Are we all born right-handed? Nearly nine out of ten people are right-handed, limiting the percentage of left-handers in the world to just 10%. What does this division determine, is this the result of chance, is it a genetic coincidence to be right-handed, do we acquire that skill with practice?Can I become a left-hander, does it depend on our preferences?
The explanation is not so simple. There is countless research on this subject and none of them have been categorical, however, in this ambiguity, there are two hypotheses that seem to demonstrate a greater scientific basis.
- For both explanations.
- The reasons for being right-handed or left-handed are neurological.
- That is.
- A consequence of an evolutionary process of our nervous system.
- So we know for sure that we were neither right-handed nor left-handed.
- But this condition is also not the result of chance; however.
- We will transform it into early childhood.
- How’s this process going?.
The first of these theories, which has prevailed for years, offers a neurological explanation of the origin of the brain, that is, that being right-handed or left-handed is established by the brain and depends on “laterality”. Nadie. La laterality is the preference to use one of the symmetrical parts of the body: hand, eye, foot, ear, etc.
At the atomic level this concept is symmetrical, but at the functional level it is asymmetrical, the laterality occurs when one side of the body is the one that predominates over the other when performing activities (write, open doors, play tennis, etc. ) Left-handers prefer the left side and right-handers prefer the right side.
Laterality develops between the age of three and six and is completely formed at the age of seven, if at the age of five the child has not yet developed it it is necessary to consult a specialist.
Necessarily, to understand this first theory, we must explain the idea of lateralization, a process that depends on the dominance of the individual’s brain hemisphere. In general, can we say that the right brain hemisphere moves on the left side of the body, and vice versa, so we can infer that:
Recently, researchers at Ruhr University in Bochum, Germany, said that the determining factor in choosing one side or the other was not the brain, but the spinal cord, and found that during the eighth week of pregnancy there are already marked genetic differences between left-handed and right-handed.
Thus, since the fetus is in the mother’s uterus, the genes in her spinal cord that control limb movement already show differences in one group or another, for example, children already choose to suck their finger with one hand instead. How is that possible?
This process is carried out as follows: the cerebral cortex sends motor orders to the spinal cord and, in response, controls the movements of the child’s legs and arms. The discovery of the researchers is that at eight months, a baby has no communication yet. between the cerebral cortex and spinal cord, so the organ responsible for fetal movement can only be the spinal cord.
For them, the explanation of laterality (the preference for use) is epigenetics, that is, the influences that environments exert on genes and that affect the left and right sides of the spinal cord in different ways.
If you haven’t identified with right-handed or left-handed people yet, your laterality may not have fully developed properly, when this happens, kids can be ambidextrous, showing cross-sided or contradictory laterality.
This contradictory laterality relates to the traditionally prevailing abuse of left-handed people by tongue. Doing things, doing them right and being right? It means being intelligent, but the evolution of the sinister Latin word towards the term “sinister” was not so pleasant. That’s why in many countries, like China, they still look bad when someone uses their left hand and that’s why left-handed children are corrected.
There are still many unresolved questions about how we became right- or left-handed, however, neurological research indicating whether this cause is in the brain and spinal cord is much closer to providing us with an indisputable scientific explanation.