Throughout history there have been several studies that try to relate intelligence and being left-handed: Leonardo da Vinci was left-handed, also Mark Twain, Mozart, Marie Curie, Nicola Tesla or Aristotle. But is it really true that lefties - between 10 and 13.5% of the world's population - have something that differentiates them cognitively speaking?
Hand preference is a manifestation of brain function and, therefore, is related to cognition. Leftists have, on average, the most developed right hemisphere, which is specialized for processes such as spatial reasoning and the ability to rotate mental representations of objects.
In addition, the corpus callosum - the nerve cells connecting the two cerebral hemispheres - tend to be larger in the left-handers: this suggests that some lefties have better connectivity between the two hemispheres and, therefore, superior information processing.
But does this happen by nature? Certain studies argue that "living in a world of right-handedness" could force lefties to use both hands, thus increasing connectivity. This opens the possibility that we can achieve a better relationship between hemispheres using both hands.
These peculiarities may be why lefties seem to have an advantage in various professions and arts: for example, there is no real representation of lefties - there is an oversimplification - among musicians, creative artists, architects, or chess players. Needless to say, efficient processing of information and superior spatial skills are essential in all these activities.
Lefts and math
But what about the link between lefties and mathematical ability? More than 30 years ago, one study claimed that using the left hand at an early age was a premonition of mathematical precocity; The study also found that among math students the left-handed rates are higher.
Lefties appear to have, on average, an advantage in solving demanding mathematical problems, at least during primary and secondary education. These findings may demonstrate that the hand is an indicator of connectivity between the cerebral hemispheres.
That said, the hand is only an indirect expression of brain function; For example, only one-third of people with a more developed right hemisphere are left-handed. So many right-handed people will have a brain structure similar to that of the left-handed.
