Left-handers, who represent only 10 per cent of the human population, have been viewed with suspicion and persecuted across history. The word "sinister" even derives from left or left-hand.
To find out why they are a rarity, researchers from the Northwestern University looked at data from the sports world.
They developed a mathematical model that showed that the low percentage of lefties could be a result of the balance between cooperation and competition in human evolution, LiveScience reported.
Prof Daniel Abrams, who led the study, said: "The more social the animal -- where cooperation is highly valued -- the more the general population will trend toward one side."
"The most important factor for an efficient society is a high degree of cooperation. In humans, this has resulted in a right-handed majority."
According to the researchers, who detailed their work in the Journal of the Royal Society Interface, if societies were entirely cooperative everyone would be same-handed. But, if competition were more important, one could expect the population to be 50-50, Prof Abrams said.
The new model can predict accurately the percentage of left-handers in a group
