Informational social influence

Social proof (also known as informational social influence) is a psychological and social phenomenon where people assume the actions of others in an attempt to reflect correct behavior in a given situation.

Social proof is considered prominent in ambiguous social situations where people are unable to determine the appropriate mode of behavior, and is driven by the assumption that the surrounding people possess more knowledge about the current situation.

The effects of social influence can be seen in the tendency of large groups to conform to choices which are either correct or mistaken. This is referred to in some publications as the herd behavior. Although social proof reflects a rational motive to take into account, the information possessed by others, and formal analysis that shows it can cause people to converge too quickly upon a single distinct choice, so that decisions of even larger groups of individuals may be grounded in very little information (see information cascades).

Social proof is one 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. When "we conform because we believe that others' interpretation of an ambiguous situation is more accurate than ours and will help us choose an appropriate course of action", it is informational social influence. This is contrasted with normative social influence wherein a person conforms to be liked or accepted by others.

Social proof often leads not only to public compliance (conforming to the behavior of others publicly without necessarily believing it is correct) but also private acceptance (conforming out of a genuine belief that others are correct). Social proof is more powerful when being accurate is more important and when others are perceived as especially knowledgeable.

The multiple source effect occurs when people give more credence to ideas that are stated by multiple sources. This effect can be clearly seen when social proof occurs. For instance, one study observed that people who hear five positive reviews on a book as read by five different synthesized voices perceive that book more favourably than if they hear the same five reviews as read by one synthesized voice.

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