Impact of individual difference and investment heterogeneity on the collective cooperation in the spatial public goods game

In order to deeply elucidate the evolution of cooperation, we present a novel spatial public goods game (PGG) model in which the individual difference and investment heterogeneity is simultaneously taken into account. We characterize the individual difference by classifying all players into two categories: A−type and B−type, where A−type cooperators will not give perfect contribution into a PGG group and their ratio will be controlled by the parameter ε, while B−type ones will always keep the unit investment into the group that they participate in. Meanwhile, the heterogeneity can be implemented by a non-uniform investment mechanism regarding A−type cooperators, where a contribution from a cooperative agent into a PGG group is represented as a power function of fraction of cooperators inside this group. Extensive simulations indicate that the cooperation can be driven into a very high level by integrating these two components into the PGG model. Furthermore, the full cooperation phase diagrams further highlight their role in the promotion of cooperation. Current results will greatly enrich our understanding of collective cooperation behavior within many natural, social and even man-made systems.