Updated: October 22, 2002

Every time I post the information about NACD memory tapes on any home school board, it generates a flood of questions – most of which I am not qualified to answer. 

I inevitably get many questions about mixed dominance, so here is a short summery of what little I understand about what NACD teaches.  Again, these are not my ideas, and I’m not qualified to answer difficult questions, defend this theory against those who disagree, or compare/contrast this theory with other theories. I’m just throwing this out “FYI” for those who ask. It’s interesting -- fascinating, really – and sometimes helps explain a lot. But I’m not an expert! Use this information at your own discretion.

(BTW, most MDs have never been taught this information, either. So if you ask your ophthalmologist, for example, about eye dominance, you won’t get an answer that coincides with anything you’d learn from NACD.)

That being said…

Mixed Dominance

First, mixed dominance is very, very common in our culture, but it’s not normal, and it does have an effect on the person’s ability to learn.

There are four areas of dominance in the human body:

Your foot, eye, and ear should be dominant on the same side as your dominant hand. If one or more is not, you have mixed dominance issues.

People with mixed dominance often display certain characteristics, which can include any/all of the following (this is lifted directly from my NACD parent training seminar notebook):

If this describes you, you may very well be one of the thousands (millions?) of Americans with mixed dominance in one or more of your senses.

How do I determine which side of my body should be dominant?

The hand is the best way to determine which is your dominant side. It almost never gets confused unless you lose your dominant hand, or lose the use of your dominant hand. (That is why it is so detrimental to force a left-handed person to use his/her right hand. It really messes with the brain.) NACD tells me that they have never once run across a truly ambidextrous person – every single case they have seen, without exception, was actually a case of mixed dominance.

The foot.  When you go to kick a soccer ball, you generally lead with your dominant foot. You might have to observe yourself or your child over a period of time to be certain which foot is actually dominant. NACD had me do “hopping” exercises with my kids when they were little to firmly establish the right foot as their dominant foot – they’d hop on the right foot for 2 minutes, twice a day. (It was also good exercise and helped with coordination, but the primary purpose was to make sure the dominance didn’t get confused while their young, developing brains were sorting out all their dominance issues.)

Eyes are often the culprit in mixed dominance cases. Eye dominance is easily testable:

Shifting dominance in the eye.  If you are dominant in the wrong eye, dominance can be shifted back to the proper eye by occluding (covering or patching) the eye that is dominant (but should not be) for a certain amount of time per day, every day over a period of weeks or months. This is a tricky process that can take a long time, and I’m not the one to tell you how to do it.  It should only be attempted under the guidance of a qualified NACD evaluator.  I do know that to accomplish this purpose, people use eye patches, special glasses, or a contact lens that is so far off prescription that the eye can’t see through it.

The ear is a very common culprit of mixed dominance, but can be difficult to test. One simple way is this: if you’re displaying symptoms of mixed dominance, but the hand, foot, and eye seem to be okay, it’s probably your ear. You can also observe your child carefully over a period of time to see which ear they seem to favor, but it’s more difficult than the other senses to determine for certain.

A big cause of mixed ear dominance in our day and age is the telephone. Right-handed people tend to always put the telephone to the left ear in order to keep the dominant hand free for writing (and vice versa for left-hander). This is fine for writing; but over time, especially if you have a job that requires you to be on the phone for extended periods, you can inadvertently shift your dominance to the wrong ear. If you find you have a lot of trouble remembering facts you receive by phone, it may be because you’re inputting the information sub-dominantly. Try switching to the ear on the same side as your “handedness.”  You may be able to remember better.

I personally finally decided my ear was the problem when I remembered my orchestra experience. I play the cello, which is on the edge of the orchestra as they are traditionally seated. When I was 1st, 3rd, or 5th chair, I would be sitting on the outside of the music stand on the very edge of the orchestra. That is, my left ear would be to the audience, my right ear to the orchestra. When this was the case, I couldn’t “hear” very well – that is, I had more trouble processing the information. But when I sat 2nd, 4th, or 6th chair, I’d be sitting on the inside of the music stand, with one other cellist between me and the audience. I could hear that cellist through my left ear, and could process all the auditory information better. This tells me my left ear is dominant.

Shifting dominance in the ear.  You can switch ear dominance back to the correct side by occluding, or plugging, the offending ear several hours a day over a period of weeks or months. Again, I’m not the one to tell you exactly how to do it! 

One thing you’ll notice, though, if you suspect you’re mixed dominant in your ear, and you plug the dominant ear that should really not be dominant… you may think after a few minutes that you’re going insane. I did. I couldn’t process any auditory information well, and it about drove me crazy! It almost sounded like everyone around me was speaking a foreign language. This was another very good indication that I was right about my ear dominance being wrong.

Should I be concerned about switching my mixed dominant sense back to normal?

Maybe, maybe not.

NACD rarely tries to correct dominance issues in normal, high-functioning adults. First, it will drive you crazy to mess with it, so unless it’s causing you a lot of difficulty, you may be better off leaving it alone. Also, the older you are, and the longer you’ve had the problem, the longer it takes to switch it back. But it can be nice to know what the problem is, and if you’re really determined, you can do it.

NACD primarily tries to switch dominance back to normal in children where the mixed dominance is creating a problem with learning. Especially in children with brain injuries or learning disabilities, the problems created by mixed dominance can be very pronounced, and the benefits of correcting them can be the most advantageous.  When you’re dealing with a disability or injury, every little thing you do to help can make a big difference. And the younger the child, easier it is to switch (or establish it in the first place), so the more important it is to make sure the dominance is correct.