Strictly speaking, being left-handed is very rare. First of all, hand movements include pulling, throwing, twisting, holding, holding a pen, using a needle and many other movements. There are quite a few people who use their hands differently in different movements. If some people throw with their right hand and pick up with their left; Most people who write are right-handed, but many people who hold microphones are left-handed. There are also some movements that need to be coordinated by both hands, such as planing picks, hoeing, holding shovels, swinging and so on. For those who are used to one hand, the dominant hand may be the other hand.
another factor that affects the judgment of left-handedness is acquired correction. Almost all ethnic groups and different times have the habit of correcting left-handers. In the East, the two most important movements of the hand-using chopsticks and writing-are often forcibly corrected at school for people who are naturally left-handed. However, no matter how to correct it, these people are still naturally left-handed. If we consider the movements of legs and feet, the problem is more complicated. High jump, long jump, pedaling, pedaling, rubbing and so on, many people are 1% right-handed, but the movements of legs and feet are dominated by the left side.
Perhaps, most people are actually left-handed, and there is always a certain movement with a different habitual side from other movements. We can find this by looking at ourselves, or by looking closely at the people around you.
In order to have a standard, it can be generally thought that a left-handed person is a natural left-handed person who writes or uses chopsticks.
According to this standard, those who are naturally left-handed in these two movements and are forcibly corrected the day after tomorrow are still regarded as left-handed; Other movements that are left-handed are not considered left-handed. Of course, this is just a family statement, and people may set many different standards for left-handedness.
is left-handed inherited?
This is the current mainstream school, which was widely recognized at the turn of the 19th and 2th centuries. Phenomenologically speaking, handedness is a human nature. In any social form, no matter what forced correction method is adopted, for a left-hander, he or she may be very skilled in using his or her right hand, but his or her preference for using his or her left hand remains unchanged. In real life, how many parents use corporal punishment, binding, wearing gloves and other conceivable methods to restrict left-handed children from using their left hands, and often only succeed in a limited number of hand activities. Once the child moves freely, the left hand becomes popular again.
there is more obvious evidence in statistics. A medical study aimed at investigating the probability of being born in a family where both parents are left-handed or both parents are right-handed shows that in a family where both parents are left-handed, the probability of children being left-handed is 5%; In a family where both parents are right-handed, the chances of children being left-handed are only 2%. Another evidence is that the proportion of left-handed people in some families is significantly higher than that in general families, indicating that the preference for using hands is directly related to heredity. The Scots have a Kerr family, which has been famous for its many left-handed people for centuries. The stairs of the castle they built were all rotated counterclockwise to meet the needs of the Kerr left-handed soldiers in guarding the city. In this family, left-handers are the majority, while right-handers are the minority. Their public facilities and production tools are left first.
Some people use dominant genes and recessive genes to explain the causes of left and right handedness. Right-handed genes are dominant, while left-handed genes are recessive. Only in special gene pairing can the traits of left-handed recessive genes be displayed, so left-handed people become a minority in the total population.
It has also been reported that a person's habit of using his left hand or right hand is determined by a single gene, and the medical profession is trying to find out this gene. Some people have studied 1 left-handed couples, their parents and children, and found that those who inherit this gene from their parents are naturally right-handed; Without this gene, people may be left-handed or right-handed. 82% people have at least one such gene, so they are right-handed; 18% people don't have this gene, half of them are right-handed, the other half are left-handed or use both hands well. This study explains why identical twins have different handedness.
Some people have studied the genes that may control left-handed traits from the hair rotation direction. Kral, an expert from the American Cancer Institute, observed the rotation direction of human hair in crowded airports and supermarkets, and found that 95% of right-handed people's hair rotates clockwise, while left-handed people and people with flexible left and right hands rotate clockwise and counterclockwise in half. Kral thinks that there may be such a gene in human body, which has two manifestations, one with the characteristic information of right-handed hair and the other with the characteristic information of random rotation of hair. It is this gene that controls human hand bias and hair rotation. The former is dominant, while the latter is recessive. People who have one or both right-handed information genes must be right-handed, and their hair rotates clockwise. People with two random spin information genes may not be "necessarily" right-handed, but the chances of becoming left-handed or right-handed are 5/5. This theory is somewhat different from the theory of single gene determination, but it can also explain the phenomenon that identical twins are left and right-handed. Because they all carry two random rotation characteristic information genes, half left-handed and half right-handed appear according to the probability. What exactly is this basis remains to be solved by scientists' continuous efforts.
the characteristics of left-handed people
maybe we can leave medical professional problems to experts in brain nerve and cognitive behavior to study. However, the following are the things that have been proved for the supporters to be excited:
1. Thinking things are different from others. Left-handed people often think of shaped images in their minds before writing or drawing, and many left-handed people will try their best to reassemble the fragmentary data that they can't memorize into a page of pictures and memorize them. Just like bruley, the father of modern architecture, he was able to put forward digital graphics in the 14th century to explain how to build the Florence Dome Cathedral. "I have figured out what it will look like when it is finished." He said that he defeated bidders from all over Europe.
some people think that this ability explains why many left-handed people are outstanding in matters involving space and art.
