According to a new study, people with a slender jaw and a convex facial profile have more chances of being left-handed. To get to these results, researchers from the University of Washington analyzed three national surveys that included 13.536 people of the United States.
The recent study was published in the journal Laterality: Asymmetries of Body, Brain, and Cognition. According to the study findings, people with a thin shaped face have 25 percent more changes of left-handedness. However, they also find people with these features have more chances of having tuberculosis.
“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,” study author Philippe Hujoel told the University of Washington. “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.”
Curiosities of lefthander people
Several studies have tried to analyze the particularities of left-handed people in different aspects of life, including their creativity, their higher tendency to commit crimes and to drink more alcohol and mortality rate. Now, researchers have found a new connection between left-handedness and a certain facial feature.
Researchers say that people with a slender face have 25 percent more chances of being left-handed. According to them, statistics make sense, since thin jaws are almost as common as left-handedness. Only 1 out of five Americans have a slender jaw while only 10 percent of the American population is left handed.
Slender-faced people are more likely to succumb to tuberculosis
Tough there is nothing wrong with being left handed and having a slender face, it seems as if people with these features are more susceptible to tuberculosis, which is an infection that destroys lungs. According to the study, in the 19th century, the United Kingdom was considered the capital of tuberculosis in Western Europe. Additionally, UK happened to be the place of the region with the highest rate of slender-faced people and left-handedness. Slender faces have always been related to low body weight and, even today, that fact is recognized by the Centers for Disease Control and Prevention as a factor of susceptibility towards tuberculosis.
On the other hand, Eskimos, during that century, were considered to be a tuberculosis-resistant area, while the population had robust facial features and was mostly right-handed.
At least 1.8 million people were killed by tuberculosis in 2015. Tuberculosis is spread through the air through sneezes, coughs, or even just talking. It is estimated that about 10 to 15 percent of the global population is left-handed.
Tough the research is based on several national surveys taking into consideration 13,536 people, the hypothesis needs to be backed up with more and extensive research.