The reason for some people being left-handed cannot be explained with certainty
. Some authorities declare that people are born with strongly-developed tendencies towards either right- or left-handedness. Others assert that either tendency
is merely acquired
. Neither party, however, has beeen able to prove its case
. The former state that the left side of the brain
, which controls the right hand, is more highly developed than the right side, which controls the left hand. This, though, has not been proved and no explanation
as to why one side of the brain should be superior
to the other is available.
It is often surmised that the reason for the right hand being the superior is that our distant ancestors acquired the habit of using the right hand to wield weapons
while protecting their hearts
with the left and in the course of time, therefore, children began to be born with a tendency towards right-handedness.
It is estimated that fewer than 10% of people are left-handed.