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

5/20/2026 at 7:02:45 AM

As far as I understand, the imbalance of the two hands is due to the collaborative nature of a species (if I teach you something is easyer if we use the same hand). There are advantages of using the other hand as dominant, in fact in competitive environment like ping pong we see a 50-50 split between left and right hands. This is because the left hand has the advantage of being rare and so the majority is not trained to compete against the minority, while left hand people mostly compete against right handed. If two lefties face each other they are equally disadvantaged, that's why in the end a 50 left 50 right distribution emerges.

Also fun fact, kangaroos have this same 90-10 split: https://www.nationalgeographic.com/animals/article/150618-ka...

by acetofenone

5/20/2026 at 7:18:03 AM

Ah fun fact, why do we use the word “right” and “left” but also use the word “right” as correct/lawful and use left as thing that is well, left? A linguist theory says that people always been predominantly right handed, so the way you use tools is the “right” (correct) hand, and the one you don’t, well it’s the hand that is “left”. It’s how the word also became the word for directions as well.

by prox

5/20/2026 at 8:16:46 AM

> Ah fun fact, why do we use the word “right” and “left” but also use the word “right” as correct/lawful and use left as thing that is well, left? A linguist theory says that people always been predominantly right handed, so the way you use tools is the “right” (correct) hand, and the one you don’t, well it’s the hand that is “left”.

It's a bit more varied, even in the Indo-European family. What does tend to happen is that the words for handedness get positive (right) or negative (left) associations in idioms, but additional meanings are not universal. In French, "droit" additionally means right (as human right), but not "correct" (yes it does have a bunch of adjacent meanings). In German, "recht" gets to mean "law" or "justice", shared by some Slavic languages ("pravo") -- but not all of them, which have the word "desno", without any association with rights/justice/correctness. The Latin "dexter" gave us "dexterity" and "dexterous", but also nothing alluding to justice. Et cetera.

As an aside, "left" originating from "left over" sounds like folk ethymology to me. Dictionaries point to "weak" as the original meaning.

by inejge

5/20/2026 at 10:41:20 AM

Latin languages also have the words sinister, izquierdo (which seems to come from esku-okerr - crooked hand) for left.

The tendency to associate the right with positive and the left with negative is pretty much ubiquitous in Western civilization up until fairly recently.

I have a fairly exotic viewpoint on this. The left/right asymmetry (for the lack of a better term) is a small part of a larger asymmetry that's difficult to explain (at least to my satisfaction): up is better than down, light is better than dark, positive is better than negative, higher human faculties are better than lower desires, right is better than left. In my mind, none of these should inherently have a good/bad association. Is a valley worse than a hill? Is a positive electric charge better than a negative one? But, for some reason we have this cultural, linguistic baggage where what seem like highly abstract objects are rooted in a very basic world of good and bad.

I find this fascinating.

I would go as far as to add the male/female asymmetry to this: seemingly senseless, yet historically present. I'd say the rabbit hole truly starts when you get into Western esotherics and see how they associate right, up, light, male, order, knowledge as if they're different expressions of the same thing, and analogously for left, down, dark, etc.

by dmos62

5/20/2026 at 2:23:54 PM

> up is better than down

Makes sense; up gives you a better vantage point, so its easier to see danger. Not to mention that it gives you a fighting advantage; your attacker would have to run uphill to get to you, tiring them out.

> light is better than dark

Humans rely heavily on our sight, and we tend to operate in the daytime. If you were a nocturnal animal, I'm sure you would consider dark to be better than light.

> positive is better than negative

Getting something is better than giving it away.

> I would go as far as to add the male/female asymmetry to this: seemingly senseless, yet historically present

What do you mean by this?

by something765478

5/20/2026 at 11:07:20 AM

As a native non Indo European language speaker, aware of the many differences to Indo European languages, it is noteworthy that this however is similar in both. Oikea ja vasen, right and left. Oikea ja väärä, right and wrong.

In clothing you have the right side and the reverse side while here it's oikea ja nurja. Again similarities but nurja has this twisted and dark connotation. Or upside down = nurinperin.

by Gravityloss

5/20/2026 at 12:03:35 PM

Noteworthy that Latin "dexter" (right) pairs with "sinister" (left).

by chrisweekly

5/20/2026 at 8:31:49 AM

Sinister Dexter Adroit Gauche Left handed compliment Right hand man

by hexasquid

5/20/2026 at 11:58:23 AM

Does that go for all languages, or western and mostly germanic languages?

Edit: or maybe indo-european and semitic to be more broad.

by nottorp

5/20/2026 at 1:06:27 PM

Honestly I am not sure, it’s an interesting theory that matches our evolved right handedness as the “right” way to do something, and the other as left. Maybe left handed people were seen as different? And it seeped into language. There is a lot of ifs with and assumptions with this theory.

by prox

5/20/2026 at 9:25:17 AM

Interesting. Does this then become informative about the level of cooperation vs competition in the population?

In ping-pong where it is pure competition it stabilises at 50:50. In everyday life where we largely collaborate it settles around 90:10.

Would be interesting to see if there are variations over populations in time or space with differing levels of competition/conflict. Ofc these would need to persist long enough for the populations to adjust.

P.S. This is probably just another plausible sounding evo-psych bs theory. Idk why people give AI such a hard time for hallucinations. We are just the same. I guess we generally just apply more filters before expressing ourselves publicly. The problem with AI content is that humans take it at face value and publish without scrutiny.

by snthpy

5/20/2026 at 9:31:27 AM

Evolutionary temporal variation is addressed in the article. Although that could just say that without bipedalism, the pressure to use the hands to climb forces equal use over the available hands.

by snthpy

5/20/2026 at 1:23:45 AM

An interesting anecdote that comes to mind is playing old computer games with arrow keys, which used my right hand. I got pretty proficient with this.

