Trusters set subjective breakeven thresholds determining when cooperation is worth risking

Evidence

For the person of low trust in figure 5.1, the breakeven point occurs (in the subjective estimate of the low truster) at point L, or about 80 percent objective trustworthiness. For the optimal truster it occurs at point T, or about 50 percent, and for the high truster at point H, or about 25 percent trustworthiness. All three will trust only above their respective breakeven point and will not trust below it; therefore each will risk cooperating only above the breakeven point. The low truster will therefore trust and risk cooperating relatively seldom, only in the range L to 0. The excessively optimistic truster will trust and risk cooperating very often but will lose, on average, in cooperations in the range from H to T. These losses will be offset by gains from trusting and risking cooperation in the range T to 0. The optimal truster will trust and risk cooperating in the range T to 0 and will have an expected net gain throughout that range. — Russell Hardin, Trust and Trustworthiness, 559

Categorization

• XREF: Directly feeds the reader’s integration: this breakeven-point model is the formal substrate for Hardin’s trust claim — connects to the Luhmann familiarity baseline and to the doctor’s wife as the sole optimal truster in Saramago.
• DEFINE: Defines the breakeven point as the trustworthiness threshold above which a truster will risk cooperation, which is the analytical pivot of Hardin’s expected-value account.