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Why is almost everyone right-handed? A new study connects it to bipedalism

ox.ac.uk

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Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#121

Post by ticulatedspline »

Stevvo wrote: post #62

I taught English in China 20 years ago. Of the thousands of students I taught, none wrote with their left hand. "There are no left-handed in China" might sound as ridiculous as "There are no gays in Uganda". However of those thousands of students, none had messy hand writing. In any class in Europe or the US, around 10% of students have messy writing. Suspiciously equivalent to the supposed number of left-handed stud…

Seems probable that's simply because it isn't tolerated as a choice.

Though the best evidence to refute "There are no left-handed in China" is that it didn't take long to find a left handed Chinese baseball player

https://en.wikipedia.org/wiki/Chen_Hao_(baseball)

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#122

Post by usef- »

Magi604 wrote: post #114

I almost never see people using a left hand mouse these days. As younger people start using computers they generally will learn with right-handed mice and will thus develop those fine motor skills in that hand. I wonder if this will make right-handedness even more dominant.

With modern controllers the main joystick/thumbstick is on the left side. People are using both hands for fine control in different circumstances.

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#123

Post by yawpitch »

rybosworld wrote: post #44
yawpitch wrote: post #22

Earlier quoted context omitted.

Here’s my multiple years of anatomy classes response: the heart isn’t on the left. The aorta is, sure, but the vena cava is on the right. Also people with situs inversus (essentially all organs flipped laterally from “normal”) aren’t obviously more prone to left-handedness.

Not disagreeing that handedness is probably unrelated to heart position. But why would situs inversus somehow be tied to this at all? If there's a gene that favors right-handedness, it's not like it would somehow "choose" left-handedness because the individual has their internal organs flipped.

Genes don’t favor (or not favor), but if a natural selection bias for precise dexterity exists AND heart lateral orientation affects dexterity precision THEN those with flipped lateral orientation should exhibit more dexterity in the left hand, thus they should be naturally selected for because of the same bias.

Now, I’d seriously doubt there’s any evidence whatsoever for the assumed selection bias in the first place, never mind any causal relationship between fine motor control and heart asymmetry, but the selection bias should apply to both flips of the anatomical mirror.

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#124

Post by didibus »

js2 wrote: post #93
skyberrys wrote: post #74

The article didn't really help me understand what it was about bipedalism that resulted in a right handed preference. Also in my family left hand dominates, we are a cluster of left handed people. My theory is if any child wants help with fine motor control the help is provided by a left hand to a left hand.

The original paper is titled "Bipedalism and brain expansion explain human handedness". It doesn't seek to explain why we have a right-handed preference specifically (vs left-handed), but rather why humans have such a strong handedness preference compared to ancestors who had only a mild right-handed preference. IOW, why handed vs ambidextrous, not so much why left-handed vs right-handed.

> why handed vs ambidextrous

Did it even explain that? I'm ambidextrous, I have no handedness bias, so whichever I pick up to first learn something is the hand I use. So I'm a mix of left-handed and right-handed depending on the task. And yet I didn't really understand why that's odd because of my bipedalism?

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#125

Post by yawpitch »

rolph wrote: post #53
stackghost wrote: post #49

Earlier quoted context omitted.

>if you really want to kill someone you stab them through the sternum, kind of dead center, not where they hold their hand when performing patriotism. Noted, thanks.

even this is wrong, a penetrating weapon aimed for the heart is applied below the sternum at roughly the positionof the 3rd shirt button, and thrust upward at shallow angle topass behind the manubrium, and is then levered into a pommel upward position so as to lacerate the heart

First, that’s because you want to keep your weapon, which implies you don’t really want to kill the killee. I’m assuming a half inch drill, and I’m leaving it powered up and spinning.

Second, note that what you don’t do when trying to hit the heart is aim left.

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#126

Post by rcxdude »

Stevvo wrote: post #62

I taught English in China 20 years ago. Of the thousands of students I taught, none wrote with their left hand. "There are no left-handed in China" might sound as ridiculous as "There are no gays in Uganda". However of those thousands of students, none had messy hand writing. In any class in Europe or the US, around 10% of students have messy writing. Suspiciously equivalent to the supposed number of left-handed stud…

That's only meaningful if the messiness of the handwriting correlates significantly with the handedness.

(and none out of thousands seems statistically unlikely: China has lower numbers of reported left-handers, but it's 3% vs 10%)

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#127

Post by rcxdude »

moralestapia wrote: post #73
Stevvo wrote: post #62

I taught English in China 20 years ago. Of the thousands of students I taught, none wrote with their left hand. "There are no left-handed in China" might sound as ridiculous as "There are no gays in Uganda". However of those thousands of students, none had messy hand writing. In any class in Europe or the US, around 10% of students have messy writing. Suspiciously equivalent to the supposed number of left-handed stud…

In my own personal and subjective experience, the correlation between left handed people I know and "edginess"-level is almost 1. I am inclined to believe this is a learned trait rather than an innate one (excluding the obvious reasons why one would be left-handed only).

I would suspect the causation (if such a correlation does exist) goes in the other direction (or more likely, has a common cause), given how early handedness tends to appear (and how it can be quite resistant to pressure to conform).

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#128

Post by keitmo »

colkassad wrote: post #99

I always faced left when riding a skateboard back in the day, otherwise known in skater parlance as being "goofy-footed". Facing right felt as difficult as writing with my left hand. I always wondered whether that was just the way I first rode a skateboard and it stuck, but if that was the case, I would expect the distribution of which skateboarders face which way to be about even. But goofy-footed riders are in the…

I'm right-handed, but I snowboard goofy. Coincidence (or not?) my left leg is dominant. I can kick a ball just fine with my left foot, but when I try to kick with my right foot I feel like I'm going to capsize. When I'm riding a bike and I have to stop, my right foot goes down. When I start again I use my left leg to muscle the crank through the first revolution or two.

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#129

Post by koolba »

colkassad wrote: post #118
putlake wrote: post #112

Earlier quoted context omitted.

I think this is probably related to which eye is more dominant for you. I've never skateboarded, but if I imagine myself doing it, it would also be facing left. And it's because my right eye is dominant and I would like that to be facing forward.

Interesting. Never really thought about one of my eyes being dominant. I do have a bad habit of covering my left eye when reading in bed.

Quick test to find out which is pick a point in the distance, make a triangle with thumbs and fingers to look through, and slowly bring it toward your face. Wherever it ends up is your dominant eye.

Re: Why is almost everyone right-handed? A new study connects it to bipedalism

#130

Post by m463 »

colkassad wrote: post #99

I always faced left when riding a skateboard back in the day, otherwise known in skater parlance as being "goofy-footed". Facing right felt as difficult as writing with my left hand. I always wondered whether that was just the way I first rode a skateboard and it stuck, but if that was the case, I would expect the distribution of which skateboarders face which way to be about even. But goofy-footed riders are in the…

I overused my right hand with computers - mouse + many keyboard keys like arrows, enter, backspace, etc

so I switched to a left-handed mouse. I cursed for about a week, then sometimes fumbled, and then it just worked.

Now years later, if I use a right-handed mouse to do say a first-person-shooter, I overcorrect like I'm drunk on wildly pitching ship.

left-hand is dialed in and precise.

I think some of this stuff is learned and not innate.

but yeah, goofy-foot on skateboard feels... just wrong.

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