Individual variability in adherence to the norm of group interest predicts outgroup bias

The norm of group interest dictates that group members should consider the interests of their group. We propose that individual variability in adherence to this norm accounts for intergroup attitudes and behavior. Study 1 developed a measure for the norm of group interest, and found that adherence to the norm predicted evaluations of the outgroup independent of group identification and collective self-esteem. Studies 2 and 3 demonstrated that the norm of group interest increased competitive behavior only when a competitive group norm was salient, but not when a cooperative norm was salient. These findings highlight the importance of both the norm of group interest and group norms to understanding attitudes and behavior in the intergroup context.