handedness?

[anotheressence]

It's common knowledge that there are more right-handed people in the world than left handed people. This is even apparent in things such as written language itself; most (most as in MOST not all) are read/written from left to right, which is the most comfortable style when writing with your right hand.

But why is it that so many people are right-handed? Is it true that handedness depends on which side of the brain is dominant, and that more people are left-side dominant (the side that controls linear thought) than right-side dominant (the side that controls non-linear thought) ? And if it is, why is that?
Or maybe it's just chance that slightly more people were right-handed in early times, and generations imitated their predecessors and used their right hands and got used to it and so on and so on until most everyone is right-handed? Could it have gone the other way around? And is handedness something you can control, as in being able to use both sides of your brain equally? Do you have to be born ambidextrous, or can you train yourself to be so? And by just being able to use both hands, does that mean you can fully use both sides of your brain?

I've always been interested in this topic, just wanted to hear some people's opinions on it.

 

[eddymrsci]

I think it's about evolution, which is closely related to genetics
as you said, probably written language was first invented by a right-handed person, and he passed down the genetics and the skill to later generations, and because it was difficult to write with left hand, many left-handed people learned to use their right hand, and this increased use of right hand made evolutionary changes to the genes and developed the left brain more.

 

[§outh§tar]

As for being ambidextrous, I don't know..


I can draw relatively well and I have tried drawing several times with my left hand, which is not my dominant hand.

My left handed drawings are not at all that bad compared to my right handed drawings (and I'm a pretty good artist) but my left handed handwriting sucks compared to my already pathetic right handed handwriting.


Maybe I'm not "left-brained"?

 

[gendanken]

Anotheressence:

But why is it that so many people are right-handed? Is it true that handedness depends on which side of the brain is dominant, and that more people are left-side dominant (the side that controls linear thought) than right-side dominant (the side that controls non-linear thought) ? And if it is, why is that?

Because the language areas, those concerned with temporal sequencing, are on the left side of our brain: Broca's and Werinecke's (among other, smaller less "popular" sections). Consider the discipline needed in the organization of language- these centers are responsible for the stabilization, extraction, and analyzing into a complete whole the mess of chaos that is Sound and Image into a comprehensive entity we call "language".

These areas are incredibly important in not only the discrimination of objects but the organization of things that is the mark of our species- we are obsessed with order, meaning, and truth. This, the foundation of logic.

And since Logic is what thousands of years ago allowed the human to master the universe, its only natural, to me, that this area that allowed him this gift should also have dominated its lessers- the parietal lobes (which specialize in emotions and nuance) or the right lobe (which is basically the artsy one, and art, according to Wilde, is fucking useless).

This would explain the dominace of we Right Handers.

 

[Insanely Elite]

If the Catholic church is any indication, handedness can be dictated, as a learned response. My Grandfather was a leftie, he went to catholic church and the nuns struck his left hand everytime he wrote with it. He became right-handed to the end of his days.

It seems that handedness(like most other expressions) combines genetic disposition, and environmental reinforcements.

 

[Slaughterist]

It seems to me that for some tasks the left hand is superior to the right, though for a right handed person the right hand is generally superior. Most striking is typing. The left hand is much better at typing the keys on the left side of the keyboard. Also, if you drive a manual transmission vehicle your left hand may be equal or better than the right hand at steering. Depending on your habit you may leave your right hand laying on or beside the gear shift.
Likewise the left foot is clearly superior at modulating the clutch pedal while the right is better for modulating the brake and throttle.
I, along with many other soccer players, have learned to use my non-dominant foot to control the ball.
Practice doing various tasks with your left hand. It will become more coordinated.
Clearly, the non-dominant side of the body can surpass the dominant side in specific tasks due to repetition and learning. This suggests that the environment is a significant factor.
Here's another consideration. If you speak while using your right hand, the coordination of the right hand decreases. This is because both language and right hand movement are processed in the left side of the brain and it must share its facilities in order to simultaneously accomplish the two tasks. On the other hand , speaking does not decrease the ability of the left hand. This is from The Brain by Richard Restak.