2. Strong ability in mathematics, visual perspective and space, which is conducive to the development of mathematics and architecture. 199 Annet &; Manning research has found a correlation between right-handed people and lack of mathematical ability.
3. If a close relative (such as a brother or sister) of a right-handed person is left-handed, the memory of this right-handed person is better than that of a person whose whole family is purely right-handed.
A study by the University of Toledo, Ohio, found that right-handed people with close relatives of left-handed people showed strong episodic memory (such as where the keys were left at hand after entering the door). Although the semantic memory stored in the database (such as the year from the beginning to the end of World War II) was poor, it might be because the information itself existed in the left brain, but the time and space background information of things existed in the right brain, so the episodic memory was enhanced by combining the two. Researchers suspect that the corpus callosum, which may connect the left and right brains, is large, indicating that your brain structure is mixed with the left and right halves.
4. Left-handed people seem to perform well in sports that require quick response and correct spatial judgment. People who are more flexible and strong in their left hand, left foot and left eye, especially in some sports such as tennis, soccer and golf, tend to perform better than others. Tennis celebrities such as Nalatinova, Connors, Mackenzie and so on.
5. The left-handed person has another advantage, because the right-handed person is not used to taking the ball he hits. Some left-handed people can even switch to the right hand to swing or swing when necessary, which is impossible for most right-handed people. Like fencing, a sport in which two people fight each other, left-handed people also have special advantages, and the proportion of winning the championship is very high.
6. People with strong left hand, but strong right foot and right eye may have the problem of uncoordinated integration, which especially affects the movement of swinging the racket, because the visual field may sometimes be limited. However, it is conducive to gymnastics, running, basketball and other competitions that require a strong sense of physical balance.
7. It is more difficult for a right-handed person to do things with his left hand than for a left-handed person to do things with his right hand. Moreover, left-handed people are more willing to listen, accept or consider other people's opinions and ideas. This is related to the fact that left-handed people have been adapting to the environment all their lives, learning when to cross the body with their left hand or when to switch to their right hand, and overcoming the difficulty is related to continuous practice.
once again, there are many related studies, but they have not yet reached the final stage, including:
8. The autoimmune system is poor, including asthma, migraine, diabetes, autism, and learning disabilities. But in 1991, another study overturned this theory.
9. The School of Medicine of the Royal Free University of London recently suspected that left-handed people are twice as likely to suffer from inflammatory intestinal diseases (such as Crohn's disease, with symptoms of pain, severe diarrhea, intestinal bleeding, weight loss and fever) than right-handed people.
In p>186, a French surgeon, Brock, said that the left brain of left-handed people was underdeveloped, which affected their language ability. However, some people refute that it is too simplistic and irresponsible to draw the relationship between breakup and brain in this way.
In 197s, many studies found that most left-handed people, like everyone else, had the same specialized language area in their left brain, and only a few left-handed people had different language areas. Therefore, using the left hand will not cause difficulties in literacy or arithmetic. If there is a problem with the child, the real problem should be found out.
1. Left-handed people live 9 years less than right-handed people on average.
11. American psychologists Kong Rong and He Qiu suspected that the average life expectancy of left-handed people would be 9 years shorter than that of right-handed people (66 years vs.75 years). When this statement came out, the group was in uproar.
Later, it was refuted by the research community that they used fallacious research methods to forcibly support their hypothesis (left-handed people drive cars designed for right-handed people, operate backhand, and react in an emergency). Kong Rong and He Kun asked their families about 1, car accident victims in a town in southern California whether the victims were left-handed or right-handed, but only three of them turned left-handed, and there is no way to prove whether these three people really died in a car accident because of left-handedness.
