This book explores the roots of goodness and evil by gathering together the knowledge gained in a lifelong study of harmful or altruistic behavior. Ervin Staub has studied what leads children and adults to help others in need and how caring, helping, and altruism develop in children; bullying and youth violence and their prevention; the roots of genocide, mass killing, and other harmful behavior between groups of people; the prevention of violence; healing victimized groups and reconciliation between groups. He presents a broad panorama of the roots of violence and caring and how we create societies and a world that is caring, peaceful, and harmonious.