Why are some people born with left hands?

General definition of left-handed person

Left-handers are naturally left-handers who write or use chopsticks. They are also called left-handed. Studies show that left-handed people account for about one tenth of the total population. Left-handers are a peculiar physiological phenomenon, and they are a unique group. Left-handed people face special problems and give them special advantages.

Strictly speaking, left-handed people are rare. First of all, hand movements include pulling, throwing, twisting, holding, holding a pen, using a needle and many other movements. Many people use their hands differently in different movements. If someone throws it with their right hand, pick it up with their left hand; 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 picking, hoeing, holding a shovel, swinging and so on. For those who are used to one hand, the dominant hand may be the other hand.

Another factor that affects left-handers' judgment is acquired correction. Almost all ethnic groups and different times have the habit of correcting left-handers. In the East, for people who are naturally left-handed, using chopsticks and writing, the two most important hand movements, are often forcibly corrected at school. However, no matter how to correct them, these people are still naturally left-handed. If we consider the movements of legs and feet, the problem is more complicated. Many people are 100% right-handed, but the movements of legs and feet are mainly left.

Perhaps, most people are actually left-handed, and there is always a certain action with a habitual side different from other actions. We can find this by looking at ourselves or observing the people around you carefully.

In order to have a standard, it can be generally considered that left-handed people are naturally left-handed who write or use chopsticks.

According to this standard, people who are born left-handed and forcibly corrected the day after tomorrow are still left-handed; Other left-handed movements are not considered left-handed. Of course, this is just a family statement, and people may set many different standards for left-handers.

Can lefties be inherited?

This is the current mainstream school, which was widely recognized at the turn of the 19th and 20th centuries. Phenomenologically speaking, handedness is a human nature. In any social form, no matter what kind of compulsory correction is adopted, for a left-handed, 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, gloves and other conceivable methods to restrict left-handed children from using their left hands, and often only succeed in limited hand activities. Once children move 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 right-handed shows that in a family where both parents are left-handed, the probability of a child being left-handed is 50%; In a family where both parents are right-handed, the probability that the child is left-handed is only 2%. Another evidence is that the proportion of left-handed people in some families is significantly higher than that in ordinary families, indicating that the preference for using hands is directly related to heredity. The Scots have a Kerr family, which has been famous for being left-handed for centuries. The stairs of the castles they built all rotate counterclockwise to meet the needs of Kerr's left-handed soldiers guarding the city. In this family, left-handed people are in the majority and right-handed people are in the minority. Their public facilities and production tools are left behind first.

Some people use dominant genes and recessive genes to explain the causes of handedness. Right-handed genes are dominant and left-handed genes are recessive. Only in special gene pairing can the traits of left-handed recessive genes be expressed, so left-handed people become a minority in the total population.

It is also reported that a person's habit of using his left hand or his right hand is determined by a single gene, and the medical profession is trying to find out this gene. Someone studied 100 left-handed couples, their parents and children, and found that people who inherited this gene from their parents were born 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 are right-handed, the other half are left-handed or use their hands well. This study explains why identical twins have different dominant hands.

Others study genes that may control the characteristics of left-handed people from the direction of hair rotation. Kral, an expert from 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 left-handed people rotate half clockwise and half counterclockwise. Kral thinks that there may be such a gene in human body, which has two forms of expression, one with the characteristic information of right hand hair and the other with the characteristic information of random rotation of hair. It is this gene that controls human hand deviation and hair rotation. The former is dominant and the latter is recessive. People with one or two right-handed information genes must be right-handed and their hair rotates clockwise. People with two random spin information genes are not necessarily right-handed, but the probability of becoming left-handed or right-handed is 50/50. This theory is somewhat different from the single gene determination theory, but it can also explain the phenomenon that identical twins are left-handed and right-handed. Because they all carry two randomly rotating 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.

Left-handed characteristics

Maybe we can leave medical problems to experts in brain nerve and cognitive behavior to study. However, the following things have been confirmed to excite supporters:

1. Think things are different from others. Before writing or drawing, left-handed people often think about the images that have been formed in their minds. Many left-handed people will try their best to reassemble the fragmentary materials they can't remember into pages of pictures and remember them. Just like Buruli, the father of modern architecture, in the14th century, he could put forward digital graphics to explain how to build Florence Dome Cathedral. "I have thought about what it will look like when it is finished." He said that he beat the 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 mathematical ability, strong visual perspective ability and strong spatial ability are conducive to the development of mathematics and architecture. 1990 Annet &； Manning's research found a correlation between right-handedness and lack of mathematical ability.

