Evolutionary games on scale-free networks with a preferential selection mechanism

Considering the heterogeneity of individuals' influence in the real world, we introduce a preferential selection mechanism to evolutionary games (the Prisoner's Dilemma Game and the Snowdrift Game) on scale-free networks and focus on the cooperative behavior of the system. In every step, each agent chooses an individual from all its neighbors with a probability proportional to k(alpha) indicating the influence of the neighbor, where k is the degree. Simulation results show that the cooperation level has a non-trivial dependence on alpha. To understand the effect of preferential selection mechanism oil the evolution of the system, we investigate the time series of the cooperator frequency in detail. It is found that the cooperator frequency is greatly influenced by the initial strategy of hub nodes when alpha > 0. This observation is confirmed by investigating the system behavior when some hub nodes' strategies are fixed. (C) 2009 Elsevier B.V. All rights reserved.