Existing research supports two opposing mechanisms through which positive mood might affect cooperation. Some studies have suggested that positive mood produces more altruistic, open and helpful behavior, fostering cooperation. However, there is contrasting research supporting the idea that...

Subjects who played a payoff-maximising strategy against a computer algorithm ("sophisticates") are more cooperative in a finitely repeated Prisoner's Dilemma than subjects who did not play a payoff-maximising strategy ("naifs"). The difference in cooperation rates increases as the subjects gain...

This paper investigates the importance of concerns about intentions and outcomes in a sequential prisoner’s dilemma game with nature. In the game, there is a chance that the first mover’s choice is reversed. This allows the separation of intended actions from the resulting outcomes....

We aim to understand the role and evolution of beliefs in the indefinitely repeated prisoner’s dilemma (IRPD). To do so, we elicit beliefs about the supergame strategies chosen by others. We find that heterogeneity in beliefs and changes in beliefs with experience are central to understanding...