Effects of Mass Media and Opinion Exchange on Extremist Group Formation

Contemporary communication technologies are thought to facilitate the growth of the small autonomous terrorist groups indicative of ‘modern’ terrorism. In this study, the Animal Liberation Front provides an example of a culturally distinct organisation from which an extremist force—the Animal Rights Militia—emerges to pose the threat of violence. Agent-based modelling is used to simulate this emergence, and subsequent dynamics, under a variety of conditions. The simulation model not only implements local opinion exchange within a population, but also the polarising effect of mass media. Results show the significance of mass media, of limits on the cell size that are independent of the policing efforts, and the impact of societies with rapid population turn over, such as are found near universities.