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The mystery of why left-handers are so much rarer (2016)

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Re: The mystery of why left-handers are so much rarer (2016)

#251

Post by lolc »

emporas wrote: post #172
HarHarVeryFunny wrote: post #141

Well, our brains are asymmetrical in terms of function, and our bodies are asymmetrical internally too (heart, liver). So, which came first? Are we mostly right handed because of left brain functionality (each side of brain controls opposite side of body), or is handedness innate in some other way and perhaps influences brain sidedness? Or, are these two things unrelated?

With so many poisonous plants reptiles and insects, it is better to use the hand further away from the heart. In case it gets stinged or bitten or pricked the poison will affect a slightly more remote area.

Thank you, that is the best just-so story I've read in a long while!

If the subtext is not apparent: https://en.m.wikipedia.org/wiki/Just-so_story

Re: The mystery of why left-handers are so much rarer (2016)

#252

Post by emporas »

lolc wrote: post #251
emporas wrote: post #172

Earlier quoted context omitted.

With so many poisonous plants reptiles and insects, it is better to use the hand further away from the heart. In case it gets stinged or bitten or pricked the poison will affect a slightly more remote area.

Thank you, that is the best just-so story I've read in a long while! If the subtext is not apparent: https://en.m.wikipedia.org/wiki/Just-so_story

Even if the distance of the right hand to the heart (on the left) is just 10% more than if it was located on the right side, that small difference for 50 million years might be significant enough for a right hand trait to be established in the population.

Any scientist who wants to verify this hypothesis (or the-just-so story) is welcomed, and this explanation might be upgraded to totally valid scientific theory or serve as a warning to the general public about unproven scientific falsehoods.

Re: The mystery of why left-handers are so much rarer (2016)

#253

Post by FinnKuhn »

pram wrote: post #139

Just throwing in my left handed anecdote here: the bottom of my hand was always covered in pencil graphite when I was in school because your hand drags over what you've been writing from left -> right. Also ring binders were a pain in the ass (your hand is blocked at the left margin lol)

> Also ring binders were a pain in the ass.

My suggestion would be to just turn them around so the spiral is on the right side

Re: The mystery of why left-handers are so much rarer (2016)

#254

Post by giraffe_lady »

n4r9 wrote: post #228
giraffe_lady wrote: post #140

Earlier quoted context omitted.

Yes left-handed advantage is a major thing in combat sports including fencing. IIRC close to 50% of professional boxers and fencers are left handed, which is similar to the rate for pitchers I believe.

This study suggests 25% among top-rate boxers: https://www.researchgate.net/publication/286024810_The_influ... Which is still higher than average, and around the level seen in more violent societies. I think it makes sense that it wouldn't get up to 50% since you're sampling from a smaller pool in the first place.

They're also conflating stance and handedness, which may make sense in boxing I don't know much about that sport. But in judo for example there are other factors in stance choice and only about half of left handers mainly use the "left handed" stance, and plenty of right handers prefer it also.

Overall probably just really hard to get good universal data on this. I'm curious about fencing though. Another sport I don't know much about.

Re: The mystery of why left-handers are so much rarer (2016)

#255

Post by HarHarVeryFunny »

emporas wrote: post #252
lolc wrote: post #251

Earlier quoted context omitted.

Thank you, that is the best just-so story I've read in a long while! If the subtext is not apparent: https://en.m.wikipedia.org/wiki/Just-so_story

Even if the distance of the right hand to the heart (on the left) is just 10% more than if it was located on the right side, that small difference for 50 million years might be significant enough for a right hand trait to be established in the population. Any scientist who wants to verify this hypothesis (or the-just-so story) is welcomed, and this explanation might be upgraded to totally valid scientific theory or s…

We've got veins returning blood to the heart on both sides of our body, and it all has to go via the circulatory system - not as-the-crow-flies from any point directly to the heart.

In any case, even if there was (seems not) a few seconds delay in terms of how quickly poison from a snake bite on one side of body vs other got to the heart, that's not going to make any difference to survivability.

It seems that developmental asymmetry, resulting in (fairly major) left vs right brain functional differences, is what has lead to left vs right handedness.

Re: The mystery of why left-handers are so much rarer (2016)

#256

Post by H1Supreme »

Since there seems to be a few others who use one hand or the other depending on the task at hand, here's my seemingly random list:

- writing, eating, soldering iron, painting: left hand

- throwing, kicking, anything that requires more strength: right hand

- guitar: right

- hand that holds a drink: left

Here's some weird ones:

- Chop an onion: right hand

- Butter a piece of bread: left hand

- Use a mouse: right hand. This one makes no sense. My left hand is my precision hand. I assume this was learned.

