Social nucleation: Group formation as a phase transition

TL;DR

This paper models social group formation as a phase transition, analyzing how opinions, costs, and social influence lead to the emergence of large groups or multiple stable groups, using an agent-based approach.

Contribution

It introduces a novel agent-based model linking opinion dynamics and network formation, applying physical phase transition concepts to social group emergence.

Findings

Critical parameters for group size and density identified.

Conditions for single large group versus multiple groups derived.

Analytic critical densities for group coexistence established.

Abstract

The spontaneous formation and subsequent growth, dissolution, merger and competition of social groups bears similarities to physical phase transitions in metastable finite systems. We examine three different scenarios, percolation, spinodal decomposition and nucleation, to describe the formation of social groups of varying size and density. In our agent-based model, we use a feedback between the opinions of agents and their ability to establish links. Groups can restrict further link formation, but agents can also leave if costs exceed the group benefits. We identify the critical parameters for costs/benefits and social influence to obtain either one large group or the stable coexistence of several groups with different opinions. Analytic investigations allow to derive different critical densities that control the formation and coexistence of groups. Our novel approach sheds new light on the early stage of network growth and the emergence of large connected components.