Effect of spatial structure on the evolution of cooperation

TL;DR

This study systematically explores how spatial structure influences cooperation evolution across various settings, clarifying contradictions and challenging established beliefs in the field.

Contribution

It provides a comprehensive simulation-based analysis of spatial effects on cooperation across different games, update rules, and network structures, broadening understanding.

Findings

Spatial effects vary significantly across different game types.

Robustness of spatial influence is challenged by update rule variations.

Intensity of selection affects cooperation asymmetrically in mixed equilibrium games.

Abstract

Spatial structure is known to have an impact on the evolution of cooperation, and so it has been intensively studied during recent years. Previous work has shown the relevance of some features, such as the synchronicity of the updating, the clustering of the network or the influence of the update rule. This has been done, however, for concrete settings with particular games, networks and update rules, with the consequence that some contradictions have arisen and a general understanding of these topics is missing in the broader context of the space of 2x2 games. To address this issue, we have performed a systematic and exhaustive simulation in the different degrees of freedom of the problem. In some cases, we generalize previous knowledge to the broader context of our study and explain the apparent contradictions. In other cases, however, our conclusions refute what seems to be established opinions in the field, as for example the robustness of the effect of spatial structure against changes in the update rule, or offer new insights into the subject, e.g. the relation between the intensity of selection and the asymmetry between the effects on games with mixed equilibria.