Eur. Phys. J. B 83, 507-518 (2011)
https://doi.org/10.1140/epjb/e2011-10359-0

Regular Article

Social dynamics with peer support on heterogeneous networks

The “mafia model”

Arnold Sommerfeld Center for Theoretical Physics and CeNS, Department of Physics, Ludwig-Maximilians-Universität München, Theresienstrasse 37, 80333 München, Germany

^a e-mail: frey@lmu.de

Received: 6 May 2010
Received in final form: 7 August 2011
Published online: 17 October 2011

Abstract

Human behavior often exhibits a scheme in which individuals adopt indifferent, neutral, or radical positions on a given topic. The mechanisms leading to community formation are strongly related with social pressure and the topology of the contact network. Here, we discuss an approach to model social behavior which accounts for the protection by alike peers proportional to their relative abundance in the closest neighborhood. We explore the ensuing non-linear dynamics emphasizing the role of the specific structure of the social network, modeled by scale-free graphs. We find that both coexistence of opinions and consensus on the default position are possible stationary states of the model. In particular, we show how these states critically depend on the heterogeneity of the social network and the specific distribution of external control elements.