Boosting cooperation by involving extortion in spatial Prisoner's dilemma

TL;DR

This study demonstrates that involving extortion strategies in spatial Prisoner's dilemma games promotes cooperation, especially when extortioners form checkerboard patterns, and the effects depend on the strategy updating mode.

Contribution

It reveals that extortion strategies can facilitate cooperation and are evolutionarily stable, with effects influenced by strategy updating methods.

Findings

Extortioners promote cooperation in spatial Prisoner's dilemma.

Checkerboard ordering of extortioners and cooperators enhances cooperation.

Extortion acts as an incubator for the evolution of cooperation.

Abstract

We study the evolution of cooperation in spatial Prisoner's dilemma games with and without extortion by adopting aspiration-driven strategy updating rule. We focus explicitly on how the strategy updating manner (whether synchronous or asynchronous) and also the introduction of extortion strategy affect the collective outcome of the games. By means of Monte Carlo (MC) simulations as well as dynamical cluster techniques, we find that the involvement of extortioners facilitates the boom of cooperators in the population (and whom can always dominate the population if the temptation to defect is not too large) for both synchronous and asynchronous strategy updating, in stark contrast to the otherwise case, where cooperation is promoted for intermediate aspiration level with synchronous strategy updating, but is remarkably inhibited if the strategy updating is implemented asynchronously. We explain the results by configurational analysis and find that the presence of extortion leads to the checkerboard-like ordering of cooperators and extortioners, which enable cooperators to prevail in the population with both strategy updating manners. Moreover, extortion itself is evolutionary stable, and therefore acts as the incubator for the evolution of cooperation.