What is group polarization in simple terms?

When people who mildly favor an opinion get together and talk, they often end up favoring it much more strongly. Discussion among like-minded people can push views toward the extreme.

How does group polarization differ from groupthink?

Groupthink occurs when a highly cohesive group values consensus so much that it fails to examine dissent and alternatives and makes poor decisions. Group polarization is the shift of a group's position after discussion toward a more extreme version of its initial leaning. The two can occur together but are distinct concepts.

Group Polarization

🧠 Psychology By CampusDown Wiki Editorial Team Last updated October 27, 2026 Views 6

Group polarization is the phenomenon in which, after discussion, a group's position moves to a more extreme point in the direction its members initially leaned on average. It began with James Stoner's 1961 discovery of the risky shift, in which groups made riskier decisions after discussion; later research found shifts toward caution as well, and the phenomenon was generalized as group polarization. The concept is widely used to understand jury verdicts, political deliberation and polarization on social media.

Contents

1. From the risky shift to group polarization
2. Why it happens
3. Deliberation, law and social media
4. FAQ
5. References

From the risky shift to group polarization

In his MIT master's thesis, Stoner (1961) presented people with dilemmas between risky and safe options and found that decisions reached by groups after discussion tended to be riskier than individuals' prior judgments. Wallach, Kogan and Bem (1962) replicated this systematically and popularized the term risky shift. Later studies, however, found shifts toward caution on some items. Moscovici and Zavalloni (1969) showed that French students' positive attitudes toward de Gaulle and negative attitudes toward Americans each became stronger after discussion, proposing the general principle that groups polarize attitudes. Myers and Bishop (1970) reported that discussion among highly prejudiced students increased prejudice while discussion among low-prejudice students decreased it.

Why it happens

Reviewing the research to that point, Myers and Lamm (1976) set out two main explanations. Persuasive arguments theory holds that discussion produces more novel and convincing arguments favoring the side most members lean toward, so positions shift in that direction; Burnstein and Vinokur (1977) emphasized this informational influence. Social comparison theory explains that people want to be seen as representing valued positions better than others, so on learning others' positions they adopt a somewhat more extreme one. Isenberg's (1986) meta-analysis found significant effects for both processes, with larger effects for persuasive arguments. From a self-categorization perspective, Mackie (1986) reported that polarization occurs when people conform to the prototypical in-group position while differentiating themselves from out-groups.

In "The Law of Group Polarization", Sunstein (2002) argued that deliberation among like-minded people can push groups toward extremes, a pattern also found in jury verdicts, judicial panels and political movements. Schkade, Sunstein and Hastie (2007) had residents of a liberal and a conservative Colorado city deliberate in like-minded groups and found their views on global warming, same-sex unions and affirmative action became more extreme while within-group diversity shrank. By contrast, Fishkin and Luskin (2005) reported that in deliberative polls, where diverse people discuss on the basis of balanced information, polarization may not be pronounced. Sunstein (2017) warned that social media can strengthen group polarization by creating echo chambers of like-minded people. The concept is central to understanding group decision-making alongside groupthink and the Asch conformity experiments.

FAQ

What is group polarization in simple terms?: When people who mildly favor an opinion get together and talk, they often end up favoring it much more strongly. Discussion among like-minded people can push views toward the extreme.
How does group polarization differ from groupthink?: Groupthink occurs when a highly cohesive group values consensus so much that it fails to examine dissent and alternatives and makes poor decisions. Group polarization is the shift of a group's position after discussion toward a more extreme version of its initial leaning. The two can occur together but are distinct concepts.

Sources reviewed: 2026-10-26

References

Stoner, J. A. F. (1961). A comparison of individual and group decisions involving risk. Unpublished master's thesis, Massachusetts Institute of Technology.
Wallach, M. A., Kogan, N., & Bem, D. J. (1962). Group influence on individual risk taking. Journal of Abnormal and Social Psychology, 65(2), 75–86.
Moscovici, S., & Zavalloni, M. (1969). The group as a polarizer of attitudes. Journal of Personality and Social Psychology, 12(2), 125–135.
Myers, D. G., & Bishop, G. D. (1970). Discussion effects on racial attitudes. Science, 169(3947), 778–779.
Myers, D. G., & Lamm, H. (1976). The group polarization phenomenon. Psychological Bulletin, 83(4), 602–627.
Burnstein, E., & Vinokur, A. (1977). Persuasive argumentation and social comparison as determinants of attitude polarization. Journal of Experimental Social Psychology, 13(4), 315–332.
Isenberg, D. J. (1986). Group polarization: A critical review and meta-analysis. Journal of Personality and Social Psychology, 50(6), 1141–1151.
Mackie, D. M. (1986). Social identification effects in group polarization. Journal of Personality and Social Psychology, 50(4), 720–728.
Sunstein, C. R. (2002). The law of group polarization. Journal of Political Philosophy, 10(2), 175–195.
Schkade, D., Sunstein, C. R., & Hastie, R. (2007). What happened on deliberation day? California Law Review, 95(3), 915–940.
Sunstein, C. R. (2017). #Republic: Divided Democracy in the Age of Social Media. Princeton: Princeton University Press.
Fishkin, J. S., & Luskin, R. C. (2005). Experimenting with a democratic ideal: Deliberative polling and public opinion. Acta Politica, 40(3), 284–298.

Reports and materials that use this theory (Korean)

There are no materials dedicated to this theory yet, but you can search related reports in the CampusDown library (Korean).

Find more reports · Search '집단 극화' on CampusDown →

GroupthinkWhat is groupthink? Irving Janis’s definition, the conditions that cause it, its eight symptoms, classic cases such as the Bay of Pigs invasion and the Challenger launch, criticisms from later research, and practical ways to prevent it in teams and classrooms.🧠 Psychology Asch Conformity ExperimentSolomon Asch’s line-judgment conformity experiment explained: the procedure, why about a third of answers on critical trials went with a wrong majority, how one ally cut conformity, cross-cultural meta-analysis and lessons for meetings.🧠 Psychology Social Comparison TheorySocial comparison theory explained: Leon Festinger's (1954) idea that without objective standards people evaluate their abilities and opinions by comparing themselves with others. Covers the similarity hypothesis, upward and downward comparison, schadenfreude and social media.🧠 Psychology Social identity theorySocial identity theory explained: Henri Tajfel's question after the Holocaust, the minimal group experiments, the three steps of categorization, identification, and comparison, how low-status groups respond, and uses in politics, fandom, and branding.🧠 Psychology Spiral of SilenceWhat the spiral of silence theory says, Elisabeth Noelle-Neumann's original idea, fear of isolation and our quasi-statistical sense, the role of media, Pew research showing the effect on social media, the hardcore minority, and limitations.🎨 Media, Arts & Culture

Latest ArticlesView all ›

New guides for college study and assignments (Korean)

This article was last updated on October 27, 2026. It is based on widely recognized original works and textbooks; when citing it in a paper, please check the original sources listed in the references.