The appeal to popular belief – also known as the argumentum ad populum, common belief fallacy, appeal to the majority, appeal to the masses, or appeal to popularity – is the logical fallacy that states that if most or many people in general or of a particular group accept a belief as true, it is evidence that the claim must be true. Accepting another person’s belief, or many people’s beliefs, without demanding evidence as to why that person accepts the belief, is lazy thinking and a dangerous way to accept information.

This logical fallacy is often used by children as an excuse for wanting something (everybody’s got one) or getting into mischief (everybody’s doing it). Despite the juvenile nature of the argument, it is often used by people who should know better, particularly by those who are trying to force other people to their way of thinking.

Example of appeal to popular belief

The appeal to popular belief is used in many pseudoscience arguments by stating that because 90% of Americans believe that X is true, then X must surely be true. For example, over 60% of Americans believe creationism is true, so evolution must be false.