Repulsion or attraction? Group membership and assumed attitude similarity

Three studies investigated group membership effects on similarity-attraction and dissimilarity-repulsion. Membership in an in-group versus out-group was expected to create initially different levels of assumed attitude similarity. In 3 studies, ratings made after participants learned about the target's attitudes were compared with initial attraction based only on knowing target's group membership. Group membership was based on political affiliation in Study 1 and on sexual orientation in Study 2. Study 3 crossed political affiliation with target's obnoxiousness. Attitude dissimilarity produced stronger repulsion effects for in-group than for out-group members in all studies. Attitude similarity produced greater increments in attraction for political out-group members but not for targets with a stigmatic sexual orientation or personality characteristic.