Same people, different group: Social structures are a central component of group concepts.

We examine whether people conceptualize organized groups as having at least two parts: In addition to members (e.g., Alice), they also have social structures (i.e., roles and relations). If groups have members and social structures, then numerically distinct groups can have the same members if they differ in their structures. In Studies 1-4, participants numerically distinguished groups that had the same members when they had different structures. Participants numerically distinguished even when groups had the same function-the same people playing chess together Monday and Tuesday can be numerically distinct groups. In Study 4, we compare clubs to tables, and find that participants numerically distinguish tables by their structures too (i.e., the configuration of their parts) even when they have the same parts (which can be disassembled and then reassembled with ease). In Study 5, we find that participants rate groups as existing in space and time like concrete objects, suggesting that participants represent groups as at least partially concrete, such that groups have at least two parts (their structures and their members). Finally, in Study 6, we show that people will judge the same person as exemplary with respect to one group but condemnable with respect to another-even when those groups have the same members.