- Use a box cutter or exacto knife: left hand

- Scissors: right hand (Again, this must have been learned)

Here's a funny story from my youth: I worked part time at Wendy's in high school. Once when I was making sandwiches, a co-worker remarked "Why do you do that?". "Do what?" I said. "Why do you keep switching hands depending on what topping/condiment you're putting on the sandwich?". "Idk, I didn't even notice".

Re: The mystery of why left-handers are so much rarer (2016)

#257

Post by wildzzz »

squarefoot wrote: post #245

Left handed here, and having been in school from the early 70s, I had to suffer their stupid shortsighted attempts to "correct" what they thought was a voluntary mistake when writing or eating. I never stopped being left handed of course, but for some things I'm right handed, although in most of them I can also use the left almost comfortably. Here's small list: fork: left pen: left tools (screwdriver, wrench, etc):…

For me, eating and writing are the few things I'm only good at doing left handed. Knives are left handed as well. Scissor use is always right handed since most scissors are right handed, using left hand scissors is hard for me. Sports are always right handed for me. Tools are usually ambidextrous. My left hand is more dexterous but my right is stronger so my dominant hand just depends on what I'm doing with the tool. Using an xacto blade to carefully scrape solder mask off a board? Left hand. Turning a difficult screw? Right hand.

I think the defining thing for me is that if something is specifically made for right handed use or if you're more likely to encounter a right-hand version, I'm probably right handed when using/doing it. If it's ambidextrous like a pen or fork, I'm usually left handed.

Re: The mystery of why left-handers are so much rarer (2016)

#258

Post by wildzzz »

portaouflop wrote: post #200
zdragnar wrote: post #51

I write left handed, and use a fork in my left and knife in my right. Left hand for holding a phone or a drinking glass, and for shaving. I'm right eye dominant, though, so I throw, swing, shoot, use scissors, play instruments and use a mouse right handed. I'm not at all ambidextrous, I can't do most of those things with my other hand.

I do basically everything with my left — but I do use the mouse with my right. Not sure what that means…

Because there are certain things that you just learn with that hand because it's traditional. My wife usually uses her mouse in the right hand but she actually prefers using it left handed.

Re: The mystery of why left-handers are so much rarer (2016)

#259

Post by erebearalte »

H1Supreme wrote: post #256

Since there seems to be a few others who use one hand or the other depending on the task at hand, here's my seemingly random list: - writing, eating, soldering iron, painting: left hand - throwing, kicking, anything that requires more strength: right hand - guitar: right - hand that holds a drink: left Here's some weird ones: - Chop an onion: right hand - Butter a piece of bread: left hand - Use a mouse: right hand.…

To me it feels like whichever hand I start with lol, it does make me wonder if the reason I'm much better at fps games with a controller is because my left is my precision hand but I'm using the mouse with my right. (I know controllers have aa but I'm still much better than a mouse even though I've been using mouse to play rts and moba games my whole life over using a controller for just apex)

Re: The mystery of why left-handers are so much rarer (2016)

#260

Post by emporas »

HarHarVeryFunny wrote: post #255
emporas wrote: post #252

Earlier quoted context omitted.

Even if the distance of the right hand to the heart (on the left) is just 10% more than if it was located on the right side, that small difference for 50 million years might be significant enough for a right hand trait to be established in the population. Any scientist who wants to verify this hypothesis (or the-just-so story) is welcomed, and this explanation might be upgraded to totally valid scientific theory or s…

We've got veins returning blood to the heart on both sides of our body, and it all has to go via the circulatory system - not as-the-crow-flies from any point directly to the heart. In any case, even if there was (seems not) a few seconds delay in terms of how quickly poison from a snake bite on one side of body vs other got to the heart, that's not going to make any difference to survivability. It seems that develop…

I would say that brain asymmetry probably is not the cause of hand and leg asymmetry. It has to do either with venomous [1] plants and animals or with muscle use and fatigue.

When the hand is stung or burned it performs a quick centrifugal movement instinctively. Then many mammals can suck some blood out with their mouths. That minimizes the venom in circulation, and some additional time to get to the heart might be less damaging, especially when the venom is not very plentiful like bees, scorpions etc.

When the venom is of a big quantity, like big snakes then probably it doesn't make a difference.

One other factor is muscle isolation and helping the heart to not get tired from work. Considering that the whole point of gyms is muscle isolation, which is very difficult to achieve normally, a human or monkey cracking nuts or cracking bones for hours, it will tire the left side (where the heart is located) much more increase palpitations, and consequently the risk for heart attack.

That last one could be tested, working more using the left hand -> increase palpitations or not. As a counter example, the chimp when it cracks the turtle, it works with both hands [2].

[1] Venomous not poisonous i misspoke previously. [2] https://www.youtube.com/watch?v=o7dRvX2f9Rs

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