Anyone who follows boxing could be forgiven for thinking that left-handedness is common: Not only is there the widespread use of the term "southpaw,” which denotes the fighting stance of a left-hander, there are household names such as Manny Pacquiao, Oleksandr Usyk and Marvin Hagler - all world champions.
But such southpaws are rare: only 10% of people are left-handed, adding another angle to the exceptionalism of notables such as Napoleon Bonaparte and Leonardo da Vinci.
Scientists at University of Oxford and the nearby University of Reading believe they have found at least part of the reason why there is not something closer to an even split between left and right.
The answer comes down to how human brains developed and expanded and - in contrast to other primates where left-handedness is more common - our walking on two legs.
“Our results suggest it is probably tied to some of the key features that make us human, especially walking upright and the evolution of larger brains,” said Thomas Püschel, professor of evolutionary anthropology at Oxford.
In a paper published by PLOS Biology, the team described the right-handedness seen in humans as not only “striking” but a “singularity.”
“The level and consistency of handedness in humans is unmatched” and remains largely “unexplained,” the scientists said in the paper, setting out why they undertook the research.
“About 90% of people across every human culture favour their right hand - with no other primate species showing a population-level preference on this scale,” the University of Oxford said, describing the prevalence of right-handedness as an “enigma.”
Researchers previously shown that handedness is established during formation of the spinal cord. As early as the 13th week of pregnancy, embryos already show a preference to suck either the right or the left thumb.