Leading theoreticians and researchers present current thinking about the role played by group memberships in people’s sense of who they are and what they are worth. The chapters build on the assumption, developed out of social identity theory, that people create a social self that both defines them and shapes their attitudes and behaviors. The authors address new developments in the theoretical frameworks through which we understand the social self, recent research on the nature of the social self, and recent findings about the influence of social context upon the development and maintenance of the social self.