Being similar versus being equal: intergroup similarity moderates the influence of in-group norms on discrimination and prejudice.

In two studies, we examined the influence of in-group norms of anti- and pro-discrimination on prejudice and discrimination as a function of intergroup similarity (Studies 1 and 2) and in-group identification (Study 2). In a condition where there was no information about intergroup similarity (Study 1) or intergroup similarity was low (Study 2), prejudice and discrimination were lower when norms prescribe anti-discrimination compared to pro-discrimination. In contrast, when intergroup similarity was high, prejudice and discrimination were higher when the in-group norm represents anti-discrimination compared to pro-discrimination. This pattern was most apparent among highly identified in-group members (Study 2). The paradoxical effect of the anti-discrimination norm in the high similarity condition is interpreted as a response to the threat this situation introduces to in-group distinctiveness.