Majority Influence - Asch (1955)

Aim: Investigate the extent to which social forces constrain people's opinions. 

Sample: 123 students from 3 universities in U.S

Method: Laboratory experiment 

Procedure: 7-9 student were assembled in a classroom, all of whom were confederates with 1 genuine participant. Told they were taking part in an experiment on visual judgement. Shown a card with a single black line and then shown another card with 3 lines and were asked which of the three was the same length as the line on the first card.

The first two times this was done, all confederates gave the right answer. However on the third occasion the confederates were told to give the all the same wrong answer or most of them to give the wrong answer ( one or two giving the correct answer).

Results: Individuals conformed in 1 out of 3 occasions.

Participant errors jumped to 32% with 3 confederates giving the wrong answer.

Increasing the number of confederates giving a wrong answer, beyond 3, had no significant effect on the participants' responses. 

Results (cont): When confronted with 1 confederate giving the wrong answer, participants would answer independently and correctly in nearly all trails. 

Evaluation: Supports situational explanations of behaviour. If asked as individuals the participants would of gave the correct answer, but in a situation where other people around them were mainly giving wrong answers, many participants conformed against their better judgement.

Individual difference were evident in the results, a quarter proved themselves to be able to maintain consistent independence of thought.  

All Male ppts - all belonged to the same age group - unrepresentative.

Task of judging line is low in ecological validity.

Ethical issues regarding deception an psychological stress.