Race relations and violence in our nation's schools are problems that stem in part from fundamental human needs to seek inclusion in social groups and to maintain and defend the boundaries that distinguish ingroups from outgroups. In this context, social psychological theory and research on the connection between individuals and their social groups is particularly critical if we are to understand how needs for social identity can be met without the devastating effects of intergroup conflict, prejudice, and discrimination. The theory of "optimal distinctiveness" is a theory of the motivational underpinnings of group identification which holds that group identities are selected and maintained to help the individual achieve a balance between the need for inclusion and the need for differentiation from others. "Optimal" identities are group memberships that meet the need for inclusion within the group and meet the need for differentiation through intergroup comparison and distinctiveness. Identity needs can be aroused if either intragroup inclusion or intergroup differentiation are threatened. The purpose of the current program of research is to extend the application of optimal distinctiveness theory to understanding what factors determine the strength of the needs for inclusion and differentiation, with particular attention to implications for intergroup attitudes and behavior. Ten interrelated studies test the effects of value orientations and multiple group memberships on an individual's sensitivity to threats to optimal social identity. Collectivist values are predicted to be associated with heightened needs for inclusion and differentiation, a limited range of optimal identity, and high levels of sensitivity to threats to that identity. Individualist values, by contrast, are expected to be associated with tolerance for inclusiveness and less concern for ingroup-outgroup distinctions. The availability of multiple alternative social identities is expected to have effects similar to those of individualist values, reducing sensitivity to threats to specific social identities and increasing acceptance of outgroups. These hypotheses are tested in a multi-methodological program of research combining laboratory experiments and cross-national surveys. Results from these studies will contribute to understanding how social structure, value systems, and individual needs combine to determine the relationship between ingroup identification and outgroup discrimination.
