The unpacking effect in allocations of responsibility for group tasks

Individuals tend to overestimate their relative contributions to collaborative endeavors. Thus, the sum of group members' estimates of the percentage they each contributed to a joint task typically exceeds the logically allowable 100%. We suggest that this tendency stems partly from individuals' inclination to regard their fellow group members as a collective rather than as individuals, and that leading people to think about their collaborators as individuals should therefore reduce the perceived relative magnitude of their own contributions. Consistent with this thesis, four experiments demonstrate that people's tendency to claim more than their fair share of the credit for a group task is attenuated when they “unpack” their collaborators, conceptualizing them as separate individuals, rather than as “the rest of the group.”