Published online by Cambridge University Press: 05 December 2008
When does self-interest counsel cooperation? This question pertains both to the labile behaviors produced by rational deliberation and to the more instinctive and fixed behaviors produced by natural selection. In both cases, a standard starting point for the investigation is the one-shot prisoners' dilemma. In this game, each player has the option of producing one or the other of two behaviors (labeled “cooperate” and “defect”). The pay-offs to the row player are as follows: