Asch (1951) - the line experiment
Early studies into conformity, such as Sherif's auto kinetic effect experiment, had used stimuli that were ambiguous and so it could be argued that participants conformed because they were unsure as to the correct answer and so went along with the information provided by the other participants in the group. This means it was impossible to know whether or not participants had actually rejected their own initial opinions in favour of the information provided by the group. To answer this, Asch designed an experiment to test conformity in a situation where the correct answer was obvious.
Asch recruited 123 male students from Swarthmore College in the USA to participate in a ‘vision test.’ They were divided into groups of 5 to 7 people in which, unknown to the participants, all but one of them were confederates of Asch and followed his instructions. In other words each group consisted of 4 to 6 confederates and 1 naive participant.
Each group was shown a set of 3 lines and a separate reference line, and group members had the task of simply stating which line was the same length as the reference line. Each set of lines consisted of one line that was obviously the same length as the reference line, and two that were obviously different. Group members gave their answer one after the other, and the real participant gave his answer in next to last place. Each group performed the task 18 times (18 trials). On the first 2 trials the confederates answered correctly, but for 12 of the remaining 16 trials they answered incorrectly. These 12 trials were the ‘critical trials’ in the experiment.
The results of Asch’s experiment were astonishing considering that the stimuli used consisted of unambiguous lines in which participants must have know the correct answer.
Participants conformed to the obviously incorrect answer given by the group majority on 32% of critical trials.
74% of participants conformed to the incorrect group majority at least once.
Only 25% of participants did not conform at all.
Factors affecting conformity: