Although they are a minority, surely you know some lefty. That boy who always had his blue-stained hand, the boy who gave out the drunken exercises, the girl who always cursed when trying to cut with scissors when doing crafts ...
From opening a can to writing on a chair-desk, which the left hand is the boss can make difficult the simplest tasks in all stages of life.
To honor them and to know something more about them, we have compiled these curiosities about them:
1. THEY ALWAYS ARE 10% OF THE POPULATION
Be a lefty has been stigmatized in most cultures until very recently. The term sinister, contrary to right-handed, has very negative connotations and comes from the Latin sinister. In English, left is left, which comes from old English lyft, meaning weak or useless.
The percentage of left-handed people in mankind has remained stable since prehistory around 10% of humanity (between 8% and 13% in its most extreme cases) in all continents, races and cultures. Scientists point out, therefore, that it has to have clear evolutionary advantages.
2. CRAZIER AND MORE HEALTHY
Is being left handed is good for health? A survey of 1,400,000 people, published in the journal Laterality, found that those who use the left hand suffer from fewer ulcers and arthritis. Scientists theorize that they may also retain memory better as they age, when brain processing slows down.
Although there are no established theories about this, many scientists point out that the reason for these and almost all the peculiarities of lefties lies in the structure and functioning of the brain, which is divided into two halves. Most people rely on the left half for language-related tasks. But 30% of left-handed people prefer the right or do not choose any.
This would give lefties greater sensitivity and speed when processing information and storing it, since the connectivity between both hemispheres is more intense and flexible. When the brain must process and file information that is passed from one half of the brain to another, left-handed people have an advantage. Another study, from the National University of Australia, notes that left-handers process several stimuli at a time better than right-handers.
The counterpart is curious. It was once thought that lefties were more likely to develop mental illness. Modern science has discovered, and can not explain, a surprising finding that seems to corroborate it: about 20% of schizophrenics are left-handed.
Science has also found more lefties to develop dyslexia, attention deficit, hyperactivity and other mood disorders, according to The Wall Street Journal. Having a dominant hemisphere is much more efficient most of the time, and not having it can pose a greater risk of developing learning problems and mental disorders.
3. MORE CREATIVES AND INTELLIGENTS?
It's a cliché. Historically, left-handers were thought to be slower, clumsier and dumb. Nowadays, seeing the lists of famous lefties, they are said to be more brilliant, brilliant and talented. What is true in all this?
It seems that it is not so much left-handed as the intensity with which one hand is preferred over another (one cerebral hemisphere over another) which determines cognitive abilities. Experimental studies suggest that memory, flexibility to change opinions, tastes and judgments, risk perception and other abilities depend on the right half of the brain.
The greater the inconstancy when preferring one hand over another, the interaction between the hemispheres of the brain and the possibility of access to the processes of the right hemisphere increases.
Hence, there are studies, such as that carried out by the University of Toledo (Ohio, USA), whose conclusions are as fun as this: the right-handed people like less alternative music or not as popular as reggae or jazz. Left-handed people are more open-minded and more inclined to update their preferences.
Right from the right hemisphere also depends one of the fundamental qualities of creativity: divergent thinking, the ability to generate innovative ideas or conclusions from the exploration of multiple solutions to a single premise or problem. Hence it tends to think that lefties have more developed the artistic temperament.
A study by Peabody College concluded that among precocious children in math and language, there are high rates of left-handed, myopic, and allergic / asthmatics. All these difficulties could point to another reason for left-handers to be so sharp-minded: the constant need to adapt to a world of right-handers.
Another theory proposes that to prove that they are different from the rest since childhood gives them greater ambition, which would explain the unusually high number of military and political leaders and left-handed dictators who have existed.
4. THEIR SIN, THE WRATH
It seems that not choosing a hemisphere in a definite way causes the left-handers to handle their emotions worse; And as a result, areas of the cerebral cortex that process negative emotions are more active. Notably, those of anger and hostility.
In addition, the confusion between the hemispheres also makes the left-handers more sensitive to fear and stressful situations: a study by Queen Margaret University projected the silence of the lambs before several people and then asked them to point out the most terrifying moments. Many leftists showed signs of post-traumatic stress, a fragmented memory and frequent repetitions in speech.
According to research by the University of Abertay, left-handers are more timid, tend to be more ashamed and more sensitive to nagging. They take more precautions not to make mistakes, they control and inhibit more when they say and do what they think, and are more hesitant when making difficult decisions. But this is not bad: according to the same study, that makes your decisions are better because they are more weighed.
