Are left-handed people more intelligent?
What do Leonardo da Vinci, Mozart, Albert Einstein, Charles Darwin, Mark Twain, Marie Curie, Nicola Tesla, Aristotle and Bill Gates all have in common? Not forgetting Benjamin Britten, Michelangelo, Rubens and Paul McCartney?
Yes, they are all left-handed and they are in the minority – it is estimated that 10% of the population are not right-handed. More men are left-handed than women too.
Being left-handed is a mixed-bag. The Incas believed left-handers possessed special spiritual powers and North American Zuni thought left-handedness meant good luck. Being a leftie has also been associated with being ill-omened and inauspicious.
There is this idea that left-handed people are more likely to be geniuses and left-handers have a particular talent for maths.
Is it just a coincidence that left-handers are over-represented among creative artists, chess players, musicians and tech wizards?
Perhaps left-handers do possess superior intellectual abilities.
Beratis et al (2013) found that lefties demonstrate superior spatial skills, mental flexibility, and working memory.
Other studies have said that left-handers are better at maths and the mass media have jumped on this and reported it as gospel medical truth. In reality, these studies varied in what they measured and turned out to be not very scientific at all. For example, some just asked people what their had preference was, some measured responses to simple maths problems whereas others measured responses to solving complex problems.
Needless to say there have been lots of discrepancies.
In order to get at more reliable results, Sala et al (2017) carried out a series of experiments including more than 2,300 students in primary school and high school. These experiments varied in terms of type and difficulty of mathematical tasks.
Their results showed when performing simple maths, there was no difference between left- and right-handers. But left-handers did perform better when engaged in difficult problem-solving, particularly male adolescents.
Left-handers seem to have, on average, an edge when solving demanding mathematical tasks – at least during primary school and high school. Also, being strongly right-handed may represent a disadvantage for mathematics. Taken together, these findings show that handedness, as an indicator of connectivity between brain hemispheres, does influence cognition to some extent.
We cannot say definitively that left-handed people are more intelligent but it could be they do have certain cognitive advantages. It’s worth remembering that ‘science’ has still not been able to explain why people are either left- or right-handed, or why around 10% of the population are left-handed. Why does it have to be so binary anyway?