Eur. Phys. J. B 45, 569-575 (2005)
https://doi.org/10.1140/epjb/e2005-00215-3

Opinion dynamics in a three-choice system

¹ Centre de Recherche en Épistémologie Appliquée, CREA-École Polytechnique, CNRS UMR 7656, 1, rue Descartes, 75005 Paris, France
² Dipartimento di Scienze Fisiche and Unità INFM, Università “Federico II”, Complesso Monte S. Angelo, 80126 Napoli, Italy

Corresponding authors: ^a sgekle@gmx.net - ^b peliti@na.infn.it - ^c galam@ccr.jussieu.fr

Received: 1 January 2005
Published online: 13 July 2005

Abstract

We generalize Galam's model of opinion spreading by introducing three competing choices. At each update, the population is randomly divided in groups of three agents, whose members adopt the opinion of the local majority. In the case of a tie, the local group adopts opinion A, B or C with probabilities α, β and respectively. We derive the associated phase diagrams and dynamics by both analytical means and simulations. Polarization is always reached within very short time scales. We point out situations in which an initially very small minority opinion can invade the whole system.