What causes left-right confusion?

It’s typical for kids to mix up left and right, especially when they’re young. Fully knowing which side is which can take until the age of 12, when kids develop certain verbal processing and visual processing skills. But some people struggle with telling left from right well beyond that, into adulthood.

Left-right confusion (LRC) is fairly common in adults. In a 2020 study, nearly one in six people, or 15 percent, reported having frequent trouble telling left from right.¹ An earlier study showed that women were nearly twice as likely to have difficulty than men.² 

As common as LRC is, little is known about why it happens — or even what the process for identifying left and right is to begin with.¹ And while telling left from right might seem simple for those who can easily tell the two apart, it’s a complex skill that involves high-level functions. These include:

• Visual-spatial processing

• Memory

• Language

• Integration of sensory information

Another important skill is “mental rotation.” This ability helps people know which side is which when it comes to something that’s facing them, since it’s the opposite of their own body.

LRC can create difficulties at school, at work, and in everyday life. But there are strategies that can help kids and adults identify left and right. 

There’s no one reason why people mix up left and right. For many people, it mostly happens when they’re distracted or trying to process other information. But for some, confusing the two sides is a constant problem. In those cases, the difficulty may be related to other conditions.

Dyslexia is a common learning disorder that makes it hard to work with letters and sounds. It mainly affects reading and spelling. But for some people, dyslexia also creates problems with spatial orientation. That can lead to difficulties telling left from right.

Dyscalculia is another common learning disorder. It makes it hard to learn and do math. A common symptom is trouble with spatial reasoning and directional awareness. This may show up as LRC.

Visual-spatial processing is the ability to know where objects are in space relative to where you are. People with visual-spatial processing issues may have trouble knowing left from right.

Damage to the parietal lobe of the brain due to injury or disease can lead to LRC. This area of the brain plays a key role in processing spatial information. 

LRC is a key symptom of a rare neurological disorder called Gerstmann syndrome. The disorder is a result of damage to the parietal lobe, often from a stroke.³ Other symptoms are the inability to name the fingers, the inability to write, and trouble doing even simple math tasks.

Other conditions that can be associated with LRC are dyspraxia, nonverbal learning disabilities (NVLD), and autism spectrum disorder (ASD).

For the most part, mixing up left and right doesn’t cause harm. But it does often lead to errors, frustration, and feelings of shame. Older kids and adults might shy away from tasks or activities that require knowing which side is which. Here are some common areas affected by LRC:

Understanding left and right and the position of objects in space are important skills for reading and writing. Trouble with those visual spatial skills can lead to letter reversal — writing letters or numbers backwards or upside down. It can also create problems with spelling.

Letter reversal is common in kids under the age of 8. But if the difficulty continues beyond that, it could be a sign of a reading or language challenge.

LRC can make it hard for people to get where they need to go, whether it’s on foot, on a bike, or in a car. Giving and following directions can be challenging, especially under pressure. (“Turn left. No, I mean right!”) 

LRC can cause people to take wrong turns and make them arrive late. And it can sometimes lead to accidents.

To tell left from right, the brain has to be able to orient itself in space. Trouble with this skill can affect how people function every day at school and at work. 

For example, they may struggle to read a graph or a chart, or to pass things around in the right direction. Getting from one location in the building to another might be difficult. So might placing objects where they’re supposed to go.

Mirror images can also be challenging. Even visual models can be hard to match, when doing things like setting a table or putting up a display.

Trouble understanding left and right can make it hard to do some sports and activities. Many team sports require making fast directional decisions to pass the ball or score a goal. Dancing and yoga involve following directions about which side of the body to move.

There are a number of simple strategies that kids and adults can use to distinguish left from right. They include:¹

• Jewelry check: Consistently wear jewelry — bracelets, watches, wedding bands — on the same hand. It’s a visual cue about which side is which. 

• The “L” trick: Make the shape of an L with the pointer finger and the thumb on the left hand. 

• Writing hand trick: Compare where an object is to the hand the person typically writes with. 

• Side of the road trick: Compare left and right to the side of the road the car drives on.

There’s no “cure” for LRC. But there are specialists who are trained to help. These include occupational therapists, who can work with adults and kids, and educational specialists. Parents can also help their child improve spatial skills with games and activities.

Mixing up left and right is a common problem for both kids and adults. Most people develop the ability to tell which side is which by the age of 12. But studies show that 15 percent of adults still struggle with left-right confusion (LRC).

Experts aren’t sure why that happens, although they do know that telling one side from another is a complex skill that involves many high-level functions. 

LRC can affect how people function and perform at school, at work, and in everyday life. It can make regular tasks and activities more difficult. These include navigating and driving, reading and spelling, and doing sports and physical activities.

There’s no “cure” for left-right confusion. But there are strategies kids and adults can use to know which side is which.