Heterogeneous Aspirations Promote Cooperation in the Prisoner's Dilemma Game

PLoS One

Matjaž Perc¹  Zhen Wang² 

[1] Faculty of Natural Sciences and Mathematics, University of Maribor, Slovenia;School of Physics, Nankai University, Tianjin, China,

关键词: Natural selection;    Prisoner's dilemma;    Game theory;    Phase diagrams;    Graphs;    Animal evolution;    Evolutionary genetics;    Social networks;   

DOI  :  10.1371/journal.pone.0015117

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

To be the fittest is central to proliferation in evolutionary games. Individuals thus adopt the strategies of better performing players in the hope of successful reproduction. In structured populations the array of those that are eligible to act as strategy sources is bounded to the immediate neighbors of each individual. But which one of these strategy sources should potentially be copied? Previous research dealt with this question either by selecting the fittest or by selecting one player uniformly at random. Here we introduce a parameterthat interpolates between these two extreme options. Settingequal to zero returns the random selection of the opponent, while positivefavor the fitter players. In addition, we divide the population into two groups. Players from groupselect their opponents as dictated by the parameter , while players from groupdo so randomly irrespective of . We denote the fraction of players contained in groupsandbyand , respectively. The two parametersandallow us to analyze in detail how aspirations in the context of the prisoner's dilemma game influence the evolution of cooperation. We find that for sufficiently positive values ofthere exist a robust intermediatefor which cooperation thrives best. The robustness of this observation is tested against different levels of uncertainty in the strategy adoption processand for different interaction networks. We also provide complete phase diagrams depicting the dependence of the impact ofandfor different values of , and contrast the validity of our conclusions by means of an alternative model where individual aspiration levels are subject to evolution as well. Our study indicates that heterogeneity in aspirations may be key for the sustainability of cooperation in structured populations.

【 授权许可】

CC BY