New York: People with a thin lower face are about 25 per cent more likely to be left-handed, new research has found.
People with slender jaws typically have a lower jaw which bites a bit backward, giving them a convex facial profile, commonly called an overbite.
This unexpected finding, published in the journal Laterality: Asymmetries of Body, Brain and Cognition, was identified in 13,536 individuals who participated in three national surveys conducted in the United States.
This association may shed new light on the origins of left-handedness, as slender jaws have also been associated with susceptibility to 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!" said study author Philippe Hujoel, Professor at the University of Washington School of Dentistry.
"Twentieth century studies confirmed his clinical observations, as slender facial features became recognised as one aspect of a slender physique of a TB-susceptible person," Hujoel said.
The new finding linking left-handedness with a slender face raises the hypothesis that the genetics that shape facial features and tuberculosis susceptibility also increase the likelihood for left-handedness, according to the study.