How Does Cooperation Reduce Intergroup Bias?

This experiment examined the hypothesis derived from the social categorization perspective that intergroup cooperation reduces bias by transforming members' cognitive representations of the aggregate from 2 groups to 1 group. Two 3-person groups experienced intergroup contact under conditions that varied (a) members' representations of the aggregate as 1 group or 2 groups (without involving cooperation) and (b) the presence or absence of intergroup cooperation. As expected, in the absence of cooperation, bias was lower among Ss induced to conceive of the 6 participants as 1 group rather than as 2 groups. Also as predicted, among Ss in the 2-groups condition, intergroup cooperation increased the strength of the 1-group representation and decreased bias. Multiple regression mediation analysis revealed, as expected, that members' representations mediated bias and that the 1-group representation primarily increased the attractiveness of former outgroup members.