4 ms·

I wonder why more people are right-handed. What could be a biological basis for that?

tomohelix 3y ago
Probably the same reason why most biomolecules are chiral, i.e. having left and right side. Last time I read about this, I think some physicist said something about the rotation of elementary particles and radiation stuff that are way over my head.
- wpietri 3y ago
  I doubt that, as we left-handers are made up of the same sort of molecule as everybody else.
  - tomohelix 3y ago
    Haha no, I think you misunderstood. I meant the underlying reason for human to have a preferred "side" is probably the same reason that life has a preferred "side" for chemicals. Both humans and enzymes can be chiral, i.e. asymmetrical so I think they might be connected. Don't worry, I am not an atom-ist or a chiral-ist. All sides are equal! (except the ambidextrous master race :D )
    - wpietri 3y ago
      What is the reason you have in mind? I suspect it's different, in that I expect the reason for people is something like "handedness makes people better at violence". Whereas I suspect chirality is more like driving on the right/left side of the road. Which one you pick doesn't matter, but picking is less chaotic than not picking.
      - tomohelix 3y ago
        I actually don't know. Like I mentioned above, there have been a few theories about how life is so strongly asymmetrical but nothing concrete or proven yet. In fact, it is a bit counterintuitive because all natural chemical reactions produces racemic mixtures and only life produces specific stereoisomers. It also means life has evolved to give up nearly half of the natural resources available, a very strange thing in terms of evolution. Not all enzymes are stereospecific though. Some of them can take any configuration of a chemical and convert them to other type of isomer. But these are rare and usually an exception, not the norm. Still, it makes it harder to figure out why chirality is so important in life and not so much in some other parts of life. Maybe your explanation about handedness makes sense. But then it would fail at explaining ambidextrous people since they are definitely better and yet still so rare. Life is really difficult to figure out.
        wpietri 3y ago
        Speaking as a nominal leftie who is effectively ambidextrous for everything but writing, I don't think we're better. I'm just not particularly good at sports. Body-things take more time to learn, and I have to practice with both sides if I want to be good at both sides. Maybe I'm an outlier, but your notion that being ambidextrous is better is a huge assumption. Having a dominant side could have the same sort of benefit that specialization usually does: better for the cases that really matter, worse for the cases that are less important.
LeoPanthera 3y ago
"It's complicated." https://en.wikipedia.org/wiki/Handedness#Causes https://en.wikipedia.org/wiki/Handedness#Causes
- orbital-decay 3y ago
  AFAIK the left/right hemisphere division is extremely complicated and cannot be reduced to being responsible for different activities.
GuB-42 3y ago
There is an interesting game theory explanation. Having the opposite handedness of most other people (i.e. being left-handed) is an advantage in a fight. That's because righties are used to fight against other righties because most people are righties, lefties are also used to fight against other righties. It means that when a lefty fights a righty, the lefty is in a familiar situation while the righty is not, giving the lefty an advantage. And indeed, in many sports where you have an opponent, at high level, there is a higher than normal proportion of lefties. On the other hand (pun not intended), having the same handedness as most other people (i.e. being right-handed) is an avantage for cooperation. For example, to righties can easily share a tool made for righties, but it will be awkward for a lefty. So there are two opposing forces here: cooperation tends to make people of all the same handedness, while competition pushes for a 50/50 distribution. We are at about 90/10, suggesting that the cooperation aspect is more important but not absolutely so. That dominant side is the right side is probably just due to random chance. That it doesn't differ between population groups suggest that it happened before humans spread around the globe, possibly before humans were human.
- sacrosancty 3y ago
  [dead]

Probably the same reason why most biomolecules are chiral, i.e. having left and right side. Last time I read about this, I think some physicist said something about the rotation of elementary particles and radiation stuff that are way over my head.

wpietri 3y ago
I doubt that, as we left-handers are made up of the same sort of molecule as everybody else.
- tomohelix 3y ago
  Haha no, I think you misunderstood. I meant the underlying reason for human to have a preferred "side" is probably the same reason that life has a preferred "side" for chemicals. Both humans and enzymes can be chiral, i.e. asymmetrical so I think they might be connected. Don't worry, I am not an atom-ist or a chiral-ist. All sides are equal! (except the ambidextrous master race :D )
  - wpietri 3y ago
    What is the reason you have in mind? I suspect it's different, in that I expect the reason for people is something like "handedness makes people better at violence". Whereas I suspect chirality is more like driving on the right/left side of the road. Which one you pick doesn't matter, but picking is less chaotic than not picking.
    - tomohelix 3y ago
      I actually don't know. Like I mentioned above, there have been a few theories about how life is so strongly asymmetrical but nothing concrete or proven yet. In fact, it is a bit counterintuitive because all natural chemical reactions produces racemic mixtures and only life produces specific stereoisomers. It also means life has evolved to give up nearly half of the natural resources available, a very strange thing in terms of evolution. Not all enzymes are stereospecific though. Some of them can take any configuration of a chemical and convert them to other type of isomer. But these are rare and usually an exception, not the norm. Still, it makes it harder to figure out why chirality is so important in life and not so much in some other parts of life. Maybe your explanation about handedness makes sense. But then it would fail at explaining ambidextrous people since they are definitely better and yet still so rare. Life is really difficult to figure out.
      - wpietri 3y ago
        Speaking as a nominal leftie who is effectively ambidextrous for everything but writing, I don't think we're better. I'm just not particularly good at sports. Body-things take more time to learn, and I have to practice with both sides if I want to be good at both sides. Maybe I'm an outlier, but your notion that being ambidextrous is better is a huge assumption. Having a dominant side could have the same sort of benefit that specialization usually does: better for the cases that really matter, worse for the cases that are less important.

LeoPanthera 3y ago

"It's complicated." https://en.wikipedia.org/wiki/Handedness#Causes https://en.wikipedia.org/wiki/Handedness#Causes

orbital-decay 3y ago
AFAIK the left/right hemisphere division is extremely complicated and cannot be reduced to being responsible for different activities.

GuB-42 3y ago

There is an interesting game theory explanation. Having the opposite handedness of most other people (i.e. being left-handed) is an advantage in a fight. That's because righties are used to fight against other righties because most people are righties, lefties are also used to fight against other righties. It means that when a lefty fights a righty, the lefty is in a familiar situation while the righty is not, giving the lefty an advantage. And indeed, in many sports where you have an opponent, at high level, there is a higher than normal proportion of lefties. On the other hand (pun not intended), having the same handedness as most other people (i.e. being right-handed) is an avantage for cooperation. For example, to righties can easily share a tool made for righties, but it will be awkward for a lefty. So there are two opposing forces here: cooperation tends to make people of all the same handedness, while competition pushes for a 50/50 distribution. We are at about 90/10, suggesting that the cooperation aspect is more important but not absolutely so. That dominant side is the right side is probably just due to random chance. That it doesn't differ between population groups suggest that it happened before humans spread around the globe, possibly before humans were human.

sacrosancty 3y ago
[dead]