For the first time, scientists have identified the genes linked to being left-handed.
And those genetic differences result in different brain structures for lefties versus right-handed people.
In lefties, communications between the left and right sides of the brain are more coordinated, suggesting that lefties have better verbal skills than those who are right-handed.
Those brain differences may also help explain why lefties are slightly more prone to schizophrenia, but less prone to Parkinson's disease.
Researchers, funded by the UK's Medical Research Council and Wellcome, a UK medical research charity, studied the DNA of 400,000 people, including 38,332 left-handers.
They isolated four genetic regions associated with left-handedness; three of those regions were linked to proteins that influence brain structure and development.
About 10% of the earth's population is left-handed.
The study was done at the University of Oxford, and reported in the journal Brain.
Study leaders suggested future research into differences between lefties and right-handed people on performing verbal tasks
Scientists identify genes that cause left-handedness