The mystery of why left-handers are so much rarer (2016) | Hacker News Reader

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

bbc.com

103 pointsblubbb279 comments

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)

I've often wonder why this isn't a big problem for right-to-left languages.

It's only a problem if you rest your hand on the paper while writing rather than holding your hand above the paper and writing with your whole arm which i suspect used to be the norm in most places.

Also in languages written vertically and then right to left it would be less of an issue because the ink would have more time to dry before you get to the left of a given character.

I'm also left handed and this was never an issue for me. You hold the pencil out from your fingers thus your hand is sitting slightly below the line that is being written, traveling over unused paper constantly.

Only people that do that weird claw thing have that problem.

The trade off is that you have less visibility of the letters you just wrote, which can be annoying sometimes and lead to spelling mistakes.

Yes, that's why we did the "weird claw thing" aforementioned.

Anyway, no more handwriting these days...

I did the weird claw thing, worked for me

What's the claw thing?

Some lefties look as if they are wrapping half their bodies around the pen/cil when writing.

I also do not write like this, smudging fresh ink as I write has never been an issue for me.

As a child I solved this problem by rotating my paper 90° to the right and writing “down”. Still do it til this day.

Although it gets awkward when someone wants to hold the paper for me while I sign. I have to gently tug it away from them so I can turn it.

You can write "down" with your left because immediately above your hand on the page there's no hand to "drag behind." I had to think about your sentence for a while. (It might just mean I'm not very bright.)

I turn my paper about 45 degrees.

I have the same problem when people want to hold the paper for me to sign.

Fountain pens are fun too in the places that did those

Just imagine what it's like to spend three years doing technical drawing in high school using Rotring pens [1], not to mention practicing calligraphy based on IRAM/ISO standards [2][3]

[1] https://en.wikipedia.org/wiki/Rotring

[2] https://en.wikipedia.org/wiki/Instituto_Argentino_de_Normali...

[3] https://youtu.be/znrD1DjYqrE?si=Z7RsTatVCw3OKTdT&t=169

You should solve this problem by simply writing every page backwards from end to beginning.

If I had to do it again, I would have learned to write with my right hand due to occlusion. It gets worse if you try to learn how to write in Chinese (at least in modern orientations). I think the reason I became a programmer is just because keyboards were so liberating for me.

Same here. Totally agree with this!

For Asian scripts like Chinese, Japanese, and Korean, a mechanical pencil works wonders, especially for ideograms. Get one of those auto-rotating ones like the Kurutoga and there is nothing hard specifically for left-handed folk.

Or indeed, use vertical writing, which is particularly well-suited for left-handed use.

I'm right handed; when I experimented with writing with my left hand, I discovered that it's much easier to write "in mirror", right to left, using mirrored cursive characters. (also slanted in mirror)

Solves the problem with the hand overlapping the fresh writing and produces some funky-looking text.

You should learn Arabic, then you can write in the other direction and watch the right-handed normies struggle with this :)

That's the reason I write my signature from right to left, starting from the last letter.

It's weirdly left slanted but actually better than my normal handwriting.

This was one of the reasons kids werent allowed to be left handed in the old days - you used fountain pens so it would smudge the ink

These days they make left-handed fountain pen ink. It dries much quicker to avoid smudging.

I struggled with this through highschool. Pencil and gel pens were the worst. I never learned to write with my paper tilted like some lefties. I write just like a mirror image of a right hander, which lead to a lot of smudging and having to rewrite papers etc

This change my sophomore year in English class when my teacher told me a trick! Place a sticky note on the side of your hand that rests on the paper. No more smudging!

You should learn Arabic: problem solved.

I used to have the same problem. Switching from pencils and pens to keyboards fixed it for me. :)

> 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

Yup. I tried that and got scolded by teachers because the lines are all off (big margin at the bottom. Thin red line on the wrong side. ) I tried to get the pads with the spiral at the top- that works.

Always have blue ink on the side of my hand where I have dragged my hand across the page and through my writing. Fountain pens were particularly messy.

Yes. And that crappy erasable ink that flourished in the 80s. It was a mess.

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 guess it's possible to be non dominant in either hand. I write left and eat with a fork or spoon in the left, but I bat, bowl, or throw with the right. In the boxing gym, I'm not a southpaw. But I play lefty guitar.

Same here. Left hand is precision, right hand is power.

ok me too. There are a lot of us here

Curious - was your mom a lefty ? (mine was)

This is me exactly. I always say "strength in my right, finesse in my left" even though it's not exactly accurate; I couldn't hit the ground with a football from my left hand.

Im also like that..randomly mixed. I write left, but use scissors always with right. Throw and kick are right, but swing and bat is left. Computer mouse left. Taking a phone call is always left hand on left ear...but holding phone to use or text is always right hand. Self check out? Back to left hand for that mostly Lol. If a backpack is on one shoulder it feels weird if it's not on my left shoulder despite being more right "armed".

I thought that scissors were made to be right handed, and you need a 'reversed' pair for left handed people. Or is that a scam?

The thing with scissors is, as a left handed person, you'll never find the "reversed" type so you learn to just use "regular" scissors pretty early on. This is probably true with a lot of things, honestly. Yeah I might theoretically be able to cut better with a left handed pair of scissors but since I've never come across a pair I never bothered.

Things get much more interesting with more complex things like golf, snowboarding & skateboarding, shooting, etc. These things all have left-hand optimized equivalants (eg: left handed clubs, snowboards with the bindings set top "goofy", guns with the safety on the opposite side, etc). In all cases its a tradeoff -- you can learn and get good on the equipment designed just for you and then wind up sucking when you are handed equipment that is used by most everybody else or you can just learn to use the "normal" equipment even if slightly suboptimal. Guns, for example, eject their used shells off the right side of the weapon--good luck getting one that ejects off the left side so you can old it opposite of everybody and not have hot metal land on your face.

Computer mice are the same deal... some of those bastards are even molded explicitly for right hand use and are pretty uncomfortable in the left hand.

Being left handed gets weird quick because you are in a minority that most product designers simply don't consider.

Scissors are one of those things that, as a mostly left-handed but extremely right-eye dominant person, I have always resented and found difficult, but using a quality pair of left-handed scissors is almost an epiphany when you realise exactly how inconvenient a lot of things in the world are just by virtue of your handedness. A significant number of cheap "left handed" scissors I've used in my life are right-handed scissors with a left-handed grip on them, and using them is more comfortable but no more precise.

All of that said, I've found the golden path of learning any new tool that has a specific handedness is just to practice doing it right handed. This is especially true of anything that is a kind of "place setting", I eat with a knife & fork in the right-handed pattern, I use a computer mouse with my right hand. If I'm going to sit down somewhere and have an array of items in front of me with an 'expected' handedness, I'll just do it that way.

I do still resent it though.

if you look far and wide you can find left hand firearms components but the price climbs up

Have you ever fired an autoloader made for a right handed person, left handed? It is truly terrifying the first time or two when a shell ejects and hits you in the face..

i have, and use goggles when going dual, also have left hand devices,ejecting to left, ive developed ambidexterity, but ultra fine motor tasks are left handed.

Fly fish hemostats drive me nuts. The lock is much more challenging with your left. Fortunately they make mitten clamps that work well. Learning to whip finish a fly left handed was a challenge too, once you know you know; I had a miserable time trying to teach my right handed kids.

There's a slight pressure you put on the hinge when closing them. The handedness aligns the pressure to a closing motion laterally (keeping the blades together) as opposed to opening (pushing the cutting edges apart).

