Evolution of prosocial behavior in multilayer populations

TL;DR

This paper investigates how multilayer social networks influence prosocial behavior, showing that coupling between different social domains can promote altruistic actions even when disfavored in individual layers.

Contribution

It provides a mathematical framework for analyzing multilayer social networks and demonstrates how inter-layer coupling fosters prosocial behavior across diverse real-world networks.

Findings

Coupling between social layers promotes prosocial behavior.

Multilayer interactions can induce prosociality even if disfavored in single layers.

Small changes in one social domain can influence behavior in others.

Abstract

Human societies include diverse social relationships. Friends, family, business colleagues, and online contacts can all contribute to one's social life. Individuals may behave differently in different domains, but success in one domain may engender success in another. Here, we study this problem using multilayer networks to model multiple domains of social interactions, in which individuals experience different environments and may express different behaviors. We provide a mathematical analysis and find that coupling between layers tends to promote prosocial behavior. Even if prosociality is disfavored in each layer alone, multilayer coupling can promote its proliferation in all layers simultaneously. We apply this analysis to six real-world multilayer networks, ranging from the socio-emotional and professional relationships in a Zambian community, to the online and offline relationships within an academic University. We discuss the implications of our results, which suggest that small modifications to interactions in one domain may catalyze prosociality in a different domain.