Over the years, I (and I imagine many others) switched over to WASD to play newer games with mouse + keyboard, but this meant using the left hand for "arrow keys"

Now I can directly compare how proficient I am with WASD vs Arrow Keys and the result surprised me. I was way worse with arrow keys (right hand) even though back when WASD was becoming a thing I'd rebind WASD to arrow keys because it felt too weird! I would've never imagined back then that WASD could ever feel as natural as arrow keys.

Makes me wonder how much of handedness is truly innate vs learned.

by Vachyas

5/20/2026 at 4:12:58 AM

Left-handed individuals living in a predominantly right-handed world possess the capacity to adapt and utilize their right hand effectively. While most right-handed individuals do not exhibit this ability unless they experience an extraordinary event, such as an injury to their right hand, left-handed individuals are compelled to learn how to use their right hand in a right-handed world.

As a left-handed individual who employs a trackpad or mouse with their right hand, stick shifts are also possible, at least in the United States. Furthermore, left-handed individuals can switch-handed, bat from either side, and use both hands equally in a fight. This adaptability may be the reason why left-handedness remains prevalent in combat sports, including swordplay, tennis, boxing, and even wrestling. In certain combat situations, the initial blows are crucial for survival, especially in the past.

by Danox

5/20/2026 at 4:38:21 AM

In fencing at least left handed fighters tend to get a bit further because there are so few of them they are a lot harder to play against. On a training night a left handed fencer might match up with 10 right handers while a right handed might only see one left hander!

by rym_

5/20/2026 at 5:26:06 AM

It’s similar in other sports. Around 30% of top cricketers are left handed. It’s 40% for some leading countries.

The “hypothesis presumes that athletes in interactive sports are much more likely to play and practice against right-handed opponents. As a result, these athletes develop both greater familiarity and highly specific skills to anticipate the action outcomes of their right-handed opponents via attunement to crucial perceptual information”

Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC7424046/

by yzydserd

5/21/2026 at 1:23:36 AM

> stick shifts are also possible

Ah, let me add on to this from the other perspective.

I live in a country where cars are driven on the left side of the road. ie., the steering wheel’s on the right side, and the gear shifter is operated by the left hand.

And until about 5 years ago stick shifts were very common (automatic transmission was considered a luxury feature only available in higher variants).

I’m right handed. I have no trouble at all shifting gears with my left hand. Feels very natural to me.

I have never driven a left-hand-drive vehicle and in my imagination it feels weird. Like, operating the clutch with the left leg, and the gear with the right hand feels weird. In RHD cars the gear is in the same side as the clutch.

But anyway I know lots of people who drive LHD cars when aboard, and they have never complained.

So I think at least for driving it’s just a matter of getting used to it.

by 2143

5/20/2026 at 12:16:40 PM

I'm right handed, but have a weird mix of "handedness" when it comes to sports: righty for lacrosse but lefty for hockey; higher batting avg righty but more power swinging for the fences lefty. I can balance much more easily on my left leg than my right - maybe partly due to muscle memory from soccer (righty to a fault, though scored plenty of goals and assists lefty, albeit ~always reactive / in the moment, vs free kicks w/ time to think) and skateboarding (stand w left, push w right).

by chrisweekly

5/20/2026 at 8:56:31 AM

it may surprise you to learn that the stick shift is on the other side in countries that drive on the left. Entire generations, regardless of handedness grow up using the other hand to operate it and thats kinda just normal, like with the wasd example from earlier

(although of course unlike your example it doesn't involve reaching across one's body to use it)

by RugnirViking

5/20/2026 at 12:25:43 PM

I'm a righty but managed to drive a stick-shift in Ireland without too much difficulty. I wonder if it actually helped that everything was on the "wrong" side (driver's seat and steering wheel, stick shift, traffic direction) -- bc I was forced to remain focused and deliberate about everything at all times. That said, navigating my first few roundabouts I found myself verbalizing the flow and my intentions, to suppress my instincts and merge smoothly. (Tangent: speaking thoughts out loud is a useful hack in many situations!)

by chrisweekly

5/20/2026 at 11:32:53 AM

Very true, see my comment playing piano as a left-hander.

by hilbert42

5/20/2026 at 4:56:30 AM

> While most right-handed individuals do not exhibit this ability unless they experience an extraordinary event, such as an injury to their right hand, left-handed individuals are compelled to learn how to use their right hand in a right-handed world.

As a person with severe hemophilia in the third world, where the condition is very under-treated (no prophylaxis, very little clotting factor and sometimes none), I've grown up facing this issue with the dominant arm being out of commission due to a bleed for days at a time. I gradually learned to do almost everything with the left hand: brush my teeth, shave, eat, shower, type with one hand (autocompleting IDEs help), even drive a stick shift (using the right hand to hold the wheel briefly while shifting, technically illegal I'll admit).

It's not that difficult to adapt. The barriers are mostly mental because it feels awkward at first. There are some dexterity issues but if you don't mind going slowly, you can get by.

Just sharing my experience, not meant to undermine the challenges faced by left-handed individuals in a right-handed world.

by kranner

5/20/2026 at 8:11:35 AM

I'm left handed but so used to switching I'll e.g. often get partway through a meal before suddenly realising I have the cutlery in the "wrong" hand. Except for writing - writing with my right hand is pretty much write only...

by vidarh

5/20/2026 at 1:43:18 AM

I remember in elementary school being amused by the idea of handedness so I decided to practice writing with my left hand as well. I'm not great at it but even to this day I can write legibly with my left hand from that little bit of practice as a child.

Anyone can get much better at using their non-dominant hand (if they have one) with just a bit of practice. The effect is much much stronger when you do so as a child.

by xenadu02

5/20/2026 at 2:53:58 AM

Children have better neuroplasticity but worse persistence than adults.

