To build cultures of peace, one must often lay aside the "expert" label and become a student in the world who is willing to learn from other cultures in pursuit of peace. To set up an intercultural dialogue on this topic, the Committee for the Psychological Study of Peace, in conjunction with the University for Peace and the Institute for Psychological Research of the University of Costa Rica, sponsored the 6th International Symposium on the Contribution of Psychology to Peace. This special issue extends the dialogue which began at the Symposium. Aiming to help define the role and contributions of psychologists in building cultures of peace, the articles in this issue address: *topics relating to human rights; *how psychologists can contribute to democratization; *how psychology has much to say on the causes and dynamics of intolerance and the processes of building tolerance in the context of intergroup relations; *how psychology can contribute to understanding and fostering nonviolence; *how cultures of peace will not be possible without a concerted effort to bring about global environmental security and that our failure to restore environmental health is fundamentally a psychological problem; and *psychologically informed policies for the promotion of cultures of peace, including the importance of gender equity.