Two halves, one team
Here’s the part of the story that’s true. Your brain has two hemispheres, and they don’t do identical work. Language is handled mainly by the left one, while spatial and nonverbal skills lean more on the right (Wikipedia sums up the research). Roger Sperry shared the 1981 Nobel Prize in Physiology or Medicine for his discoveries concerning “the functional specialization of the cerebral hemispheres”, in the Nobel Assembly’s words.
But “leans on” is doing a lot of work in that sentence. The two halves are joined by a cable of hundreds of millions of nerve fibres, and in a normal brain they swap information all the time. Specialised is not the same as solo.
Where “logical left, creative right” came from
Sperry’s most famous work was with split-brain patients: people whose connection between the hemispheres had been cut to treat severe epilepsy. With the bridge gone, each half could be tested on its own, and the results were striking. The 1981 press release describes the isolated left hemisphere as “analytical and computer-like”, the one that speaks, writes and calculates, and the right as better at “concrete thinking, spatial consciousness and comprehension of complex relationships”, and at recognising melodies.
You can see how a story grows from there. Findings about surgically separated hemispheres turned into a claim about whole people, and the claim travelled on its own. The psychologist Terence Hines argued as early as 1987 that the research itself was sound but that commercial promoters had applied it to products and management training far outside what it showed (Wikipedia summarises his paper).
What a thousand brain scans found
If some people really were left-brained, their brains should show it. In 2013, Jared Nielsen and colleagues at the University of Utah looked for exactly that in 1,011 brain scans of people aged 7 to 29, splitting the brain into 7,266 regions and measuring which side each connection favoured.
They found real left-leaning and right-leaning networks, just as the specialisation research predicts. What they didn’t find was a person-level pattern. Someone with a strongly left-leaning connection in one network wasn’t more left-leaning everywhere else. In the authors’ words, the data “are not consistent with a whole-brain phenotype of greater ‘left-brained’ or greater ‘right-brained’ network strength across individuals.”
One honest caveat: those scans came with no personality data, so the study didn’t test creativity directly. What it showed is that the thing the myth needs, a brain that runs mostly on one side, didn’t turn up. As Robert Shmerling of Harvard Health Publishing puts it, if you think of yourself as a “numbers person” or a creative sort, that’s fine, but it’s “probably inaccurate” to link those traits to one side of your brain.
You’re in very good company
This might be the most widely believed brain myth of all. In a survey published in 2012, 91% of the UK teachers and 86% of the Dutch teachers who took part agreed that “differences in hemispheric dominance (left brain, right brain) can help explain individual differences amongst learners.” The same teachers were asked whether short co-ordination exercises can improve how the left and right hemispheres work together, another popular classroom idea without good evidence behind it, and 88% and 82% said yes. The researchers also found that the UK teachers came across left brain/right brain learning programmes in their schools more often than the Dutch teachers did.
So if you picked “yes”, you share your answer with most of the people who teach for a living. The good news is the true version: you’re not half a brain with a label. Whatever you’re good at, and whatever you want to get better at, you get to use the whole thing.
Want the longer version, with split-brain experiments and what lateralization really means? Read the left-brain/right-brain myth, explained.
