In small communities, instead, general norms of cooperativeness govern many behaviors. Anthropologists and sociologists sometimes call this generalized reciprocity. These norms are enforced at the group or communal level and not in reciprocal one-on-one relationships. For example, if one of us has a serious illness or death in the family or some other crisis, others help in various ways according to their own particular capacities. I might help you but then we might never be in positions in which you should, according to our norm, help me. Hence the norm is not reciprocal but is general—it is “universal” within our community.

Russell Hardin, Trust and Trustworthiness, loc. 821