Trust operates most prominently in friendship, unmediated by kinship or contract.

Evidence

I shall argue that they had three basic models for such relationships, none of them unproblematic. One, kinship, is an extrapolation from statuses typical of traditional ideology and practice; its antithesis is the legally sanctioned contract of the modern state and civil society. There remains the zone of free-floating social relationships formed by choice in the expectation of mutuality. The most neutral term for this zone is association, but its strongest form of expression is friendship, the negotiated order of free individuals joined by affection and shared experience rather than by legal sanction or the ties of blood. It is in this third area of social life that trust plays so prominent a role, relatively unmediated by the formal obligations of kinship and contract. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 2310

Categorization

• DEFINE: Precisely distinguishes three institutional models—kinship, contract, association—and locates trust in the third zone, giving the reader’s Luhmann/Hardin synthesis its key terminology.
• XREF: The three-zone analytic maps directly onto Luhmann’s familiarity/trust distinction and Hardin’s constrained-observability account of trust.