Cooperative Emergence in Structured Populations Mixed with Imitation and Aspiration Learning Dynamics

This paper investigates the mixing scheme of social-learning imitation dynamics and self-reinforcing aspiration dynamics in spatial Prisoner’s Dilemma game, where agents update among three kinds of strategies (cooperation, defection, and extortion) through imitation or aspiration learning dynamics assigned in advance. Our results show that by introducing a few aspirants into a majority of imitators in the networked systems, the aspirants tend to adhere to cooperation strategy catalyzed by extortion strategy. Through mixing a proper proportion of these two learning dynamics, cooperative behavior easily emerges not only in regular lattice, but also in social networks. This may yield some insight into understanding the emergence of cooperation and optimizing performance of social systems.