Different reactions to adverse neighborhoods in games of cooperation

TL;DR

This paper investigates how different reactions to adverse neighborhoods, such as rewiring or migration, influence the evolution of cooperation in networked social dilemmas, finding that mixed reactions optimize cooperative outcomes.

Contribution

It introduces and compares two types of reactions to adverse neighborhoods and demonstrates that a mixture of these reactions enhances cooperation more than single reactions.

Findings

Local rewiring promotes cooperation by maintaining diversity.

A mixture of migration and rewiring yields the highest cooperation levels.

Reactions to adverse neighborhoods significantly impact cooperative dynamics.

Abstract

In social dilemmas, cooperation among randomly interacting individuals is often difficult to achieve. The situation changes if interactions take place in a network where the network structure jointly evolves with the behavioral strategies of the interacting individuals. In particular, cooperation can be stabilized if individuals tend to cut interaction links when facing adverse neighborhoods. Here we consider two different types of reaction to adverse neighborhoods, and all possible mixtures between these reactions. When faced with a gloomy outlook, players can either choose to cut and rewire some of their links to other individuals, or they can migrate to another location and establish new links in the new local neighborhood. We find that in general local rewiring is more favorable for the evolution of cooperation than emigration from adverse neighborhoods. Rewiring helps to maintain the diversity in the degree distribution of players and favors the spontaneous emergence of cooperative clusters. Both properties are known to favor the evolution of cooperation on networks. Interestingly, a mixture of migration and rewiring is even more favorable for the evolution of cooperation than rewiring on its own. While most models only consider a single type of reaction to adverse neighborhoods, the coexistence of several such reactions may actually be an optimal setting for the evolution of cooperation.