As an adult I just practiced writing with my left hand loads for basically no reason, it's not that useful, but I still did it for some reason. Now I can write illegibly with either hand :)

by kaashif

5/20/2026 at 4:57:28 AM

Generally agreed, except for the "Anyone" - because people really are different. I'm familiar with a few people (from very young to adults) who are extremely one-handed. The other hand is nearly useless, except for holding and supporting. Those individuals will typically turn newspaper pages or book pages using their right hand (if they're right-handed, and one guy told me that he didn't trust his left hand with a fork to actually hit his mouth, so he used a knife+fork the opposite way of most right-handed people. These people are in a minority, but they exist.

Then there's guitar.. some, or actually most left-handed people can learn to play a right-handed guitar if they simply start with a right-handed guitar. But there are also some people (some of them very well known) who tried learning the guitar for a very long time, and couldn't. Until they switched to a left-handed guitar. (Why it's natural to actually use the left hand for something which looks complicated - fingering, and the right hand for something simple - strumming - has been discussed forever. Apparently that's because a right-handed person typically has better timing in their right hand, and that's why it matters).

by Tor3

5/20/2026 at 2:52:38 AM

I realized at some point as a leftie I could trivially learn to write a mirror image of what everyone else was writing so learned to write backwards. Since the motions are exactly what others do it’s actually easier in a lot of ways for me. Left handed writing is all scrunched up and annoying, and I got constant smudges on my hand. Frixion ink pens are the only pen I’ll buy because they don’t smudge at all. My guess is it’s actually because it’s heat reactive so it just vanishes on skin, but that works for me! (It doesn’t disappear on the page except the time I put a hot bowl of oatmeal on my hand written deployment reminder notes, which was a bit of a surprise. Took me about an hour to recover gathering data, haha).

by wincy

5/20/2026 at 6:47:31 AM

FWIW, you can also put the paper in the freezer and it will become visible again, though usually not as strong as it was originally.

by admash

5/20/2026 at 5:41:37 AM

I also discovered the mirrored writing thing lol and it made me wonder what ambidexterity is since if ambidextrous people could presumably write non-mirrored with the other hand, aren't those completely different motions that neither hand has had any practice with?

by Vachyas

5/20/2026 at 2:31:07 PM

As a kid I found it interesting that people pretty much always crossed their arms and/or their legs when sitting on the ground in the same pattern.

After that re-trained myself a few times out of interest to do it the other way around, and one goes through the four odd phases of having to focus on it vs it just happening correctly without thinking about it.

From what I remember it could take 2-4 weeks before you would just do it both without thinking and correctly.

by animal531

5/20/2026 at 8:28:29 AM

I've been playing guitar since I was a little kid. I wonder how learning "two-handed" skills such as playing music impacts how "handy" or "polydextrous" one is.

There are left-handed guitar players that play right-handed, such as Nick Johnston, who claim the gaps in their technique or preference for certain left-hand-only techniques are informed by being left-handed; so it seems that a life-long of an insane amount of practice does not necessary change how comfortable one is using either hand for a given task.

by wvh

5/20/2026 at 12:34:15 PM

I write with my left hand but play guitar right-handed. I don't think it had any effect on my playing, because I think I'm a naturally right-handed guitar player. Here's a list of things and whether I do them right- or left-handed:

  ┌───────────────────────────┬───────────┐
  │ Activity                  │ Hand      │
  ├───────────────────────────┼───────────┤
  │ Baseball (Bat/Catch)      │ Left      │
  │ Hold Spoon                │ Left      │
  │ Soccer                    │ Left      │
  │ Tennis                    │ Left      │
  │ Throw Ball                │ Left      │
  │ Darts                     │ Left      │
  │ Write                     │ Left      │
  ├───────────────────────────┼───────────┤
  │ Bow and Arrow             │ Right     │
  │ Hold Fork/Knife           │ Right     │
  │ Play Drums                │ Right     │
  │ Scissor                   │ Right     │
  │ Shoot Rifle (Nerf Gun)    │ Right     │
  │ Skateboard/Snowboard      │ Right     │
  │ Use Mouse                 │ Right     │
  └───────────────────────────┴───────────┘

Basically, the only reason I call myself left-handed is because I write with my left hand. All in all, I have no idea if I do more things left handed or right handed.

by peepee1982

5/20/2026 at 4:16:21 PM

I'm similar. I do very little with both hands, but I'm split between left and right on individual things. Throw is right, write is left. Where I especially get hung up is learning something to do with feet - surfing, skateboarding, snowboarding, etc... I struggle to figure out which one is my preference. I usually find that I'm equally bad at both.

by daveslash

5/20/2026 at 8:46:57 PM

Our sports teacher in high-school would tell us to stand straight. Then he would shove us from the back a few times. The foot we would stop ourselves from falling would be our leading foot (for snowboarding). So if you catch your fall with your left foot, you're regular. Otherwise goofy. Don't know if that's a safe bet, but it seemed to work out for us back then.

OTOH: I am convinced I can't snap my fingers with my right hand and never will because my specific mix of handed-ness makes it impossible for me to do so, no matter how hard I try and practice. No problem at all with my left hand.

by peepee1982

5/20/2026 at 10:21:30 AM

Some of the best guitarists I have met are left-handed playing right-handed guitar ones. Which also makes sense - The more difficult part of playing the guitar is not fingering/picking, it's the fretboard. By using their dominant hand on the fretboard they have a genuine advantage. I've never understood why we formed the right handed guitar to have the dominant hand on the body. There must be a reason.

by postexitus

5/20/2026 at 10:55:44 AM

> The more difficult part of playing the guitar is not fingering/picking, it's the fretboard.