3. If a right-handed person has a close relative (such as a brother or sister) who is left-handed, then the right-handed person's memory is better than that of the whole family who are purely right-handed.

According to a study by the University of Toledo, Ohio, right-handed people, close relatives of left-handers, show strong situational memory (such as where the keys are conveniently placed after entering the door). Although the semantic memory stored in the database (for example, the year from World War II to the end) is poor, it may be because the information itself has a left brain and the spatio-temporal background information of things has a right brain, so combining the two can enhance the situational memory. Researchers suspect that the corpus callosum that may connect the left and right brains is very large, indicating that your brain structure is a mixture of 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 stronger with their left hand, left foot and left eye, especially in tennis, football and golf, often perform better than others. Tennis celebrities such as Naratinova, Connors, Mackenzie, etc.

Left-handed people also have an advantage, because right-handed people are not used to playing with him. Some left-handers can even switch to the right hand to swing or swing when necessary, which most right-handers can't do. 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, strong right foot and strong right eye may have the problem of uncoordinated integration, which especially affects the swing action, because the line of sight may sometimes be limited. But it is beneficial to gymnastics, running, basketball and other games that require a strong sense of physical balance.

7. It is much more difficult for a right-handed person to do things with his left hand than for a left-handed person. 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 their bodies with their left hands or when to switch to their right hands, and overcoming difficulties is related to constant practice.

Thirdly, 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. However, in 199 1, another study refutes this theory.

9. The School of Medicine of the Royal Free University of London recently suspected that left-handed people are twice as likely as right-handed people to suffer from inflammatory intestinal diseases (such as Crohn's disease, with symptoms of pain, severe diarrhea, intestinal bleeding, weight loss and fever).

1860 French surgeon Brock said that the left brain of left-handed people is underdeveloped, which affects their language ability. However, some people retort that it is too simplistic and irresponsible to draw the relationship between breakup and brain in this way.

/kloc-many studies in the 1970s found that most left-handed people, like others, have the same specialized language area in their left brain, and only a small number of left-handed people have different language areas. So using the left hand will not cause literacy or arithmetic difficulties. If the child has a problem, find out the real problem.

10, left-handed people live 9 years less than right-handed people on average.

1 1. American psychologists Kong Rong and He Kun suspect that the average life expectancy of left-handed people will be 9 years shorter than that of right-handed people (66 years versus 75 years). When this statement came out, the group was in an uproar.

Later, it was refuted by the research community that they used fallacious research methods to forcibly support their assumptions (left-handed people drive cars designed for right-handed people, operate backhand, and respond in an emergency). Kong Rong and He Kun asked their families about 1000 car accident victims in a small town in southern California, whether the victims were left-handed or right-handed, but only three of them became left-handed, and there was no way to prove whether these three people really died in a car accident because of being left-handed.

People's views on left-handed people

The tolerance of left-handed people varies greatly among ethnic groups. Generally speaking, the Oriental ethnic groups discriminate against lefties more, 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". The inhabitants of some primitive tribes in Africa often stubbornly admit that their wives prepare food with their right hands, which is self-evident. Legend has it that the custom of wearing a wedding ring on the left hand is to ward off evil spirits. Also reflected in Chinese, people are accustomed to taking the right as the top, while the left is always associated with some negative and derogatory concepts, which mean deviation, evil and mistakes, such as "taking the side door and the left voice", while "disagreement" means opposition and "moving left" means demotion.

Uighur compatriots never use their left hand when they see people salute and stick their right hand to their chest. Give others things and gifts with your right hand. Knock on the door with your right hand when you get the answer. Be sure to move your right leg forward when you enter the door. If you step on your left leg in Uighur areas, your host will be unhappy. When people eat pilaf, they always hold it with their right hand and send it to their mouths. It is a universal rule to put correctness first.

When you arrive in America, you will find many people writing with their left hands. Some people usually put their left hand on the left and write on the right; Some put the whole left hand on it and bend their wrists to write; Some simply put the whole left hand on the bottom to write.

international left handers day

1On August 3rd, 975, a group of left-handed people in Topeka, Kansas, USA set up an organization called Left-handed International. They envision uniting left-handed people 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 could celebrate their festival together. August 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 one after another. 1992, the left-handed club in London, England also designated August 13 as International Left-Handed Day, and held their first celebration of International Left-Handed Day that year. In Britain, a special website of International Left-Handed Day was established 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 setting up 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 left-handers, remind people to improve product design and consider the convenience and safety of left-handers more in a right-handed society, and eliminate the prejudice against left-handers that has existed in various cultures for thousands of years and is still being made today. Now, left-handed organizations in dozens of countries around the world celebrate this festival. Europe is a place where left-handed organizations are more active, and the celebrations are more grand.

