Adoption of different strategies in diversity-optimized populations promotes cooperation

In this work, a sophisticated model is proposed to study the effects of heterogeneous types of individuals on the evolution of cooperation. In the prisoner’s dilemma game, the whole population which adopts different strategies against different neighbors, is divided into two types: the imitator and the responsor. The imitator updates his strategy depending on the payoffs while the responsor changes his strategies according to the other’s attitude. Interestingly, it is found that there exists an intermediate value of the fraction of imitators which can guarantee the best cooperative level on the square lattice and random network. The feedback reciprocity mechanism of the responsor, the strategy transmission probability, and the connection density are also studied. Our results are helpful for understanding the specific roles played by each type of individual and the coexistence of the two groups in the real society.