I would have said the opposite. The fretting hand only needs to press onto the strings in the correct places whereas the picking hand is responsible for all the subtlety of expression in terms of how you attack the string.

Saying this as a professional mandolin player fwiw.

by AlecSchueler

5/20/2026 at 11:42:44 AM

While true - left hand changes position all the time and has to go on the correct frets all the time - right hand is gentle and subtler, I agree, but is also a lot more forgiving.

by postexitus

5/21/2026 at 4:15:14 AM

I think this reason is dependency. Anything I'm doing where the action of one hand depends on the other has to go left-to-right. I can only finger frets with the left and then pick with the right. Can't go the other way, can't have the right hand act before the left, even if the left has the more complex task.

It's like Super Mario Bros. With a 4-way d-pad and 2 action buttons, why is the more complex 4-way on the left? Because most of the time you're holding a direction first with less requirement for precise timing, and then pressing the button at the correct instant depending on the movement. (We're talking general platformer play, not hyper precise d-pad moves for something like Super Metroid speedrunning.)

Even typing on a keyboard, I never hold a right-side shift or other modifier key, it's always left-shift then the target key.

by vikingerik

5/20/2026 at 11:29:38 AM

See my comment, I'm much better at playing with my less dominant hand (even after many years).

by hilbert42

5/20/2026 at 2:49:43 AM

I’m left handed and never understood left handed mice at all. I write with my left and swing and kick left handed, but all gaming stuff has always been the same way anyone else does. I’m pretty sure up down left right switching to wasd is a function of that setup being more comfortable with the mouse to the right of the keyboard, correct?

by wincy

5/20/2026 at 5:48:19 AM

correct, and I think games which needed action keys in addition to arrow keys (but no mouse) preferred arrow keys on the right so the left hand could handle the other moves and stuff.

I write with my left too but using right handed peripherals feels natural. I also use my phone right handed.

by Vachyas

5/20/2026 at 3:53:56 PM

I’m left handed and can use a mouse with either hand. It’s just a matter of habit.

by benhurmarcel

5/20/2026 at 11:48:23 AM

I'm left-handed too and frankly a left-handed mouse is a nuisance and awkward to use (I never use one), same with other peripherals.

Still I prefer to use scissors with the left hand and most are right-handed. It's a damn nuisance as the loop handles are the wrong way around/wrong size for a leftie.

by hilbert42

5/20/2026 at 4:49:43 AM

I'm right-handed, I'm pretty sure of that. But it's also an observed fact that if there's something I'm not used to to yet then it doesn't really matter which hand I start doing whatever it is with, if it's the right hand that'll be the preferred hand for that activity in the future, or if it's the left hand then that'll be the one. Things I do "both ways" I can do.. both ways.

by Tor3

5/20/2026 at 10:13:40 AM

I've found the same thing. I'm quite left handed for most things, including writing and throwing. But when I learned to shoot rifles, I learned right handed because 1) otherwise the ejected brass can hit you, and 2) I'm right eye dominant and its easier to shoot without crossed hand and eye. So now it feels very strange to shoot any gun left handed. But things like using a mouse or a stick shift car RHD vs LHD, I can use either hand and it doesn't much matter.

by technothrasher

5/20/2026 at 11:19:38 AM

It's interesting that the piano is essentially a right handed instrument in that melody/the main theme is mostly played by the right hand.

As a left-hander, it's very obvious to me. That said—because of the above point—my right hand is much stronger and more adept at playing. In short, I'm right handed when playing the piano.

No sarcastic comments please, I well know more practice and playing those damn Czerny scales ad nauseam would have restored proper balance. :-)

by hilbert42

5/20/2026 at 11:41:42 AM

Can I recommend playing Bach?

The specialization goes both ways, though, I'm much better playing Alberti bass with my left hand compared to the right.

by olau

5/20/2026 at 12:22:32 PM

I can play Bach to some extent with practice. I'd qualify that though by saying a multi-part fugue from say The Musical Offering would be a tall order.

I've never had any pretense at being good enough to entertain people with those works as everyone knows them so well (from professional recordings). Even Mozart's a problem here. For example the Romance in the D Minor Concerto, K.466 looks deceptively simple (at least in parts) but it's anything but after hearing someone like Brendel play it. Everyone knows it so well it's not worth the embarrassment of even trying (except perhaps in secret).

(Mozart has a habit of looking simple until one tries to play it, Bach is none of that—one knows what one's in for at pretty much first glance.)

by hilbert42

5/20/2026 at 1:38:44 AM

For this sort of motor skill, it’s definitely learned. For stringed instruments, for example, it’s the left hand which has the more finely managed manipulation than the right (it’s interesting to note that only guitar-family instruments are commonly made in left-handed versions, although some of that may come down to logistics of string ensembles where having one left-handed violin in the violin section would cause a bit of chaos with colliding bows that is less of an issue with guitar ensembles where there are fewer musicians and they’re less tightly packed in the performance space). Likewise, the fingering on woodwind instruments doesn’t really favor one hand over the other. In contrast, brass instruments are decidedly right-handed (I suppose one might be able to manage a trumpet left-handed, but I’ve never tried. I don’t think other brass instruments could be fingered with the left hand at all.

by dhosek

5/20/2026 at 4:28:46 AM

This left-hander did, guitars can be used/adapted too if you’re left-handed, you might have to adapt like a certain well known person named Jimi Hendrix…

by Danox

5/20/2026 at 5:00:09 AM

The French Horn is played left-handed.

by Tor3

5/20/2026 at 8:49:55 AM

From my experiences, I think it's mainly learned.

I'm right-handed, but I trained myself to use a mouse/trackball left-handed due to better ergonomics. I was getting back/shoulder pain and thought that it was related to computer use and realised that with the typical keyboard with numeric pad and a mouse setup, that my body was twisting more due to the mouse being more to the right than it needed to be. Using my left hand instead means less twisting as there's no numeric keypad on the left.

