How are Cross Dominance and Learning Disabilities Linked?

Having a child who is mixed-handed or ambidextrous -- where they use different sides of their body for different tasks -- seems like a benign physical talent. But recent studies have found that children who don't prefer one side to the other are "more likely to suffer from language and learning problems, such as attention deficit/hyperactivity disorder (ADHD), than their right- or left-handed peers."

Does your ambidextrous child exhibit developmental delays? The two may be linked due to a brain function called cross dominance.

What is cross dominance?

Most people have one side of their body that's stronger than the other. If you're right-handed, chances are you do everything with your right hand -- writing, brushing your teeth, eating, etc. That also means you likely have stronger sight in your right eye, stronger hearing in your right ear, and would react more with your right foot. When we write, hit, kick, and turn our head to hear, we're typically doing it all with the same side.

However, cross dominance -- also known as "mixed handedness" -- is a manifestation of motor skills where the dominance is mixed, and different sides of each body part are stronger than the other (having left eye dominance while being right-handed, for example.) Someone with cross dominance may even prefer to perform different tasks on different sides with the same body part, like prefering to write with the right hand but eat with the left hand.

Where does cross dominance come from?

According to a piece from Brain Balance Centers, cross dominance is likely the result of brains that are "imbalanced and not developing properly." This is related to a concept called functional disconnection syndrome, a naturally occurring disconnect in the brain not related to any kind of trauma or surgery. The different hemispheres of brains with this syndrome don't comunicate properly, or at least at the correct speed, causing miscommunications and longer processing time. Though functional disconnection syndrome is not a medically recognized condition, it is theorized as being related to the cause of autism and dyslexia.

Cross dominance as a learning disability

In a cross dominant brain, information that would normally be processed on both sides of the brain has to jump back and forth between each hemisphere. Instead of processing vision and hearing on the same side, for example, the brain struggles to process the vision information and the hearing information from the respective left and right sides at the same time. And when information takes longer to process, that results in a developmental delay -- which many would recognize as a learning disability.

In a way, the mixed dominance causes the brain to be "disorganized," with information and responses scattered over both sides. Think of it as a filing cabinet -- if it's organized well, in alphabetical order, it's easy to find a file. In a disorganized and unalphabetized cabinet, even if the files are there, it will inevitably take much longer to find them. Likewise, students with cross dominance may run into this problem when studying for a test -- they'll know something the night before when studying, but by test time, it's lost in their disorganized "filing cabinets". With information so scattered in the brain, it's much harder to take it in, assimilate it, and process it, because the brain couldn't make a firm pathway when the information first arrived.

 Signs and symptoms of cross dominance

A 2010 study showed that people with mixed dominance are more likely to have language and scholastic issues, and ADHD symptoms. A student with cross dominance affecting the eyes may have similar problems to dyslexic students, like confusing printed letters and words (b and d, saw and was). It can affect reading comprehension, too; if information comes from the dominant right eye (reading the blackboard) and dominant left ear (listening to the teacher), the information will be going to opposite sides of the brain. That means the brain has to work extra hard to get the two messages together, meaning a higher likelihood of mixing up or incorrectly remembering information. 

In fact, cross dominance can explain many learning behaviors such as:

  • Misplacing objects.
  • A tendency to rotate papers strangely or rotate the head 40 degrees when writing.
  • Switching or difficulty reading and writing the left and right sides of letters.
  • Constant indecisiveness.
  • Poor handwriting.
  • Difficulty with organization, motor movements, and performing tasks that cross the body midline.

What to do with a cross dominant child?

The most important thing to remember is, like any learning disability, this does not make your child "unintelligent." In fact, in some cases cross dominance can be an advantage. In baseball, for example, having cross dominance or being ambidextrous often allows left-handed pitchers to also be right-handed hitters, which gives that player a huge advantage, based on a 2009 study.

Cross dominance isn't synonymous with ambidextrous, however; being cross dominant doesn't necessarily mean both sides are equally strong. But it still means that someone with cross dominance has a uniquely built brain. As a parent, it's helpful to find the strengths your child has with their unique brain, and help keep them as organized and focused as possible.

Learning Success can provide the tools and skills you need to improve learning with cross dominance. If you'd like to learn more, sign up for our free course!

Can You Really Increase Learning Ability Simply by Identifying the One Missing Micro-Skill?