They do in fact make a difference. Trimming my beard with beard scissors requires a bit of a strange grip in my left hand to actually cut well when I switch sides.

Nail scissors can be quite the experience for a left-hander, instead of achieving the proper cutting/shearing motion it will just try to bend your nails due to the widened gap between the blades. A bit less painful but also annoying is cutting paper for the same reason.

But don't you use nail scissors with both hands, cutting the nails on the hand that's not using the scissors?

Indeed, I never thought of that!

A problem these days is that the scissors are sculpted.. they fit a right hand. But there are supposedly-left-handed scissors.. except that 99.9% of them are still crossing the blades the same way! My father bought one like that, as he was left handed. The scissors are mostly useless, at least for anything where you need that slight pressure to get a good cut.

Left-handed scissors are a thing. I own a couple of pairs but they feel funny because I've simply used right-handed scissors backwards most of my life.

One big difference is visibility. On right-handed scissors you can see the cut from the (top) left, while left-handed ones are the opposite. If you cut lefty with righty scissors you can't see what you're doing (unless you awkwardly hold everything to the right side).

Left-handed screwdrivers are not real, but left-handed scissors are real.

Left-handed watches are also real, the crown is on the left side: https://www.fratellowatches.com/help-my-son-is-a-lefty-a-loo...

Wait do people wear their watch on their dominant hand? I can’t do that, need to use that hand to manipulate the watch. Maybe because it’s a smartwatch.

I'm guessing that the idea is either way you wear it on your non-dominant hand, and it's easy to reach the crown with your dominant hand.

Like many artifacts of modernity, the buttons on digital watches are usually biased toward right-handed operation from the left wrist.

As far as I understand, the point of a "left-handed watch" is if you wear it on the right hand, the controls are easily accessible with the left hand.

(Personally I'm ambidextrous enough to never have felt the need for one.)

I’m right handed and wear a watch on my left wrist, the crown is on the right side of the watch head.

A left-handed watch has the crown on the left side of the watch head, it’s meant to be worn by a left-handed person on their right wrist.

Apple Watch has a left hand mode. Just that the crown is pointing out from your hand (so you don’t accidentally press when you flex your wrist), and inside rather than outside toward your center.

There are also left-handed pens. They're geometrically identical to right-handed[1], but they contain faster-drying ink.

[1] Unless they are a high-end pen with a nub, rather than just a ballpoint. A pen with a nub may have left-handed or right-handed versions of the nub.

It's nicer to use right-handed scissors left-handed because you get an unobstructed view of the cut line. The children's stamped ones hurt your hand and the ergo ones are impossible but once you learn to keep the blades in shear it's a better experience than lefty scissors.

The trick to using right handed scissors as a lefty is you have to kind of pull in with your thumb where naturally you push down and out with your thumb. But once you figure that out, it isn't so hard. Still, my scissor game is laughable compared to my wife who can do that "sliding the open blade in a straight line to cut wrapping paper" thing that I always stuff up.

It's not a scam. My son is left-handed and his left-handed scissors don't work for me, while my right-handed scissors don't work for him.

I have never understood why, though. In my mind, if you rotate the scissors 180 degrees, they should become the other kind (assuming the handles are symmetric, not those ergonomic asymmetric ones, I mean). And I just don't see why not no matter how hard I think. I'm not a dumb person but I have always had a particular weakness to understand certain spatial-related things, e.g. that method to change the duvet cover where you roll it and unroll it and when you unroll it it ends up inside... for me, it might as well be magic :D

When you say they don't work, do you mean they don't cut, or they just feel awkward?

If they don't cut, it's because your fingers are pulling the blades apart instead of pushing them together.

If they just feel awkward, it's because the blade that is on "top" is obscuring your view of the cut, because the sharp edge is facing away from you.

Rotating the scissors doesn't turn them into the other kind for the same reason that rotating yourself doesn't turn you into a mirror image.

There's more to a good pair of scissors (eg: Dressmakers scissors) than you may have considered.

Left and Right handed versions are asymmetric mirror images of each other than cannot be rotated to match.

Consider:

* Smaller top loop for thumb.

* Larger bottom loop for fingers.

* Loops have width and are bevelled; wider where the thumb first enters, narrower on the side the thumb comes out, these are shaped for comfort and control.

* The action of moving a thumb and fingers "up and down" has a slight twisting action to it that is factored into how the anvil and cutting blades of the scissors are arranged so that the left twist causes the blades to run tight against each other when left handed and mirrored for the right twist of the right hand.

I'm right-handed, and usually use scissors with my right hand. When I try using them with my left hand, two things happen: First, they doesn't sit right in my palm, because of the way they are sculpted. Beyond this, and more importantly, they are no longer as effective in cutting things.

Here's my understanding of why this is. When holding the scissors with your hands, in addition to the up-and-down force you exert on the blade with your fingers, you also exert a small side-to-side force with your fingers. With my right handed scissors in my right hand, this force pushes to the outside on the upper handle and to the inside on the lower handle. This force also makes the scissors feel more comfortable.

On the other side of the fulcrum, though, the upper handle controls the lower blade and the lower handle controls the upper blade. Here, the lateral forces end up drawing the blades closer together, giving a tighter pair of edges between which shearing forces are applied. This makes the cutting action more effective than if lateral forces were absent.

In my left hand, the (outside at the top and inside at the bottom) lateral forces end up pushing the blades further apart on the other side of the fulcrum. This reduces the shear force and makes the cutting action less effective.

To compensate for this while operating the scissors with your left hand, you would need to adopt a weird style: Consciously pull to the inside with your thumb, and to the outside with your remaining fingers. You'll notice that the scissors are now much more effective than before. It is also a deeply uncomfortable grip.

The issue is that scissors are (surprisingly) chiral sculptures. In the case of regular right-handed scissors, when viewed edge down, the handle closer to the viewer passes through the left of the fulcrum. I have never used a pair of left-handed scissors, but I would presume that for them, the closer handle passes through the right side of the fulcrum.

This is exactly right. Scissors depend on you to exert sideways pressure on the blades. It should be possible to build scissors with e.g. a spring at the joint that exerts the proper sideways force automatically. This is how paper cutters work. (A square surface with a blade on the side that swings down.)

To be fair I've always used scissors with the blade pointing towards me because it always felt more natural despite being told off for using it the wrong way.

Me too. It's called mixed-handedness.

https://en.m.wikipedia.org/wiki/Cross-dominance

I'm exactly the same on all those (and add kicking to the right-sided list). Cross-dominant [1] is the usual term I use for it.

[1] https://en.wikipedia.org/wiki/Cross-dominance

I write with my left hand, play guitar with my right, and use the mouse with my right. Same as you though, I'm not ambidextrous

> I'm right eye dominant, though, so I throw, swing, shoot, use scissors, play instruments and use a mouse right handed.

Dominant eye and hand don't have to match; in fact, they often don't. To quote Wikipedia:

> ...the side of the dominant eye and the dominant hand do not always match. This is because both hemispheres control both eyes, but each one takes charge of a different half of the field of vision, and therefore a different half of both retinas

im embarrassingly right handed but also left eye dominant. my family is obsessed with bird hunting and took a while before my dad realized i had to close my left eye to hit anything

Metoo kind of... Write right-handed, fork on the right, but knife on the left. Throw with the left hand, kick with the left. Mouse on the right. Also wished the gas pedal was on the left :D

Left:

Write, eat, brush teeth, scissors, chop vegetables, etc. Basically fine motor skills on the left.

Right:

Throw a baseball, shoot a basketball, play tennis, etc. Power movements on the right.

