The Description-Experience Gap in Cooperation

Conditional cooperation is usually investigated in experiments where the choices of others are known. In many circumstances, however, there is uncertainty about others’ cooperativeness. Using a novel experimental protocol, we manipulate the perceived likelihood of cooperation in a Prisoner's Dilemma, and whether such information is described unambiguously or learned through experience and thus ambiguous. We report on a ‘description-experience gap’ in which rare events appear to be more influential under experience than under description. This contrasts with earlier results from the individual choice literature. We show how stronger priors under social than individual uncertainty can account for this reversal