The Effects Of Attribute Persistence On Cooperation In Evolutionary Games

There are many complex systems in nature.Researchers use nodes of the networks to represent individuals in complex systems,and use links in the networks to represent relationships between individuals.And then a large amount of dynamical systems can be studied based on complex networks.In the real world,there is a phenomenon that attracts the attention of many researchers:spontaneous cooperation emerges from selfish individuals.Evolutionary game theory offers a very powerful theoretical foundation for studying the emergence and maintenance of cooperation.In the evolutionary games on complex networks,individuals located on the sites of networks evolve their strategies under certain updating rules.We study the mechanisms of how cooperative behavior is emerged,maintained and improved.In ordinary evolutionary game theory,players update their strategies according to some payoff-driven rules.But in real life,people sometimes adopt the behavior of majority and show the characteristic of conformity.In the previous study of Szolnoki and Perc[1],they found conformity-enhanced network reciprocity by introducing conformity-driven strategy-updating rule to an appropriate fraction of players.Here,we consider whether the individual is payoff-driven or conformity-driven as the two choices of the individual's attribute SU,and then introduce the conformity-driven individuals with the proportion p in the population.We also introduce an attribute persistence period parameter T that gives the individuals the opportunity to change their attributes every T Monte Carlo time units.Whether the individuals change their own attributes is determined by the probability PU.The value of PU is determined by the attribute-updating rule.In our research,we studied two attribute-updating rules:unbiased rule and aspiration rule.With unbiased rules,PU is a fixed constant.Whereas with the aspiration rule,PU is related to the individual's aspiration,which is determined by the average payoff of its neighbors and itself.We find that frequent alternation of strategy-updating rule improves the conformity-enhanced network reciprocity for the unbiased rule,which leads that small T greatly promotes cooperation.On the other hand,we find no improvement of conformity-enhanced network reciprocity for the aspiration rule.