Social influence occurs when one's emotions, opinions, or behaviors are affected by others. Social influence takes many forms and can be seen in conformity, socialization, peer pressure, obedience, leadership, persuasion, sales and marketing. In 1958, Harvard psychologist, Herbert Kelman identified three broad varieties of social influence.

1. Compliance is when people appear to agree with others, but actually keep their dissenting opinions private.
2. Identification is when people are influenced by someone who is liked and respected, such as a famous celebrity.
3. Internalization is when people accept a belief or behavior and agree both publicly and privately.