Kids' Health

Why Some Kids Are Left Handed, Some Are Right, And Some Are Both

Let's be even-handed about this.

by Chase Scheinbaum

Unless you’re nun from a century ago, chances are you won’t force a naturally left-handed kid to become righty. And that’s good, because besides being weirdly superstitious, training children to have a different dominant hand can have repercussions on their brain.

But what about baseball players? Piano prodigies? Goofy-footed skateboarders? What’s happening to their impressionable minds? Michael Corballis, a neuroscientist at the University Of Auckland, is pretty even-handed when it comes to the facts about ambidexterity. Here’s what you should know when your kid starts exhibiting a dominant hand, and what you can and can’t do to foster a budding switch-hitter.

What Is The Deal With Handedness?

The short answer is that science isn’t sure. For years, left-handedness was believed to be due to birth stress (is there birth relaxation?). Another theory gaining currency says lefties and ambidextrous kids are born without the gene for right-handedness. In other words, left-handedness is just the lack of right-handedness.

Apparently, fetuses already have a dominant hand in utero. If it’s a genetic thing, “that explains why the majority of people should be right-handed,” says Corballis. Left-handedness could have also persisted for so long because it has some advantage. “Maybe there was something about warfare going back in time that gave reason for a minority of people to be wired that way.” Of course, if Game Of Thrones taught you anything, it’s to watch out for the guy with both hands on the sword.

Lefties Shouldn’t Be Righties

“It goes right back to Biblical times,” says Corballis, who says that the idea of a left hand being “sinister” has been around for centuries. Of course, in these less superstitious times, science has determined that forcing a kid to use the opposite hand has no ostensible value and can be “disastrous.”

This has to do with how the 2 hemispheres of the brain govern language and movement. Forcing a switch confuses the process, and there’s even evidence it can cause stuttering. “The brain is not quite sure which side should be used for language, so there’s a competition that may cause a breakdown in fluency,” he says. Basically, if you’re looking to exorcise the devil from their left hand, you might end up teaching them to speak in tongues.

But They Also Shouldn’t Be Taught To Use Both Hands

Ok, so maybe it wasn’t all the nuns’ fault. Just as forcing lefties to be righties didn’t achieve much, neither did a counter-movement of sorts that sprang up in the early 20th Century called the Ambidextral Culture Society. This group thought it would benefit all kids to be trained to be ambidextrous. Although, if you really want to blame someone for starting this handedness business, blame French philosopher Jean-Jacques Rousseau. He was the guy who talked about the social contract, and you see how well that’s working out.

Let Them Do What Comes Naturally

A lot of lefties naturally perform some tasks with the right hand, or in an unorthodox manner with the left. But, Corballis says let them do whatever comes naturally. In the rare event a kid seems confused about which hand to write, throw, or chop onions with, feel free to guide them to be dominant with one hand. You won’t screw them up (more than you already do).

You Can’t Force It, But It’s Not Bad To Encourage It

Corballis believes that athletes who are great switch-hitters, goofy-footed skateboarders, or switch-stance boxers are able to do it because it’s innate, not because it’s taught. So, if you find your kid juggling LEGOs or playing 2 Xbox controllers at once, let them go for it.

Corballis says letting kids explore natural ambidexterity can be “healthy and beneficial.” The same goes for pianists or drummers who strengthen their weak hand, but don’t switch dominant hands entirely. “The human brain is built to be asymmetrical,” he says” But, if you mess with it too much you get into trouble.”