A person is ambidextrous when he is able to function with the same ability with both the right and left hand. It must be taken into account that normally each individual has greater dexterity with one hand than with the other and the ability to use both hands with the same efficiency is very rare.
Regarding the use of the hands, there are three options. The most common is to be right-handed, which consists of using the right hand for most actions (writing, eating, throwing an object, etc).
Those who handle themselves better with their left are left-handed and this possibility is less frequent and, on the other hand, historically the prevalence of the left hand has been considered a suspicious deviation (curiously, the word left has the same etymological root as sinister).
A third possibility is to be ambidextrous, a very unusual circumstance and one that could be considered a real rarity. Among the three possibilities, only the last one is valued as something extraordinary and out of the ordinary.
Why are we right-handed, left-handed or ambidextrous?
The left hemisphere of the brain controls the movement of the right part of the body and, conversely, the right hemisphere is the one that regulates the activity of the left part of our organism. Despite knowing much of brain function, neuroscientists do not have a definitive answer that explains why we are mostly right-handed (more than 80% of the world’s population).
One of the explanations for this question could be the fact that the capacity for language is found in the left hemisphere and since the human being is the only animal that has developed language, this would explain the prevalence of the right over the left. In any case, the fact that there are ambidextrous people remains a mystery. What is known is that ambidextrous people are just 1% of the world’s population, do not have a dominant hemisphere and, according to some studies, are prone to schizophrenia and learning disabilities.
The importance of the hand in human evolution
From an evolutionary point of view we could say that the hand has its own “history”. In the physiological process of transformation, the first human beings took an important step when we became bipedal.
Bipedalism allowed our hands to stop acting as support for walking and they became very useful tools, both for grasping food and for manipulating objects. In this way, the perfection of manual dexterity is one of the genuine characteristics of man’s evolution.
Photos: Fotolia – A.KaZaK / Syda
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