A selective overview of theoretical formulations regarding the etiology and development of aggression and violence is provided, and data on individual and contextual factors that elucidate how patterns of violence develop and how they can be changed are presented. Individual factors include temperament and learned problemsolving skills, while contextual factors encompass school, family, and peers. Gender differences in the development of aggression and violence are examined, along with biological factors, socialization experiences, and developmental outcomes of aggression and violence. Based on theory and data, the authors suggest guidelines for prevention, intervention, and social policy development. The focus is on instinct, drive, cognitive-neoassociation, social learning, social-cognitive, and developmental theories of aggression and violence. The guidelines concern developmental continuity, family factors and child rearing, school factors and academic achievement, social and cultural factors in cognitive development, and developmental perspectives in violence interventions. The authors note that aggressive children do not constitute a homogeneous group, that violence and victimization have multiple causes, and that prevention and intervention efforts must be tailored to children's developmental levels. 149 references