The enlightenment of left-handed phenomenon to us

Idle 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 thinking in images can we be invincible in the competition in the computer age.

The use of the left hand and the exercise of the left limb can strengthen the body, benefit the brain and improve intelligence, strengthen the body and prolong life.

For left-handers, some people take it easy, while others suffer for life. But in any case, this is an objective thing. 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, molecular biology and so on. This in-depth study may trigger a new brain revolution.

The real human body is not completely symmetrical. Everyone has hands, feet, even ears and eyes, and their strength is different. The eyesight and hearing test in the physical examination report are rarely the same data, just as the feet are not the same size, which always makes it more troublesome to buy shoes. So, why make a fuss about lefties?

Left-handed celebrities

Politicians and militarists

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 three continents: Europe, Asia and Africa.

Caesar, an ancient Roman politician, commander-in-chief and writer, was famous for his dictatorship.

Napoleon, emperor, strategist and commander-in-chief of the First French Empire.

During the reign of Louis XVI, the French Revolution broke out and he died on the guillotine.

Queen Elizabeth.

Queen Victoria, the Queen of England.

King George II of England, the wise monarch of England.

The Pharaoh Ramses II of the first 19 dynasty in ancient Egypt created the most prosperous period in ancient Egypt.

According to the legend in the Ehud Bible, the left-handed enemy chief of ancient Israel was the hero who liberated Israel from alien rule.

Charlemagne, king of Carolingian dynasty in Frankish kingdom, Charlemagne. 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.

Jia Benji, the emperor of the Inca Empire, experienced the most glorious era of the ancient Inca Empire.

Elizabeth II is now the Queen of England.

King George VI of England was the king of England during World War II. He loved beauty and gave up his country.

Joan of Arc is a French heroine and a fighter against the British invaders.

Mahatma Gandhi, father of India.

Churchill was the British Prime Minister during World War II.

Israeli Prime Minister Benjamin Netanyahu.

Callahan, British Prime Minister.

South African President De Klerk.

Castro, Cuban leader.

Singapore Prime Minister Lee Hsien Loong.

Garfield, 20th president of the United States.

Hoover, the 3rd1president of the United States.

Truman, the 33rd president of the United States.

Ford, the 38th president of the United States.

Reagan, 40th president of the United States.

George Bush, 4th1President of the United States.

Clinton, the 42nd president of the United States, just added a little more gossip.

General Patton was a famous American general in World War II.

General Powell, an American general and former Secretary of State, is famous for directing the Gulf War.

General schwarzkopf, American general.

Scientists (physicists, biologists, etc. )

Einstein, a physicist and proposer of the theory of relativity, won the Nobel Prize in physics.

Newton, a physicist and mathematician, founded the theory of calculus and discovered the law of gravity.

Franklin was a famous American scientist and national activist. The famous kite experiment proves that lightning is a cloud discharge phenomenon.

The discoverer of Marie Curie radium, two Polish female scientists who won the Nobel Prize.

Li Zhengdao, a famous physicist in China, put forward the theory of parity non-conservation and won the Nobel Prize in physics.

Linus Pauline, a famous chemist and social activist, won the Nobel Prize in chemistry and the Nobel Peace Prize respectively.

August Picard, inventor of deep-sea submersible.

Albert schweitzer was a famous French doctor and missionary in the18th century.

British mathematician Allen Tanning is the founder of computer science.

August Picard, discoverer of stratosphere.

Astronaut Edwin Bartz Aldrin.

Astronaut Wally Hinla.

entrepreneur

Ford, the king of cars, created a country sitting on wheels with his left hand.

Founder of Oz Motor Company.

Gates, the founder of Microsoft, is the richest man in the world.

Forbes, the king of American media.

John rockefeller oil magnate, the first billionaire in history.

David rockefeller, an American banker, is the head of the Rockefeller family in finance.

Guo Shina, President of IBM.

Davis, the founder of Davis Open.

