The first section examines risk factors for later antisocial and delinquent child behavior, concluding that family factors are among the best predictors of later problem behaviors. Some family factors, referred to as sleeper effects, have a much more long-ranging effect than others. Other social factors, including peer influence, also play roles in the development of delinquency. The second section explores the progression of antisocial behavior, three different developmental paths (aggressive/versatile, nonaggressive, and exclusive substance abuse) toward different antisocial outcomes, the relationship between desistance and progression. The third section focuses on different degrees of vulnerability and how vulnerability interacts with critical developmental periods during which behavior changes. Different methods of screening at risk youngsters are described. Finally, the impact of risk and development factors on the success of intervention is discussed. High priority research areas are recommended including studies to identify causal factors, preventive and rehabilitative interventions, annual surveys of precursors to antisocial behavior, and training for professionals and paraprofessionals. 9 tables, 4 figures, 162 references. (Author abstract modified)