Most of the papers on social dilemmas in this book were presented at a conference on social dilemmas that was held at the University of Groningen in the spring of 1984. Social dilemmas are interpersonal situations that are characterized by a conflict between private and collective interest, i.e. in attempting to further their private interests, participants may end up worser off than if they had abandonned self-interest and worked for the good of the community. The chapters in this book describe efforts made by social psychologists, sociologists, and political scientists to advance our understanding of the psychological processes that influence people's behavior in social dilemmas. It is assumed that understanding of these processes can help our search for solutions.