Could always do some sports lefty, like switch hit in baseball, kick a football (soccer) past half field, or play pool, those kinds of things, but right side has always been stronger.

The only sport where I am much better lefty than righty is table tennis -- probably because to play at higher levels you need fine motor skills, not just brute force.

I'm right-handed for almost everything but a few years ago I tried bowling with my left hand and my scores improved.

I cannot imagine trying to throw a baseball with my left hand, but maybe I should do it anyway.

I'm the same - I call it "pseudoambidextrous".

I lived in Europe for 10 years and that was nice as far as eating goes. Here in the USA I always try to grab a left corner so I'm not bumping elbows with anyone.

I had an uncle just like us, my son is a true full on lefty.

Same. Small motor lefty, large motor righty

There’s a term for this: cross dominant. I have the same condition, the research is all over the place about whether it’s a good or bad thing. It generally means the brain hasn’t fully picked a side, so some operations have to cross the corpus callosum which can add latency.

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

As a (mostly) rightie, I use the mouse with my right, except if I feel shoulder pain. Then I take a week on the left hand. And my shoulder avoids developing a chronic issue.

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.

Anything I didn't have to be taught to do, I do with my left hand or the left handed way. Opening bottles etc. But I write and play sports/musical instruments with my right hand.

With a bit of practise I can write neatly with my left but it's a bit slower. I started using a computer mouse with my left hand so that I could put a notepad just to the right of the keyboard and not compete for space with the mouse.

I am exactly like this. When I was learning to write I frequently changed hands, until my teacher told me, that I have 3 days to figure out with which hand I want to write. Left felt slightly better to me, but by that time I was eating like my completely right-handed family and using scissors with the right. I also play guitar as a right-handed would. I tried a left-handed bass for a bit and it was super awkward. It also means strumming is much harder for me than changing notes on the guitar. I struggled so hard with clawfinger banjo playing, that I gave it up.

All later skills, like shooting a bow, I do as a right-handed, since I am right-eyed. This is hard to do, since my left arm is much stronger than my right and you need more strength in the string-pulling arm.

I feel wrong and awkward a lot. Writing on a keyboard is very liberating. But when I was playing first person shooters in my teenage years, my aim (right-hand mouse) was always bad, while my footwork (left-hand WASD) was very good :D

I'm sure like many left-handers here, my right hand is nearly as dexterous as my left. Writing is the only thing I can do with left which I cannot do with right; other tasks are either equally natural or just a little awkward but still effective.

But some right-handers who have been forced to (by breaking an arm for example) can learn to write with the left hand. I have to assume they could learn to be more ambidexterous if they were motivated. It almost seems more like a cultural (see/copy) behavior to be right-only handed. Left-handers may have an inclination to do some things with the left hand, but we also grow up in a world of right-hand designed products.

As for the "handedness" of feet, eyes, ears, etc., I also suspect that has more to do with our patterns of hand use. I'm right-eared probably because I hold my phone in my right hand so my left hand is free to do fine motor tasks. It's not because I prefer to listen with my right ear. I'm also somewhat left-footed because I tend to carry heavy things in my right arm; so my right leg is busy supporting the extra weight as I step up on a step with the left.

I doubt any/many of these studies have been large or thorough enough to really learn anything meaningful about handedness and its related effects.

I am a lefty for small motor skills (like writing and eating) and a righty for large motor skills (like throwing a ball or swinging a bat)

Seems like the most useful would be the other way around.

batting left handed often gives an advantage over right handed pitchers, as well as putting the left-handed batters a step or two closer to first base

> I'm also somewhat left-footed because I tend to carry heavy things in my right arm; so my right leg is busy supporting the extra weight as I step up on a step with the left.

As a skateboarder that regularly teach the basic ropes of skateboarding I noticed that footedness (giving you stance) has little to no relationship with handedness.

I'm the same, just mirrored.. I'm technically right-handed, but my left hand works as well as the right one for stuff that I haven't exclusively trained my right hand to do (or the left one, for that matter, as far as the right hand is concerned). So I can't write with my left hand (except that I can mirror-write, especially if I write with my right hand at the same time. Apparently Leonardo Da Vinci used his left hand when he mirror-wrote, and his right hand when he didn't. Read that somewhere).

I'm also like that. When I was a child (not sure what age), I would take two pencils and write one line with the left hand, and the next with the right, indistinctly. But my school teachers said I should choose one and stick to it (not sure if that would still be advised today). I really had no preference so my mother advised me to choose the right, as it would give me less trouble due to everything being designed for right-handers, etc. A reasonable advice.

I did so, and now I wouldn't be able to write with my left hand, but when I take up a new activity, it's still basically arbitrary. For example, I started playing golf recently, and I deliberately chose the right-handed way for the same reasons as for writing (it's easier to find right-handed clubs, etc.) but I could have chosen the opposite and I suppose my skill would be the same, initially there is no option that looks more "natural" than the other for my body. And with trivial things where I didn't choose consciously, sometimes I'm told I do them as a left-hander, e.g. I stir tea counterclockwise.

I'm a fountain pen aficionado and I would have liked my son to enjoy my fountain pens someday, but he's a clear left-hander, so he probably won't :)

About feet...

I was forced to write right-handed at primary school. I can't write with left, but I'm ambidextrous. At work, I've got my mouse to the left, at home to the right. There's an 'inventory' if you want to check, the Edinburgh Handedness Inventory: https://brainmapping.org/shared/Edinburgh.php

Anyway, back on topic. I play musical keyboards, so that definitely helps being ambidextrous. But I also play classical organ, and my feet have no preference. Left is just as agile (or clumsy) as right. But that's not different for right-handed organists. So at least in that case, there doesn't seem to be a connection between handedness and feetedness.

This is of course just some observations, but it is rather obvious that we do use our legs/feet a lot, and almost always in a symmetrical fashion. And for turning corners while running and such, we need to be able to rely on strength and agility in both.

> But some right-handers who have been forced to (by breaking an arm for example) can learn to write with the left hand.

I'm right handed and taught myself to write left handed out of boredom. In college I would just start taking notes with my left hand in classes where they prof conveyed information slowly enough that I had the time to do it. It was a good way to stay engaged and awake.

As a consequence I can still today, 25 years later, write with both hands (although to be fair, my handwriting is terrible with both hands so that could be why it's hard to tell the difference).

Here's a fun test - we're all in socks on a slippery wood floor. I'll give you $500 if you can run and slide further than I can.

Close you eyes and really imagine it (or do it right now). Really feel yourself sliding along, that tingly feeling of almost losing control, etc. etc. Going a little further with each try.

REALLY run and slide AS FAR AS YOU CAN.

Which foot did you have in front?

I'm very much right handed and footed in life, but in this test I can really only do it right foot forward (called 'goofy' in snowboarding) - left foot forward feels super sketchy to me even after years of practice, and I can't slide nearly as far.

The vast majority of people (left and right handed) are left foot forward.

(This is the best way to determine which foot a beginner should put forward on their snowboard or surfboard. Do the test without telling them you are doing the test. If they can equally do both, then it doesn't matter)

Right handed with right-foot-forward as well.

Me too.

Right handed, but I pictured my left foot forward. I guess because I'd expect the power to come from my right foot (I'm right footed).

Same but I disagree on the explanation. When in comes to jumps I usually use my left foot but here it's more about balance than power I think and having played handball for a long time, I feel more stable with left foot in front

An easier snowboard test is to tell someone to turn around and tell them you are going to give them a push. Give them a shove to the upper back and see which foot they put forward first to brace.

That is an old myth that doesn't work very well.

