The error of crowds is the idea that under some scoring rules, the average error becomes less than the error of the average, thus making the average belief tautologically worse than a belief of a random person. Compare this to the ideas of modesty argument and wisdom of the crowd.

A related idea is that a popular belief is likely to be wrong because the less popular ones couldn't maintain support if they were worse than the popular one.

Blog posts

The Error of Crowds
The Majority Is Always Wrong

See also

Modesty argument