It’s a popular belief that we have a dominant side to our brains making us either left-brained (analytical, verbal, logical and focused) or right-brained (artistic, creative and more emotionally in touch with the world).
However, while this may be a basic truth, recent research in the States doesn’t bear this out.
So why has this myth persisted? Well, first of all because of its neatness and simplicity, but secondly, because pop psychologists continue to peddle the idea that left or right brain dominance affects personality. As a result, there is a myriad of books, workshops, party games, apps and online tests that exploit the idea.
The brain is divided into two hemispheres which communicate with each other through the corpus callosum, an information highway connecting the two. In general, the left part of the brain is dominant in language, processing most functions of speech, plus logic, analysis and mathematics computations. It also retrieves facts from our memories. The right side, on the other hand, is more in charge of spatial abilities, face recognition and emotional and musical processing.
We also know that the right part of the brain controls muscles on the left side of the body and the left brain is in charge of the right side of the body.
However, the workings of the brain are complex, so that is only half the story and scientific research to unravel the truth has taken a long time.
It wasn’t until the 1800s that scientists found an injury to one side of the brain caused a loss of specific abilities. The following century, Robert Sperry and Michael Gazzaniga, while treating severe epilepsy by cutting the corpus callosum, discovered that the two sides of the brain no longer communicated with each other and it became clear that those hemispheres responded to different stimuli.
Their ground-breaking work demonstrated that the left and right hemispheres are specialized in different tasks and by cutting the information highway between them, each hemisphere – although able still to learn – had no idea what the other was experiencing or learning; a case of the left hand literally not knowing what the right hand is doing.
Or as Sperry put it:
“The great pleasure and feeling in my right brain is more than my left brain can find the words to tell you.”
It was Dr Jeff Anderson, Professor of Neuroradiology at the University of Utah, who took Sperry and Gazzaniga’s work further when he led a recent two-year study of the brain using imaging.
MRI was used to look at brain connectivity in more than one thousand people aged 7-29. The data, taken while they were lying quietly or reading, measured the specific mental processes taking place on each side of the brain. Researchers looked for something called ‘lateralization’, which is the idea that certain mental processes occur mainly in the right or the left hemisphere of the brain. The study broke the brain into 7,000 regions to see if any brain connections between the regions were left-lateralised or right-lateralized. While the study did uncover patterns which might explain why a brain connection could be strongly left or right-localised, they found no evidence that the study participants had stronger left or right-sided brains.
“It’s absolutely true that some brain functions occur in one or the other side of the brain. Language tends to be on the left, attention more on the right. But people don’t tend to have a stronger left- or right-sided brain network,” said Dr. Anderson.
“The truth is that it would be highly ineffective for one half of the brain to consistently be more active than the other.”
Although the myth is pretty harmless and simply plays to some people’s vanity, one of the problems is that it can limit people’s potential and become a self-fulfilling prophecy. How many times have you heard someone insist that they have a more developed right brain and that is why they can’t do maths? Maybe they can do maths, but they just don’t try because they’ve done a personality test which indicated that they are right-brained.
But what if you really are more creative than mathematical? Well, we all have strengths and weaknesses but we are all multi-talented as well, so it could be that some people fail to develop new skills, concentrating instead on the ones they believe they have and leaving alone the ones they believe they don’t have.
Christian Jarrett said in Psychology Today:
“There is more than a grain of truth to the left-brain right-brain myth. While they look alike, the two hemispheres of the brain do function differently. However, the distinctions aren’t as clear cut as the myth makes out – for instance, the right hemisphere is involved in processing some aspects of language, such as intonation and emphasis.”
Jarrett says it’s difficult to combat the myth because it is so well embedded.
“But,” he says, “it’s worth trying, because it would be a shame if the simplistic myth drowned out the more fascinating story of how our brains really work.”