Two relatives of mine (who will remain anonymous) are notorious within my family for confusing right with left.
I don’t mean politics. I mean directions.
Both of these individuals have acted as my map-reader and navigator as I’ve driven through unfamiliar territory, in the United States and abroad. This is what happens, repeatedly:
“Turn left here,” says my navigator, and I start making the turn. “No, no!” shouts the navigator. “Turn left!”
“I am turning left,” I say.
“Ah, yes, so you are,” says the navigator, now much subdued. “Well, I meant right.”
Needless to say, I was more than a bit intrigued to see an article this week in MSNBC’s “Body Odd” blog about “Why some people can’t tell right from left.”
Apparently, “left-right confusion,” as neuroscientists appropriately call the phenomenon, is quite common. More than 25 percent of college students and about 20 percent of college professors reported the problem in one study, according to an expert on the topic. People with it shouldn’t be concerned, however. It’s not a form of dyslexia. Nor does it reflect any neurological problem.
Still, scientists remain in the dark about exactly why some people experience frequent left-right confusion. It appears, however, to be linked to brain lateralization — the idea that the right and left halves of the brain’s cerebral cortex control different functions. The more asymmetric that lateralization, the more vulnerable we may be to left-right confusion.
“The degree of asymmetry of one’s brain hemispheres, or the degree of lateralization, may be important,” writes MSNBC’s Brian Alexander. “In 2009, British scientists found that those whose hearing was more biased toward one ear over another, a sign of asymmetry, were more likely to display confusion.”
Explanations for gender differences
In the past, scientists believed that left-right confusion might be linked to spatial reasoning. This theory seemed to explain why some studies (but not all) had found left-right confusion to be more prevalent among women.
“As a group,” writes Alexander, “women tend to underperform on a critical test of spatial reasoning, called mental rotation, that requires subjects to mentally rotate images to tell if they’re identical or mirror images of each other.”
But, as Alexander reports, a 2011 study found that left-right confusion does not appear to be connected with mental rotation abilities.
Although Alexander doesn’t mention it in his article, back in 2006, the authors of another study concluded that gender differences in left-right confusion may have a very simple explanation: Women, that study found, tend to more willing to acknowledge the problem.
Take a test
Want to test your own level of left-right confusion? Eric Chudler, director of the Center for Sensorimotor Neural Engineering at the University of Washington, has a test on his website.