It took probably a couple of weeks to get comfortable with left-handed mouse use and these days, I am fairly ambidextrous on a computer.

The other thing that makes me think that handedness can be learned is learning to juggle. I found that it's easier to start doing a new movement (i.e. a trick) with my right hand, but once I learn it with my left hand, the left hand becomes more accurate than my right.

by ndsipa_pomu

5/20/2026 at 9:23:55 AM

I’m a leftie and I don’t think I learnt it. My mother said as a very young child she noticed I’d mainly used my left hand to take things - probably food :) These days the only real problem for me is scissors, especially the ones with moulded plastic handles.

by markb139

5/20/2026 at 9:29:39 AM

I didn't mean that most people don't have an innate handedness, but that it's quite possible to learn to do tasks with your non-favoured hand - it just takes a period of adjustment during which it feels incredibly clumsy to use that hand.

by ndsipa_pomu

5/20/2026 at 1:46:59 AM

Something super simple and revealing is try pressing on the brakes with your left foot.

by kelipso

5/20/2026 at 6:59:24 AM

I do this once or twice a year in a borrowed/hired auto car. Usually about 10 minutes into the drive when I've got used to it, and started to drive more naturally. Approach junction, throttle back, stamp full uncoordinate force of left foot on to 'clutch' pedal, send passengers through the windscreen.

by Skwid

5/20/2026 at 5:02:28 AM

That's because after you've learned to drive, everything the feet do is muscle memory. You don't consciously adjust the pressure (you just believe you do..), so switching around the pedals will need re-learning. And indeed it's common among rally cross drivers to learn to use the left foot with the brake pedal as well.

by Tor3

5/20/2026 at 11:56:32 AM

If you usually drive a manual transmission you might have a bad time if you try to brake with your left foot

by whynotmaybe

5/20/2026 at 12:49:05 PM

Yeah it’s a big contrast, I guess that’s why I mentioned it. I forgot it would be easier to learn with an automatic, or at least the difference wouldn’t be so obvious with it.

by kelipso

5/20/2026 at 4:01:55 PM

Useful for controlling a car at speed through tight turns though

by westmeal

5/20/2026 at 3:20:04 AM

A few of my relatives who grew up on a farm drives that way (right for gas, left for brakes)

by ahurmazda

5/20/2026 at 8:33:43 AM

IMO heel-and-toe is harder than left foot braking.

by tmtvl

5/20/2026 at 9:13:07 AM

you get used to it within a couple of hours

by jpfromlondon

5/20/2026 at 6:17:23 AM

[dead]

by sph

5/19/2026 at 8:30:26 PM

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.

by skyberrys

5/19/2026 at 9:40:09 PM

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.

by js2

5/19/2026 at 10:53:47 PM

> 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?

by didibus

5/20/2026 at 12:20:18 AM

There is also a category of people who are “mixed-handed”, who have a strong handedness preference for a given task, but which hand one prefers varies based on the task. I didn’t know about this category until recently, but it describes my personal experience.

Mildly informative Wikipedia article: https://en.wikipedia.org/wiki/Cross-dominance

by p00dles

5/20/2026 at 6:04:44 AM

Interesting, but it confuses me a bit.

Ambidextrous means: "that the person has no marked preference for the use of the right or left hand".

Unlike what is normally assumed, it doesn't mean you've mastered both hands, it doesn't imply you can write equally well with the left or the right, but that you could have just as easily learned either. You had no marked preference when you picked up the activity initially.

Cross-dominance seem to imply there was a marked preference, but that it is the left or right hand differs per activity.

That said, I wonder if they're really the same. Often people say ambidextrous as you are equally good with both hands, which would always require practice on both side. But maybe cross-dominant people can equally learn?

Under that reading, cross-dominance could be what ambidexterity actually looks like in practice. If you genuinely have no preference, there's no reason you'd consistently land on the same hand across all activities, you'd be influenced by context, who taught you, which hand was free, etc.

Have you ever tried your other hand at activities? And are you surprisingly good with it, even if not as good? I tend to be better using my other hand at most things than say a fully right handed person, but never as good as the hand I've been using for that activity consistently.

by didibus

5/20/2026 at 5:14:23 AM

I'm like that, except for those things I can do both ways, because it's useful and sometimes necessary - like using a shovel. There are a bunch of things I only do with either the left hand only, or the right hand only. A right-handed friend always throw balls with his left hand. Most other things he does with his right hand.

I'm right-handed. I'm definitely sure of that. It's just that what hand I use depends on which hand I start with from the beginning. And that'll be the preferred hand, except for things where it's natural to switch from the very beginning.

But there are also some things I've learned to do with both hands much later, e.g. washing dishes - there was a reason for having to do that for a while, and now I just switch when I like it, or if the kitchen happens to be arranged in a way which makes one side more preferable.

(BTW, when building carpenters still used common hammers it was completely normal to use either hand, as access space may be limited and there's basically no choice sometimes.)

by Tor3

5/20/2026 at 10:05:51 AM

Isn't that normal? I'm very strongly left handed, but I will often carry heavy things with my right hand

by voidUpdate

5/20/2026 at 12:52:38 AM

>why handed vs ambidextrous

may be high dexterity is expensive, brain-wise, i.e. may be the choice given average brain is either 2 hands with mild dexterity or a one of high dexterity at the expense of the other. With tools, etc. the latter choice seem to be preferable and was selected for (and the lucky ones get to have 2 of high dexterity) Bipedalism and brain expansion in this situation are indirectly connected to the handedness as they are enablers and drivers of tools use.

by trhway

5/20/2026 at 2:41:59 AM

> My theory is if any child wants help with fine motor control the help is provided by a left hand to a left hand.

