10 Science Myths You Probably Still Believe

9. Tongue Rolling Ability Is Genetic

Between 65 and 81 percent of people on the planet can roll thier tongue and most people will learn that this is down to their genes. Seeing as we knew by the 1950s that pairs of twins could have different tongue rolling abilities, this seems highly unlikely.

In reality, it's likely to be a developmental difference. Perhaps a trick that is learnt by some in early infancy by discovering a certain group of muscles, but others never master it, a bit like ear-wiggling. In fact, an experiment in the 1940s found that the skill could be taught, increasing the number of tongue rollers in a group of of 6–12 year olds by 20%. For the same reason you can learn how to walk, but not how to have blue eyes, this implies that it is not genetic but learnt behaviour.

If this were true, then two non-rolling parents could never produce a tongue roller, providing a simple alternative to paternity testing.