Concept in Definition ABC

A person is ambidextrous when he is able to cope with the same skill both with the right hand and with the left. It must be borne in mind that normally each individual has a greater skill with one hand as with the other, and the ability to use both hands equally effectively is rare.

With regard to the use of the hands, there are three options. The most common is being right-handed, which consists of using the right hand for most actions (to write, eat, throw an object, etc).

Those who deal better with the 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 being ambidextrous, a very unusual circumstance 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, inversely, the hemisphere right It is what regulates the activity of the left part of our body. Despite knowing a large part of brain functions, neuroscientists do not have a definitive answer that explains why we are mostly right-handed (more than 80% of the population world).

One of the explanations for this question could be the fact that the ability of language is found in the hemisphere the left and as humans are 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 simply 1% of the world population, they do not have a dominant hemisphere and, according to some studies, they are prone to schizophrenia and problems in the learning.

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 bipeds.

Bipedalism allowed our hands to stop acting as support for walking and they became very useful tools, both for grasping food as to manipulate objects. In this way, the improvement of manual dexterity is one of the genuine characteristics of the evolution of man.

Photos: Fotolia - A.KaZaK / Syda