"Three out of four people call white black when the group does — humans are sheep." That is how Solomon Asch's line experiment appears in almost every textbook. It is one of the most elegant experiments in social psychology — but the figure is misremembered, and the lesson drawn from it is almost the opposite of what Asch himself emphasised. That correction is the interesting part.
The Setup: a Study Without an Excuse
Solomon Asch, a social psychologist, ran his experiments from 1951. The genius lay in the unambiguity of the task: subjects merely had to say which of three comparison lines was the same length as a reference line — a trivial perceptual question with no ambiguity at all. On their own, people were practically always right: in the control group the error rate was below 1%.
In the actual experiment, though, the real subject sat with seven to nine confederates — and answered almost last. On 12 of 18 trials (the "critical" ones) all confederates unanimously named the same, obviously wrong line. The question: does the subject follow their own eyes or the group?
The Number Everyone Knows — and the One Everyone Forgets
The often-cited result: on about 37% of the critical trials subjects went along with the group error, and roughly three in four conformed at least once. From this came the sheep headline.
But the same data also say this — and it is rarely in the textbook:
- On about two thirds of the critical trials people stuck with the correct answer, despite unanimous pressure.
- A quarter of subjects conformed not even once.
- Conformity was the exception, not the rule — the most common response was independence.
A survey of US textbooks (Friend, Rafferty & Bramel, 1990) found that most concealed exactly this: they turned Asch's study into a demonstration of the "power of the situation" — and quietly dropped the independence. Asch himself emphasised the opposite. He was struck by the resistance, not the compliance.
What Asch Actually Said
Asch was no apostle of the herd but was concerned about the conditions under which people deny their own perception. In Opinions and Social Pressure (Scientific American, 1955) he writes:
"That we have found the tendency to conformity in our society so strong that reasonably intelligent and well-meaning young people are willing to call white black is a matter of concern. It raises questions about our ways of education and about the values that guide our conduct."
That is no celebration of going along, but a wake-up call to independence — and Asch supplied the strongest antidote right alongside it.
The One Ally: the Most Important Result
Asch varied the setup, and one variation stands out. When he placed a single ally beside the subject — another "participant" who said the correct answer aloud — the group pressure collapsed: conformity fell from about a third to roughly 5–6%, a drop of about three quarters.
The truly striking thing: it did not even have to be the correct answer. A dissenter who named a different wrong line also largely freed the subject (conformity around 9%). What broke the spell was therefore not the ally's correctness but simply that unanimity was broken. As soon as the subject was no longer alone against all, they found their way back to their own judgement.
Unanimity Beats Numbers
A second finding ties in here. One might think the bigger the group, the stronger the pressure. But that is true only at first. Asch increased the number of confederates who unanimously gave the wrong answer step by step: against a single opponent the subject usually stayed calm; with a second and third added, conformity rose sharply. Yet beyond about three confederates little changed — a unanimous group of three exerts almost the same pressure as a group of twelve. It is not the number that counts but the unanimity. That is exactly why a single dissenter is so powerful: he does not take a few votes from the majority, he takes its unanimity.
Why People Go Along: Knowledge or Belonging?
When Asch interviewed the "conformers" afterwards, it emerged: most had clearly seen the correct answer — they just did not want to be the only one to stand out, to look odd or like a troublemaker. They denied their perception not because they distrusted it, but in order to belong. Social psychology calls this the difference between:
- normative influence — I conform so as not to stand out (dominant in Asch, since the task was unambiguous), and
- informational influence — I assume the others know better (above all in ambiguous situations; Deutsch & Gerard, 1955).
An elegant proof: when subjects were allowed to write their answer privately rather than say it aloud, conformity dropped sharply. Where no one is watching, people trust their own eyes again. That points clearly to the "belonging" motive — not to genuine doubt about perception.
How Solid Is the Finding?
Asch has been replicated many times, but the effect is not constant. It varies with culture and the spirit of the age: in more collectivist societies conformity is on average higher, and within the USA it declined over the decades (meta-analysis Bond & Smith, 1996). A British replication with engineering students (Perrin & Spencer, 1980) found almost no conformity at all. This fits Asch's own reading: conformity is no fixed "human nature" but depends on context — and can be broken. The broader framing (Sherif, neuroscience, markets, culture) is in the piece Herd Behaviour in Humans.
The Real Lesson
Read correctly, Asch is no bankruptcy of the individual but almost an encouragement:
- Under unanimous pressure many waver — but the majority of judgements stay independent.
- A single visible ally is enough to break the spell almost entirely. Moral courage is contagious.
- Those who go along mostly do so against their better knowledge — their own perception is still there, it is merely kept quiet.
This puts Asch in the same series as Milgram's obedience experiment and the Stanford Prison Experiment — and provides the laboratory model for what Hannah Arendt and Dietrich Bonhoeffer write about the followers. Asch's ally is the small, concrete version of what both name as the rescue: not to stay alone with one's own judgement, but to speak it — and thereby free others too.
And the point that fits this site remains: even a canonical finding like "Asch = proof of sheepishness" must be checked against the original — because the original says something better. Examine first, then believe, even with the textbook.
Sources
- Asch, S. E. (1951): Effects of group pressure upon the modification and distortion of judgments. — the line experiment.
- Asch, S. E. (1955): Opinions and Social Pressure. Scientific American 193(5) — the popular account including the quote; ally and group size.
- Asch, S. E. (1956): Studies of independence and conformity: A minority of one against a unanimous majority. Psychological Monographs 70(9) — emphasis on independence, ~25% never conformed.
- Deutsch, M. & Gerard, H. B. (1955): A study of normative and informational social influences. — the two motives.
- Friend, R., Rafferty, Y. & Bramel, D. (1990): A puzzling misinterpretation of the Asch 'conformity' study. European Journal of Social Psychology 20 — how textbooks dropped the independence.
- Perrin, S. & Spencer, C. (1980); Bond, R. & Smith, P. B. (1996) — context and cultural dependence.