Solomon Asch, a Polish-born American psychologist, conducted a series of experiments in the 1950s that demonstrated the power of conformity. In his most famous experiment, participants were asked to match the length of a line with one of three comparison lines. When the participants were tested alone, they were highly accurate in their judgments. However, when they were tested in a group, they were much more likely to conform to the judgments of the other group members, even when those judgments were incorrect.
Asch concluded that one reason people conform to a group is because they believe that the group is correct. This is known as informational social influence. People look to the group for guidance on how to behave, and they are more likely to conform when they believe that the group knows more than they do. This can be a powerful force, and it can lead people to conform even when they know that the group is wrong.