Mass media destabilizes the cultural homogeneous regime in Axelrod's model

TL;DR

This paper investigates how introducing mass media as a global interaction in Axelrod's model unexpectedly increases cultural diversity, destabilizing homogeneous states even at minimal influence levels.

Contribution

It demonstrates that a small probability of mass media interaction can destabilize cultural homogeneity in Axelrod's model, contrary to previous assumptions.

Findings

Mass media interaction increases cultural diversity.

Even minimal influence destabilizes homogeneous states.

Destabilization occurs at large lattice sizes.

Abstract

An important feature of Axelrod's model for culture dissemination or social influence is the emergence of many multicultural absorbing states, despite the fact that the local rules that specify the agents interactions are explicitly designed to decrease the cultural differences between agents. Here we re-examine the problem of introducing an external, global interaction -- the mass media -- in the rules of Axelrod's model: in addition to their nearest-neighbors, each agent has a certain probability $p$ to interact with a virtual neighbor whose cultural features are fixed from the outset. Most surprisingly, this apparently homogenizing effect actually increases the cultural diversity of the population. We show that, contrary to previous claims in the literature, even a vanishingly small value of $p$ is sufficient to destabilize the homogeneous regime for very large lattice sizes.