A survey of more than 13,000 people found that those with a slender lower face are 25 per cent more likely to be left-handed.
Researchers said that slender jaws have also been associated with susceptibility to tuberculosis.
Professor Philippe Hujoel, of the University of Washington School of Dentistry in the US, said: “Slender jaws are a common facial feature, affecting about one in five adolescents.
“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.
“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.
“The low body weight of this slender physique is still today recognised by the Centres for Disease Control and Prevention as a marker for TB susceptibility.“
The new research, published in the journal Laterality: Asymmetries of Body, Brain and Cognition. could explain geographical coincidences, such as the prevalence of slender faces and left-handed people in Britian.
In the early 20th Century, thin people were described as ectomorphs, a term still popular as a reference to dieting and bodybuilding.
Prof Hujoel added: “In a world dominated by an obesity crisis and right-handers, ectomorphs can be different in their desires.
“Popular websites suggest they commonly express a desire to gain weight or muscle mass. Their slightly increased chance of being a ‘leftie’ is an additional feature that makes them different.”