The author maintains that the gang, for the period in a boy's life from age 10 to 18, is one of his three primary social groups: the family, the neighborhood, and the play group. For the normal boy, the play group is the gang. The boy's reaction to his gang is neither more nor less reasonable than "the reaction of a mother to her babe, the tribesman to his chief, or the lover to his sweetheart." A gang becomes the training ground for the development of the fundamental virtues of cooperation, self-sacrifice, and loyalty. The author advises that parents should recognize the "good" gang as an ally in the raising of their children. The parent, however, should influence the child's choice of a gang and be aware of the gang's activities and influences. Positive gangs include the Boy Scouts and the Boys' Club. This book contains chapters on the activities of gangs, the management of predatory impulses within gangs, the psychology of the gang, the gang's organization, and the gang in the context of the school.