Asch carried out a number of variations of his original study to find out which variables had the most significant effects on the level of conformity shown by participants.

Group size – Asch found that there was little conformity when the majority consisted of juts one or two confederates. However, under the pressure of a majority of  3 confederates the proportion of conforming responses jumped up to about 30%. Further increases in the size of the majority did not increase this level of conformity substantially, indicating that the size of majority is important, but only up to a point.

Unanimity of the majority – When the real participant was given the support of either another real participant or a confederate of their own, conformity levels dropped from 33% to just 5.5%.

Difficulty of the task – When Asch manipulated the lines so that the test was much harder the level of conformity increased.

EVALUATION:

Historical validity – It is possible that Asch’s findings are unique because the research took place in a particular period of US history when conformity was high. In 1956, the US was in the grip McCarthyism, a strong anti-Communist period when people were scared to go against the majority and so more likely to conform.

Population validity – All of the participants were male and so the results cannot be generalized to females.

Independent variable rather than conformity – You have to remember that only about  one-third of the trials where the majority unanimously gave the same wrong answer produced a conforming response. In other words, in two-thirds of these trials the participants resolutely stuck to their original judgement despite being faced with an overwhelming majority expressing a totally different view. Asch believed that rather than showing human beings to be overly conformist, his study demonstrated a commendable tendency for participants to stick to what they believed to be the correct judgement, ie: show independent behaviour.

Ecological validity – You must remember that this study was a lab experiment and so is difficult to generalise to other situations and real-life experiences as various extraneous variables were controlled.

Unconvincing confederates – One problem was that the confederates found it difficult to act convincingly when giving the wrong answer, which could affect the internal validity of the study.