Online Group Dynamics Reveal New Gel Science

TL;DR

This paper introduces a generalized gelation model and a novel Burgers equation to accurately describe the growth dynamics of online extremist groups, providing insights for managing their formation and expansion.

Contribution

It develops a new mathematical framework that accounts for time-dependent recruitment and human heterogeneity in modeling online group growth.

Findings

Identifies a critical influx rate for group formation.

Provides a predictive model for group growth curves.

Suggests strategies for controlling undesirable online groups.

Abstract

A better understanding of how support evolves online for undesirable behaviors such as extremism and hate, could help mitigate future harms. Here we show how the highly irregular growth curves of groups supporting two high-profile extremism movements, can be accurately described if we generalize existing gelation models to account for the facts that the number of potential recruits is time-dependent and humans are heterogeneous. This leads to a novel generalized Burgers equation that describes these groups' temporal evolution, and predicts a critical influx rate for potential recruits beyond which such groups will not form. Our findings offer a new approach to managing undesirable groups online -- and more broadly, managing the sudden appearance and growth of large macroscopic aggregates in a complex system -- by manipulating their onset and engineering their growth curves.