 

[vslayer]

to be right hande tou must have 1 right handed gene, to be left handed you must have 2 left handed genes, to be ambidextrous you must have 1 left handed gene and one undecided gene.

so yes there ar 1/4 lefties among us but during the middle ages when tools became commercially produced and not custom made lefties were forced to use there right hands, and its the same with writing:

because of this a lot of people who are genetically left handed will learn to use their right hand and join the masses

 

[cosmictraveler]

I too am ambidextrous so can't help you out at all.

 

[the_greenvision]

because of this a lot of people who are genetically left handed will learn to use their right hand and join the masses

Then again, we were genetically predisposed towards right-handedness, shouldn't it be that the characteristic gene creating left-handedness tendecies be a super-recessive gene? The offspring of right-handers will inherit their right-handedness... and subsequently pass it on.

And if we also consider the righty nurturing/external influences...

The 1/4 of lefty people during the Middle Ages should have been whittled down to a mere 1/400 or lesser by now. But i think the world-wide average ratio still stands at around 20 - 25%.

So what's keeping lefties alive?

 

[vslayer]

in the persons dna there are instructiuons on hair color, skin color, handedness, etc.

if there are 2 left handed instruction(not sure of the proper term) the person is a leftie, if there is one then they default to a rightie, if there is a defect or anomily the person will be ambidextrous

 

[eddymrsci]

are you sure that handedness is determined by multiple allels?

 

[Slaughterist]

Handedness is controlled by 2 alleles. One allele causes a right hand preference and the other causes a random preference. Having two "right handed" genes causes a very strong preference for the right hand. Having two "chance" genes causes a 50/50 chance of right or left hand preference. Having one of each gene is somewhere inbetween.
SOURCE:
http://www.scientificamerican.com/a...6F-10D2-BE6F83414B7FFE9F&catID=3&chanID=sa005

 

[the_greenvision]

Great link, thanks.

Practice doing various tasks with your left hand. It will become more coordinated.

In practising different physical tasks with the left hand, are we effectively exercising the abstract, non-linear thinking ability of the right brain? Or is that merely a process of familiarisation in motor skills?

I'm pretty sure there're separate facilities for cognitive thinking and motor coordination in both hemispheres of the brain. And that makes four different departments in our heads dedicated to thinking and moving. Being adept in coordination of the right hand (right side of the body) would not definitely equate to a superior grasp of logic and reason.

If that is so, there'd be a weak argument in right-handers being more adept in logical reasoning (linear thinking) than lefties. And vice versa - lefties being more capable in abstract-thinking (and arty farty) than righties.

 

[§outh§tar]

It seems to me that for some tasks the left hand is superior to the right, though for a right handed person the right hand is generally superior. Most striking is typing. The left hand is much better at typing the keys on the left side of the keyboard. Also, if you drive a manual transmission vehicle your left hand may be equal or better than the right hand at steering. Depending on your habit you may leave your right hand laying on or beside the gear shift.
Likewise the left foot is clearly superior at modulating the clutch pedal while the right is better for modulating the brake and throttle.
I, along with many other soccer players, have learned to use my non-dominant foot to control the ball.
Practice doing various tasks with your left hand. It will become more coordinated.
Clearly, the non-dominant side of the body can surpass the dominant side in specific tasks due to repetition and learning. This suggests that the environment is a significant factor.
Here's another consideration. If you speak while using your right hand, the coordination of the right hand decreases. This is because both language and right hand movement are processed in the left side of the brain and it must share its facilities in order to simultaneously accomplish the two tasks. On the other hand , speaking does not decrease the ability of the left hand. This is from The Brain by Richard Restak.

You obviously haven't tried playing ping-pong/basketball with your non-dominant hand..

 

[dfp]

I am right handed, right eyed, and right foot. But I play ping pong and darts left handed. IN playing volleyball ( I use to play mens USVBA AA as a middle hitter) I am just as likely to spike with my left as my right. My hand writing is about the same with my left hand as it is with my right.


WHile genetics may determine a lot of what hand you use. Usage and practice can and does determine what you use as a dominant hand for an activity.

THink about a baseball player. Catching with the left hand should not be naturaly for a right handed person