Psychology › Social psychology › Social influence: conformity and obedience
Asch conformity experiments
1951· Finding or experiment
Well replicatedStrong, repeated evidence.
Solomon Asch showed that many people will give an obviously wrong answer to match a unanimous group.
See it on the Psychology map →What it says
At Swarthmore College in 1951, Asch asked students which of three lines matched a reference line. Everyone else in the room was secretly an actor who, on some rounds, gave the same wrong answer. Real participants went along on about a third of those rounds, and roughly three-quarters conformed at least once; a quarter never did. One ally giving the correct answer cut conformity sharply, and writing answers privately reduced it too.
Why it matters
It showed how group pressure can override plain evidence, which helps explain herding in markets, meetings and committees.
The evidence
Repeated many times; a 1996 meta-analysis of 133 studies in 17 countries found conformity higher in collectivist cultures and declining in the US since the 1950s.
Open questions
Asch himself stressed that most answers were correct. Scholars debate whether conformers changed what they saw or simply avoided public embarrassment.
Connections (4)
▸Asch conformity experiments demonstrated Social influence: conformity and obedienceWell replicated
The connection
Asch's line studies became the classic demonstration of normative influence: going along to fit in, even when the right answer is plain. They helped Morton Deutsch and Harold Gerard separate this from informational influence, trusting others when you are unsure, a distinction still used today.
Who showed it and when
Swarthmore College, Pennsylvania, 1951–1956; Deutsch and Gerard's 1955 paper at New York University built on Asch's procedure.
The evidence
Asch's 1956 monograph reported 123 participants, and the effect has been reproduced in many countries, though often at lower levels than Asch found.
Open questions
How much the effect reflected 1950s American culture: a 1980 British repeat with science and engineering students found almost no conformity, though most later studies still find some.
▸Milgram obedience experiments built on the work of Asch conformity experimentsWell replicated
The connection
Milgram worked as Asch's assistant and wanted to make conformity research weightier by studying actions with consequences, not judgments of lines. He planned to test group pressure on shocks, but obedience alone proved so high it became the focus. One variation echoed Asch's ally effect: when two peers refused, obedience fell sharply.
Who showed it and when
Princeton's Institute for Advanced Study, 1959–1960, where Milgram assisted Asch; the obedience studies followed at Yale in 1961.
The evidence
Milgram's own essays and Thomas Blass's 2004 biography, The Man Who Shocked the World, document the influence.
Open questions
How much the design came from Asch versus Milgram's concern with the Holocaust; the 1961 Eichmann trial coincided with the first studies.
▸Asch conformity experiments help explain herding in Behavioral economicsMixed evidence
The connection
Asch showed people often go along with a group's obviously wrong answer. Economists and finance researchers cite such social pressure, alongside sensible copying of others' information, to explain herding: piling into hot stocks, bank runs and housing bubbles. How much is conformity versus inference is hard to separate.
Who showed it and when
Asch at Swarthmore College, 1951; herding models by Abhijit Banerjee and by Bikhchandani, Hirshleifer and Welch (both 1992); Robert Shiller's Irrational Exuberance (2000).
How solid is it?
Lab markets and fund-manager data show herding, but the link to Asch-style conformity is mostly inferred rather than directly tested, hence the mixed rating.
Open questions
Herding can be rational: copying others makes sense if they might know something, and many economic models explain it without any conformity pressure.
▸The bystander effect shares social-cue mechanisms with Asch conformity experimentsMixed evidence
The connection
Both rest on reading other people's behavior. In Latané and Darley's smoke-filled room study, students sitting with calm actors rarely reported the smoke, much as Asch's subjects echoed actors' wrong answers. Each person takes others' inaction as evidence nothing is wrong, called pluralistic ignorance.
Who showed it and when
Latané and Darley's 1968 smoke study at Columbia University, drawing on conformity research dating to Asch's 1951 studies.
How solid is it?
In the smoke study, 75 percent of students alone reported it, versus 10 percent of those sitting with two passive actors.
Open questions
Whether bystanders are conforming to fit in, unsure what is happening, or diffusing responsibility; these mechanisms are hard to separate.