Intensive trust investments require time budgets that scale poorly

Evidence

In our more complex, open, mobile, and relatively impersonal society, Breton and Wintrobe (1982, 80) note that large investments in trust in a small number of intensive relationships are unusual. What we see instead are many contacts that are less intense. … The differences in the two patterns are, again, virtually a matter of arithmetic logic, because the development of intensive relationships requires substantial investments of time. If I must have relations with large numbers of people, I cannot have intensive relations with many of them. — Russell Hardin, Trust and Trustworthiness, 867