Source: I've been a level 3 snowboard instructor in Canada for 10+ years. There are only 4 levels.

It also doesn't work if you're with a group of students because it won't be a surprise after everyone sees you do it to the first student. If you have a "slide on snow" competition but don't say why, you can watch everyone and what foot is forward before you tell them what is going on.

Duly noted!

On ice skates I (left handed and left footed) find it easier to come to a prompt stop with the left foot forward, and I naturally slide across ice and such with my left foot forward so, naturally, I thought I'd have the left foot forward while snowboarding.

Everything felt absolutely right, UNTIL I gained some real speed for the first time. Nope! Suddenly everything felt wrong, and I instinctively turned so I had my right foot forward.

So weirdly goofy it is.

Huh, weird.

I tend to default to right foot forward for most things. Sport fencing did it, maybe…

I brush my teeth and write with the left, dribble and throw with the right.

I kick the ball with the right, and on the boards sports I'm goofy.

I feel I can imagine myself sliding both ways. Actually doing it would more than likely reveal my preference though.

But when I try to imagine myself standing on a skateboard, it gets clear immediately: left foot forward. Right foot forward feels completely wrong.

It's even embedded in our language — “Ambidextrous” means “both right” lol

And lots of people use “sinister” as a stand-in for “malicious” or “evil” https://english.stackexchange.com/questions/39092/how-did-si...

https://en.wikipedia.org/wiki/Sinistral_and_dextral

https://en.wikipedia.org/wiki/Dexter_and_sinister

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".

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)

I had a short lived job at Taco bell as a teenager, and at Taco Bell there is a 2 sided table for assembling the food. Newbies start on the right side, experienced on the left.

The left side prioritized the drive thru, so it was more speed oriented than the right side, which prioritized the dine-in.

I had a really difficult time on the right side, being left handed. All of the assembly steps were backwards for me. The left side would have been a better fit for me.

I tried to explain this to my boss, but she made it evident to me that she wasn't being paid to care.

It was a stupid minimum wage job and I only made it 3 weeks, which was my second or third shortest lived job.

As far as "accommodations" go, I was especially equipped to work faster in their higher priority lane, but since I didn't fit into their box, it just wasn't meant to be.

The percentage of left-handedness correlates strongly with how pacifist vs warlike the society is. According to this 2005 study it varies from 3% up to 27%: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1634940/

Wow, this really blew my mind.

Imagine a society of red-headed left-handers.

Study does not exactly imply that left-handers are the cause of the violence, just corelated to societies' total violence. Perhaps we are exceptionally annoying to right-handers. This 'um, actually...' post would then be a salient self-referential sample of what I mean.

"Well that guy is obviously left-handed"

This has to take the cake for "most spurious correlation." The most coherent reading is "places which report more homocide data are correlated with reporting more left-handedness"

I believe the accepted explanation is that southpaws have more of an advantage the rarer they are. So there's a balancing effect in violent societies.

Interesting that the scale is logarithmic on the homicides number axis.

I wonder if this is where the whole left handedness being associated with the hand of the devil (or any evil) came from historically. Our ancestors probably weren't doing studies like this but like many religious/spiritual restrictions that seem like they are backed by "nothing" at first turn out to have a fair application to life behind them it's probably not too much of a stretch that someone at some point or other noticed something like hey, that village/tribe/whatever near us has a LOT of left handers and they have an awfully suspicious amount of violent incidents happening.

No it's probably much simpler. Humans love to shit on anyone who doesn't follow the tribe program.

It could also be that when fighting (pre guns) people with left handed weapons took normal right handers off guard (sort of like how in baseball a leftie might throw off other players). I can imagine in a sword battle if you are used to fighting people right handing swords that suddenly fighting a left handed person could be unexpected and disadvantage you.

Where I am going with this is that it might not be that left handedness directly correlates with violence in any way - but perhaps societies with more left handed people were simply more likely to survive in more war like times.

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.

This is the explanation I know of. And I didn't mean to suggest anything else in my post!

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?

The findings in chimpanzees indicate that both humans and chimpanzees exhibit population-level asymmetries in handedness, though humans show more pronounced lateralization (e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676728). I think this suggests that anatomical asymmetries in the brain likely preceded handedness and contributed to the evolution of hemispheric specialization. As brain size increased and corpus callosum connectivity decreased, specialized functions in each hemisphere became more pronounced. Thus, handedness and brain asymmetry likely co-evolved, influenced by both genetic and environmental (including socio-cultural) factors, rather than one directly causing the other.

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.

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.

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

Your reasoning makes no sense. Using your left hand to crack nuts vs your right hand makes no difference as far as your heart is concerned. If you are working hard enough to increase your metabolic rate, then your heart will be pumping faster in either case. Also, your theory that increased exercise leads to heart attacks is the opposite of reality!

Exercise prevents heart attacks when you have excessive calories, you get adequate sleep and do not sleep outside in the winter, you have a dry place to stand and are not out in the rain and so on. Exercise leads to muscle loss when the fat reserves are depleted and calorie intake is limited.

Anyway there are ways to falsify or verify that hypothesis, but it needs some resources, not much but still, it needs time and subjects to test the hypothesis on. So for the foreseeable future, it will stay as it is, a hypothesis.

If your hypothesis was true, then it'd be glaringly obvious, because there'd be a high correlation between left handedness and increased lifespan.

In your logic obviously the majority of people must be left handed because the left arm being closer to the heart means higher blood flow and thus better stamina.

Oh but why isn't it so? Because of venom? Let's set our scientists on that. No wait I got one: Attacking prey is easier with the sun in the back so the hunters would often return from the north. The right handed ones would show better muscle tone in the setting sun and we know women select for muscle mass! Sexual selection baby! Way better story I'm sure you agree. Scientists gotta switch.

“ when you look at rare conditions, like Down Syndrome, epilepsy and cerebral palsy, the ratio of left- to right-handers is more like 50:50 rather than 1:10.”

Is this a typo? Or are left-handed people way, way more likely to suffer from these rare diseases?

There are a lot of myths and anecdata about lefties having shorter life expectancy. That might indicate health consequences in some way.

IIRC the major factor in that was found to be that left-handed people within the age ranges where significant numbers of them are dying of natural causes had usually been brought up to suppress left-handedness, so are reporting as right-handed and skewing the data.

But why would that mean that the people who didn't suppress died so much younger?

> [A]ccording Chris McManus, the researchers made a "very subtle error"...

> Halpern and Coren took a list of the people who had recently died and contacted their families, asking whether or not their relative had been right- or left-handed.

> Looking at 2,000 cases, they saw that the average age at death of the left-handers was about nine years younger than of the right-handers.

> On that basis, they concluded that left-handers died earlier.

> At first glance, that seems persuasive. What did the researchers do wrong?

> "Their mistake was that they only looked at the dead," Chris McManus explains.

> The point is that left-handers are more common now than they used to be, so - at least at the time the research was published - left-handers were on average younger than right-handers.

https://www.bbc.com/news/magazine-23988352

Could also be due to right-handed tools. Chainsaws...

People who have them are more likely to have other disturbances. One of the few things I recall clearly from embryology in med school is that any disturbance of the midline and sided structures of the body often reflects some abnormal development: there's rarely only one (e.g., if their brain is abnormal, you had better look for cardiac abnormalities).

Left-handedness is unusual, but not per se pathologic. There is a running joke among neurologists that the average neurologist is a left-handed person with migraines. They aren't all, of course, but if you had chronic headaches and were left-handed, wouldn't that predispose you to pursuing a specialty where you try to figure out what's going on in brains? I majored in chemistry; it's not a huge stretch to imagine why I became an anesthesiologist. It's interesting, and it makes some intuitive sense. We tend to be more of the "analyst" personality; former engineers and accountants are not rare in anesthesia.

