Populations contain people with differing natural dispositions toward honest dealing.

Evidence

In what follows I will suppose that while people appear to be the same there are in fact two types of persons in the population, one given to more honest urges (type 1) than the other (type 2). — Diego Gambetta, Trust - Making and Breaking Cooperative…, 860

Categorization

• DEFINE: Defines the two-type population structure that the equilibrium analysis builds on — and usefully contrasts with Saramago, where the population appears heterogeneous but observability failure erases the difference.
• XREF: The type-1 vs type-2 distinction parallels Hardin’s point that some agents are intrinsically trustworthy while others are only constrained — a heterogeneity observability-and-trust arguments must accommodate.