Allen Fent, a famous TV manufacturer.

artist

Leonardo da Vinci was a great painter, scientist and engineer in the Italian Renaissance.

Michelangelo was a sculptor, painter, architect and poet in the Italian Renaissance.

Raphael, Italian Renaissance painter and architect.

Beethoven, German composer and pianist.

Picasso, Spanish painter. His paintings are very tall now.

Bob Dylan, a famous American folk poet, was once listed as the man of the twentieth century by Time magazine.

Bach is a famous German composer.

Austrian musician Mozart.

litterateur

Mark Twain, a famous American novelist.

Goethe poet.

Heine poet.

Ni Kuang, pen name Wesley, is a famous science fiction writer in China.

Jean Jeanette is a famous French writer and playwright.

Akihara is the most successful commercial cartoonist in Japan in the 1990s, and his works include bastard.

Shigeru Miyamoto is a Japanese video game manufacturer and the founder of Nintendo's game culture.

Actor (singer)

Chaplin's master of comedy.

Ma Lilian Monroe is a famous actress in Hollywood.

Garbo is a famous actress in Hollywood.

Robert De Niro Hollywood movie star.

Jimi hendrix, an American black rock musician, is a talented electric guitar player.

Paul mccartney is one of the soul figures in The Beatles, England.

Liu Laogen, a famous artist in China, Zhao Benshan, is still eating with his left hand.

Xu Zhian, the king of Hong Kong singer.

athlete

Gehlsen and Sweden, 3 1 World Table Tennis Championships singles champions.

Park Young-soon, North Korea, the women's singles champion of the 33rd and 34th World Table Tennis Championships.

Xiao Ye Chengsi, Japanese, singles champion of the 35th World Table Tennis Championships.

China, Cai Zhenhua, team champion of the 36th, 37th and 38th World Table Tennis Championships.

Gated France, the singles champion of the 42nd World Table Tennis Championships.

Wang Tao China, team champion of 43rd and 44th World Table Tennis Championships.

Liu Nankui and South Korea, singles champions in the 24th Olympic Games.

China and Chen Jing, singles champions in the 24th Olympic Games.

China, Wang Nan, champion of women's singles and women's doubles in the 27th Olympic Games, champion of women's singles and women's doubles in the 45th and 46th World Table Tennis Championships, and champion of women's singles, women's doubles and mixed doubles in the 47th World Table Tennis Championships.

Jensen China, champion of men's doubles in the 27th Olympic Games; Men's doubles champions in the 46th and 47th World Table Tennis Championships.

China, Qin Zhijian, mixed doubles champion of 46th World Table Tennis Championships.

Jackson, the former head coach of Bulls, was a famous left-handed player in NBA.

Wang is the first China basketball player to land in the NBA.

Korean volleyball player in Jin Shizhen, "Asia's first attacker" of the Asian Volleyball Federation.

Diego maradona, a famous Argentine star, participated in the World Cup four times and led the Argentine team to win the championship.

Ronaldo, a famous Brazilian player, was named World Footballer of the Year twice.

Milu, the head coach of Chinese national football team, plays with his left foot as a football player.

Shen Xiangfu, the head coach of China's national football team, plays with his left foot as a football player.

Zhao Jianhua, a famous badminton player in China, won the Thomas Cup, World Championships, World Cup, All England Badminton Open and World Grand Prix Finals.

Chen is a famous left-handed young badminton player in Malaysia. He is the first player to win two consecutive championships in the history of the World Youth Badminton Championship and a two-time champion.

Yang Yang is a famous badminton player in China.

American tennis star mcenroe won the US Open four times and Wimbledon three times.

Seles, a famous American tennis player and former Yugoslav tennis player, has won the world's four major open tennis championships nine times.

Navratilova tennis queen, Czech naturalized in the United States. Won the singles championship with 18 times in the four major open competitions.

Ivani Savage, Croatian Powerball player, singles champion of 200 1 Wimbledon Grand Slam.

Koda, a famous Czech tennis player, 1998 won the Wimbledon singles title.

A famous female fencer in China, Luan Jujie.

Mark spitz, winner of six Olympic swimming gold medals.

Mike Will, a Canadian, won the 2003 American Masters Golf Championship and four major golf tournaments.

Bob charles 1963 British Open Golf Champion.

Mueller, American boxing champion, 1994 World Boxing Association and International Boxing Federation.

Senna Brazilian racing prince.

other

Prince Charles may become king of England in the future.

Prince William Jr. may become king of England in the future.