A tag-mediated game designed to study cooperation in human populations

How and why cooperation develops in human populations is not known. The iterated prisoner's dilemma game provides a natural framework for studying cooperation growth in human populations. However, recent experiments with human subjects has exposed a number of serious flaws in virtually all of the game-theoretical models that have appeared in the literature. Indeed, some experiments suggest network reciprocity-thought to be essential for cooperation in human populationsmay actually play no role whatsoever. In this paper we briefly review some human experiments that were conducted in the last three years. We then present preliminary results of a new tag-mediated model designed for studying cooperation in human populations. The model exhibits many characteristics found in the human experiments including assortment, which many researchers now believe is necessary for maintaining cooperation.