Why some people are left-handed: the most unexpected hypotheses

Did you know that 15% of humanity are left-handed? Most often, the left hand predominates in men, but scientists still cannot understand what this is connected with. In some countries, they try to teach children who write with their left hand to use their right hand so that they meet the “standards.” Until about the end of the 20th century, people even laughed at left-handed people, but today the situation has changed somewhat. In fencing, handball, football and many other sports, left-handers are highly valued because they show good results. Perhaps there are left-handed people among your friends, or you yourself are one of them. It's time to find out why some people write with their left hand, while most of humanity writes with their right.

Why some people are left-handed: the most unexpected hypotheses. Which hand a person writes depends on the characteristics of his brain. Source: noyabrsk-inform.ru. Photo.

The hand with which a person writes depends on the functioning of his brain. Source: noyabrsk-inform.ru

Contents

  • 1 Why people become left-handed
    • 1.1 Brain damage changes leading hand
    • 1.2 Geschwind's theory of left-handed people
    • 1.3 How ultrasound affects people
    • 1.4 Discovery of the gene for left-handedness
  • 2 How left-handedness affects other organs
  • 3 Problems of left-handers in everyday life

Why people become left-handed

In fact, scientists still cannot understand why people become left-handed. It is known that this is somehow influenced by the activity of the brain hemispheres, but exactly how it is is not clear to anyone. But there are some interesting theories that may explain why people become left-handed.

Brain damage changes dominant hand

One version says that people become left-handed due to brain damage. In particular, we are talking about the incorrect functioning of the left hemisphere, which controls the work of the right hand. If there is something wrong with the left hemisphere, a person uses his right hand less often, and the left becomes the dominant one.

Brain damage changes the dominant hand. Perhaps in left-handed people the left hemisphere, which is responsible for the work of the right hand, does not work well. Source: kostroma.mk.ru. Photo.

Perhaps the left hemisphere, which is responsible for the work of the right hand, does not work well in left-handers. Source: kostroma.mk.ru

Geschwind’s theory of left-handers

According to Geschwind's theory, people can become left-handed if they were exposed to high levels of testosterone before birth. According to neurologist Norman Geschwind, during fetal development, the male hormone slows down the growth of the left hemisphere. Again, because of this, a person uses the right hand less often and the left hand becomes dominant.

How ultrasound affects people

The ultrasound theory states that left-handedness develops due to ultrasound examinations in childhood. The results of some studies have shown that after this type of examination, children's brain development changed. However, these studies were carried out a long time ago and today their results are not particularly valid. Moreover, if this version is correct, then why did left-handed people exist at a time when medicine was not developed to such an extent?

How ultrasound affects people. There is even a version that ultrasound leads to left-handedness. Source: elklinik.ru. Photo.

There is even a version that ultrasound leads to left-handedness. Source: elklinik.ru

Discovery of the left-handedness gene

In 2008, news appeared on the Internet that scientists had managed to discover the “left-handedness gene”. According to the news, the gene responsible for this was LRRTM1, which also plays an important role in the development of speech and emotions. In fact, no left-handed gene exists. The news about this discovery was published only in dubious sources, and no one in the scientific community talked about it.

How left-handedness affects other organs

So, despite many studies, scientists are still unable to explain the reason for the left-handedness of some people. This is all due to the passivity of the left hemisphere and the activity of the right, but what causes such a difference is a big mystery. Most likely, this is influenced by a number of factors.

How left-handedness affects other organs. People may even have a dominant eye. Source: photopole.ru. Photo.

People can even have a dominant eye. Source: photopole.ru

Scientists believe that due to the increased activity of the right hemisphere in people, not only the left hand becomes dominant, but also the leg, eye and other parts of the body. These changes are much more difficult to notice, and even left-handers themselves often do not notice it.

Read also:Why the buttons on men's and women's clothing are on different sides

Problems of left-handers in everyday life

Since most people are right-handed, left-handed people face big challenges every day. Many everyday objects are designed for right-handed people, so they have to either get used to them or buy left-handed versions. Left-handed people also have difficulty learning and are at risk of getting hurt while riding in public transport due to the peculiarities of their perception of the world.

Fun fact: Left-Handed Day is celebrated every year on August 13th. This holiday was first celebrated in 1976. Its goal is to draw the attention of product manufacturers to the problems of people who use them with their left hand.

Problems of left-handers in everyday life. There are scissors and other tools created specifically for left-handers. Source: goodslike.ru. Photo.

There are scissors and other tools created specifically for left-handers. Source: goodslike.ru

Along with all this, left-handers are valued in some sports, and also often achieve great success in other fields of activity. Among the most famous left-handers are theoretical physicist Albert Einstein, American inventor Nikola Tesla, artist Leonardo da Vinci, musician Paul McCartney, and so on.

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Finally, it is worth noting that our website has previously published an article entitled “Why are people divided into right-handed and left-handed?” Be sure to pay attention to it, after reading it you will learn something else interesting about people who write with their left hand.


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