The Grapevine

The Downside Of Left-Handedness: Strange Link Between Lefties, Facial Shape, And Tuberculosis Risk

There are a lot of crazy rumors about left-handedness; for example, these people are more inclined to be violent and drink more alcohol, but I bet you’ve never heard that the trait is also associated with more slender faces and increased susceptibility to disease. While it may sound odd, that's the conclusion of a new study based on a survey of over 13,536 individuals.

In a study published online in the journal Laterality: Asymmetries of Body, Brain and Cognition, Philippe Hujoel from the University of Washington School of Dentistry, found that individuals with slender lower faces were about 25 percent more likely to be left-handed. In addition, because of this specific face shape, this group was also more likely to have an overbite and an increased susceptibility to tuberculosis (TB). According to Hujoel, this may explain why the United Kingdom, where a large portion of the population have slender faces, have some of the highest rates of TB in Western Europe, where in ethnic groups with more robust faces, such as the Eskimo Indians, TB is extremely rare.

Read: August 13 Is International Left-Handers' Day: Let's Separate Facts From Myths About Lefties

"Almost 2,000 years ago a Greek physician was first to identify slender jaws as a marker for TB susceptibility, and he turned out to be right!" Hujoel explained in a recent statement. "Twentieth-century studies confirmed his clinical observations, as slender facial features became recognized as one aspect of a slender physique of a TB-susceptible person. The low body weight of this slender physique is still today recognized by the Centers for Disease Control and Prevention as a marker for TB susceptibility."

slenderface Slender faces with an overbite may be the tell-tale sign of a left-handed individual. Photo Courtesy of Philippe Hujoel

According to Medical News Today, TB is an infectious disease that mainly affects the lungs. It is one of the biggest global killers in the world, and in 2015 killed an estimated 1.8 million people. The disease is caused by a bacterial infection spread through the air through sneezes, coughs, or even just talking or laughing. In addition to individuals with slender faces, individuals with compromised immune systems or who use tobacco are more likely to become infected with TB.

For their research, the team looked at the facial structure and handedness of 13,536 individuals who had participated in three different national surveys within the United States. The finding is interesting, but it's not clear if it's any more than a surprising coincidence.

Left-handed people make up only about 10 to 15 percent of the world’s population. In a world dominated by righties, lefties can often face inconveniences for beyond susceptibility to TB. For example, many report aching hands or backs while writing and sitting in desks made for right-handed people.

Source: Hujeol PP. Handedness and lower face variability: Findings in three national surveys. Laterality: Asymmetries of Body, Brain and Cognition . 2017

See Also:

Left-Handed People Have Ups And Downs, And Sometimes Rights: The (Possible) Dangers Of Being A Lefty

International Left-Handers Day 2016: Lefties Face Psychological Battles, But Are More Creative Thinkers

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