Let's work it out: 1 in 10 are lefty, 1 in 1000 have Downs. Supposedly 50% of people with Downs are lefty, therefore:

P(A) = 0.001

P(B|A) = 0.5

P(B) = 0.1

P(A|B) = P(B|A)xP(A)/P(B) = 0.5x0.001/0.1 = 0.005 = 0.50%

So the chances of having Downs given being a lefty is 1 in 200, or which is 5 times higher than the base rate, but still quite rare. It's probably more a case of "having developmental abnormalities interferes with handedness" rather than "being a lefty predisposes you to having sundry developmental abnormalities".

Down syndrome (trisomy 21) and cerebral palsy are something you're born with no? Epilepsy too maybe? (even if it only declares later on in life?)

So how is this not inversing cause and effect:

> Or are left-handed people way, way more likely to suffer from these rare diseases?

Or there are simply a lot of people who might be left handed by default but then adapt and learn to be right handed. People with rare conditions like the above might either have more trouble adapting or perhaps socially we put them more in special ed programs where they are observed more closely and stick with their default.

It might just mean that people with certain disorders have much bigger immediate problems in hand-movement to overcome, so that there's no extra capacity/opportunity to engage in mimicking the right-handedness of people around them.

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): right

solder iron: right

fighting stance: mostly traditional, but sometimes southpaw by instinct

Also applies to feet. playing football (soccer), kicking: mostly right

Curiously, I developed as right handed (and foot) on the things nobody ever tried to push me to correct.

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.

It depends on the context, I have been in meetings where everyone except for one PHB was left handed. The ratio was probably 50:50 across the company as a whole.

What is a PHB? I searched online, and found that it could mean bachelor's in philosophy (PhB) or polyhydroxybutyrate (https://en.wikipedia.org/wiki/Polyhydroxybutyrate), but neither makes much sense in this context.

Pointy haired boss. Coined by Dilbert.

This is not a criticism, but I’m amused that someone with an HN account as old as yours is just now finding out what “PHB” means.

I actually own the 20th anniversary Dilbert collection, but it didn't come to mind. I probably have acronym-blindness from encountering too many.

Don't we mean PHD? PHB is unfamiliar to me too

My memory of PHB (from Dilbert) was overwritten with PFY (from BOFH).

I have an old hn account. Dilbert was something I was dimly aware of my dad reading in newspapers when I was a kid in the 90s. Never heard the term PHB before today.

If you're a Waldorf fan, you might be interested to learn that Steiner was against left-handedness, thinking it caused by a spiritual deficiency. Modern Waldorf schools actively "correct" left handedness because of this. [1]

[1]: https://waldorfcritics.org/faq/

The root meaning of the word sinister is left-handed

Mine didn't...

I'm predominantly left-handed, except on the computer. Where I use the mouse with my right hand and play FPS games using the mouse on my right hand, as well. Not sure how common this is.

Yep me too, I'm sure there are many things we've subconsciously adapted to using with our right hands. Actually I've never bought a product purpose made for left-handed people.

I'm guessing your school or home computer had it on the right growing up? I got used to using it on the right because I didn't want to move the mouse to the left in the school computer labs as it was always a clutter of cords. At home half my family was left handed and mainly the PC was used by the lefties so I got used to playing FPSs with the left hand. I kinda hate playing on PC now because WASD is trash left hand mousing and it's A HUGE PITA to remap every single key to make sense on the the other side of the keyboard, some games don't even let you map keys like ';' because IDK, fuck me I guess.

I do think I'm more accurate with my left too.

I didn't really use a computer until my 1st year in college. And I didn't own a computer until I was 19, so I didn't learn to play FPS until I was in my 20's.

Before using WASD, I used WER and Space key for movement. Q=Jump, W=Forward, E=Strafe Left, R=Strafe Right. This allowed me to easily reach the number row and remap T=Chat 123456ASDFG for switching weapons and game controls. I switched to WASD with World of Warcraft, and use that for everything now mostly out of laziness and inertia (tired of rebinding everything, as you do).

I tried to use the mouse w/ my left hand and couldn't. Too much of the controls are right-hand centric. Keyboard shortcuts for browsing are all on the left side, etc. It does feel nicer to have it on the left hand sometimes.

So many left-handers here that feel disadvantaged in our right-handed society. If you ever want to do one thing where you feel you left-handedness gives you an advantage, pick up Kendo (the Japanese swordfighting). You have to wield your sword like everybody else but the aiming is done with your left while the right just provides the power for the stroke (the katana is a two-handed weapon). Since you are not supposed to fully power your slashes anyway, I felt being left-handed is a slight advantage in Kendo.

This is completely wrong btw.

No power ever comes from the right.

That is why there are warm up exercises using katate (single left hand warm up) to loosen and focus on your left.

It makes no sense for power to come from the right as fumikomi (the leaping motion at the time of the strike) is done using your left hips and legs.

~~Uh, did you read the comment?~~

Ah, I think that is a typo, otherwise the whole comment doesn't make sense and my brain corrected it.

Doesn't left-handedness give an advantage in most sword fighting and fencing sports? As demonstrated by the percentage of left-handed players at the top level is higher than the population average? I heard the same thing is true with boxing, presumably other martial arts, and tennis (and who knows what else).

The explanation I've heard is that in any sport, on average one would train more with right-handed opponents. So when facing a left-handed opponent you are significantly less experienced, which results in left-handedness having a slight advantage.

That is a bit different than what you describe (since you're not allowed to use your katana in a left-handed fashion), but still.

Can talk about foil fencing perspective: lefties get a competitive advantage only in junior years because training exercises are done against same-handed opponent (be it a coach or dummy) while they spar and compete mostly against righties. It diminishes with time.

> left-handers [..] feel disadvantaged in our right-handed society

> You have to wield your sword like everybody else

This right here is why.

I am a 100% left and I can do most (except writing) with my right. Well I can do writing if I do it slow but it looks horrible. I have a group of friends that I know from 25 years ago and the weird thing is: all my friends are left as well. On of my friends also married a left handed partner, so the lefties are in the majority in my friends group.

Wouldn't a 50/50 split be just as unlikely as any other? You've already broken symmetry by asking by a preference of one over the other, so it would be pretty spooky if something came along and restored that symmetry. Unless it was truly random, and what in biology is truly random?

I really wonder if it has something to do with humans using tools, and it just works better for a tribe if most people use tools with the same "handedness", because they can share more and be more efficient. Like if hunters could swap bows when one broke, their tribe would get more meat?

No, clear "handedness" is seen in a lot of animals not just primates. You can see it easily in pets: cats tend to reach with a certain paw, dogs tend to dig with a certain rear leg over the other. Horses lead with a preferred side when possible. Similar things are observed in non-domesticated animals like wild birds and whales also. Lateral preference isn't a universal animal behavior but it's very common.

was right handed for 20 years, got paralyzed, became left handed.

of course relative to the physical therapy/rehab that was easy -- but it still surprised me how quickly it became fluent. it kind of made me think that it's more just a coin-flip as to which you are, and the conveniences available during critical learning moments early in life.

if my favorite rattle or play-thing was placed on my left versus my right in the crib predominantly would things have turned out different? makes me think that might be the case a bit.

But that wouldn't explain why most people are right handed, would it?

