Emergence of extreme opinions in social networks

The emergence and spreading of “extreme opinions” are studied in networks with agents sharing mild opinions. The turning extreme shift is driven by social groupmeetings.The extremization process is apprehended according to the social psychology phenomenon of group polarization and illustrated in the case of terrorism. In particular the focus is on the dynamics of emergence of “passive supporters” from which terrorists can then be recruited. Becoming a passive supporter being considered as taking an extreme opinion, group polarization is shown to play an important role for increasing the transition probabilities frommild opinion (e.g., anti-western feeling) to its extreme form (e.g., passive supporter or terrorist). Accordingly a simple agent-based model is defined to implement interactions among agents on networks. Three opinions are considered, pro-western opinion, anti-western opinion and extreme anti-western opinion. The latter may lead people to become passive supporters and, potentially, terrorists. Results of simulations show that a substantial fraction of anti-western agents adopt the extreme opinion exhibiting an emergent phenomenon which may shed some new light on real social phenomena of political violence.