prisoner’s dilemma
a mixed-motive game used in investigations of competition and cooperation. Each participant in the game must choose between a self-beneficial course of action that could be costly for the other players and an action that would bring a smaller individual payoff but would lead to some benefits for all the players. The name derives from a police tactic, used when incriminating evidence is lacking, in which two suspects are separated and told that the one who confesses will go free whereas the other will receive a heavy sentence. If both confess, both will receive a moderate sentence; if neither confesses, lack of evidence means that they will both escape with a light sentence. Each prisoner may choose silence (the cooperative strategy), hoping that the other does the same but risking a long sentence if the other confesses. Alternatively, either prisoner may confess (the competitive strategy), hoping to improve his or her own situation even though this will be at the
expense of the other prisoner. Each prisoner has an incentive to confess regardless of what the other does. However, if both parties choose the competitive option, both will do worse than if they together choose the cooperative strategy. The prisoner’s dilemma has implications for social exchange theory and the study of social dilemmas.