Neither of my parents were left handed, and yet, here I am; despite attempts otherwise I might add.

by necheffa

5/20/2026 at 6:01:44 AM

Kind of feel like preference probably comes from a compounding effect of practice. One starts learning how to do simple things with a chosen hand as a baby and as one tries to learn more complicated things they develop an ever-growing preference to use the one that'll necessitate less practice for the new skill due to already having some practice.

As for which hand is chosen as a baby, it might be most typical to mirror one's parents, but it doesn't always have to be like that. Some babies may just randomly start doing things with a hand different to the preference of their parents due to not having them or other adults in their sight at critical moments. As for parents trying and failing to stop their kids from using their left hand, they might've just caught it too late.

So, I guess what I'm saying is that both you and GP can be correct.

by jolmg

5/19/2026 at 11:16:34 PM

Oddly enough, a lot of my "nerd friends" are left handed, and I'm also left handed. /shrug

by nubinetwork

5/20/2026 at 2:16:41 AM

Funny enough, this made me realize that although I'm right-handed, I'm left-footed when it comes to football. As an amateur player, using my right foot with proper shooting form still feels surprisingly awkward to me.

by Viacol

5/20/2026 at 12:24:38 AM

All our maths teachers were at school were left handed, along with 25% of the top maths set in our year. The teacher and student population of left handed people were close to the normal 10% levels too.

by nmstoker

5/20/2026 at 12:57:46 AM

Autistic people are 2 to 3 times more likely to be left handed than the general population.

by pixl97

5/20/2026 at 10:09:06 AM

Do you know about the ambidextrous rates too?

by voidUpdate

5/19/2026 at 8:34:20 PM

without reading .. my immediate guess is that one hand is needed for maintaining upright balance, while the other hand grasps something important ?

by jgord

5/20/2026 at 12:48:46 AM

As someone who is fairly ambidextrous, but predominately a lefty - the things that are harder to switch between are some of the gross motor skills.

For example, throwing (or kicking) with your non-preferred side is not as simple as picking up and throwing a ball or simply kicking it. You have to adjust your position and stride to lead with the correct foot. I found learning right-handed pace bowling in cricket (for fun) especially challenging as you have to land your back foot in the right place as you bowl through the popping crease. A few steps and rolling the arm over to spin was easy, and I actually can get more spin on the ball with my right hand.

My theory is that the handedness came about through learning basic survival activities such as running and jumping, throwing spears or rocks, etc that require using a preferred or learned hand.

by dwd

5/20/2026 at 3:08:02 AM

This is true for me as well. I can't really play volleyball, because you are supposed to hit the ball with both hands, but my left hand is constantly ahead of my right hand. All my shots are crooked.

by skyberrys

5/19/2026 at 9:55:17 PM

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 minority. I'm right-handed as well. I wonder what's up with that.

by colkassad

5/19/2026 at 11:02:42 PM

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.

by m463

5/20/2026 at 5:03:00 AM

    I overused my right hand with computers...

In your teens, right? Happens to a lot of people. :)

by imp0cat

5/19/2026 at 10:31:31 PM

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.

by putlake

5/19/2026 at 11:39:33 PM

> I think this is probably related to which eye is more dominant for you.

I think it's more about a person's personal stability/biomechanics. The back foot is the stable one, forward is the "quick" lead. The preferred "plant" foot when kicking a ball is the stable one (though many people use both, so this is best used only when there is a strong preference), the one used to push off with when at the bottom of stairs or jumping is the stable one (the lead foot is the `quick` one). The best way I found to help determine footedness: have a person stand straight (feet together) walk around them (pretending to look at posture or something), once behind them push them forward (evenly with some force). Watch for which foot they catch themselves with. Thats the lead foot.

As for the eye dominance, in archery having the right eye dominant means your stance is regular (left foot forward). An archery open stance is near identical to a snowboard neutral stance (~ +15°, 0°). The 2 most important things to get right in (olympic recurve) archery is eye dominance and a proper open stance. As a goofy footed snowboarder and a right eye dominant archer, the archery stance took awhile for me to adapt too. It still feels weird.

by 1659447091

5/19/2026 at 10:40:00 PM

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.

by colkassad

5/19/2026 at 11:02:22 PM

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.

by koolba

5/19/2026 at 10:05:19 PM

Me too, but on a snowboard. (I suppose I'd be the same on a skateboard) My second time snowboarding was quite a few years after my first, and I just could not get the hang of it, wondering how I was faring so much worse than before. It took me all day to remember I was "goofy", and once I switched it was much better.

by hydrogen7800

5/19/2026 at 10:43:03 PM

Yeah, I went snowboarding once in my life (loved it but it was exhausting) and naturally rode goofy-footed. They only thing I really needed to learn was slowing myself down.

by colkassad

5/19/2026 at 11:00:36 PM

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.

by keitmo

5/20/2026 at 12:13:13 AM

You can be right handed and left footed (and vice versa), and you'd typically snowboard and skateboard etc with your dominant foot.

by onlyrealcuzzo

5/20/2026 at 1:13:10 AM

I'm goofy footed as well - skate boarding with my left foot forward is like trying to throw a ball with my left hand. I also found that if I was rollerblading or ice-skating, turning to my left (counter clockwise) with a foot-over-foot action I can do super easy, but turning turning clockwise I always struggled with.

by laserDinosaur

5/20/2026 at 5:02:25 AM

Here is an interesting experiment you can try - think about it more like "skate with the right foot back" then "skate with the left foot forward" and see if it gets any easier for you. It definitely does work for me.

Obviously it won't sudenly make you a perfect regular-stance skater though. :)

by imp0cat

5/19/2026 at 11:52:49 PM

Do you hold a baseball bat lefty too?

