title: Heterogeneous beliefs, segregation, and extremism in the making of public opinions.
abstract: The connection between contradictory public opinions, heterogeneous beliefs, and the emergence of majority- or minority-induced extremism is studied, extending our former two-state dynamic opinion model. Agents are attached to a social-cultural class. At each step they are distributed randomly in different groups within their respective classes to evolve locally by majority rule. In case of a tie the group adopts one or another opinion with respective probabilities k and (1-k) . The value of k accounts for the average of individual biases driven by the existence of heterogeneous beliefs within the corresponding class. It may vary from class to class. The process leads to extremism with a full polarization of each class along one opinion. For homogeneous classes the extremism can be along the initial minority making it minority induced. In contrast, heterogeneous classes exhibit more balanced dynamics, which results in a majority-induced extremism. Segregation among subclasses may produce a coexistence of opinions at the class level, thus averting global extremism. Insight into the existence of contradictory public opinions in similar social-cultural neighborhoods is given.
authors.affiliation: Centre de Recherche en Epistémologie Appliquée (CREA), Ecole Polytechnique et CNRS (UMR 7656) 1 rue Descartes, 75005 Paris, France. galam@shs.polytechnique.fr
authors.forename: Serge
authors.initials: S
authors.lastname: Galam