Daniel Voyer, Ph.D.,

Daniel Voyer Ph.D.

Perceptual Asymmetries

The Truth About Being Left-Brained or Right-Brained

Do you think of yourself as a right- or left-brained person and does it matter?

Posted May 28, 2015

Iakov Filimonov/Shutterstock
Source: Iakov Filimonov/Shutterstock

Which side of your brain gets the most use, the right or the left? Today, most people have heard that each hemisphere of the brain manages different tasks. If we favor one type of thinking over another, we could be classified as favoring left or right hemisphere strategies, making us “left-brained” or “right-brained." Right-brained individuals, according to this general idea, tend to be creative, curious, and intuitive, whereas left-brained individuals are more logical, methodical, and rational.

In reality, according to scientific evidence, this conceptualization is based on a complete misunderstanding of the "concept of laterality." But this is nothing new. The craze began when the concept of laterality was first introduced. In 1978, Bryden reported that the idea of laterality initially met skepticism—but not for long!

Essentially, it came to be seen as correlated with almost any possible variable, including hypnotizability, choice of profession, and personality characteristics. This last point is interesting, as the notion that you could be a left- or right-brained person becomes a personality test. In fact, when I started writing this blog, I did a Google search on "left brain or right brain" and it produced nearly 30,000 hits. Among the first 10, three "debunked" the myth that you could be a left- or right-brain thinker (some of them throwing away the baby with the bath water) and six were links to tests measuring whether you are left- or right-brained. For the most part, of course, these tests are silly and invalid. They assume that the left-brain/right-brain distinction is clear-cut, when it is really not that straightforward. (For an interesting take on the left-brain/right-brain-personality connection, as well as other laterality myths, see this post by Steven Novella.) 

Still, it is somewhat puzzling that so many people are still “buying” the notion that someone could be left- or right-brained. Many books try to sell the notion that you could invest with your left brain, or adapt to your students' left- or right-brain style, among many other topics. Yet neuroimaging research suggests that we use structures in both cerebral hemispheres to perform most activities. Essentially, if there was such a thing as “left-brained” individuals, would it mean that they are half-brain dead? Should we expect such people to be totally emotion-free and logical at all times? After all, emotions are seen as the realm of the right hemisphere—although even that is debatable (according to Demaree et al., 2005).

The notion of left- and right-brained humans takes on a different dimension when we consider that cerebral specialization is also found in many animal species. Ingram (2015) wrote a nice piece for Canadian Wildlife on this topic. In brief, he claims that the bulk of relevant animal research suggests that cerebral specialization is more a matter of survival than of personality. From this perspective, the left hemisphere of many animals would be involved in the perception of details, whereas the right hemisphere would be involved in the detection of novelty. The former would therefore contribute to the ability to perceive, for example, an edible object in the environment, while the latter would help with the detection of potentially threatening changes in the environment. This means that if my pet cockatiel had a “left-brained personality," he would likely ignore novel objects—and would not survive very long!

In reality, even though we can think of left- and right-hemispheric functions in humans as much more complex than the simple dichotomy that might be found in other species, we all need to use our whole brain to survive in our complex world. Of course, perhaps it is just my logical left brain denying my right-hemispheric creative side. No, this is not possible: A test I took on the Internet concluded that I have a “balanced brain," using both sides relatively equally. So, there you have it: I must always be right! (...or left!)
 

References

Bryden, M. P. (1978). Strategy effects in the assessment of hemispheric asymmetry. In G. Underwood (Ed.), Strategies of information processing (Pp. 117-149). London: Academic Press.

Demaree, H.A., Everhart, D.E., Youngstrom, E.A., & Harrison, D.W. (2005). Brain lateralization of emotional processing: Historical roots and a future incorporating “dominance”. Behavioral and Cognitive Neuroscience Review, 4, 3-20.

Ingram, J. (2015). What does a brain know anyway? Canadian Wildlife, March/April 2015, 13-14. Retrieved from http://cwf-fcf.org/en/discover-wildlife/resources/magazines/canadian-wil....

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