The research used multiple methods and multiple information to study two cohorts, one starting in fourth grade and the other starting in seventh grade and both continuing through high school. The analysis focused on the developmental roots of violence; social networks and the functions of friendships; self-esteem and beliefs; issues related to dropouts, throwaways, and runaways; suicidal behaviors; the role of social relations in protecting against or promoting self-destructive behaviors; and gun ownership and firearm injuries. The analysis focused on avenues by which redirection and help may be provided to youth at risk of violence, deviant social groups, school dropout, teenage parenthood, drug abuse, suicide, and other problems. Findings indicated that problem behaviors are more readily prevented than reduced after they have been established and that the conditions for problem behavior appear not only in early development but also in middle childhood and adolescence. Effective prevention requires attention to the social, cognitive, school, family, peer, and community levels of influence. Figures, tables, chapter notes, subject and author indexes, and approximately 350 references