This is one of the oldest theories that people have come up with, stemming back to the era of Aristotle and Mozart. But we come to wonder how much truth actually lies in this hypothesis?
The preference to use one hand rather than the other one is nothing more than how the brain works. Left-handed people have a more developed right cerebral hemisphere and the corpus callosum that joins both hemispheres is larger therefore, it is also related to their cognition.
Does this mean that their information processing is more advanced?
That's right, although why this is the case isn't 100% clear. These particularities in their brain allow them to advance in certain types of professions such as chess, music, architecture and arts, much faster than right-handed people.
Mathematics has been a topic of particular interest to scientists, so many studies have been carried out to explore the link between left- handed people and their performance in the field.
The results concluded that the performance of left-handed people was much higher than that of the general population.
However, the idea that left-handedness is an indicator of superior intellectual ability has been somewhat problematic. It’s an idea that has recently been challenged with the thought that it may have detrimental effects on the overall cognitive function and academic performance.
A recent study published in the journal Science with children as participants, between the ages of 5- 14, found that left-handed children performed worse in maths tests compared to right-handed children.
The fact that such contrasting scientific results exist may be due to the structure of the study itself and the design or the experiment in particular.
The latest study published in the journal Frontiers in Psychology tried to obtain more reliable results by inviting 2,300 participants who were primary or secondary school students.
These students were asked to carry out several experiments with different levels of difficulty in mathematical tests, using the Edinburgh Inventory, which has the objective to evaluate manual dominance.
The results of the experiment revealed that left-handers outperformed the rest of the participants when the tasks involved associating mathematical function with a given set of data.This pattern was particularly clear in adolescent boys.
However, when the task was not as demanding and was just a simple arithmetic task, there was no difference between left-handed and right-handed.
On average, left-handers seem to have greater ability when solving demanding mathematical tasks, at least during primary and secondary school.
These findings show that by looking at which hand the participant is writing in, can act as an indicator of connectivity between brain hemispheres.
Reference: The Relationship between Handedness and Mathematics Is Non-linear and Is Moderated by Gender, Age, and Type of Task. June 2017. Frontiers in Psychology. doi.org/10.3389/fpsyg.2017.00948