Group Polarization

Group polarization names the empirically robust phenomenon in which like-minded individuals, discussing a topic together, shift collectively toward a more extreme version of the position they already held. Cass Sunstein's synthesis of decades of experimental evidence demonstrated that the mechanism operates through two channels: informational influence, in which discussion surfaces arguments that favor the group's existing tendency, and social influence, in which each member perceives the group climate as supporting a more extreme position than they initially held and adjusts their expressed view toward the perceived consensus. The result is that a group of moderate enthusiasts becomes a group of strong enthusiasts, and a group of moderate skeptics becomes a group of strong skeptics, and the distance between the two groups widens — not because anyone encountered new evidence but because the social dynamics of each group pushed its members toward the extreme of their initial tendency. When combined with Noelle-Neumann's spiral of silence, group polarization produces the binary