Consider the limits on how many individuals one can trust. Even before getting to trust, someone who already has several friends may not think the possible benefits of investing in developing a friendship with yet another person is worth the risk. This problem may explain at least part of the phenomenon of clique and friendship-group formation. It might also be part of the explanation of familism in contexts in which families are relatively large, that is, large enough to exhaust a substantial part of the resources any member might have for investing in rich relationships. It may also be part of the explanation of ethnic exclusion.

XREF: Connects to social capital and Dunbar's number literature on cognitive limits to relationships. Also echoes network closure arguments in sociology. SEED: Angles: why trust is a finite resource in polarized groups; how relationship-investment limits explain in-group/out-group boundaries and familism across cultures. QUESTION: What is the actual empirical ceiling on deep relationships, and how does it scale with group size?

Russell Hardin, Trust and Trustworthiness, loc. 789