An old joke runs like this: "If the left side of the brain controls the right side of the body, then only left-handed people are in their right minds". As funny as that sounds, the reality is that no one is absolutely left or right brain dominant. What we know is that we are "more" left or right brained, and yet it takes "two hemispheres to be logical or to be creative" according to the experts. (NPR)
There are many debates about the dominance of hemispheres, but it is helpful to understand just what we are talking about when we say something like right brain dominance.
As an article in Psychology Today pointed out: "our brains, contrary to popular belief, are not actually divided into two spheres. But something called the Neocortex is, and it makes up two-thirds of the brain." As the most advanced part of our brain, its two sides are what determine how it is we think and whether we are more right brained or left brained, per se.
The dominance is what determines how the rest of the Neocortex is going to function. As a prime example, while the left brain is the seat of language, it does not mean that the right side of the brain is devoid of it. Damage the right side and some parts of the speech will show signs of damage as well. However, someone who is left brain dominant is likely to learn new languages far easier than someone who is right brain dominant.
Confused? Don't worry; scientists remain a bit unclear and challenged by it all, even disagreeing with one another over the whole issue. What they can agree on is that there is "hemispheric specialization across people" and that it really matters most when we are dealing with medical issues. For example, a test known as WADA uses drugs to shut down one hemisphere in order to gauge whether or not someone is right or left dominant prior to performing surgery. Re-sectioning a tumor or performing a procedure to treat epilepsy requires knowing where critical functions occur, and avoiding the disruption or removal of tissue that provide them.
When using any of the self-tests for determining whether you are right or left brain dominant, the experts suggest taking the results with a grain of salt. After all, it is very hard to determine the realities of dominance with simple testing as both sides are actively participating in almost everything that we do.
However, as another group of scientists indicated, there are structural asymmetries in the two sides, including shape, size, and even how they respond to hormones or use neurotransmitters. A "stroke to either side of the brain does indeed result in significant different forms of pathology" (CreativityPost)
Because of these realities, it would seem that doing an array of different tests is the best way to gauge whether your brain is more left or right dominant. Finding out which, is going to reveal to you some details about the ways that your brain processes information, or as one study proved the way the sides of the brain "pay attention".
In the end, we must recognize that dominance is probably not all that important because both sides are functioning at all times. We are not one or the other, explaining why a scientist can be very analytical and mathematical in the lab, but at the same time can be extremely creative and inventive when making up experiments that will evaluate or test facts.
So, whether your tests show you that you are left or right dominant, what you'll want to focus on is total brain health. Use your brain in as many ways possible, challenging it creatively and analytically. Make sure you exercise and eat a good diet, and even consider the innovative use of nootropics (functional foods, supplements, and nutraceuticals that improve brain performance).
CreativityPost. The Myth of… http://www.creativitypost.com/psychology/the_myth_of_the_myth_of_the_right_brain_difference_and_why_it_matters
NPR. The Truth about… http://www.npr.org/sections/13.7/2013/12/02/248089436/the-truth-about-the-left-brain-right-brain-relationship
PyschologyToday. Are You Left… https://www.psychologytoday.com/blog/not-born-yesterday/201210/are-you-left-or-right-brain-dominant