Evolutionary escape from the prisonerʹs dilemma

The classic prisonerʹs dilemma model of game theory is modified by introducing occasional variations on the options available to players. Mutation and selection of game options reliably change the game matrix, gradually, from a prisonerʹs dilemma game into a byproduct mutualism one, in which cooperation is stable, and “temptation to defect” is replaced by temptation to cooperate. This result suggests that when there are many different potential ways of interacting, exploring those possibilities may make escape from prisonerʹs dilemmas a common outcome in the world. A consequence is that persistent prisonerʹs dilemma structures may be less common than one might otherwise expect.