RISK AND TEMPTATION: A META-STUDY ON PRISONER'S DILEMMA GAMES

This article reports the results of a meta-study of 96 prisoner's dilemma studies comprising more than 3,500 participants. I disentangle the role of 'risk' (to co-operate unilaterally) and 'temptation' (to defect against a co-operator) and find that: (i) an index of risk best explains the variation in cooperation rates across one-shot games, while (ii) an index of temptation best explains the variation in finitely repeated games. Risk and temptation indices also affect gender comparisons. Women are more co-operative than the average man if risk is low and less co-operative if risk is high. There are no gender differences on average.