What Makes a Lefty: Myths and Mysteries Persist
“Can openers, scissors and spiral-bound notebooks discriminate against lefties. Despite such challenges, 10 to 12 percent of the human population has historically preferred the left hand.
Why doesn’t the number ever waiver? Nobody knows for sure, but new research supports a body of evidence that suggests genetics have a hand in it all.
In the meantime, the myth remains that lefties are more artistic. And the idea that left-handed fighters have an advantage persists on scant evidence, supported by Scottish lore and Rocky Balboa’s heroics in the ring.
Look, Mom: Both hands!
Like many traits, handedness is probably determined by a complex interaction between genes and the environment, experts figure.
Left-handers are more likely to have a left-handed relative. But researchers have yet to find the gene or set of genes that pick one hand over the other.
Most scientists agree that handedness exists on a continuum. The idea helps explain why some people bowl with their left but hold a spoon in their right. Truly ambidextrous people, who have indifferent preference for either hand, are extremely rare.
In a new study, researchers measured the width of elbows in living people and in skeletons from a medieval British farming community.
The researchers assumed the 9-to-1 ratio of handedness would match the ratio of bigger right to left elbows. The prediction held true in the modern-day group, but not for the medieval bones.
Most of the ancient farmers’ left and right elbows were the same size.
“It’s obvious that they were using both hands equally,” said anthropologist Amanda Blackburn from the University of Manitoba. “It’s not fair to say they were ambidextrous in the true sense of the word, but they may have had a tendency to use both hands equally. It’s a behavior they may have learned rather than just being born like that.”
The findings will be published in the April issue of the journal Current Anthropology.”
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