Why do suppose humans are not naturally ambidextrous?
Asked by
josie (
30934)
July 20th, 2011
The species is bilaterally symmetrical.
So how did it come about that human beings favor one side over the other.
And since that is the case, why is it not uniform over the species? All righties. All lefties.
Is this a transitional state?
Will primates eventually be ambidextrous as the righties. interbreed with the lefties?
Observing members:
0
Composing members:
0
12 Answers
Two words, Hokey cokey…. oh yeah, that’s what i’m talkin about!
My folks did it to me. They said the lefthanded people were devil spawn.
@lucillelucillelucille Lol!
I don’t know either, but I assume it has something to do with the brain of course. Just like some brains are wired to be much different, whatever determines handedness isn’t common enough to make us ambidextrous. I think I’m just going to stop typing now lol.
I think we get used to handedness. And it’s reinforced by tools and machines and gadgets all around us. Try looking for a left-handed trackball for your computer.
If you try using your ‘other’ hand for common tasks, after a while you can probably do it.
There is some marvelous sci-fi future-fiction movie in which people over a certain age (60?) are euthanized to free up resources. a rogue group of oldies have stolen off into the forest to live and they do exercises like walking around with one eye covered (or both), or one hand tied, to develop skills for when the body begins to break down.
Someone near and dear had a stroke and found it was not possible to wipe after toilet with the hand normally used. “If I have any advice for the future generations, learn to wipe with either hand!” was the wisdom drawn from that.
Our handedness ia a reflection of our brains favoring one hemisphere over another.
We’re mostly bi-laterally symmetrical. The cerebral hemispheres aren’t functionally symmetrical, and it’s from this functional asymmetry of the brain that handedness arises.
Because particular brain functions tend to be localized in one or the other of the hemispheres, there are efficiencies to be had by localizing the related sensory inputs and motor functions within that same hemisphere. The right eye and right hand are controlled by the left hemisphere. In many animals with lateralized brains, that’s the hemisphere that is concerned with capturing food. Studies in animals have demonstrated that individuals with strong preference for one side are more efficient at gathering up food than are more ambidextrous individuals. These efficiencies could explain how handedness got an evolutionary toe-hold.
The theory is that strong lateralization allows the brain to function as a parallel processor, with specific regions consistently performing their specialized tasks while others carry on with their areas of expertise. No energy or time is wasted working out what does what.
As for why a small population of different-handed individuals persists, Game theory has been invoked to explain that a certain degree of variation makes the chances of survival of the whole group better. As a simple example, most of the members of a school of fish will veer the same diraection when threatened, but a small number will veer the other way. Over time, this has survival insurance value.
Ladies want to “interbreed” with the leftie? I’m one.
My answer is that way more people are lefties but cultural and religious notions have stigmatized being a sinister. I’m not ambidextrous, but I can use my right hand almost as well as my left. I’d say I was ambisinister but apparently that a massive insult. Of course when you start with a pejorative it’s hard not to end with one too.
How come not everyone one is blue eyed? The Nazi didn’t win.
I was completely ambidextrious until the third grade in school. I literally would switch hands half way across the paper when doing a writing assignment. My third grade teacher stood over me with a ruler and rapped my knuckles every time I tried to write with my left hand.
I still use either hand to do many of my routine tasks.
A lot of it is cultural, we are programmed to be one handed or the other.
I am ambidextrous. Having a lack of cerebral dominance interferes with stereoscopic vision. Believe me that is no benefit. Being able to use most tools with either hand is however beneficial.
Not being ambi-destroys comes from having one dominant brain sphere that tends to focus on certain tasks more than the other one.
There seem to be strong advantages in having one dominant sphere, but two common examples:
It creates a left-right reference.
It allows for quicker reaction, since an individual does not have to waist time on allocating control to one brain sphere.
Lateralization therefore comes with evolutionary advantages, for instance when reaction time is vital to a prey animal that is surprised by a predator.
Ambidextrous children often have (more) trouble learning to read and write and a longer movement inertia. They will read words from right to left, for instance and hesitate too long when tasked to catch a ball thrown straight at them. (Where two brain spheres are in competition for making ‘the catch’)
And there is a lot more to be said on the topic, I guess, by smarter people.
I think I shouldn’t be typing this late anymore and I sometimes hate what my iPad turns my typos into. Ambi-destroys should of course be ambidextrous.
Answer this question