We compare the effect of four activation regimes by measuring the appropriate opinion clustering statistics and also the number of emergent extremists.

We investigate the interplay of homophily, differentiation, and in-group cooperation mechanisms on the formation of opinion clusters and emergence of radical opinions.

We develop an agent-based model to explore the effect of perceived intergroup conflict escalation on the number of extremists. The proposed model builds on the 2D bounded confidence model proposed by Huet et al (2008).