April 28 (UPI) -- A study by researchers at the University of Washington has found that people with slender faces are 25 percent more likely to be left-handed.
Researchers analyzed 13,536 individuals who participated in three national surveys in the United States also discovered that slender faces and jaws were associated with overbite and tuberculosis.
About one in five U.S. adolescents have slender jaws and past studies have shown the prevalence of overbite and tuberculosis in individuals with slender jaws.
"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," Philippe Hujoel, professor at the School of Dentistry and professor of epidemiology at the School of Public Health at the University of Washington, said in a press release. "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."
Researchers found the genetics responsible for shaping facial features and tuberculosis susceptibility also increase the likelihood of being left-handed.
There are also geographical elements to the phenomenon, researchers say, such as Britain being known as the tuberculosis capital of Western Europe, while also having a high prevalence of left-handedness and higher proportion of people with slender faces.
The study was published in Laterality: Asymmetries of Body, Brain and Cognition.