Tongue rolling, the ability to curl the sides of one’s tongue, is a common human trait. While many believe it is rare or genetically fixed, evidence suggests otherwise. This misconception stems from outdated scientific understanding. In reality, a significant portion of the population can perform this maneuver.
What is Tongue Rolling?
Tongue rolling involves curling the lateral edges of the tongue upwards to form a tube or U-shape. This movement relies on the dexterity and control of the tongue’s intrinsic muscles, enabling precise manipulation to achieve the tubular form.
The Truth About Tongue Rolling Genetics
For many years, tongue rolling was widely taught in science classes as a straightforward example of a dominant genetic trait. This belief originated from a 1940 paper by geneticist Alfred Sturtevant, who suggested it was inherited through a single dominant gene. However, this theory was later disproven, with Sturtevant himself acknowledging his error in 1965.
Subsequent studies, notably one in 1952 by Philip Matlock involving identical twins, provided clear evidence against the simple genetic model. Matlock found that among 33 pairs of identical twins, seven pairs had one twin who could roll their tongue and one who could not. This discordance indicates that non-genetic influences play a significant role. While some genetic predisposition might influence overall tongue flexibility or muscle tone, it is not controlled by a simple dominant gene.
Can Tongue Rolling Be Learned?
The ability to roll one’s tongue is not purely innate; it can often be acquired through practice. Many individuals who initially cannot perform the trick can develop the necessary muscular control over time. This suggests that muscle memory and consistent effort are significant factors in acquiring the skill.
Studies have shown that the prevalence of tongue rolling increases with age, particularly in children, indicating a learning curve. For example, research on Japanese schoolchildren found that the percentage of tongue rollers rose from 54% at ages 6-7 to 76% at age 12. Simple exercises, like attempting to raise the edges of the tongue upwards, can help individuals develop the coordination needed for this movement. This learnability further supports that it is not solely a genetic trait.
Other Fascinating Tongue Abilities
Beyond simple tongue rolling, the human tongue is capable of various other movements. These include folding the tongue, twisting it, or forming a more complex “cloverleaf” shape. The cloverleaf tongue, which involves creating multiple bends, is considerably rarer than basic tongue rolling, with only about 13.7% to 14.7% of people able to do it.
Like tongue rolling, these advanced tongue movements likely involve a combination of inherent tongue flexibility and learned muscular control. The diverse capabilities of the tongue highlight its complex muscular structure and the potential for developing intricate motor skills through practice.