Left-handed people occur in equal proportions in all parts of the world. Left-handers know very well: that the world is entirely tailored for right-handers, which is actually not surprising, since the vast majority of the population, 90%, belongs to this group. But would they really be smarter than their right-handed peers?
There are still countless legends about left-handedness in the public mind. Throughout history, the use of the “left hand” has often been associated with evil and impurity, nowadays left-handed people are considered more special and more creative than average. But is left-handedness really a sign of talent and intelligence? and what determines which hand you prefer to use?
Some say that as a result of thousands of years of communal living and cooperation, right-handed people once came to a more dominant position when tool use and shared dwellings forced people to do so. At that time, identifying with other people through the use of hands made life easier and helped cooperation.
The notion that left-handers are smarter than right-handers has been floating around in the public mind for some time. While some studies suggest a correlation between left-handedness and higher IQ, others show that right-handed people are at an advantage. In fact, several serious studies have already been conducted on the subject, and several of them have established completely opposite things about the relationship between left-handedness and intelligence.
Here’s what the research says about left-handers and IQ
Some famous left-handers were really great minds or at least known in their profession, such as the philosopher Aristotle, the French emperor Napoleon Bonaparte, the Renaissance artist Leonardo da Vinci, and the founder of Microsoft, Bill Gates. Throughout history, left-handed people have long been viewed and treated as outcasts. In the Middle Ages, left-handed people could also fear being accused of witchcraft.
Previously, scientists also thought that left-handedness was caused by minor brain damage early in development. These myths have been debunked over the years, and later some even claimed that left-handedness is actually associated with higher intelligence.
Although the claim is intriguing, the medical literature has not revealed conclusive results.
Hand preference has been believed to be related to intelligence for centuries, and research supports both sides of the argument. Here’s what studies have shown for and against the idea that left-handedness has anything to do with intelligence.
Are right-handed people smarter?
A 2010 study in the Journal of the International Neuropsychological Society found that right-handers perform slightly better on cognitive tests than left-handers. A 2015 study in Neuroscience & Biobehavioral Reviews looked at five meta-analyses that included data from more than 16,000 individuals. They found no difference in IQ between left- and right-handers, but left-handers appeared to be more likely to have an intellectual disability. So one point for right-handers.
In a review that looked at 18 studies, more than 20,000 participants were measured for total IQ. Although the data suggested that right-handers had slightly higher IQs than left-handers, the scientists noted that the overall difference in intelligence between right-handers and left-handers was negligible. One point for a draw.
Are left-handed people smarter?
Other studies have found that left-handed people are in the majority when it comes to intelligence. According to a study published in the Journal of the Indian Academy of Applied Psychology in 2007, among 150 subjects, left-handed participants were significantly more likely to perform better on an intelligence test than right-handed participants. It also took longer for right-handed people to complete the test. Another point, this time for the group of left-handers.
Another study published in the journal Brain in 2019 showed that there are genetic differences between left- and right-handers. Examining data from around 400,000 people, the scientists discovered that the left and right hemispheres of the brain are more connected and more coordinated in the language regions of left-handed people. These characteristics suggest that left-handers have better verbal abilities.
What makes you left-handed?
Scientists believe that hand preference is a complex trait influenced by many factors, including:
- and chance
Hand preference develops before birth and becomes more evident in early childhood and lasts throughout life. The researchers believe that hand preference may be related to differences in the development of the right and left hemispheres of the brain. The right hemisphere controls movement on the left side of the body, while the left hemisphere controls movement on the right side of the body. Recent studies have also suggested that several genes, as many as nearly 40, are associated with hand preference.
Children of left-handed parents are more likely to be left-handed than children of right-handed parents. But since left-handers are relatively rare, most children of left-handed parents are right-handed. Cultural influences, environment, and prenatal exposure may also play a role in determining handedness.
Are there other important characteristics of left-handed people?
Some research has shown that left-handed people are more likely to develop certain diseases, such as:
- Parkinson’s disease,
- breast cancer,
- post-traumatic stress syndrome,
- learning disabilities such as dyslexia.
However, other studies show that being left-handed can be an advantage in certain areas. Some research shows that left-handed people have a lower risk of developing ulcers and arthritis. They can also recover faster after a stroke. An older article in the American Journal of Psychology suggests that left-handers are better at divergent thinking, the thought process used to generate creative ideas. Some studies also suggest that left-handed people are better at sports. While only about 10 percent of the total population is left-handed, former “sets” are overrepresented in some elite sports.