Handed?

One person in ten, are left-handed and the rest... you guessed it, they are right handed.

• But why do humans have a dominant hand (and foot) at all?

• Another question that pops right is why are some ambidextrous?

• Why also can some children learn to switch "handedness"?

• And why do more strict and regimented societies have statistically higher percentages of Right Handers than more relaxed societies with less?

There is no evidence of any human population of which the predominance has been left handed.

Well the general cop out answer is that it is biological and, most likely, genetic. But the more focused ideas at present are based on the correlation between speech center being of the left brain, which in turn controls the right side, as more developed. This ties in with writing as the speech control is converted to writing...again the left brain controlling the right hand and as it becomes more refined so too does the interaction.

However the gene argument also holds some credence. It is held that the alleles (a variant form of a given gene) is a D gene standing for dextral and meaning "right" and the other allele being a C gene or "chance". The D gene is more typical in humans and believed responsible for the right handedness, whereas the presence of the C gene only yields a 50% "chance" of left handedness.

The C gene left handers have also been documented to be influenced by cultural and or societal pressures (the teacher makes the lefty learn to write righty).

Brain Control

The premise is that it evolved in humans this way as it is more efficient for the two hemispheres to take on different computations and or tasks at the same time. The left side brain as example, may have evolved to accomplish routine mechanical operations like foraging for food as the right side was tasked to detect and react rapidly to sudden and unexpected challenges in the environment,such as an approaching predator or danger.

As we evolved to walking upright, that left our hands free to accomplish other things, like making tools. This theory is reinforced by the study of chimpanzees, where it is noted that while on all fours the have no predisposition to sidedness. However once the upright themselves to a standing position, a lateral preference occurs.

Right-handedness, then, may simply be due to our the way most of our brains are wired. But proving this hypothesis would daunting or even impossible, as it would ideally need to involve neurological testing on our deceased ancestral lineage.

We may never know the reality of this evolution that made our species to be so overwhelmingly right handed and left brained.
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Good Health – Evan Pantazi #Kyusho

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