Asch's line judgement study

• Asch conducted the line judgment study in 1951 to investigate the extent to which social pressure from a majority group could affect a person's conformity.
• Asch's line judgment study aimed to investigate whether people would conform to a majority's incorrect answer in an unambiguous situation. It involved 123 male undergraduate students from the USA.
• Procedure:

  • participants shown a standard line and 3 comparison lines
  • had to identify which comparison line matched the standard line in length
  • each group consisted of 7-9 people, with all except one participant being a confederate, who gave incorrect answers on certain trials.
• Findings:

  • naive participants gave a wrong (conforming) answer 37% of the time
  • 75% of participants conformed at least once
  • 25% of participants never conformed
• Asch's study suggests that people are willing to conform to an incorrect majority opinion, even in unambiguous situations due to social pressure.
• Conclusion:

  • when participants were interviewed, most of them said they went along with the group despite knowing the conforming answer was wrong due to fear of social rejection.
  • a few of them said they did believe the group's answers were correct
• Asch variations to see their effect on conformity included: group size, unanimity and task difficulty.
• Group size:

  Conformity increased with group size up to a point:

  • with 1 confederate, conformity was low
  • with 3 confederates, conformity rose to 31.8%
  • addition of further confederates made little difference
• Unanimity

  Asch tested if the presence of another non-conforming person would affect the naïve participant's conformity

  • Found that the presence of a dissenting confederate reduced conformity by a quarter from the level it was when the majority was unanimous ​
  • The influence of the majority depends to some extent on the group being unanimous ​
• Task difficulty

  Asch made the line judging task more difficult by making the stimulus and comparison line more similar​

  • He found conformity increased under these conditions ​
  • Suggesting informational social influence (ISI) plays a greater role when the task becomes harder ​because people are less confident in their own judgment
• A weakness of Asch's study into conformity is that there are ethical issues. The participants were deceived into believing that the confederates were real participants and that the study was a vision test. The element of deception limits the study as information was withheld from the participants, meaning that they could not give fully informed consent.
• A weakness of Asch's study into conformity is its low population validity. Asch only used 50 male, American college students. This means that his findings have limited application as the findings may not generalise to other genders, ages or cultures because of the small sample size. This limits Asch's study as it is likely that it isn't representative of the wider population.
• A limitation of Asch's study into conformity is that it lacks ecological validity. The study took place in an artificial setting and the participants completed an artificial task as part of a research study. This may have led to demand characteristics which undermine the validity of the findings. This limits the study because it means that the findings may not generalise to real-life situations. After all, conformity may be different.