An Evolutionary Study on Cooperation in N-person Iterated Prisoner’s Dilemma Game

Abstract

The iterated prisoner’s dilemma game has been used to study on the evolution of cooperation in social, economic and biological systems. There have been much work on the relationship of number of players and cooperation, evolutionary strategy learning as a kind of machine learning, and the effect of payoff function to cooperation. This paper attempts to reveal that cooperative coalition size depends on payoff function and localization affects the evolution of cooperation in the N-player Iterated Prisoner’s Dilemma (NIPD). Localization makes individuals to interact or learn with adjacent individuals. Experimental result reports that cooperative coalition size increases as the gradient of the payoff function for cooperation becomes steeper than that of defector’s payoff function or as minimum coalition size gets smaller. It is also shown that localization of interaction is an important factor to affect cooperative coalition.