Just a thought: rightie parents naturally put the crib along a wall oriented so they can interact with the baby with their right hand, which means most of the world is to the right from the baby's perspective.

Is it really a mystery? The human body isn't symmetrical on the inside. We evolved to look symmetrical on the outside, because that looks attractive.

Last week I asked my Chinese painting prof if we could try calligraphy, and he said "no".

"Left-handedness is too much of a problem, movements would be too awkward with the brush.

- So what happens with the small percentage of natural left-handed in China?

- It's beat out of them. I still use chopsticks with my left hand, because it's tolerated, but writing is just unacceptable."

So yeah, it's a complete mystery.

Recently there were some interesting papers looking at laterality from a more general point of view (which is a bit touched on with the simian examples in the article).

Given that there are strong genetic factors involved, it's not surprising that with tools becoming more prevalent in complex societies there would be a human co-evolution.

Curious: any people around who trained themselves to do fine control activities (writing but not only) with their non dominant hand? How did that go?

Being forced in school or because of an accident doesn't count; curious if anyone did it on their own, voluntarily.

I mean, I'm here typing with my left hand.

My father did it when he was a child so he could "be like his brother" who was 1.5 year older and the favorite son of his mother (this brother was the first male son after a female who was the first overall).

He is now right handed for almost everything but really skilled with the left hand, I remember that once he broke the right wrist and could easily write with the left hand for example.

I have an older sibling who is left Andes and challenged me to use my left hand since they could use both. So I’m at about a typical left handed person’s level of dexterity with their right hand. I switch off on tasks like shoveling or sweeping. I can write badly. Etc. I wouldn’t say it is useful, really.

Rafael Nadal, one of the best tennis players in history, supposedly is a natural righty who was taught to play lefty.

I was originally left-handed, but my father made me switch to my right hand because he believed being left-handed was the "hand of the devil." Now, I’ve become ambidextrous, and I instinctively choose which hand to use depending on the activity. Sometimes, when I'm trying something for the first time and I'm unsure which hand is best, I get stuck and have to go through some trial and error before it feels natural.

Similar story for my wife, though it was an underfunded Catholic school with only right-handed sports equipment that pushed her to be ambidextrous. She's split pretty much 50:50 on which hand she does something with, though I've noticed she does actually seem to pick her left hand when its a totally new skill she hasn't done before.

My right hand is all but useless, I'm very left handed. Golf is the only exception, but I'm terrible in either direction and right handed clubs are easier to rent or buy.

I'm right handed for everything in life, except chopping wood. It's the one thing my leftie Dad taught me that stuck.

I had no idea until recently when someone said "Hey, you're doing that left handed"

I'm right handed for everything except snooker/pool. I have no idea why, it just felt more natural to put my right hand down as the rest and hold the cue with my left.

My dad was left handed, I'm left handed and my daughter is left handed. It certainly helps in troubleshooting things, because when anyone else uses a pair of scissors, they work. When a left handed person uses a pair of scissors, they don't work, so you have to figure out how scissors work, or just use your right hand. Imagine doing that with everything.

I did pick up some ambidextrous habits. My daughter and I mouse with my right hand but my dad left handed a mouse.

My father was left handed.

While in school, before WWII, he was beaten on the offending hand, to discourage him from writing with the left hand. So eventually he became accustomed to write with the right hand, and then he has continued to write with the right hand, even if he always did most other kinds of precision work with his left hand.

I was originally ambidextrous, but my mother taught me to be left handed because that seemed more interesting to her. I'm mostly left handed these days, though I bat either way, use my mouse either way, and shoot guns right handed (I forced myself to learn to shoot right, so semi-auto casings are ejected away from me instead of toward me).

Dang I'm right handed but left eyed so I need to hold guns left handed. How did you switch your eyedness for guns?

When I was in the army I switched to holding my assault rifle right handed because I was near sighted on my left eye. (Not getting the casings ejected onto my right arm when they later gave me an LMG was an added bonus, man that gun was poorly designed)

It took maybe a week to get used to the switch but wasn't that big of a problem even though I'm both left handed and left eyed.

So you just.. do it, I guess?

I'm similar, but no parent or teacher forced me to be so. I do write with my left hand, but so many other things are just easier right-handed that I do both (sometimes switching between them during the same task). Pretty sure my right hand is faster and my left hand is more precise.

I always use left hand for everything that does not requires right hand. The only activities I need to use right hand is when I use a desktop computer or writing. I was tried to use right hand for the other activities but it is never comfortable no matter how much I practice.

Unless you really can switch hands at the drop of a hat (which is incredibly rare), the term is cross-dominant or mixed-handed. I prefer my right hand for fine motor skills and left for gross. I have a coworker is who is almost exactly the opposite.

Exactly, ambidextrous people are freaks of nature, like a professional baseball player who can pitch with either hand from inning to inning, and even then there will be a stronger side -- in other words, it is unlikely that a human being could be equally dominant across both hands.

I've literally forgotten which hand I hold a hammer in. Last time I assembled some furniture, I just couldn't figure out any difference. I think I remember there used to be some slight preference earlier, but I just can't say one side would be any better at it than the other.

(I do have clear preferences for many other activities, though which activities go left and which right seems pretty arbitrary, and might just be what I got used to instead of actual dominance. Like, I hold my phone on the right hand because it's in the right pocket, but is that a preference, or just avoiding putting the phone in the same pocket as keys/flashlight/etc?)

A right-handed friend of mine was forced, as a result of spinal damage, to make use of his left hand. He always used to say "I was was right-handed, but now I am ambisinistral... equally useless with both hands"

curiously, the etymology of sinister is from the latin for left (with dex for right)

I’m ambidextrous as well, but always was I guess. Most things feel more natural to do with one hand or the other, and I just do that. I never felt like ambidextrous was accurate, so I say weird-handed.

The reason I write right-handed is that my friend kept “correcting” me when we were learning. I still hold the pencil like a lefty, though, which gets funny looks.

I wonder if this is more a p-hacking phenomenon than a real advantage.

Much like how when you test every jelly bean [1] you'll find one with an unexpected outcome. If you evaluate every "duplicative" pairing in the human body, it seems like you should find at least a pair where one is more effective than the other.

[1]: https://xkcd.com/882/

found this supplemental:

Bias against left-handed people

https://en.wikipedia.org/wiki/Bias_against_left-handed_peopl...

Curiously, almost every lighting control desk I've ever seen or heard about is left handed: the faders for controlling the lights are almost invariably on the left.

So what makes that left-handed? Is there nothing on the right side?

It's typically buttons and programming stuff on the right. So you could argue that it's right handed because the keyboard stuff is on the right. But when you're running a show, it's the faders you need, and need to manipulate accurately and carefully, not the programming stuff. If they were for people who were most used to manipulating things accurately with their right hand, then I think the faders would be on the right.

So I guess it's a long winded way of saying that it seems as though most lighting operators are fundamentally left-handed, which is quite .. curious? I don't know what the right word is

The symmetry or lack thereof between mirrored “left-handed/right-handed” phenomena is a deep problem up and down the physical world:

https://en.wikipedia.org/wiki/Chirality

Often times chirality is not just a fun quirk. For certain drugs, the left handed and the right handed versions can have completely different effects on the human body: https://en.wikipedia.org/wiki/Chiral_drugs#Drug_toxicity. To avoid making the wrong type of drug, a specific way of producing the chemical molecule has to be derived: https://en.wikipedia.org/wiki/Enantioselective_synthesis.

And sometimes it doesn't change much at all except for the patent and withdrawal as with citalopram/escitalopram (generic Celexa/Lexapro).

