Understanding the psychological mechanisms of aggression has the potential to solve some of the world's most vexing problems among families, social groups, and nations. In this lecture, Kenneth Dodge will discuss how his research has improved our understanding of the development and prevention of chronic violence in children and adolescents. Dodge, recently elected to the National Academy of Medicine, has conducted both laboratory and longitudinal studies of how chronic aggressive behavior develops across the life span. His work has identified how biological and early family experience factors lead to a social-cognitive pattern that serves as a catalyst for development of aggressive behavior. This acquired pattern is one of overly defensive response to threatening events that includes perceptual readiness to attribute hostile intent to others, testosterone release, and heart rate hyperreactivity. This talk will have implications for education policy and family living. Dodge is the William McDougall Professor of Public Policy and Professor of Psychology and Neuroscience and director of the Center for Child and Family Policy. He was elected to the National Academy of Medicine in October 2015. Membership in the National Academy of Medicine is considered one of the highest honors in the fields of health and medicine and recognizes individuals who have demonstrated outstanding professional achievements and commitment to service.