Social Proof is a psychological phenomenon where people assume the actions of others in an attempt to reflect correct behavior for a given situation. This effect is prominent in ambiguous social situations where people are unable to determine the appropriate mode of behavior, and is driven by the assumption that surrounding people possess more knowledge about the situation.
The effects of social influence can be seen in the tendency of large groups to conform to choices, which may be either correct or mistaken, a phenomenon sometimes referred to as herd behavior. Social proof is a type of conformity. When a person is in a situation where they are unsure of the correct way to behave, they will often look to others for cues concerning the correct behavior.