The psychological and cerebral differences between left and right

Great historical figures like Napoleon, Albert Einstein, Leonardo da Vinci, Charlot or Mozart had one characteristic in common (in addition, of course, to their popularity): they were all left-handed.

Today we also coincided with several celebrities and celebrities who used their left hands to write, such as the late Hugo Chávez, or four of the last seven presidents of the United States, including Barack Obama.

Science studies the peculiarities of left and right-handed people

They were all left-handed. Judging from this introduction, one would think that history has left us with great left-wing personalities. Maybe more capacity to govern countries? With better artistic and creative talents? Science has been studying the impact of this peculiarity for decades.

Basically, it is often said that 90% of the population is right-handedIn other words, use your right hand and your right foot first. A much smaller percentage, 10%, is left. The research on this question is a bit confusing, but in this article I will try to explain what are the main differences in the health, brain and psyche of individuals depending on whether they are left or right handed.

Left-handed or right-handed: what is the cause of this characteristic?

As neuroscientists recognize, there is no definitive evidence or contrasting neurobiological marker that makes a person left-handed or right-handed. however, yes, they agree that in the fetal stage, humans have already started to develop a preference for one hand or the other. Other theories point out that in ultrasounds done on pregnant women, you can tell whether a baby will be right-handed or left-handed by observing which hand is closest to the mouth most of the time.

10% of the world population preferentially use the left hand

While science still doesn’t know exactly many questions about leftists and right-handed people, it has been able to publish several pieces of data of interest. As I mentioned before, the percentage of left-handed people in the world is estimated to be around 10%, although it is also true that there are individuals who are not “natural dexterity”, but are born. left-handed people. but would have been corrected to use the right hand.

And in fact, until a few decades ago, many people were forced, by all kinds of methods, to use their right hand instead of their left when writing. This was a common practice at the start of the Spanish Franco regime.

The historic misfortune of the leftists

This is not the only historical tragedy leftists have suffered. People with this peculiarity they have been particularly repudiated at different times, under the stigma of being possessed by the devil, Or by false stereotypes that called them criminals and evildoers.

It is therefore not surprising that this persecution of leftists has resulted in certain, say “educational” methods to correct this alleged deviation. Many former leftists in Spain remember with all their might how they were coerced and coerced into writing with the right hand during their school years, converted to dexterity and all against their nature.

scientific studies

Several surveys have attempted to explain why some people are left-handed and others right-handed, And their cerebral, biological and psychological differences.

The dexterities are “more skillful”

With regard to science, it should be noted that, according to a study conducted at the University of Ontario, “Right-handed people are more skillful than left-handed people, who tend to be more ambidextrous; to perform two hands more skillfully ”. In other words, the researchers say that people who preferentially use the left hand are much more adept with the right than right-handed people who do so with the left hand.

This could explain why leftists were forced, from an early age, to use utensils and tools designed for right-handed peopleSo they end up developing a greater ability to control their “bad hand”.

Leftists live fewer years, on average

One of the aspects that science has looked at the most is the longevity of leftists and right-handed people. And this is it, as it has been shown, leftists tend to live about nine years less on average than righties. But why does this happen? Several hypotheses attempt to explain this difference.

One of the most common is that leftists may be more likely to undergo minor changes during their development, which would make them more likely to suffer from certain illnesses.

Genetics come into play

Yes, it seems that there is already some data to suggest that the preference for one hand or the other could have a genetic origin. Specifically, this is what a group of researchers at the University of Oxford discovered by isolating a genetic variable linked to preferring to use the left hand. This variant, called LRRTM1, is also a predictor of schizophrenia. In other words, people who have this genetic variable are more likely to suffer from this neurological disease.

However, the relationship between having this genetic variation and suffering from schizophrenia has only been weakly correlated; it is not known exactly what role this gene plays in the multitude of characteristics and propensities that an individual will develop over their lifetime. In fact, the degree of correlation between left-handed and owning this gene is still under investigation.

Cross-laterality and brain differences

The differences between the brains of left and right-handed people help to deepen the few answers and the many unknowns about the laterality of human beings. As we have explained in previous articles on psychology and the mind, our brain is made up of two hemispheres, right and left, and although the brain functions as a whole, each of these hemispheres specializes in certain functions.

It is often said, although this is a somewhat unscientific simplification, that the left side of the brain is responsible for processing digital and logical information, while the right hemisphere is more closely related to creativity and how we we feel. and we get excited. And to all of this, what about the writing? In over 80% of the population, writing is more closely related to activity in the left hemisphere, Which in turn governs our right side (yes, although that seems counterintuitive). These people are therefore clever. In the case of left-handers, things get a bit more complicated, as the writing activity is more evenly distributed between the two hemispheres.

Further research will be needed on this question to continue to provide interesting data on the causes of laterality and the differences between left and right. At present, we had more questions than certainties.

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