Conflict, interpersonal assessment, and the evolution of cooperation: Simulation results

How cooperative dispositions might have evolved among social animals has, for many years, been productively addressed within the prisoner's dilemma paradigm. That game captures the intuition that by cooperating, individuals can often produce more than is possible by their separate efforts and also that self-interest can lead individuals to undermine their cooperative efforts. The structure is robust, with only minor elaborations necessary to show how populations can realize their cooperative opportunities. The best-known such elaboration is iteration of the game; simply requiring players to interact in a sequence of prisoner's dilemmas can lead them to adopt cooperation-inducing strategies such as tit-for-tat (see, for example, Axelrod 1984; Nowak and Sigmund 1992) and winstay, lose-shift (Nowak and Sigmund 1993, see also Schuessler 1989 and Vanberg and Congleton 1992).