The Real Reason Not Everyone Can Roll Their Tongue

Some tricks take hours to master. Others seem to come naturally to some people, while others struggle to understand them. These sorts of tricks include wiggling your ears, arching just one brow, and perhaps most popular, being able to roll your tongue.

Maybe it's because it's easier to control your tongue than your ears. Or, perhaps it's because an entire generation of kids spent hours trying to copy the whale from the "Free Willy" movies. Whatever the reason, it's a trick most kids try pretty early on, and most of the time, they can do it. In fact, a 1951 study of Japanese schoolchildren found that at least 20% of the population learns to roll their tongues between ages 6-12 (via the University of Delaware). Of course, that leads to the question, what about the other kids?

For years, people who can roll their tongues gave credit to their genetics. On the flip side, people who couldn't roll their tongues blamed their luck on the genetic lottery. However, multiple studies over the last decade have found that the source of the tongue-rolling skill is not so easy to pin down.

There are lots of traits we can blame solely on genetics, but as the Children's Museum of Indianapolis explains, several studies over the last few decades have proved that belief wrong. Many of these studies involved identical twins. In some cases, one twin could roll their tongue while the other could not.

Even more interesting is the same 1951 study that looked at Japanese school children and the ratio of them that could roll their tongues. The University of Delaware states that while only 54% of children aged 6-7 could roll their tongues, 76% could roll their tongues by the age of 12. With other variables accounted for, the researchers concluded that the majority of the additional 22% had learned how to roll their tongues in the 5-6 years since they were last polled. 

As Good Housekeeping puts it, people who want to roll their tongues may be able to learn the skill, regardless of their genetics. The skill itself is likely rooted in a mix of environmental and biological factors, leaving its single-source — if there is one — a mystery.