Any lefty here who knits with your right hand and crochets with your left hand? I do :D although I do continental knitting.

I lost a little faith when I saw the article referred to Neanderthals as "our ancestors"...

Intrigued by the throwaway comment that we know handedness is genetically determined. Is that true? I was under the impression it was a developmental issue (identical twins with opposite orientation being one piece of evidence here).

I lose a little faith when I see people nitpick while being wrong.

"Neanderthals were our ancestors" is more wrong than it's right.

Only need to get 'a little bit pregnant` though.

I remember an article in Nature that’s better than this one. Stats:

Men are 13%, women 9% Being a twin is very high, like 17% Scandinavia is 13%, China <3%

Basically all people with ancestry outside Subsaharan Africa have nontrivial Neanderthal admixture. Even many Africans do, although it is a fresh (post-1600 or so) contribution from other parts of the world. So they were "our" ancestors, just not the dominant ones.

That statement would only be categorically wrong if made about pureblood Khoisan etc.

i was hit on the hand with a ruler and the crayon pulled from my left hand and forced into my right. i wonder if that has happened to others and if so does it contribute to skew of frequency.

My grandmother was hit with a ruler on the left hand. She learnt to write with both hands as a result.

Very standard in Ireland where I went to primary school, I got hit with a ruler a lot.

"Left" probably comes from the proto-indo-european root "laiwos", which means to bend or curve. "Right" probably comes from "hregtos", which means straight and correct.

Makes sense, since most people don't write well with their left hand.

English retains this connotation strongly since "right" also literally means "correct" or "straight" (both of which come from the same root too)

Then you add in the political connotations "right wing" and "Human Rights" and the subject becomes endlessly fascinating.

Right wing is just the side of the room some guys sat on during some arguments in the French Revolution, or something like that, right?

I always assumed “rights” as in human rights were derived from writ, as in a type of written document issued by a court (which could be used to clarify somebody’s rights). I guess write and right could be related though.

No, I don't believe "rights" come from "writ". It comes from "right" meaning correct and straight, since "right" also had a legal connotation (think "rule" which also comes from the same PIE root).

You see this clearly in other IE languages like Spanish where "a la derecha" means to the right, "derecho" means straight (which can be confusing), and "derechos" means "rights" in the legal sense.

It's worth pointing out cigar smokers that are left handers exceed 1:10 and I've read elsewhere smoking is a preferred Neanderthal trait.

Not in baseball.

I recently watched some Mets games and it’s just incredible how commonly you use a left handed hitter go up against a left handed pitcher.

I'm of the generation that were forced to write with the right even though I was a natural lefty. I also broke my left arm when I was 2, which may have made things even more messed up. These days I:

  * Write with my right, my left is not quite as quick/tidy as my right
  * Swing/grip with my left (cricket / golf / etc)
  * Use my phone with my left
  * Mouse with my right
  * Cut (scissors) with my right (but we don't have any lefty scissors so...)
  * Drink a pint with my left
  * Play guitar with my right (but i learnt with a RH acoustic, so...)

I'm not sure why people have started to make reversed musical instruments. I saw a video with a reversed piano, calling it "left-handed." I am a left-handed person who plays the piano and I had always thought the keyboard was laid out like an ascending scale on paper rather than having something to do with handedness - low notes on the left and high notes on the right.

The motions involved in playing music are so weird that I don't think it matters that much. Even if it does, there might be techniques that you find easier to master with one handedness or the other.

I will also add that I have been complemented on the facility of my left hand when playing, but when I hear the people who say that play scales, it's very clear that they don't practice technique with both hands equally.

I don't think it matters too much on a piano but on a guitar it does a lot because your hands do very different things.

Wouldn't you want the more dextrous hand to be the one choosing which notes to play? My sister plays string instruments, and she has commented many times that I am lucky for being left handed because lefties have a better time with complex fingering.

I suppose that it's easier to start out right handed on guitar, though, when the right hand is more active than the left hand.

I'm a lefty and I played right handed guitar growing up. I never got very good at strumming and picking. Five years ago I switched to left-handed guitars and I think I'm much better than I ever was as a righty. Picking the strings well, to me, is the most difficult part of playing a guitar.

I've never really liked that reasoning. If that's the case, then right-handed people should be playing "left-handed" guitars, with their right hands doing the fretting.

Personally, fretting with my left hand just doesn't feel natural. When I first got interested in playing, I asked a salesman at a Guitar Center about left-handed instruments. He handed me a standard guitar, and showed me the fingering for a G chord. It was uncomfortable, but that's obviously expected for the first time I'd ever held a guitar. However, when I flipped it around and fretted with my right hand, it felt much more natural. So ever since, I've played left-handed.

I'm left handed and play the piano.

I think if I had a learned on a reversed piano - it would not transfer to a regular piano - I would be able to play better.

What which hand is responsible for (melody, accompaniment/rhythm) have very different dexterity requirements. Learning melody on the dominate hand would be preferable to me, in hindsight.

With an electronic keyboard, reversing the tones should be easy enough to do. However, I have not noticed that feature.

I play a right handed ukulele left handed (neck in my right hand, strumming with the left hand, but strung normally). Since the body is symmetrical, and I learnt like that from the start, I've not really had an issue. Plus, it means I can pick up and play any old ukulele without having to re-string it first. However this doesn't work for something like an electric guitar which you cant really play "upside down"

Piano music is mostly written by right-handers for right-handers. I'm strongly left-hand dominant. For music that's intended to be easy to play, the primary voice is almost always on the right hand. Where the music wants the most dexterity, I have the least.

At the developed level where the composer doesn't give a damn about how easy it is for the musician to play, yes, both left and right-handers have to figure out how to realize the piece and would make use of their strengths to do so.

For instruments like guitar I think the case for reversing the handedness of the instrument is a bit stronger, since the hands serve very different roles there.

I don't think that's the actual reason, even for teaching music. The primary voice is in the right hand because the right hand is higher and so the waves it generates have higher energy at the same volume, making it the easiest voice to hear. I assume that in arrangements and pop music, the arranger naturally puts the melody on top and fills in as much harmony as they care to (which is usually not a lot unless you pay for the arrangement).

This in no way disagrees with the GP comment and in most ways reinforces it.

> Piano music is mostly written by right-handers for right-handers

Even if that does not directly say that people (right-handers, specifically) insert their handedness bias into the things they write, it does certainly imply that that is important for people who write piano music to put the athletic part (the melody) in the more dextrous hand. It is not. The reason for the right hand to carry the melody is the sound projection of high notes, nothing to do with handedness.

Incidentally, many famous composers in the piano canon were lefties. Rachmaninov, Prokofiev, and Ravel all have strong evidence of being left-handed. CPE Bach may have also been a lefty, as may have Mozart and Beethoven. This is not "right-handed people making right-handed music" by any means.

You ever played Bach?

I taught guitar for three years to groups of undergrads. I noticed that most lefties had no problem playing a right-handed guitar. However, occasionally I would have a student that just struggled mightily and things clicked when they switched to a left-handed guitar.

I went to a Don Ross workshop once and there was a left handed player there doing the upside down RH guitar thing, which was especially impressive due to the style of music and having to play the bass notes with their pinky.

My lefty friends use RH golf clubs

Yeah my body is all kinds of confused also:

  - Write with my left
  - Cricket/golf right
  - Tennis/squash left
  - Bowl/throw left
  - Mouse right
  - Drink left
  - Eat right (fork in left hand, knife in right)
  - Cut left (but usually don't bother because scissors never work)
  - I also kick well off both feet (although favor the left foot slightly)

I'm definitely more left dominant but can usually do most things well enough with my right. I was also never told/forced to be right-handed.

