Impact of neighborhood separation on the spatial reciprocity in the prisoner’s dilemma game

• We present a novel game model in which interaction and learning neighborhood is not identical.
• The separation between interaction and learning neighborhood can largely influence the cooperative behaviors.
• Monte Carlo simulations are utilized to verify the evolution of cooperation.
• When IN is fixed to be 4, medium-sized LN = 8 is the optimal size to promote the cooperation.
• When LN is fixed to be 4, the cooperation can also be highly enhanced when IN > 4.

The evolutionary game theory is a very powerful tool to understand the collective cooperation behavior in many real-world systems. In the spatial game model, the payoff is often first obtained within a specific neighborhood (i.e., interaction neighborhood) and then the focal player imitates or learns the behavior of a randomly selected one inside another neighborhood which is named after the learning neighborhood. However, most studies often assume that the interaction neighborhood is identical with the learning neighborhood. Beyond this assumption, we present a spatial prisoner’s dilemma game model to discuss the impact of separation between interaction neighborhood and learning neighborhood on the cooperative behaviors among players on the square lattice. Extensive numerical simulations demonstrate that separating the interaction neighborhood from the learning neighborhood can dramatically affect the density of cooperators (ρC) in the population at the stationary state. In particular, compared to the standard case, we find that the medium-sized learning (interaction) neighborhood allows the cooperators to thrive and substantially favors the evolution of cooperation and ρC can be greatly elevated when the interaction (learning) neighborhood is fixed, that is, too little or much information is not beneficial for players to make the contributions for the collective cooperation. Current results are conducive to further analyzing and understanding the emergence of cooperation in many natural, economic and social systems.