Evolutionary Prisoner's Dilemma Game in Flocks

TL;DR

This study explores how collective motion influences cooperation in an evolutionary prisoner's dilemma game among self-driven agents, revealing optimal interaction sizes and conditions that enhance cooperation compared to static systems.

Contribution

It introduces a model combining flocking behavior with evolutionary game dynamics, showing mobility can promote cooperation under specific parameters.

Findings

Optimal neighborhood size maximizes cooperation.

Mobility can enhance cooperation compared to static agents.

Cooperators and defectors coexist at equilibrium.

Abstract

We investigate an evolutionary prisoner's dilemma game among self-driven agents, where collective motion of biological flocks is imitated through averaging directions of neighbors. Depending on the temptation to defect and the velocity at which agents move, we find that cooperation can not only be maintained in such a system but there exists an optimal size of interaction neighborhood, which can induce the maximum cooperation level. When compared with the case that all agents do not move, cooperation can even be enhanced by the mobility of individuals, provided that the velocity and the size of neighborhood are not too large. Besides, we find that the system exhibits aggregation behavior, and cooperators may coexist with defectors at equilibrium.