Running head: OPINION ALLIES OF NEWCOMERS

This research investigates the impact of allying with socially dissimilar group members on members’ feelings and behavior, and the ultimate performance of the group. In the context of having a newcomer join a group, we conducted a 2 (social similarity of newcomer to oldtimers; in-group or out-group) x 3 (opinion agreement: newcomer has no opinion ally, 1 opinion ally, or 2 opinion allies) interacting group experiment with four-person groups. Groups with out-group newcomers perceived their group interactions as less effective, yet performed better than groups with in-group newcomers. Moreover, this result was not due to newcomers bringing new ideas to the group discussion. Instead, the behavior and feelings of oldtimers who agreed with newcomers (i.e., opinion allies to the newcomer) had a larger impact on the groups’ outcomes. The results add to the idea that surface-level (i.e., social) diversity may ultimately be beneficial for groups even when out-group members do not bring different deep-level task perspectives to the group.