Mindreading and manipulation in an ecology of Prisoner's Dilemma games: Laboratory experiments

Humans have a rational reason to seek out and selectively play Prisoner's Dilemma games with others who (for whatever reason) will play cooperatively, while avoiding those who will defect. It follows that they also have reason to try and persuade others that they will personally cooperate if a game is joined (using the term from Evolutionary Psychology, to 'manipulate' others' beliefs) and, thus, to penetrate to the truth underlying such efforts (to 'mindread' others intentions). We develop an economic model of mindreading and manipulation that can govern exchange relationships in natural circumstances, and report laboratory data showing that, absent constraining institutions that make play with cooperators likely, intending defectors are more likely to be chosen as partners than are intending cooperators. Intending defectors' efforts at manipulation appear to be more successful than their potential victims' efforts at mindreading. The findings suggest the nature of the problem that must be addressed for would-be traders in the absence of well-enforced rules governing contracts, and we discuss the patterns of behavior that are likely responses in such circumstances. © Springer 2006.