The current study investigated the effects of intragroup interaction and cohesion on intergroup bias in a minimal group setting. As expected, interacting groups displayed a stronger intergroup bias than did individual group members acting in isolation. Moreover, there was a tendency for cohesive groups to show more intergroup bias than did groups formed on an ad hoc basis. Additional analyses showed that while groups and individuals did not differ in their treatment of the ingroup, groups discriminated against outgroup members more strongly than did individually acting group members. The findings are discussed with respect to their implications for understanding the differences in intergroup bias between groups, whose members interact, and individually acting group members.