This feels like a great introduction to the “Lizardman’s constant” (https://slatestarcodex.com/2013/04/12/noisy-poll-results-and...)

> Lizardman’s Constant is an idea proposed by Scott Alexander that each poll always has about 4% weird answers. In one poll, 4% of Americans said that reptilian people do control our world and, in another 4% answered ‘Yes’ to the question ‘Have you ever been decapitated?’