5. BORN FIGHTERS
What could be the clearest evolutionary advantage of left-handed people? It seems that people who favor the left side of the body are better fighters and win in clashes against similar rivals. The main reason is that, because of their rarity, the right-handers have fewer opportunities to train against left-handers, whereas the latter will only have known right-handed opponents.
This seems to be perpetuated over time. Two professors from the University of Montpellier investigated nine primitive tribes today and found that there was a greater presence of lefties in the more violent societies, and these prospered in that environment.
Scientists relate this to the balance between cooperation and competitiveness of the human race. That 90% of humans are right-handed points to the fact that Humanity is fundamentally cooperative, since this allows them to use the same tools. The remaining 10%, the lefties, are the percentage reserved for competitiveness, the advantage that gives them in the fight using the opposite side to the usual.
Other research suggests that, in addition, lefties are often more athletic and have better spatial vision. Perhaps all this explains why there are so many left-handed professional athletes.
6. GENETIC CONNECTION... AND ENVIRONMENTAL
People often think that lefty is a genetic condition that is transmitted from parents to children, and has good reasons for it: it is clear that left-handed families proliferate lefties. One gene, LRRTM1, is closely related to the preferred use of the left half of the body, but that does not explain everything, if only for one thing: identical twins, who have the same genetic code, do not always use the same hand.
Scientists point out the importance of environmental factors in the development of the leotard, particularly having undergone stress in the maternal uterus. A 2009 research, published in the journal Neuropsychologia, points out that only 25% of the probability of being left-handed depends on the genes. Babies of older mothers or those who are born premature are more likely to be left-handed.
And since we mentioned the twins, some research has pointed out that double deliveries often produce lefties at a higher rate than normal deliveries. Other demographics characteristic of lefties: there are more men left-handed than women and homosexuals have higher lefties.
A scientist at the US National Cancer Institute, Amar Klar, discovered a feature common to the new left-handed: hair growth in the back of the head. The whirlwind of the right-handers goes clockwise, while the left-handed is arbitrary.
7. DO THEY LIVE LESS?
In 1991, several media published a study by scientists from the universities of British Columbia and San Bernardino who claimed that lefties lived nine years less than right-handers.
The article caused much stir, because it would have been one of the most known determinants of life expectancy. If it had been true.
Years later the scientific community found several flaws in the study procedure: it had been performed among deceased persons of advanced age, and many of those classified as right-handed could be lefties corrected by society and forced to use the right hand.
In addition, this discrimination could have increased the stress that the left-handers of the study had suffered, all born in the early twentieth century and condemned to a harder life, which would have altered their longevity.
Today, new research has made it clear: there is nothing that points to a lower life expectancy of those who prefer the left hand and foot.
8. IN GOOD COMPANY
We have written rivers of ink on the famous left-handers, so here we will only leave a small number of artists, leaders, historical figures and scientists:
Left-handed were Aristotle, Newton, Darwin, Marie Curie and Einstein; Bill Gates and four of the five founders of Mac; Caesar, Ramses II, Louis XIV, Alexander the Great, Charlemagne, Joan of Arc, Ghandi, Benjamin Franklin, Churchill, Hitler, Simon Bolivar and Napoleon; Da Vinci, Michelangelo and Picasso; Marilyn Monroe, Chaplin, Angelina Jolie and Robert de Niro.
Musicians, from all eras, are not far behind: Mozart, Beethoven, Bob Dylan, Jimi Hendrix, David Bowie and half of the Beatles used the left; Miley Cyrus and Lady Gaga; Mark Twain and Lewis Carroll; Pelé, Maradona, Messi, Casillas and Nadal; Castro, Chavez, Putin, Bin Laden, Obama and Netanyahu.
Entrepreneurs also have their representatives: Henry Ford, Forbes, Rockefeller. Disney has left-handed princesses, Mulan and Tiana, and in The Simpsons we find Bart. Even Jack the Ripper used the sinister for his crimes!
9. THEY EARN LESS
Not everything was going to be good. A recent Harvard study has found that, as a rule, lefties charge less.
The reason could be found in the effects that the lefty has in some skills. According to the author of the study, left-handers "tend to suffer more emotional, behavioral and learning problems, and many drop out and work in less qualified positions." Interestingly, this does not occur in lefties born to left-handed mothers.
10. THEY LIKE TO DRINK
Lefties love to drink! This is what Kevin Denny discovered when he undertook a study to banish the prejudice that those who use the left half of the body are more prone to alcoholism. He got away with it, since, although the left-handers drink more, they do not have to develop this disorder more than the right-handed ones.
