Stefan Stürmer, Ph.D., is Professor of Psychology at the Fern Universität in Hagen (Germany), and the Chair in Social Psychology. In his research, he investigates inter- and intragroup processes, with a particular emphasis on the role of group processes in social movement participation, cooperation, helping, and altruism. He also serves as a consultant for various city councils and community agencies, ... Read moreconcerning measures and policies to foster community action and civic participation. Mark Snyder, Ph.D., is Professor of Psychology at the University of Minnesota, where he holds the McKnight Presidential Chair in Psychology and is the Director of the Center for the Study of the Individual and Society. His research examines the motivational foundations of individual and collective action. He is recipient of the Society for Personality and Social Psychology’s Donald T. Campbell Award and the Kurt Lewin Award of the Society for the Psychological Study of Social Issues. He is the author of the book, Public Appearances/Private Realities: The Psychology of Self-Monitoring, and co-editor of Cooperation: The Political Psychology of Effective Human Interaction. Show Less