Surely every right-hander at least once in his life tried to write with his left hand, and left-handed with his right. Most likely, what was written could hardly be called calligraphic writing or even read. So why are some of us better at using our right hand and others with our left?
First, let's figure out what is called the dominant hand. The dominant hand is a symptom that arises from the unequal development of motor skills of the left and right hands, so those who are better at the right are called right-handers, and the left - left-handed.
Why are there fewer left-handers?
The dominant hand is a unique feature of humans compared to primates. For example, chimpanzees or gorillas do not have this feature, but many other animals prefer one or another paw; however, the ratio of right-handers and left-handers among animals is almost the same.
Right-handed dominance is the most common, while left-handed people are approximately 5 to 30% in the world. Such a spread in percentage arises from the disagreement of scientists in the methods of identifying the dominant hand.
There are many theories explaining this phenomenon, including the one that the predominance of the right hand developed in the process of evolution, when natural selection weeds out rare and strengthens the necessary skills for human development and survival. Then why are left-handers still among us?
The most common theory for the appearance of a dominant hand is that the prevalence of one or another upper limb is associated with the hemispheres of our brain. Everyone knows that the left hemisphere, which controls logic and speech, controls the right side of the body, and the right hemisphere, which is responsible for the perception of spatial orientation, controls the left.
Promotional video:
It follows from this that the left part of our brain, which controls speech, is also responsible for the writing hand, but the left-handed brain processes this information not only in the left hemisphere, but also in the right.
Whether left-handers inherit a left-hand preference, and whether this trait can be inherited at all, is unknown, since scientists have not yet found a gene responsible for the predominance of one or another hand.
Handyman
“And I can work well with both my right and left hands,” you say. Great, because this is a unique gift that only the elves from the works of J. R. R. Tolkien have: they used both their right and left hands to write.
But seriously, ambidexterity - congenital or developed in training equal development of the functions of both hands - is very rare. Only 1% of children born have this feature.
Right-handedness: a dominant evolutionary trait or a consequence of a social factor? Scientists have yet to figure this out, but for now, do not ask yourself who is better - right-handed or left-handed, because among both there are enough geniuses and criminals.