I skate/surf goofy (or used to... haven't done much of either lately :P) and prefer to hold a baseball bat or a golf club lefty, despite being right-handed. And I have an immediate family member who's left-handed but bats righty!

by cryzinger

5/20/2026 at 12:03:21 AM

I’m the opposite… write lefty bit bat/swing (rackets and gol) righty. Not sure about surfing - I only paddle board and the stance is more straight-on (because you paddle both sides to avoid turning in a circle).

Of course, I’m terrible at baseball and my handwringing is atrocious, so maybe I’m just broken.

by alistairSH

5/19/2026 at 10:23:31 PM

What does "face left" mean? Left foot front? That's regular.

by emil-lp

5/19/2026 at 10:35:39 PM

When I stand on a skateboard, both feet on, I face to the left. My right foot is in front, which I steer with while pushing myself with my left foot.

by colkassad

5/20/2026 at 12:25:09 AM

Missing is the assumption that "direction of travel" is forwards.

by _carbyau_

5/20/2026 at 8:41:50 AM

If I were to skateboard, I would face port. When I'm coming to a halt on a bicycle I prefer keeping my right foot on the pedal and landing on my left foot, so I believe I'd have the same preference when skateboarding.

by tmtvl

5/20/2026 at 3:17:10 PM

A goofy skater’s head faces right, over their shoulder, and body faces left, relative to their forward movement.

Orientations are so confusing, I thought the parent was describing regular too

by larrry

5/19/2026 at 10:03:50 PM

I think skate stance is much more evenly distributed (closer to 50/50) than handedness (about 10% left).

by ivanjermakov

5/19/2026 at 10:22:35 PM

Citation needed

by emil-lp

5/19/2026 at 10:38:09 PM

"Of the 4,000 skaters in the Skatepark of Tampa Database, about half are goofy (44%) and half are regular (56%). But this near equality between skate stances doesn’t align with statistics on handedness. According to Scientific American, 90% of people are right-handed." ¹

"Out of the 610 professional skateboarders, 291 ride regular and 329 ride goofy. This means that 53% of skateboarders ride goofy and 47% ride regular! Way more skateboarders than expected ride goofy." ²

---

¹ Dobija-Nootens, N., & Harrison-Caldwell, M. (2017, October 12). What determines your skate stance? Jenkem Magazine. https://www.jenkemmag.com/home/2017/10/12/determines-skate-s...

² Bande-Ali, A. (2024, August 25). Skateboarding: How many people ride goofy? Azeem Bande-Ali. https://azeemba.com/posts/skateboarding-how-many-people-ride...

by mmastrac

5/19/2026 at 10:19:11 PM

[dead]

by ruffel__

5/20/2026 at 12:33:31 PM

Not my area of expertise, but this article appears to completely ignore several factors which were true when I was growing up as a leftie in 1970s UK (admittedly some time ago):

1. Some schools actively punished children for writing left-handed.

2. Pretty much every utensil was made for right-handed people. I don't recall ever seeing left-handed scissors, for example.

3. You learn by copying those around you. If your parents, teachers, and peers are predominantly right-handed (and are even actively encouraging you to be right-handed), then you're likely to toe the line.

I imagine the final point would remain a factor long after the first two are addressed.

by monooso

5/19/2026 at 4:08:40 PM

So why are us southpaws a rarity? The article and the linked research paper both point to bipedalism and bigger brains as the cause, and the paper vaguely seems to hint at selective pressures leading to the right hand getting favoured by the majority of the population, but why?

The question from the headline is excellent, if only it was actually answered.

by Freak_NL

5/19/2026 at 4:38:01 PM

Here's my five minute lunchtime hypothesis: it's because the heart is on the left. As human behavior demanded increasing precision from the hands, being a little farther from the heartbeat was a slight advantage.

by scythe

5/19/2026 at 4:48:00 PM

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.

by yawpitch

5/19/2026 at 6:04:26 PM

> Also people with situs inversus (essentially all organs flipped laterally from “normal”) aren’t obviously more prone to left-handedness.

I feel like this isn’t really an argument against the theory. If right handedness did evolve because of heart position, a later genetic mutation to have the heart on the opposite side wouldn’t suddenly undo the previous evolution towards right handedness.

by cortesoft

5/19/2026 at 10:40:42 PM

Why are you assuming situs inversus, which occurs in species with no handedness (or, indeed, hands) came after handedness?

The argument is that the selection bias was towards precision and the hypothesis was that precision is influenced by heart position (which is, still, in the middle in humans)… individuals with situs inversus would be more precise in the left hand, thus if the causal hypothesis is correct AND the argument holds then there should be a selection bias that would result in a correlation between situs inversus presence and left-handedness.

In the end I don’t believe either the argument or the hypothesis hold even as much water as I can in either hand.

by yawpitch

5/20/2026 at 1:30:37 AM

I’ve wondered ever since fourth grade (where an anatomical model in a corner of the classroom always made it clear that the heart is centrally located) how the vernacular conception of the heart as located on the left originated and persisted.

Your post finally made it click for me – the aorta extending to the left gives the superficial impression of that being the heart’s location because it’s easier to feel the heartbeat through the skin, versus the more deeply embedded vena cava on the right.

Presumably this means, evolutionarily, greater vulnerability on the left, predisposing the left hand to shielding duties, leaving the right to more dexterous tasks like spearing. The cardiological hypothesis of right-handedness holds!

by mortenjorck

5/19/2026 at 5:56:48 PM

It might be hard to eliminate confounding factors depending on when the research was done. A lot of people in my generation were still dissuaded pretty heavily from writing with their left hands. I'm not entirely convinced anymore as a lay person that "handedness" is a real, distinct phenomenon that's primarily genetically determined or a result of the organization of the brain. It's equally possible that it's a learned preference and that the way the brain organizes around it is as a result of the preference's impact on how you have to solve problems with your preferred hand in a society that preferences right-handedness.

by throwway120385

5/19/2026 at 5:47:30 PM

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.

by rybosworld

5/19/2026 at 10:51:29 PM

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.

by yawpitch

5/19/2026 at 5:00:46 PM

>Here’s my multiple years of anatomy classes response: the heart isn’t on the left.

