Origins of handedness
Throughout the world, between about 5 and 20 percent of the population is left-handed. Favoring one hand for most tasks can allow people to do things more quickly, but exactly why there's such a strong bias towards right-handedness in humans is a mystery. Humans' close relatives, such as chimpanzees, are equally likely to be southpaws.
A 2012 study suggested that more cooperative societies that share tools and tasks have more people with the same dominant hand. Other studies propose that being a leftie is handy in a fistfight — but only if most people are expecting a right hook.
Although a few genes have been implicated in handedness, genes are not the entire story, as identical twins often favor different hands. Some have even proposed that brain damage in utero causes brains to rewire to make people lefties.
Origins of handedness
Throughout the world, between about 5 and 20 percent of the population is left-handed. Favoring one hand for most tasks can allow people to do things more quickly, but exactly why there's such a strong bias towards right-handedness in humans is a mystery. Humans' close relatives, such as chimpanzees, are equally likely to be southpaws.
A 2012 study suggested that more cooperative societies that share tools and tasks have more people with the same dominant hand. Other studies propose that being a leftie is handy in a fistfight — but only if most people are expecting a right hook.
Although a few genes have been implicated in handedness, genes are not the entire story, as identical twins often favor different hands. Some have even proposed that brain damage in utero causes brains to rewire to make people lefties.
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