This experimental article helps to understand the motives behind cooperation in the prisoner’s dilemma. It manipulates the pay-off in case both players defect in a two-player, one-shot prisoner’s dilemma and explains the degree of cooperation by a combination of four motives: efficiency, conditional cooperation, fear and greed. All motives are significant but some become only significant if one controls for all remaining ones. This seems to be the reason why earlier attempts at explaining choices in the prisoner’s dilemma with personality have not been successful.
Applied Economics Letters
Rotterdam Institute of Law and Economics

Engel, C., & Zhurakshovska, L. (2016). When is the Risk of Cooperation Worth Taking? The Prisoner's Dilemma as a Game of Multiple Motives. Applied Economics Letters, 2016(23), 1157–1161. Retrieved from