Contents:
- Medical Video: Why are some people left-handed? - Daniel M. Abrams
- Babies can move their hands from the womb
- Genetic and environmental factors influence a person's tendency to be left-handed
- So right-handed people have many advantages
- More creative
- Left-handed people tend to be smart
- Can use two hands
Medical Video: Why are some people left-handed? - Daniel M. Abrams
Ten percent of the total 7.6 billion people in the world are left-handed people. Left-handed people don't just use their left hand to write, eat, comb their hair, pick noses, but also chew on the left side of the mouth and step first with the left foot. What, what causes left-handed people?
Babies can move their hands from the womb
Quoted from Medical Daily, the tendency to use one side of the hand has been formed since the womb - precisely at the 8th week of pregnancy. Meanwhile, the habit of thumbing with one side of the hand appeared at week 13 based on ultrasound examination.
A joint research team from the Netherlands, England and China found that the cause of a person being left-handed came from nerves in the spinal cord. This finding refutes the old theories that the brain is the main determinant.
Initially, many researchers thought the brain's motor cortex sent signals to the spinal cord to move hands and feet. But the study reported that the motor cortex has not even been connected to the spinal cord at 8 weeks' gestation. In fact, babies can move their hands in the direction they prefer at that age. In other words, the baby can start the movement and choose his favorite hand before the brain begins to control his body movements.
Genetic and environmental factors influence a person's tendency to be left-handed
The researchers from Ruhr University Bochum, Germany, observed DNA sequences in the baby's spinal cordat the 8th to 12th week of pregnancy. They found that DNA sequences in nerve segments that control foot movements and hands on the right and left bone marrow are quite different.
"This is not impossible because many nerve fibers cross from one side to the other at the boundary between the hindbrain and the spinal cord," explained Carolien de Kovel, lead author of the study and researcher at the Max Plank Institute for Psycholinguistics.The researcher concluded that this difference could be influenced by the environment, whichlater it will affect baby's growth.
Simply put, left-handed development has occurred since the womb. Genetic factors and environmental exposure during pregnancy together play a role in making someone left-handed, de Kovel closes.
So right-handed people have many advantages
Even though it's a "rare population", you who are left-handed don't get discouraged. Prince William, Bill Gates, Oprah Winfrey, Barack Obama, Kurt Cobain, until Maradona is a world-famous figure with a left arm.
Research reveals some of the privileges of being left-handed, including:
More creative
According to research in Journal of Mental and Nervous Disease, musicians, painters and writers mostly tend to be left-handed. Michael Corballis, PhD, a brain specialist and a psychologist at the University of Auckland in New Zealand shows the fact that left-handed people tend to be creative-minded to solve problems
Left-handed people tend to be smart
According to a study from St. Lawrence University, USA, left-handed people tend to be smart. Many left-handed people have IQs of more than 140 such as Da Vinci, Michelangelo, Einstein, and Newton. In addition, left-handed people are usually more fond of observing and having good language skills.
Can use two hands
The number of household utensils and activities aimed at right-handed people ultimately "forces" left-handed people to go with the flow and train their right hand.The result, not infrequently left-handed people who were finally able to use both hands equally well. These people are referred to as ambidexterous, and even more scarce the population around the world.
