You know how some things just make you cringe. Well, for me, this is one of them. When people start talking about being either left-brain or right-brain dominant. Grrrr…
So where did this myth come from?
It is believed to have originated in the 1960s, when a neurobiologist called Roger Sperry asserted that everyone has one hemisphere of their brain which is more dominant. Remember, at this time, people were being operated on to remove the connections between their hemispheres, as a way of ‘treating’ epilepsy, so there was no shortage of individuals to study. Sperry went on to propose that their dominant hemisphere also determines key aspects of their personality, behaviours and thoughts.
This theory is responsible for the erroneous assertion that so called ‘left-brained’ people are typically very logical, more analytical, better with numbers, obsess with detail and facts, and are likely to think in words.
Conversely, so called ‘right-brained’ people were labelled as being more creative, interested in the broad picture, were more free-thinking, intuitive and tend to visualise images instead of thinking in words.
It may be tempting to think that we can be either left-brain or right-brain dominant as we know that each hemisphere does relate to different core functions. However, the research simply does not back it up.
Is there any truth behind it at all?
Well, as already stated, the two hemispheres do support some very different functions. Everyone knows that the left side of your brain controls the right side of your body, and vice versa. It is also quite well known that the left-side is more actively involved in the production and comprehension of language. Another, less known difference, is that, although the brain uses a number of areas across the whole brain when generating and processing emotions, the right-side tends to dominate most of these processes.
However, a study conducted in 2013 examined 3D images of 1,011 participants and examined activity within each hemisphere. Their conclusion was that people use both hemispheres of our brains, and there was no significant data to support the hypothesis that we have a so-called ‘dominant’ side.
So, is it total rubbish then?
Further research carried out in 2014, examined the concept of brain dominance in relation to handedness (that is, being left or right handed). They found that preferences can develop in a fetus as early as 15 weeks old, and are shown in their choice to consistently suck either their left or right thumb.
To conclude then, neuroscience studies do not support the assertion that people have a dominant side of their brain which affects their personalities and their behaviours. The two hemispheres do operate differently and control separate processes, but there is currently no connection between these physiological preferences and underlying personality traits and behaviours.