Evolutionary dynamics of friendship-driven reputation strategies

Indirect reciprocity refers to a cooperative mechanism in which individuals evaluate each other’s reputation and take corresponding action. It is predicated on the idea that community members frequently discuss their opinions with each other and utilize the information to determine who deserves to cooperate with. When information is disseminated publicly, all community members are able to communicate on how each other has performed in the past. We combine balanced structural relationships in social networks with reputation strategies and find that friendship-driven reputation strategies can maintain cooperation and resist the invasion of defectors. Under the condition of rare mutations, several individual decision reputation strategies based on the partners’ evaluation can enjoy higher abundances in evolutionary races. In competition with ALLD, the strategy that rely on the negative partners’ opinions is outcompeted by ALLC. The reputation strategy based on the positive partners’ opinions always maintains a very high level of cooperation even for frequent mutations. We also find that in a heterogeneous population consisting of unconditional strategies and one of the reputation strategies, a chain reaction of defection occurs. Our results highlight the significant roles of friendship-driven reputation strategies in promoting cooperation when it is challenging for individuals to observe each other’s behavior but easy for them to share information on interacting experiences of third-party members.