The early adolescent age from twelve to fifteen years is characterized by a rapid and uneven growth during which vitality and energy alternate with languorousness, and the boy is awkward and lazy, with bones greatly outgrowing muscle. The boy also begins to take a new interest in sex and sex relations, his features and voice change, and the inherited tendencies begin to assert themselves. His health is usually at its best, and during his active moments he is boisterous and vigorously energetic. He is selfish, but shows signs of altruism; his regard for law increases; the spirit of gang leadership begins to show itself; his longing for friendship is noticeable; his sense of secretiveness is apparent; and his self-assertiveness first begins to be manifested. He is creative in imagination, shows marvelous powers of inference, becomes strongly intellectual, begins to manifest analytic reasoning, imitates the ideal, is uncertain in making decisions, is influenced by suggestion, and possesses generally a strong but not a logical memory. He develops natural religious notions, has strong impulses to do big things, has definite convictions as to his belief in God and Heaven and the understanding of traditional religious terms, shows a noticeable lack of interest in the forms of worship, but a keen appreciation of the spiritual, and is passing through a period when great resolves are most often made. CHARACTERISTICS OF LATER ADOLESCENCE During the period of later adolescence from fifteen to eighteen years of age, the body nearly attains its maximum growth, the mind begins to show its dominance over the body, and all the bodily impulses grow stronger and more vigorous. Altruism steadily increases; the consciousness of society grows; an appreciation of individual worth and thought develops; the call of sex and the love emotion grows in strength; sentiment is inclined to become strong; boundless enthusiasm manifests itself; and organization and cooperation begin to appeal and be appreciated more and more. There is a growth in logic, independent thought, alertness in thinking, and quickness of receptive powers. The boy at this age is in the period of highest resolves and greatest endeavor, is apt to show religious skepticism, and reason often takes the place of his faith. =Classes of Boys or Boy Types=