People's views on left-handers
The tolerance of different ethnic groups to left-handers is very different. Generally speaking, the eastern ethnic groups are more discriminating against left-handers and often take more severe measures to correct them. It is said that left-handed people were not understood in ancient times. In some languages, the word "left" can be interpreted as "clumsy" or "inexperienced". Residents of some primitive tribes in Africa often stubbornly confess that their wives prepared food with their right hands, and their intention is self-evident. Legend has it that the custom of wearing a wedding ring on the left hand means avoiding evil desires. Also reflected in Chinese, people are used to taking the right as the top, and the left is always associated with some negative and derogatory concepts, which mean "deviation", "evil" and "wrong", such as "going by the side door" and "left voice", while "disagreement" means opposing opinions, and "moving left" means demotion.
Uighurs stick their right hands to their chests when they greet people, and never use their left hands. Give people things and gifts with your right hand. Knock on the door with your right hand when you get the answer. When you enter the door, you must advance your right leg. If you step into your left leg in Uygur areas, your host will be unhappy. When people eat pilaf, they always grab it with their right hand and send it to their mouths. It is a general rule to put right first.
when you get to America, you will find many people who write with their left hands. Some normally put their left hand on the left and write to the right; Some put the whole left hand above and bend their wrists to write; Some simply put the whole left hand below to write.
International Left-Handers Day
On August 13th, 1975, a group of left-handers in Topeka, Kansas, USA set up an organization called Left-Handers International. They envisioned uniting left-handers all over the world to fight for their rights and interests. A year later, the organization held a celebration and designated this day as International Left-handed Day, hoping that one day left-handed people all over the world would celebrate their festival together. August 13th, 1976 became the first international left-handed day.
International Left-handed Day has been gradually recognized by left-handed organizations all over the world, and celebrations have been held in succession. In 1992, the London Left-Handers Club also designated August 13th as International Left-Handers Day, and held their first International Left-Handers Day celebration that year. In Britain, a special website for International Left-Handed Day has been set up to publicize the International Left-Handed Day, popularize the knowledge of left-handers, introduce the annual activities of the International Left-Handed Day, and report the celebrations around the world.
Left-handers declare that the purpose of establishing International Left-handers Day is to unite left-handers all over the world to fight for their own interests, arouse the attention of the whole society to the problem of left-handers, remind people to improve the design of products in a society dominated by right-handers and pay more attention to the convenience and safety of left-handers, and dispel the prejudice against left-handers that has existed in various cultures for thousands of years and is still being created today. Now, left-handed organizations in dozens of countries celebrate this festival, all over the world. Europe is a place where left-handed organizations are active, and the celebrations are more grand.
The phenomenon of left-handed people inspires us that
the idleness of the left hand is a huge waste of human resources.
Only by training the left hand and tapping the potential of the right brain in perception, intuition and image thinking can we be in an invincible position in the competition in the computer age.
the use of the left hand and the movement of the left limb can strengthen the body, benefit the brain, strengthen the body and prolong life.
As for being left-handed, some people deal with it easily, while others are troubled for life. But in any case, this is an objective thing, and left-handed people do account for a considerable proportion of the population. Because of this, the research on left-handed people has become increasingly active in recent years. This kind of research has gone far beyond the investigation of customs and gone deep into the fields of brain function, genetics, cytology and molecular biology. This in-depth study may lead to a new brain revolution.
The real human body is not completely symmetrical. Everyone has hands, feet, even ears and eyes with different strengths. The visual acuity and hearing test in the physical examination report rarely have the same data, just as the feet are not the same size, which always leads to more trouble in buying shoes. So, why make a fuss about lefties?
Left-handed celebrities
Politicians and military strategists
Alexander the Great, king of ancient Greece and Macedonia. Established a huge empire from the Indus River in the east to the Nile and the Balkans in the west, spanning Europe, Asia and Africa.
Caesar, an ancient Roman politician, commander-in-chief and writer, was famous for his dictatorship.
Napoleon was the emperor, strategist and commander-in-chief of the first French Empire.
The French Revolution broke out in the reign of Louis XVI, king of France, and he died in the guillotine.
queen Elizabeth, the queen of England.
Queen Victoria, the Queen of England.
King George II, the wise monarch of England.
ramses ii, the 19th dynasty Pharaoh of ancient Egypt, created the most prosperous period of ancient Egypt.
According to the legend of Ehud Bible, the left-handed enemy chieftain of ancient Israel was the hero who liberated Israel from alien rule.
Charlemagne, king of Carolingian dynasty in Frankish kingdom, Charlemagne emperor. Carry out the expansion policy, so that the imperial territory is adjacent to the Atlantic Ocean in the west, the Elbe River and Bohemia in the east, the North Sea in the north and central Italy in the south.