This report, the first Surgeon General's report on youth violence in the United States, summarizes an extensive body of research and seeks to clarify seemingly contradictory trends, such as the discrepancies noted above between official records of youth violence and young people's self-reports of violent behaviors. It describes research identifying and clarifying the factors that increase the risk, or statistical probability, that a young person will become violent, as well as studies that have begun to identify developmental pathways that may lead a young person into a violent lifestyle. The report also explores the less well developed research area of factors that seem to protect youths from viewing violence as an acceptable -- or inevitable -- way of approaching or responding to life events. Finally, the report reviews research on the effectiveness of specific strategies and programs designed to reduce and prevent youth violence.