Why Some People Are Left-Handed?
About 12 percent of the world population is left-handed. Why?
Like many human traits, the hand we prefer to use is probably determined by a complex interaction between genes and our environment, although researchers have yet to find the gene or set of genes that select one hand over another, reports LiveScience.com.
Psychologist Marian Annett at the University of Leicester in Great Britain developed what she calls the "right shift theory," which suggests that a single gene increases the likelihood of being right-handed. "The essence of my right shift theory is that there is a gene that helps to develop speech in the left hemisphere of the brain and increases the probability of right-handedness," Annett told LiveScience. She credits evolution, which made humans left-brain dominant for speech and right-side dominant for handedness.
If that's true, why are some people left-handed?
Some scientists believe that the answer lies in our asymmetrical and lopsided brains, specifically one gene or possibly a set of genes that give a preference to the left hand. However, some insist it's caused by prenatal levels of testosterone or even brain damage from trauma at birth, reports LiveScience.
We do know the following about handedness:
Preference for handedness develops in the womb.
Our hands are controlled by the motor center of the brain. Those who are left-handed have a more dominant motor center on the right side of their brain and vice-versa.
Most lefties are likely to have a left-handed relative.
Handedness exists on a continuum, so you might eat with your left hand, but throw a ball with your right.
It is exceedingly rare to be truly ambidextrous; that is, to be able to do anything with either hand.
Left-handed men make about 5 percent more in lifetime earnings than their right-handed colleagues, the Press Association reports of a study by Dr. Kevin Denny, senior lecturer with the school of economics at University College Dublin, Ireland. However, left-handed women earn about 4 percent less than right-handed people.
Persistent myths about lefties and the left hand that are not true:
They are more artistic.
Left-handed fighters have an advantage in hand-to-hand combat.
The left side is associated with evil. In the 17th century, the Devil was often portrayed as being left-handed.
We can only see ghosts by looking over the left shoulder.
The Devil watches us over the left shoulder.
If you get out of bed with your left foot, you'll have a bad day.
If you get a ringing in your left ear, it means someone is cursing or maligning you.
When your left palm itches, it means you have to pay someone money.
If you hear the sound of a cuckoo from the left side, it will be an unlucky year.
If your right eye twitches, you'll see an enemy.
When sewing clothing, it's bad luck to sew the left-hand sleeve onto the garment before the right-hand sleeve.
Make a toast with your left hand and you're really cursing the recipient.
Lefties, take heart with this: The ancient Zuni tribe considered left-handedness to be a sign of good luck since the left was older and wiser.
Ok….12% is approximately 787,917,948 people in the world. That’s a lot of testosterone filled babies having some type of trauma at birth if you ask me.
We call these people scientists? How do they explain numerous lefties in a family or family history of left-handedness? Aside from the older generation before me, quite a few whom are or were lefties, I am left-handed and two of my kids are also left-handed. Do they think all of us lefties through the generations have had some form of brain damage due to birth trauma?
That's a load of crap if I've ever heard one.
Could be it’s just plain, good old genetics at work
, like any other trait that is passed down from generation to generation or maybe we, as testosterone filled, brain damaged babies, decided before ever leaving the comfort of our womb, want to say "fuck you" with our LEFT HAND to some so-called scientists!!!