Most people are right-handed. Only around 10 percent of the population use their left hand for everyday activities such as writing or playing. Only two percent of all people use both hands equally skillfully. But why are some people left-handed? Let’s find out.
Lefties have not always been treated well in human history. They were times when they were even called witches or a bad omen. While left-handers make ten percent of the population, over the decades, some theories have been knitted about why some people are left-handed.
The Reason is Spinal Cord And Not The Brain – Why Are Some People Left-Handed
Research since the 1980s has shown that our preference for the right or left hand is probably there before birth. Ultrasound examinations indicate that the preference is already around the eighth week of pregnancy. From the 13th week in the womb, babies tend to suck on the right or left thumb.
At the beginning it was believed that genetic differences between the left and right brain are decisive for whether someone is right or left-handed. However, the answer to Why Are Some People left-handed, could be found in the spinal cord.
The First Tendencies Can Already Be Seen in The Womb
Arm and hand movements begin in the brain, in an area called the motor cortex, which then sends a signal to the spinal cord, which in turn is converted into movement. The motor cortex and spinal cord are only connected to one another at 15-week-old embryos. Whether a baby is right-handed or left-handed is determined beforehand.
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In other words, the fetus can start moving and favoring a hand before the brain controls the body. The gene expression in the spinal cord between the eighth and twelfth week of pregnancy was analyzed. Significant differences were found in the right and left parts of the spinal cord that control the movements of the arms and legs.
The conclusion was that the natural asymmetry of the spinal cord could be responsible. The asymmetry is often caused by environmental factors and can affect a baby’s growth. These differences in gene expression can affect the right and left parts of the spinal cord differently and thus lead to Why Are Some People left-handed and others are right-handed.
Then Why Are Lefties So Rare? – Left Handed People
Scientists have been researching this question for a long time. According to the researchers, in addition to the genetic predisposition, a social factor may also play a role in explaining why the proportion of right-handed people is so large.
The crucial factor to achieve an efficient society is a high level of cooperation between society members. In humans, that resulted in a right-handed society. In other words, for some reason we developed to prefer the right hand. Someone who deviates from this may have been conditioned to use the other hand more despite genetic predisposition. It could be stored as our genetic predisposition and might be a subconscious expression.
Exact Causes Have Not Yet Been Clarified
Nevertheless, it remains a secret why exactly people become right or left-handed. Perhaps this ignorance is due to the fact that even after birth, it is difficult to predict whether a child will develop to be right or left-handed.
But there is one thing we do know that the neurological differences between right-handed and left-handed people are small, and behavioral or psychological differences have largely been refuted.
Hope this answers the question of why are some people left-handed. There are numerous other mythological beliefs that link the left-handed people to have a different thought process.
Some of the best brains and most influential people in the history of the world have been left-handed like Albert Einstein, Albert Einstein, Ludwig van Beethoven, Napoleon Bonaparte, Pablo Picasso, Bill Gates and Barack Obama. Though there is hardly any proven link between success and being left-handed.