(CNN)Left-handed people are better in combat than their right-handed counterparts, according to new research -- something that may help to explain the continued existence of the trait.
Around 10% of the population is left-handed, and research has linked the preference to higher rates of breast cancer, bowel problems such as Crohn's disease, and schizophrenia.
Given the costs of left-handedness you might expect the trait to have disappeared as humans evolved, but there is an interesting explanation.
According to the "fighting hypothesis," right-handed people are more used to fighting fellow right-handers due to the relative rarity of left-handed people.
As a result, left-handed people, also known as southpaws, have a competitive advantage in combat because their opponents are likely to be disoriented by their fighting stance.
During more violent eras in human history this meant that left-handed people would have been dominant in physical confrontation and therefore more able to spread their genes, explained researcher Thomas Richardson, an evolutionary biologist and PhD student at the UK's University of Manchester.
Richardson co-authored new research, which has not yet been peer reviewed, with University of Manchester lecturer Tucker Gilman. It is published in full on the online journal BioRxiv.