Social goods dilemmas in heterogeneous societies

TL;DR

This paper investigates how heterogeneous social networks influence the evolution of prosocial behaviors, revealing they can promote cooperation but also lead to inequality and benefit concentration.

Contribution

It extends evolutionary dynamics models to arbitrary spatial structures and social goods, showing heterogeneous networks can both promote prosocial behaviors and create inequality.

Findings

Heterogeneous networks enhance prosocial behavior evolution.

Benefits often concentrate among highly-connected individuals.

Selection can favor social good producers even when costs exceed benefits.

Abstract

Prosocial behaviors are encountered in the donation game, the prisoner's dilemma, relaxed social dilemmas, and public goods games. Many studies assume that the population structure is homogeneous, meaning all individuals have the same number of interaction partners, or that the social good is of one particular type. Here, we explore general evolutionary dynamics for arbitrary spatial structures and social goods. We find that heterogeneous networks, wherein some individuals have many more interaction partners than others, can enhance the evolution of prosocial behaviors. However, they often accumulate most of the benefits in the hands of a few highly-connected individuals, while many others receive low or negative payoff. Surprisingly, selection can favor producers of social goods even if the total costs exceed the total benefits. In summary, heterogeneous structures have the ability to strongly promote the emergence of prosocial behaviors, but they also create the possibility of generating large inequality.