Right Tighty - Lefty Loosey

[TeeDee]

Maybe some of the more erudite historians can help with the following.

I was musing on how being right handed is so prevalent and the various brain related explanations for such.

My question is - is this reinforced from an evidence point of view from primitive tools found through out historical findings? Were knapped stones or axes clearly shown to be right handed ?

Or when brains were less developed were the tools more found to be equally spread?

As mentioned - just musing.

 

[Broch]

There are many theories as to why humans evolved to be predominantly right-handed (around 90%). I find the most plausible being based on the left hand side of the brain that controls speech, fine motor skills etc. developing to deal with the evolutionary advantages of those and, of course, the left hand side of the brain controls the right hand - so an accident not an evolutionary advantage

 

[HillBill]

Righty tighty, lefty loosey is a modern term based on screw threads. I don't think it has anything to do with evolution.

I think its more to do with if a parent is right handed... then when they pass something to a child, they are more likely to use their own right to grab it, as using the left is counter intuitive. You'd have to twist your wrist to show the palm in this case, which is awkward. Generations pass, Right becomes dominant...Suggesting right handed was more common initially. Perhaps due to the heart being on the left, and using the left under load stress put more pressure on it, didn't help with blood flow... The stomach swinging left etc, so when youd eating it was more comfortable to tense on the right side, making it less uncomfortable and aiding food pass through the system more easily? Dunno, just musing myself there really.

Edit to add. Most vital organs are situated on the left. So theres many reason why one would favour the right. Defense/protection, comfort/less pressure while tensing muscles etc... that trait passed on from parents..... i don't think there's much more to it than that.

 

[demographic]

My mother was left handed and when she was a kid (she was born in 1933) the schoolteachers made her write with her right hand.
To be fair, that meant when she was an adult she was more or less ambidexterous which has some advantages.
Oh and being left handed is "Sinister" to various versions of ancient god botherers.
Link.

 

[TeeDee]

Righty tighty, lefty loosey is a modern term based on screw threads. I don't think it has anything to do with evolution.

No doubt Bill.

I was just thinking for an amusing thread title darling.

 

[TeeDee]

Righty tighty, lefty loosey is a modern term based on screw threads. I don't think it has anything to do with evolution.

I think its more to do with if a parent is right handed... then when they pass something to a child, they are more likely to use their own right to grab it, as using the left is counter intuitive. You'd have to twist your wrist to show the palm in this case, which is awkward. Generations pass, Right becomes dominant...Suggesting right handed was more common initially. Perhaps due to the heart being on the left, and using the left under load stress put more pressure on it, didn't help with blood flow... The stomach swinging left etc, so when youd eating it was more comfortable to tense on the right side, making it less uncomfortable and aiding food pass through the system more easily? Dunno, just musing myself there really.

Edit to add. Most vital organs are situated on the left. So theres many reason why one would favour the right. Defense/protection, comfort/less pressure while tensing muscles etc... that trait passed on from parents..... i don't think there's much more to it than that.

I have also wondered about the asymmetrical location of organs and how thats occurred - assuming its come from being a most quadruped based creature a purely bipedal one - chest and belly cavity becoming smaller over time? what about the appendix?

 

[Stew]

I have also wondered about the asymmetrical location of organs and how thats occurred - assuming its come from being a most quadruped based creature a purely bipedal one - chest and belly cavity becoming smaller over time? what about the appendix?

I have no idea but are asymmetrical organs common across all creatures?

Paired organs (ie lungs) it makes sense to be symmetrical but odd numbers, it would have to be asym else there would be a lot stacked on the mid line.

 

[oldtimer]

We are both right handed. The elder of our two sons is left handed the younger is right handed. No other family members are left handed. This would suggest that handedness is neither genetically nor socially acquired. There are, however, variations in dominant eyes within our families. I wonder if this is significant?

