What is the Asch experiment in sociology

Class CheckUp!

Peer pressure or the desire to belong can be thematized with the help of this material via the Asch experiment. This is particularly impressive if the experiment is carried out in the class before the students deal with it in more detail.

The experiment:

Which lines are the same length? (& copy public domain)
In a psychological experiment, six students in a group deliberately give the same wrong answers over and over again. What is the seventh doing? In contrast to the other six, this one is the actual test person.

Which lines are the same length?

The so-called Asch experiment by the psychologist Salomon Asch in 1951 examined the influence of the opinion or judgment of a group on the opinion or judgment of an individual. In the experiment, the test subjects must first decide on their own which line on the comparison map (right) is as long as the line on the standard map (right). Result: Almost all test persons solve the task successfully, the test persons answer "C" in the example opposite.

Perception adjustment in the group?

Schematic representation of the Asch experiment. (& copy http://www.iminologie.uni-hamburg.de/wiki/images/f/fc/Asch.gif)
In the actual experiment, the ignorant test person sits in a room with six other people who have been informed about the actual purpose of the experiment. One after the other, the people should indicate which of the lines is the same length as the starting line. In the first four rounds, all initiates and the actual test subject give the correct answer. The interesting part of the experiment begins when the group of six others asserts in the fifth round that in our example “B” corresponds to the line on the “standard card”, that is, the group as a whole gives a wrong answer. The experiment is repeated several times in this way. How does the test person behave?

The result is astonishing: 76% of the test persons conformed to the wrong judgment of the group at least once. A quarter of the test persons were not influenced by the group and did not behave in compliance. The adaptation to the majority perception of a group is also called the Asch effect, following the experiment.

Under the term conformity one understands the change in judgment or behavior in favor of the judgments of a majority of the members of a group.

The Asch Experiment as a play

Recreate the test situation shown for your classmates. Your classmates should find out what you represent and what is the meaning and purpose of the experiment scene you represent. At first glance, you should think that this is an experiment from perception research. Assigns the following roles:
  • Investigator:
    Your task is to say a few introductory words to the supposed experiment on perceptual performance. Imagine you are a serious scientist. Try to speak calmly and clearly. Sieze all members of the group:
    “Hello, thank you for your willingness to take part in our experiment on perceptual performance. With your participation you make an important contribution to psychological and medical research. I'll show you two cards with lines at a time. You will find one line on the standard map and three lines on the comparison map. You have to decide which of the lines corresponds to the line on the standard map. I will question you in turn. Then please give me your answer. "
    Now put the slides on one by one and ask the group members for each slide about their perception: “Which line corresponds to the line on the standard card on the left?” Then write down the answers on a pad. You are a researcher.
  • Test subject:
    You're in the penultimate position. Your task is to initially give the correct answers as normal. In the case of card 4, you initially hesitate a little with the answer and then give the actually correct answer “C”. With card 5 you also hesitate, but then you join the wrong answer of the other group members. On card 6 you give the same wrong answer as the other group members without hesitation.
  • Group member 1 - 6:
    Your task is to give the correct answers for cards 1 to 3 and to consistently give the wrong answer from card 4 onwards. Share your opinion with the first person interviewed. Some of you should look at each other in disbelief after the subject has given the different correct answer to card 4.


  • Floren, Franz-Josef: Economy, society, politics. Social sciences in grade 11, Paderborn: Schöningh 2007, p.265-267.
  • Lindgren, H.C .: Introduction to Social Psychology, Weinheim: Beltz 1973, p.139.
  • Stroebe, Wolfgang et al .: Social Psychology. An introduction, Heidelberg: Springer 2003, pp. 452-462.
  • Sader, Manfred: Psychology of the group, Munich: Juventa 2008, p.161ff.

You can use the worksheet on the topic download here in PDF format.