Group polarization

Group polarization is the phenomenon by which groups of like-minded individuals, after discussion, tend to adopt more extreme positions than the average of their initial individual views. The mechanism combines information pooling (groups hear more arguments supporting their initial position) and social comparison (individuals adjust views to align with perceived group norms). Group polarization is the engine behind echo chambers and the structural explanation for why digital platforms that sort users by similarity tend to produce more extreme outputs than their inputs. It challenges the classical assumption that deliberation leads to moderation, suggesting that deliberation without ideological diversity is a centrifuge, not a bridge.