A Study on the Evolution of Cooperation in Networks

This paper studies the phenomenon of the evolution of cooperation in networks, where each player in networks plays an iterated game against its neighbours. An iterated game in a network is a multiple round game, where, in each round, a player gains payoff by playing a game with its neighbours and updates its action by using the actions and/or payoffs of its neighbours. The interaction model between the players is usually represented as a two-player, two-action (i.e., cooperation and defection) Prisoner's Dilemma game. Currently, many researchers developed strategies for the evolution of cooperation in structured networks in order to enhance cooperation, i.e., to increase the proportion of cooperators. However, experimental results, reported in current literature, demonstrated that each of these strategies has advantages and disadvantages. In this paper, a self-organisation based strategy is proposed for the evolution of cooperation in networks, which can utilise the strengths of current strategies and avoid the limitations of current strategies. The proposed strategy is empirically evaluated and its good performance is exhibited. Moreover, we also theoretically find that, in static networks, the final proportion of cooperators evolved by any pure (or deterministic) strategies fluctuates cyclically irrespective of the initial proportion of cooperators.