It is more common than we think: things that almost everyone believes, but have long been refuted by science. Why do we persist in believing such myths?
There are various factors, says Professor Johan Braeckman of the department of Philosophy and Moral Science: 'Very basic: if something doesn't sound too far-fetched and you're not informed about the opposite, for example by scientific studies or journalists, then you tend to believe it. From an early age, people have a strong intuition of how the world works - that stones cannot walk and animals can, for example. If something corresponds to their intuition, they will usually believe it.'
'That intuition can also be given a helping hand. For example, stories that are intuitive and have something exciting or sexy. What also helps is group thinking. We are inclined to believe other people anyway, especially if they belong to our own group. We often believe the neighbour who says that a quack has helped her, faster than a double-blind study about the same thing.'
‘Stories are also more likely to be believed if they come from a source with authority or a source that arises in this way. Fake news sites copy the looks of classic news sources precisely to claim that authority. What's more, our memory doesn't help: if we read a story and we see a correction a week later, after two months we don't know what the story was like precisely. Research has clearly shown that. In short: if a story doesn't sound too far-fetched and it pushes the right psychological buttons, there is a good chance that it will be believed and live on for a long time.’
You get acne from eating chocolate
Evelien Verhaeghe of the department of Dermatology: 'There is no evidence for that. In general, it is very difficult to get hard evidence that any food has an effect on acne.'