Social proof

First coined by Robert Cialdini in 1984, social proof is also known as informational social influence. In his book Influence: Science and Practice, he discusses social proof as one of the influential psychological principles that persuade us to behave in certain ways.

In ambiguous situations, decision-making is made difficult by uncertainty regarding the potential outcomes, which may result in decision anxiety. Social proof (safety in numbers, or reliance on the authority of others) therefore becomes a powerful influencer of decision making if we feel that others are better qualified to decide.