Telling the difference between left and right might seem as natural as knowing up from down. But it’s not that easy for a significant portion of the population.
Lauren Winzer, a tattoo artist in Sydney, Australia, recently posted a photo of a client who requested that the letters “L” and “R” be permanently inked on her hands to help her navigate the world.
“I’ve had hundreds, including myself and friends, talk about getting (similar tattoos)," Winzer told TODAY.
“Not only are (the) tattoos cute, but they can also be super functional!!!” she wrote on her Instagram page.
Winzer’s client did not respond to a TODAY request for comment, but she told Daily Mail Australia she had always found it difficult to distinguish between left and right, to the point where a friend once drew an “L” and “R” on her hands. That’s when the idea for something more permanent began.
“It started as a joke, but it's actually super useful,” D'Kodia Laine, a 23-year-old student from Canberra, told the newspaper after getting the tattoos.
Almost 15% of the general population reported having trouble identifying left from right, according to a study published last fall in the Quarterly Journal of Experimental Psychology.
Previous research has put the number as high as a quarter of college students and a third of adults. One early study concluded right-left confusion “occurs often in adults, even of superior intellect.” Women appear to be more susceptible to it than men, another found.
It may seem like a minor annoyance, causing someone to take a wrong turn when hearing directions or lift the wrong leg in yoga class.
But right-left confusion can have devastating consequences if the person affected is a doctor who might mix up which lung, kidney, eye, limb or side of a patient to operate on.
It’s estimated wrong site surgery — operating on the wrong organ — happens 40 times per week in hospitals and clinics in the U.S.
Some of it is due to misperception — when the surgeon or staff mixes up the left and right, or the front and back of the patient despite having the correct information, said Dr. John Clarke, an emeritus professor in the department of surgery at Drexel University in Philadelphia, who studies medical errors.
With right and left confusion, people “can't immediately tell their right from their left without having to think about it first,” Clarke told Outpatient Surgery Magazine. That means if he were to say, "Raise your right hand" to a group of people, a portion of them might raise their left hand or have to take a few moments to think about it.
Why do healthy people have trouble telling left from right?
At least two processes are critical for this seemingly simple task: a perceptual/spatial process — picking some side, not the middle; and a labeling process — sticking the “right” word to the “right” side, said Marco Andre Hirnstein, a professor in the department of biological and medical psychology at the University of Bergen in Norway who studies the phenomenon.
It’s the labeling process where things typically go wrong, he noted.
“Why do we struggle less with other orientation labels such ‘up-down’ or ‘front-back’? Well, all those labels have absolute, physical features that make them more easily distinguishable: ‘Down’ is where things fall. ‘Up’ is from where things fall. ‘Front’ is what I can reach more easily,” Hirnstein told TODAY.
“But there is no such absolute, physical feature with ‘left’ and ‘right.’”
People try to make it easier by remembering that the right hand is the one they write with, or the left hand is where they wear their wristwatch or the one that allows them to form the letter “L” with their thumb and index finger.
But once you figure out your own left and right, you need to grasp that it’s not necessarily another person’s left and right, he added.
To illustrate the challenge, Hirnstein recommended a thought experiment from Chris McManus, author of the book “Right Hand, Left Hand”: Imagine you have to tell a Martian what left or right is, but you are only connected via loudspeakers. How do you do it? The wristwatch, hand-writing and thumb trick don't work because the Martian doesn't have any of those. “It’s tricky,” Hirnstein said. “(But) despite the struggle, we get it ‘right’ most of the time.”
Brain damage can also cause the phenomenon: Gerstmann's syndrome is a rare neurological disorder that can happen after a stroke and leave patients unable to distinguish between the right and left sides of their body.
But for the vast majority of people with right-left confusion, it’s just a quirk of the brain.
You can check out your own degree of left-right confusion in an online test. Many people take a longer time identifying up and down vs. left and right.