The mechanism of alliance promotes cooperation in the spatial multi-games

Abstract

In reality, individuals often tend to enhance their competitiveness by forming alliances with the partners sharing the same view. Motivated by this phenomenon, we propose a novel model considering the mechanism of alliance to investigate the evolution of cooperation in the spatial multi-games, in which the intensity of alliance could be adjusted by a parameter μ. In detail, the focal individual will contribute the ratio μ of his own payoff as a cost of the alliance, and then expect to gain the equal portion of average benefits of the neighbors holding the same strategy, which means that the individual fitness can be tuned by the intensity of alliance. Through extensive numerical simulations, one could find that the mechanism of alliance can significantly promote the prosperity of cooperation. Moreover, the larger the value of μ, the stronger the intensity of alliance, which could lead to the higher the level of cooperation. In particular, the evolutionary dynamics presents a complex situation when the co-changes of the intensity of alliance μ and sucker's payoff δ are commonly considered. Furthermore, we also verify the robustness of the proposed mechanism by using the diversity of the intensity of alliance and different network topologies. The current results are conducive to comprehending the emergence and persistence of cooperation within the real-world population.