony., which allows only the simplest adequate explanation.