Scientists Still Don’t Really Know Why Some People Are Left-Handed

We know people (including this blogger) have been left-handed since humans painted caves, but the origin of this mutation — genetic, chemical or other — remains a mystery.

It may be an abundance of testosterone or just a womb preference that continues into adult life.

Left-handedness is associated with creativity, depression and dyslexia. Left-handed people are in many cases quicker and likelier to recover from brain damage, but also may be likelier to suffer post-traumatic stress disorder.

Of course we’re also really good at sports and getting elected president. Of the last seven presidents, five were either left-handed or ambidextrous. (The righties were Jimmy Carter and George W. Bush.) Al Gore, who won the popular vote in 2000, would have been the fourth consecutive left-handed president.

It’s hard to go back further than that, because it used to be quite common for parents and nuns to beat the left-handedness out of children. Cultures across the world have derided and feared left-handed people. The word sinister comes from the Latin word for left, sinistra. In parts of Asia, the left hand is reserved for the filthiest of duties.

Despite all the centuries of hatred and fear, lefties continue to make up a consistent minority of the population. In other words, you can try to wipe us out, but we keep coming back.

Tuesday was the 37th International Lefthanders Day, a good opportunity to bask in the mysterious miracle of our existence, asymmetrical brains and all.

— Posted by Peter Z. Scheer, who is left-handed.