ARE YOU LEFT HANDED??
Humans have two hands located at the distal end of each arm.
The scientific use of the term hand in this sense to distinguish the
terminations of the front paws from the hind ones is an example
of anthropomorphism.
Left-handed people are more dextrous with their left hand
apart from their right hand. They will probably
also use their left hand for all the tasks orientation. Writing is not suppose
to be as good indicator of handedness as it might seems. As the fact that many
people who write with their right hand, use their left for everything else.Approximately
10-14% of the population is left-handed.
People who can use both hands equally well are ambidextrous.
True ambidexterity is rare. Generally, males are 3 times more likely to be
left-handed than females. Statistically, one twin of a pair has a 20% chance to
be left-handed.
The human population is right handed dominated but no one
knows the real fact about it yet. But there are certian assumption about the
“Hand Theories”.
Evolutionary Assumptions
It is being assume by taking the example of Warrior and his
shield/weapon. The position of warrior in the field of war with his weapon and
shield in hand determines this assumption. Basically, since the heart is on the
left side of the body, a warrior holding his shield with his left hand would be
better able to protect his heart than if he held it with his right.
Birth
Some researchers argue there is evidence for cases of
"pathological" left-handedness related to brain trauma during birth.
And many researchers trace the cause of handedness back to pre-natal, interuterine
developmental processes, back to the time when the fetal brain is first
developing distinct cerebral hemispheres.
Brain hemisphere
In this theory,
speaking and handiwork require fine motor skills having one hemisphere of the
brain do both would be more efficient than having it divided up. This is
the most commonly accepted theory of handedness. It also predicts that
left-handed people would have a reversed brain division of labour.
Genetic
Handedness runs in families, although even when both parents
are left-handed, there is only a 26% chance of their child being left-handed.
Thus, it is clear that genetics is not the only cause but many members of the
British royal family are left-handed. Genetics is usually used to explain this.
