Simplicial models of social contagion

TL;DR

This paper introduces a higher-order social contagion model using simplicial complexes, revealing complex phenomena like discontinuous transitions and bistability, which enhance understanding of social influence beyond pairwise interactions.

Contribution

It presents a novel higher-order contagion model based on simplicial complexes, demonstrating new phenomena such as discontinuous transitions and bistability in social systems.

Findings

Discontinuous transition induced by higher-order interactions

Existence of a bistable region with co-existing states

Higher-order models explain critical mass effects in social change

Abstract

Complex networks have been successfully used to describe the spread of diseases in populations of interacting individuals. Conversely, pairwise interactions are often not enough to characterize social contagion processes such as opinion formation or the adoption of novelties, where complex mechanisms of influence and reinforcement are at work. Here we introduce a higher-order model of social contagion in which a social system is represented by a simplicial complex and contagion can occur through interactions in groups of different sizes. Numerical simulations of the model on both empirical and synthetic simplicial complexes highlight the emergence of novel phenomena such as a discontinuous transition induced by higher-order interactions. We show analytically that the transition is discontinuous and that a bistable region appears where healthy and endemic states co-exist. Our results help explain why critical masses are required to initiate social changes and contribute to the understanding of higher-order interactions in complex systems.