Oh bowling - I do that with both hands, equally bad at each (well, maybe slightly better with the left).

I thought I was the only one like that, except my dominant leg for kicking is the right one, and I eat with fork on right hand, knife on left; and I use scissors with my right hand. I also play the guitar as a right-handed person.

When I tell people these things, I can see total confusion on their faces. Quite funny.

One interesting data point is the majority of hockey players shoot left but are not left handed.

https://www.purehockey.com/c/why-are-so-many-hockey-players-...

But shooting left in Hockey is what a right hander does. (Dominant hand on the top of the stick) I’m left-handed and shoot right in Hockey

I'm right handed and shoot right, so do a lot of people.

I'm one of those lefties who have been forced to write using my right hand too.

It cost me grades throughout my whole time at school and university. This is why I write with my right hand. It's ugly, but most of the time I can read it. Luckily, we have devices today which make handwriting not so necessary anymore.

It was a blessing when I learned spreading butter on bread with my left hand...in my late 20s. Those many times I just ripped through the bread. Also forced upon me on some church vacation where me doing it with my left hand was just uncomfortable for my table neighbor and why I had to stop it according to the adult watching us.

Yeah...it is more than "a bit annoying" in this right-handed world sometimes.

Get those lefty scissors. They are such a blessing!

Left handed. Right eyed. Right eared. Mouse with right because I had to in 1992. Overall, I’m unhappy with my brain, so my vote is on it being a bad thing. It’s very discouraging in a left to right language society to smear your own handwriting constantly. Also, guitar tabs and all kinds of other things are built for the majority. I’d much rather be right handed.

"Similarly, you can test your ears: which ear would you naturally use on the telephone?"

Well, I'm right-handed, so...

i'm left handed but i tend to hold phones to my right ear.

Interesting - I would guess you usually hold it with your right hand? Is your hearing noticeably asymmetric?

Come to think of it, if I'm doing something else at the same time - such as, of course, writing - I will hold the phone to my left ear with my left hand. Whichever way, in my case, it has little to do with my hearing.

yes, with my right hand. i don't think my hearing is asymmetric, i think i just appreciate having my dominant hand free while i talk.

a doctor once observed i tend to do "fine motor skills" (e.g. handwriting) left-handed but "large motor skills" (e.g. swinging a baseball bat) right-handed.

I’m right handed but I often use my left hand and left ear, or sometimes even my right hand and left ear

Right hand/left ear feels incredibly awkward to me — almost as bad as trying to get something from your left pocket with your right hand.

The thing is, we may have an ear preference but switching doesn't seem to be that big a deal. UK cops are taught to pick up the phone with their non-dominant hand so that their dominant hand can take notes. I'm guessing _most_ people use their dominant hand to hold their phone unless they're accustomed to taking notes.

I'm right-handed and hold my phone to my left ear. Actually I tried holding it to my right ear a couple of times and it felt so unnatural that I had trouble focusing on the conversation. I have no idea why this is.

This is the one thing that seemed off. I don't have any preference for one ear over the other. If I hold the phone up to an ear, it would depend on what I wanted to do with the other hand. If I'm writing, I would hold the phone in my left hand to my left ear. If I'm typing one-handed, I would type with my left hand while i hold the phone in my right hand to my right ear.

If I went to listen up against a door, it would depend on other things which ear I used, like which ear might already be closer to the door.

Smart phones confuse this, I think. I bet most right-handers hold their phone in their left hand so they can touch the screen with their right. So it then naturally follows that, to hold the phone to the ear, we'd keep it in that left hand. Of course, sometimes I also use it one-handed, in which case it's in my right hand — on reflection, I think most phone use is probably ambidextrous.

> Smart phones confuse this, I think. I bet most right-handers hold their phone in their left hand so they can touch the screen with their right.

Phones used to be small enough that you could use them one-handed, and I still tend try. The only grips I use are one-handed or equally split between two hands, like holding a vertical video game controller. I never use a phone in the way you describe, except maybe to rarely to hit a single button that's out of reach. I tend to rock it in my hand to reach with my thumb.

Have I ever told you I think all phones are slightly too big now?

There might be an age component to that. Anecdotally, holding the phone with the opposite hand from the one touching the screen feels correlated with age to me. I'm right-handed, and primarily use my phone one-handed with my right hand.

It could be an age thing, but I feel like it's more a size & situational thing. I would definitely use a smaller phone one-handed. And when I'm out and about, I do too.

I think talking on the phone is sufficiently different from using it as a tiny computer, we just hold it completely differently in that scenario, so I bet we tend to go to the default state (right hand). I’m trying to think back, but I can’t ever remember using a phone left-handed.

I hold the phone to my left ear, but that has nothing to do with ear preference. It's because it feels more natural holding it up with my left hand (which conveniently leaves my dominant right hand free for doing other things).

No answer in the article. Oh well.

I’m right-handed for everything except eating crisps. But that’s just because I don’t want to get grease on my phone.

About 10% of the world's population is left-handed, while 90% are right-handed. The remaining 1% of people are ambidextrous, meaning they have no dominant hand.

10% does not seem that rare.

Could it just be that for centuries leading up to now left handedness was considered "bad" to "very bad" (still many languages have the connotation) and before that we have no real data about how common it was?

From the article, "when you compare the number of left- and right-handed Neanderthals, this same ratio of 1 in 10 left-handers that we see today pops out"

I feel we’re giving a lot of credit to Neanderthals by assuming they had no superstitions around something as basic as handedness.

They might have and even without speaking of superstitions, we learn a lot by imitation, so that could be a factor too. But having the same ratio is a weird coincidence and it's also said in the article that babies already have their preference in the womb.

More than teeth scratches point to this

https://www.sapiens.org/biology/handedness-neanderthals/

Assuming that research was not biased... Maybe through them is how we became righties?

There is no mystery on why left handers are rare.

With the left hand shielding the liver side, the right hand becomes the weapon bearer.

With the left side protexted, the deaths by liver puncture is greatly diminished.

This is called survivorship bias.

https://en.m.wikipedia.org/wiki/Survivorship_bias

A fun history fact:

> The stair spirals counter-clockwise and is known as the "left-handed staircase" as it would put right-handed attackers at a disadvantage. The story is that in 1513 when the left-handed Sir Andrew Kerr came back from the Battle of Flodden, he had his men learn to use their left hands when swordfighting. In Scotland, left-handedness has been dubbed "Corrie-fisted" or "Kerr-handed".

https://en.wikipedia.org/wiki/Ferniehirst_Castle

Nice, except the liver is on the right hand side.

I live for these satisfying moments of simple, pithy, indisputable proof/disproof.

You're right!

https://www.hopkinsmedicine.org/health/conditions-and-diseas....

Also the stomach is on the other side, so if the pointy stick wouldn't puncture the liver, it would puncture the stomach.

Stomach puncture is far more survivable than a liver tear; far far more likely to survive.

The spleen is on the left though, and that is an organ that is far more vulnerable and where a rupture is lethal without surgical treatment. I still think this is bullshit, but that would be the organ to choose.

Spleen is tiny compared to liver. It's nowhere near as viable as a target. 200g vs 1.5kg.

The heart is slightly on the left though. This paper takes the "fighting hypothesis" seriously:

https://www.mdpi.com/2073-8994/15/4/940

You are using "survivorship bias" incorrectly: if it doesn't lead someone to an incorrect conclusion, then it is not survivorship bias.

What you describe is a selection pressure for right-handedness.

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