Adaptive behaviors neutralize bistable explosive transitions in higher-order contagion

TL;DR

This paper investigates how adaptive behaviors based on risk perception influence higher-order contagion processes, revealing that such adaptivity can suppress complex bistable dynamics and simplify the contagion to pairwise interactions.

Contribution

It introduces a combined numerical and analytical study of adaptive behaviors in higher-order contagion, highlighting their role in reducing bistability and complex dynamics.

Findings

Adaptive behavior impacts only the endemic state in pairwise contagion.

In higher-order contagion, adaptivity suppresses bistability.

Adaptive mechanisms can transform higher-order processes into pairwise-like interactions.

Abstract

During contagion phenomena, individuals perceiving a risk of infection commonly adapt their behavior and reduce their exposure. The effects of such adaptive mechanisms have been studied for processes in which pairwise interactions drive contagion. However, contagion and the perception of infection risk can also involve ("higher-order") group interactions, leading potentially to new phenomenology. How adaptive behavior resulting from risk perception affects higher-order processes remains an open question. Here, we consider the impact of several risk-based adaptive behaviors on pairwise and higher-order contagion processes, using numerical simulations and an analytical mean-field approach. For pairwise contagion, adaptive mechanisms based on local (pairwise or group-based) risk perception impact only the endemic state, without affecting the epidemic phase transition. For higher-order contagion processes, instead, the adaptivity defuses the impact of non-linear group interactions: this reduces or even completely suppresses the parameter range in which bistability is possible, effectively transforming a higher-order contagion process into a pairwise one.