2. CHILDHOOD
A. Physical Characteristics.—In the earlier period of childhood, from three to seven years, bodily growth is very rapid. Much of the vital force is thus consumed, and less energy is available for physical activity. The child has also less power of resistance and is thus susceptible to the diseases of childhood. His movements are for the same reason lacking in co-ordination. In the later period, from seven to twelve years, the bodily growth is less rapid, more energy is available for physical activity, and the co-ordination of muscles is greater. The brain has now reached its maximum size and weight, any further changes being due to the formation of associative pathways along nerve centres. This is, therefore, pre-eminently the habit-forming period. From the physical standpoint this means that those activities that are essentially habitual must have their genesis during the period between seven and twelve if they are to function perfectly in later life. The mastery of a musical instrument must be begun then if technique is ever to be perfect. If a foreign language is to be acquired, it should be begun in this period, or there will always be inaccuracies in pronunciation and articulation.
B. Mental Characteristics.—The instinct of curiosity is very active in the earlier period of childhood, and this, combined with greater language power, leads to incessant questionings on the part of the child. He wants to know what, where, why, and how, in regard to everything that comes under his notice, and fortunate indeed is that child whose parent or teacher is sufficiently long-suffering to give satisfactory answers to his many and varied questions. To ignore the inquiries of the child, or to return impatient or grudging answers may inhibit the instinct and lead later to a lack of interest in the world about him. The imitative instinct is also still active and reveals itself particularly in the child's play, which in the main reflects the activities of those about him. He plays horse, policeman, school, Indian, in imitation of the occupations of others. Parents and teachers should depend largely upon this imitative tendency to secure desirable physical habits, such as erect and graceful carriage, cleanliness of person, orderly arrangement of personal belongings, neatness in dress, etc. The imagination is exceedingly active during childhood, fantastic and unregulated in the earlier period, under better control and direction in the later. It reveals itself in the love of hearing, reading, or inventing stories. The imitative play mentioned above is one phase of imaginative activity. The child's ideas of conduct, in this earlier stage of childhood, are derived from the pleasure or pain of their consequences. He has as yet little power of subordinating his lower impulses to an ideal end, and hence is not properly a moral being. Good conduct must, therefore, be secured principally through the exercise of arbitrary authority from without.
In the later period of childhood, acquired interests begin to be formed and, coincident with this, active attention appears. The child begins to be interested in the product, not merely in the process. The mind at this period is most retentive of sense impressions. This is consequently the time to bring the child into immediate contact with his environment through his senses, in such departments as nature study and field work in geography. Thus is laid the basis of future potentialities of imagery, and through it appreciation of literature. On account of the acuteness of sense activity at this period, this is also the time for memorization of fine passages of prose and poetry. The child's thinking is still of the pictorial rather than of the abstract order, though the powers of generalization and language are considerably extended. The social interests are not yet strong, and hence co-operation for a common purpose is largely absent. His games show a tendency toward individualism. When co-operative games are indulged in, he is usually willing to sacrifice the interests of his team to his own personal glorification.
3. ADOLESCENCE
A. Physical Characteristics.—In early adolescence the characteristic physical accompaniments of early childhood are repeated, namely, rapid growth and lack of muscular co-ordination. From twelve to fifteen, girls grow more rapidly than boys and are actually taller and heavier than boys at corresponding ages. From fifteen onward, however, the boys rapidly outstrip the girls in growth. Lack of muscular co-ordination is responsible for the awkward movements, ungainly appearance, ungraceful carriage, with their attendant self-consciousness, so characteristic of both boys and girls in early adolescence.
B. Mental Characteristics.—Ideas are gradually freed from their sensory accompaniments. The child thinks in symbols rather than in sensory images. Consequently there is a greater power of abstraction and reflective thought. This is therefore the period for emphasizing those subjects requiring logical reasoning, for example, mathematics, science, and the reflective aspects of grammar, history, and geography.
From association with others or from literature and history, ideals begin to be formed which influence conduct. This is brought about largely through the principle of suggestion. In the early years of adolescence children are very susceptible to suggestions, but the suggestive ideas must be introduced by a person who is trusted, admired, or loved, or under circumstances inspiring these feelings; hence the importance to the adolescent of having teachers of strong and inspiring personality. However, if the suggestive idea is to influence action, it must be introduced in such a way as not to set up a reaction against it. Reaction will be set up if the idea is antagonistic to the present ideas, feelings, or aims, or if it is so persistently thrust upon the child that he begins to suspect that he is being unduly influenced. To avoid reaction the parent or teacher should introduce suggestive ideas indirectly. For instance, while the mind is concentrated upon one set of ideas, a suggestive idea that would otherwise be distasteful may be tolerated. It may lie latent for a time, and when it recurs it may be regarded as original, under which condition it is likely to issue in action.
The adolescent stage is the period of greatest emotional development, and care should therefore be exercised to have the child's mind dwell upon only those ideas with which worthy emotions are associated. The emotional bent, whether good or bad, is determined to a large extent during this period of adolescence. So far as morality is the subordination of primitive instincts to higher ideas, the child now becomes a moral being. His conduct is now determined by reason and by ideals, and the primitive pleasure-pain motives disappear. It follows that coercion and arbitrary authority have little place in discipline at this period. Social interests are prominent, evidenced by the tendency to co-operate with others for a common end. The games of the period are mainly of the co-operative variety and are marked by a willingness to sacrifice personal interests for the sake of the team, or side.