The internet is flooded with articles on the left-right Brain divide, and even Facebook offers a test which determines whether you are left or right Brain and there is an abundance of workshops that promise to unleash your right Brain (creative) power. There are loads of books on the subject as well – one of the most popular being “The Right Mind: Makin Sense of the Hemispheres” by Robert Ornstein (1997) who suggested different ways to tap into your “creative right brain”. I even came across right-brain coaches recently… Really??? The left-brain versus right-brain dominance “theory” (or myth) suggests that each hemisphere of the brain controls different functions and that people prefer one type of thinking over another. So, according to this approach left-brain preference makes a person more logical, analytical, linear, objective, and even more …masculine, while the right-brain preference suggests that a person is more intuitive, artistic, spontaneous and … feminine.

Where did all this come from? It all originated in the work by Roger Sperry who started his experiments on split-brains in the 1950s and in 1981 he won a Nobel Prize for his studies. He discovered that cutting the corpus callosum (the structure that connects the two hemispheres of the brain) could reduce or eliminate seizures. However, during this procedure the patients also experienced other symptoms after the communication pathway between the two sides of the brain was cut. Some of them found themselves unable to name objects that were processed by the right side of the brain but were able to name objects that were processed by the left side of the brain. Based on this information, Sperry suggested that the left side of the brain controlled language.

Generally speaking, the left side of the brain tends to control many aspects of language and logic, while the right side tends to handle spatial information and visual comprehension.

The reality is that brain imaging research shows that the two hemispheres in a healthy brain actually routinely communicate during most tasks. The two hemispheres are much more similar than different in their functions. Researchers have confirmed that the two hemispheres are relatively better at different mental activities or in other words they differ in HOW they process tasks rather than WHATthey process. The right brain is better at dealing with a general sense of space, while the left brain becomes more active when the person locates objects in specific places. If it helps, you could think about this in the following way: there is a task to be performed and whoever is better at it, grabs it first. So, a normal, healthy brain works in an integrated manner and all this dichotomania has been the product of pop psychology, New Age, social and commercial values around how our society is being structured, etc.

So, we don’t have adequate scientific evidence to support the ‘theory’ of the left versus right brain dominance, and certainly even less evidence that this divide would also affect one’s personality. It sounds plausible because it may align with our aptitudes, however brain activity is asymmetrical anyway and it varies from person to person. Therefore, if you are a ‘numbers person’ this is probably less linked to your brain hemisphere and more linked to aspects we don’t even know yet. And that’s an other subject for another article.