The Psychological And Brain Differences Between Left-handed And Right-handed People
Great historical figures such as Napoleon, Albert Einstein, Leonardo Da Vinci, Charlot or Mozart had one characteristic in common (in addition, obviously, to their popularity): They were all left-handed
Currently, we also meet several celebrities and illustrious people who used their left hand to write, such as the late Hugo Chávez, or four of the last seven presidents of the United States, including Barack Obama.
Science investigates the peculiarities of left-handed and right-handed people
They were all left-handed Judging by this introduction, one would think that history has left us great left-handed personalities. Maybe more capable of governing countries? With better artistic and creative skills? For decades, science has been investigating the incidence of this particularity.
Approximately, it is often said that 90% of the population is right-handed, that is, use the right hand and right foot primarily. A much smaller percentage, 10%, are left-handed. The research on this issue is somewhat confusing, but in this article I am going to try to explain what the main differences are in the health, brain and psyche of individuals depending on whether they are left- or right-handed.
Left-handed or right-handed: what causes this characteristic?
As neuroscience experts recognize, there is no definitive evidence or proven neurobiological marker that causes a person to be left- or right-handed. However, They do agree that, in the fetal stage, humans already begin to develop a preference for one hand or the other Other theories indicate that, during ultrasounds performed on pregnant women, it can be distinguished whether a baby will be right- or left-handed by observing which hand is closest to the mouth most of the time.
10% of the world’s population preferentially uses their left hand
Although science still does not know exactly many questions about left-handed and right-handed people, it has been able to provide several interesting data. As I mentioned before, it is estimated that the percentage of left-handed people in the world is around 10%, although it is also true that there are individuals who would not be “naturally right-handed”, but rather would have been born left-handed but would have been corrected to use their right hand. .
And, in fact, Until a few decades ago, many people were forced, with all kinds of methods, to use their right hand instead of their left to write It was a common practice during the beginning of the Spanish Franco regime.
The historical misfortune of left-handed people
It is not the only historical abuse that left-handers have suffered. People with this peculiarity They have been especially repudiated at different times, under the stigma of being possessed by the devil or because of false stereotypes that branded them as criminals and thugs.
It is not surprising, then, that this persecution of left-handed people culminated in certain—let’s say—“pedagogical” methods to correct this supposed deviation. Many left-handed elderly in Spain remember with regret how they were pressured and forced to write with their right hand during their school years, converted to right-handedness even against their nature.
Scientific studies
Several investigations have attempted to explain Why are some people left-handed and others right-handed? and their cerebral, biological and psychological differences.
Right-handed people are “more right-handed”
Going into scientific matters, it is worth noting that, according to a study carried out at the University of Ontario, “right-handed people are more right-handed compared to left-handed people, who tend more to be ambidextrous; to execute both hands with more skill.” In other words, researchers assure that people who preferentially use their left hand are much more skilled with their right hand than right-handed people with their left hand.
This could be explained because Left-handed people have been forced, from an early age, to handle utensils and tools designed for right-handed people with which they end up developing a greater ability to control their “bad hand.”
Left-handed people live fewer years, on average
One of the aspects on which science has delved the most is the longevity of left-handed and right-handed people. And, as has been demonstrated, Left-handed people tend to live nine years less on average than right-handed people But why does this happen? There are several hypotheses that try to explain this difference.
One of the most widespread is that it is possible that left-handed people are more likely to suffer some minor alterations during their development, which would make them more prone to suffering from certain diseases.
Genetics come into play
Yes, it seems that there is already data that suggests that the preference for one hand or the other could have a genetic origin. Specifically, this is what a group of researchers from the University of Oxford discovered, when they isolated a genetic variable that is related to preferring to use the left hand. This variant, called LRRTM1, is also a predictor of schizophrenia. That is, people who have this genetic variable have a greater risk of suffering from this neurological disease.
In any case, the relationship between having this genetic variation and suffering from schizophrenia has only been slightly correlated; It is unknown exactly what role this gene plays in the multitude of characteristics and propensities that the individual will develop during their life. In fact, the degree of correlation between left-handedness and having said gene is still being studied.
The differences between the brains of left-handed and right-handed people contribute to delving into the few answers and many unknowns about the laterality of human beings. As we have already explained in previous articles of Psychology and Mindour brain consists of two hemispheres, right and left, and although the brain operates globally, each of these hemispheres is specialized for certain functions.
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It is often said, although it is a somewhat unscientific simplification, that the left side of the brain is in charge of processing numerical and logical information, while the right hemisphere is more linked to creativity and the way we feel and get emotional. And to all this, what happens with writing? In more than 80% of the population, writing is more linked to activity in the left hemisphere, which in turn governs our right side (yes, although it may sound counterintuitive). These people, therefore, are right-handed. In the case of left-handed people, things get a little complicated, since the activity related to writing is more evenly distributed between both hemispheres.
It will be necessary to continue researching this issue to continue providing interesting data on the causes of laterality and the differences between left-handed and right-handed people. For now, we are left with more questions than certainties
