Cooperation - The Prisoner's Dilemma

The Prisoner's Dilemma

Even if all members of a group would benefit if all cooperate, individual self-interest may not favor cooperation. The prisoner's dilemma codifies this problem and has been the subject of much research, both theoretical and experimental. Results from experimental economics show that humans often act more cooperatively than strict self-interest would seem to dictate. While economic experiments require subjects to make relatively abstract decisions for small stakes, evidence from natural experiments for high stakes support the claim that humans act more cooperatively than strict self-interest would dictate.

One reason may be that if the prisoner's dilemma situation is repeated (the iterated prisoner's dilemma), it allows non-cooperation to be punished more, and cooperation to be rewarded more, than the single-shot version of the problem would suggest. It has been suggested that this is one reason for the evolution of complex emotions in higher life forms, who, at least as infants, and usually thereafter, cannot survive without cooperating – although with maturation they gain much more choice about the kinds of cooperation they wish to have.

There are four main conditions that tend to be necessary for cooperative behaviour to develop between two individuals :

• An overlap in desires
• A chance of future encounters with the same individual
• Memory of past encounters with that individual
• A value associated with future outcomes