The Asch Conformity Experiment was conducted by Solomon Asch in the 1950s to investigate how social pressure from a majority group could influence an individual to conform. The experiment was designed to test the extent to which social pressure from a majority group could affect a person to conform.

Aim: The aim of the experiment was to investigate the extent to which social pressure from a majority group could affect a person to conform.

Procedure: Asch used a lab experiment to study conformity, whereby 50 male students from Swarthmore College in the USA participated in a ‘vision test.’ Using a line judgment task, Asch put a naive participant in a room with seven confederates/stooges. The confederates had agreed in advance what their responses would be when presented with the line task. The real participant did not know this and was led to believe that the other seven confederates/stooges were also real participants like themselves. Each person in the room had to state aloud which comparison line (A, B or C) was most like the target line. The answer was always obvious. The real participant sat at the end of the row and gave his or her answer last. At the start, all participants (including the confederates) gave the correct answers. However, after a few rounds, the confederates started to provide unanimously incorrect answers. There were 18 trials in total, and the confederates gave the wrong answer on 12 trials (called the critical trials). Asch was interested to see if the real participant would conform to the majority view. Asch’s experiment also had a control condition where there were no confederates, only a “real participant”.

Results: Asch measured the number of times each participant conformed to the majority view. On average, about one third (32%) of the participants who were placed in this situation went along and conformed with the clearly incorrect majority on the critical trials. Over the 12 critical trials, about 75% of participants conformed at least once, and 25% of participants never conformed. In contrast, in the control group, with no pressure to conform to confederates, less than 1% of participants gave an incorrect answer.

Conclusion: Asch concluded that people conform for two main reasons: because they want to fit in with the group (normative influence) and because they believe that the group is better informed than they are (informational influence) . The study has been replicated many times since its original publication and has become one of psychology’s most famous experiments.