 

[TeeDee]

We are both right handed. The elder of our two sons is left handed the younger is right handed. No other family members are left handed. This would suggest that handedness is neither genetically nor socially acquired. There are, however, variations in dominant eyes within our families. I wonder if this is significant?

I think NOW there must be somewhat of a societal bias to handiness - I was thinking in countries where they write , right to left if that would change or alter the data on that. ?

My main question was where there was less developed cerebral development if the hand tools used by the ancients showed a right / left/ neutral preference?

 

[Keith_Beef]

Maybe some of the more erudite historians can help with the following.

I was musing on how being right handed is so prevalent and the various brain related explanations for such.

My question is - is this reinforced from an evidence point of view from primitive tools found through out historical findings? Were knapped stones or axes clearly shown to be right handed ?

Or when brains were less developed were the tools more found to be equally spread?

As mentioned - just musing.

You might find this article interesting. I suggest you read it soon, before the NIH gets shut down...

 

[Furbles]

In answer to the OP, yes there is evidence that humanity has been right-handed-dominant for as long as we can find evidence.

See: https://discoveryplace.org/stay-at-...arly-man-right-handed-archeologists-think-so/

 

[Paul_B]

My mother was left handed and when she was a kid (she was born in 1933) the schoolteachers made her write with her right hand.
To be fair, that meant when she was an adult she was more or less ambidexterous which has some advantages.
Oh and being left handed is "Sinister" to various versions of ancient god botherers.
Link.

Left in Latin is sinister, right is Dexter. So one became a meaning for unfavourable and even later for slightly evil things. The other joined with the word for "both" to become the word for being able to use both hands equally.

I think the lefties lost out in the word origins game there. Left is unfavourable but right became a useful ability. Now that is a little evil if you ask me, and I'm not even a Leftie!

 

[HillBill]

I have also wondered about the asymmetrical location of organs and how thats occurred - assuming its come from being a most quadruped based creature a purely bipedal one - chest and belly cavity becoming smaller over time? what about the appendix?

Appendix, Pancreas, Liver... all on the right side (larger portion of the liver anyway)... Appendix is vestigial, Pancreas causes problems and likes to kill people (diabetes, pancreatitis) Liver has no end of issues... That to me just poses a question... Would they be in the same position, or have such negative effects in a population dominantly left handed? And if there was a net positive to the right side organs, would we then have a negative to the left? And if so, which is more important? Or did the larger/main organs get pushed to the right, due to using the right side muscles of our torso more?

 

[HillBill]

You might find this article interesting. I suggest you read it soon, before the NIH gets shut down...

I don't have time to read all of it, got a bit less than half way. But it's interesting to see, that children with 2 left handed parents, were still predominantly right handed. Not so much as those with right handed parents but still, you would expect it to swing the other way, which is does a little, but not enough to claim left handed parents produce left handed children. Interesting.

 

[Paul_B]

I don't have time to read all of it, got a bit less than half way. But it's interesting to see, that children with 2 left handed parents, were still predominantly right handed. Not so much as those with right handed parents but still, you would expect it to swing the other way, which is does a little, but not enough to claim left handed parents produce left handed children. Interesting.

Isn't there something about recessive genes going on there? I recal something about recessive and not genes and two recessive gene carrying parents might only produce offspring with that recessive gene something like one in four cases. Something about needing recessive-recessive but getting recessive-nonrecessive or nonrecessive-recessive or nonrecessive-nonrecessive which results in nonrecessive characteristics?

Although I have no idea if left handedness is a recessive gene characteristic or not. Or even if it is that simple. Just that two parents with the same characteristices might only create a likewise offspring less often than a different offspring. If that makes any sense. If leftie is recessive gene and rightie is nonrecessive it would explain how righties are more often even with both leftie parents.

All from my half ignorant half nonignorant knowledge of genetics from GCSE Biology from many moons ago. I expect it is nowhere near as simple. Just leftie is minority and I suspect selection is not the only cause.