The aim of the book is to enhance understanding of the great danger and some sources of animosity between human groups and to focus on developmental processes by which it should be possible to diminish orientations of ethnocentrism, prejudice and hatred.Teaching prejudice and ethnocentrism to children has, all too often in so many places, been virtually automatic and has been conducive to terrible harm in the past. The dangers of hateful outlooks are likely to be much greater as the twenty-first century unfolds.Scholarship and practice in international relations, including war and peace issues, have gravely neglected the crucial psychological aspects of these terrible problems and the educational opportunities. There is a fruitful conjunction of developmental and social psychology in understanding such vital issues and in working toward a more humane, democratic and safe course of adolescent and child development than can in turn affect the safety of humanity in the long run. There are many intriguing examples of research, educational innovations, and visionary leadership in several countries. Most of the book is devoted to promising lines of inquiry and innovation that foster a more humane and less violent development in childhood and adolescence. It should be of interest to scholars, to the education community, and to a well-educated and socially concerned segment of the community.