Why do we conform? Two basic sources of influence: normative social influence, the need to be liked, accepted by others and Informational influence: need to be correct and to behave in accordance with reality.
Solomon Asch (1956) devised an experiment to see if subjects would conform even if they were uncertain that the group norm was incorrect. In his study he asked subjects to take part in an experiment. They were each asked to match a standard length line with three other lines.
He found that one of the situational factors of conformity is the size of the opposing majority. In a series of studies he varied the number of confederates that gave correct answers from 1 -15. He found that subjects conformed to a group of 3 or 4 as readily as they did to a larger group. Some of the subjects indicated afterward that they assumed the rest of the people were correct and that their own perceptions were wrong. Others knew they were correct but didn't want to be different from the rest of the group. Some even insisted that they saw the line lengths as the majority claimed to see them.
Asch and his students did many variations of the study for example they altered the differences between the line lengths making them much smaller and so the correct answer was much less certain, this showed that the conformity increased. What seems to happen is that we have more need for a groups input as a task becomes more difficult. If in the beginning of Asch's experiment we conformed because we didn't want to be embarrassed then in the more ambiguous situation we also conform' because we are less sure of ourselves and so the others in the group become our source of information. This is an example of the difference between normative influence and informational influence. Normative influence is where we have a need psychologically to be accepted and do not want to risk not being accepted. Humans have a need for social approval by conforming then we are