Are you a logical, rational thinker? Then you are primarily left-brained. Are you a creative, artistic type? Then you are right-brained. That is the story we tell ourselves. It has a commonsense appeal; we like to categorise people into distinct groupings. The brain has hemispheres, and particular human behaviours are controlled by specific locations in the brain, right?

The left-brained/right-brained dichotomy is false – we all use both hemispheres of the brain. It is true that functional lateralisation is apparent in the brain; the left hemisphere is where language is largely controlled. Damage to Broca’s area, for instance, located in the front left temporal lobe, impairs a person’s ability to understand and process language.

No, your personality and abilities do not depend on which hemisphere of the brain you use.

There has been extensive research on split-brain patients; the latter have had their corpus callosum severed. The corpus callosum is a bundle of nerves which connects the two hemispheres. Interruption to this interhemispheric transmission of information impacts a patient’s perception, motor skills, spatial reasoning and language processing. No, still this does not mean we all fit neatly into left/right brained personality or temperament types.

From the 1960s onwards, psychologist and neuroscientist Roger Sperry (1913 – 1994), and his protege, the psychologist Michael Gazzaniga (1939 – ) undertook pioneering experiments on split-brain patients. Numerous epileptic patients, who were experiencing multiple uncontrollable and violent seizures, underwent an invasive brain operation – cutting the corpus callosum.

This procedure, which is rarely if ever used today, effectively separated the hemispheres of the brain. Did this procedure have any impact on a patient’s mental abilities?

Sperry and Gazzaniga designed and conducted a series of clever experiments; each hemisphere was exposed to images or tactile stimuli. Would the patient understand what they were seeing or doing? The brain’s wiring, as it stands, means that the left hemisphere controls the right side of the body, and vice versa.

A patient was asked to stare at a dot – and then an image, say of a circle, was flashed to their right eye only. Language processing is located in the left hemisphere. The patient could articulate the image they saw.

However, if a circle was flashed to their left eye only, that information was sent to the isolated right hemisphere. The patient could not verbally identify what they witnessed. However, using their left hand, they successfully pointed to a picture of a circle.

That is just one example of an entire range of experiments conducted by Sperry and Gazzaniga. Does this mean that consciousness can be localised? Can the sense of self be divided? Is the mind entirely dependent on the successful functioning of neurons and synaptic activity in the brain?

Here is where pop psychology took hold.

The notion of the brain as a computer, and a corresponding computational theory of mind, ascended into widespread popularity after the Second World War. Brain lateralisation was a hot topic; identifying which areas of the brain controlled which functions gave us an image of the brain as a compact Swiss army-knife. Each component, equally important, fit smoothly into a single compartment.

Added to that was the rise of computerisation. Conceiving of the brain/mind duality as a hardware/software analogy gained public popularity.

It is heartening to see a major IT company, Atlassian, respond to this myth of left/right brain dominance with a debunking. Certainly, the right hemisphere is largely responsible for processing spatial and visual cues, which are important in producing art. But consider the following; physics, mathematics, cosmology and so on, are creative endeavours, each in their own way.

Solving mathematical problems, or resolving questions in physics and astronomy, requires not just logical deductions and pure rationality, but also thinking creatively. Einstein was a giant of twentieth century physics, and he also approached scientific questions with remarkable creativity.

Ironically, over the last 25 years, new neuroscience research has emphasised the importance of neuroplasticity. The brain is not a Swiss Army knife with specific components. The hemispheres of the brain work together. The brain is not a computer, but an entire network of interlocking and interdependent computers.

Neuroplasticity refers to the ability of the brain to evolve and respond to life experiences. While the left hemisphere is heavily involved in language processing, the right hemisphere is responsible for understanding intonation and pitch. Have we all forgotten that one of the most important stages of human communication and experience is nonverbal communication. Language would not be possible without the ability to express and process nonverbal cues.

So what if this neuromyth of being left/right brained persists? What is the harm? When self help books, corporate bonding courses, and social media pop quizzes are all telling you that you are right-brained and therefore artistic, does that encourage you to pursue maths or the sciences? What happens when a 13 year old is told that s/he is left-brained and mathematically inclined – would they pursue art, painting or creative writing?

What happens when a person – whether a child, an adolescent or an adult – makes life decisions that will impact them over decades on the basis of a neuromyth? For generations, we have advised schoolgirls that they are ‘bad at math’. Are we doing them a favour by stating to them that their aptitude for maths is determined by the brain hemisphere they use?

While the current article is not the place to bring up issues regarding current politics, one observation will suffice here. Muslim majority nations are leading the world in women graduating in STEM subjects. Women working as scientists have been comprehensively interviewed over the years from Lebanon, Egypt, Pakistan, Iran and other Muslim majority nations. So when it comes to mathematics, engineering and subjects requiring logical and analytical thinking, women’s brains are outpacing the men’s.

We all have our talents, skills and abilities. No, we cannot be good at everything. But please, dispense with this myth that we are the products of left/right brain predominance.