Prisoner's dilemma in structured scale-free networks

TL;DR

This paper investigates how structured scale-free networks inhibit cooperation in the prisoner's dilemma game, challenging the belief that such networks promote cooperation spreading, and identifies key structural factors responsible.

Contribution

It reveals that structured scale-free networks inhibit cooperation, contrary to prior assumptions, and highlights the roles of age correlations and 'large-world' behavior in this process.

Findings

Cooperation is inhibited on structured scale-free networks.

Scale-free property and high clustering do not explain inhibition.

Lack of age correlations and 'large-world' behavior are key factors.

Abstract

The conventional wisdom is that scale-free networks are prone to cooperation spreading. In this paper we investigate the cooperative behaviors on the structured scale-free network. On the contrary of the conventional wisdom that scale-free networks are prone to cooperation spreading, the evolution of cooperation is inhibited on the structured scale-free network while performing the prisoner's dilemma (PD) game. Firstly, we demonstrate that neither the scale-free property nor the high clustering coefficient is responsible for the inhibition of cooperation spreading on the structured scale-free network. Then we provide one heuristic method to argue that the lack of age correlations and its associated `large-world' behavior in the structured scale-free network inhibit the spread of cooperation. The findings may help enlighten further studies on evolutionary dynamics of the PD game in scale-free networks.