The capacity of fold the tongue into a U shape (as if it were a eclair) is one of those body “tricks” that usually circulate as if they were a simple genetics test. But the accumulated evidence points to the opposite. Does not depend on a single genedoes not follow a clean Mendelian pattern and, furthermore, can be modulated by anatomy and learning.
In Spain and other countries it has been used for decades as a school example of dominant inheritance, although family studies and twin studies have shown that the fit is, at the very least, imperfect.
In different populations, classic works and informative reviews based on these data place the prevalence of “rollers” in a wide range (approximately between two thirds and four fifths). The margin varies depending on how the gesture is defined and how it is verified.
An interesting clue is that, when various lingual movements are evaluated in a healthy sample, some of the participants believe that they can make certain gestures but do not execute them correctly when asked. That difference between perception and execution suggests that “yes or no” is not always as obvious as it seems in the mirror.
The most solid explanation (genes, anatomy and practice)
The specialists consulted in the source information (geneticists Olavo Siqueira, Samuel Nogueira y Bethany Loures) point out two big pieces of the puzzle.
One is biomechanics. The tongue is a complex muscular organ and its ability to adopt a shape depends on the flexibilitythe fine control and coordination of their muscles, in addition to anatomical factors such as palate and the space available in the oral cavity.
The other is inheritance. The most accepted hypothesis today is that, if there is a genetic component, it is more like a polygenic and multifactorial trait (many genes with small effects, more environment) than to a “single gene” switch. In genetics, that category is used for traits that do not follow Mendel’s simple rules and can also be influenced by the environment.
That approach fits with what the data cited by researchers and academic disseminators show. Studies in families and twins indicate that there is genetic influencebut also room for non-genetic factors (from anatomical variations to learning).
Can you learn to bend your tongue?
The idea that skill can train It is not just an urban myth. If the gesture depends in part on muscle control and coordination, it stands to reason that some people will improve with practice. This does not mean that anyone will get it, but it does mean that the trait does not work as a “home genetic test.”
A practical recommendation for the reader is simple. If after several attempts the tongue does not take shape, there is no reason to worry. It is not a health indicator or a clinical sign.
Another point on which specialists agree is that there does not seem to be a direct evolutionary advantage associated with this gesture. Rather, it is a useful example of how small differences in anatomy, development, and heredity can translate into different bodily capabilities without implying biological superiority.