Why is the left lung smaller, then?

by stackghost

5/19/2026 at 5:46:17 PM

The heart is asymmetrical, but it’s in roughly the center of the chest. The left auricle and ventricle are larger muscles because they’re pumping through the descending aorta to the extremities, that’s the systemic circulatory branch, the plumbing for which is also largely to the right, while the right are pumping into the lungs alone as part of the pulmonary circulatory branch. The left lung (right on those with situs inversus) has two lobes and basically accommodates the extra muscle mass on its side of the heart, but 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.

by yawpitch

5/19/2026 at 5:55:34 PM

>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.

by stackghost

5/19/2026 at 6:01:19 PM

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

by rolph

5/19/2026 at 10:55:30 PM

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.

by yawpitch

5/19/2026 at 9:44:56 PM

Well, yes, the point of the solid bone plate right in front of your heart is to block stabbings. And it works!

If you had a weapon that wasn't bothered by the presence of the sternum, and you wanted to stab the heart, you'd go right through the sternum.

by thaumasiotes

5/19/2026 at 9:57:07 PM

the risk is one of being unable to extract the weapon expediently.

there is an unacceptable risk of having to abandon it.

by rolph

5/19/2026 at 10:19:30 PM

Unless you're also trying to send a message where leaving the weapon is the message

by dylan604

5/19/2026 at 11:05:16 PM

such as, a sculpture or other improvisation perhaps even advertising material.

https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F... [JPG]

by rolph

5/19/2026 at 5:33:38 PM

not only smaller but having 2 lobes rather than 3, the left lung is possessed of a featureknown as the cardiac "notch" an involution of the lobe that corresponds to the larger left ventricle of the heart.

by rolph

5/19/2026 at 5:27:32 PM

More piping to and from the heart exists on the left instead of the right?

by altruios

5/19/2026 at 5:40:50 PM

the Aorta and Vena Cava are muchmore central than sinistral.

the aortic arch begins decent left of the coronary corpus, but becomes centralized, tandem with the Vena Cava.

by rolph

5/19/2026 at 4:52:04 PM

Wikipedia on Situs Inversus (visceral organs are mirrored, heart on the right, liver on left) [0], mentions mixed results regarding handedness. There would be a load of other confounding factors here and I know nothing about medicine.

0 - https://en.wikipedia.org/wiki/Situs_inversus

by gherkinnn

5/19/2026 at 6:16:38 PM

Situs inversus ("dextrocardia") is a rare disorder. What I postulated is a (very) small selective advantage leading to a neurological mechanism evolving over generations, not a direct line from the heart to handedness during development. Anyway, the effect would be very slight, and even if it did exist, it could have gone away later, but dexterity would have been baked in at that point (see also the ocular blind spot).

by scythe

5/19/2026 at 5:54:15 PM

Childhood handedness development within the brain became independent of organ positioning, after positioning had become established.

by xattt

5/19/2026 at 8:39:34 PM

That's a long time hypothesis of mine as well, but I think it stems from being stung or bitten by venom. If venom is injected into the bloodstream, it is desirable to be injected as far away from the heart as possible.

Some centimeters might not sound much, but over millions of years, the cumulative effect might be that 1% of human population every 10.000 years gets genetically optimized to hold their heart at a more protective spot.

by emporas

5/19/2026 at 9:45:55 PM

Interesting!

Handedness is probably not (often) captured in healthcare records, but I'm wondering if epidemiologists could mine insurance claims (or some other data rich resource) to see if there's a correlation with serious outcomes (death, hospitalization, etc.) from venom and handedness.

by busyant

5/19/2026 at 10:11:13 PM

That's a good idea, a very good idea actually, but I wonder about it's effectiveness due to a very small total number of snake bites nowadays, compared to the past.

Hundreds of thousands years in the past, hominids lived into much more tropical areas than today and there are a lot more spiders, scorpions, lizards and snakes in these warm places. It makes sense that insects and especially reptiles pushed the evolution of mammals in certain directions and the positioning of the heart in the human body might be one of them.

Today people live a much different lifestyle than having to deal with insects and reptiles all day long. I don't know if it is possible to decipher the past from today's data.

by emporas

5/19/2026 at 4:44:40 PM

If this was the case wouldn't it be easier to measure the pulse in peoples left wrists? Which doesn't seem to be a thing?

by gpm

5/20/2026 at 5:24:55 AM

But it is a thing. That's how it was always explained in school, among other places, when I was a kid.

by Tor3

5/20/2026 at 5:16:59 AM

There is also a bias for how babies are held [1]. It holds even with left-handers. Holding a baby's head near the mother's heart helps the baby get to sleep. Which means the baby doesn't cry (and attract predators) and also gives the parents more time to sleep at night.

It also allows right-handed mothers to do something with their dominant hand while cradling the baby in that position.

[1]: https://sites.psu.edu/clarep/2024/04/12/the-left-cradling-bi...

by abernard1

5/19/2026 at 5:56:36 PM

I wonder why you're getting downvoted? Even if it turns out you're completely wrong it's still an interesting point and something I never even considered before.

by booleandilemma

5/19/2026 at 6:19:17 PM

Sometimes I think people downvote me because they're frustrated that I didn't engage further. After twenty years of Internet discussions, I'm a little burned out and I tend to fire and forget.

by scythe

5/19/2026 at 7:32:45 PM

You might enjoy this: https://serjaimelannister.github.io/hn-words/

by booleandilemma

5/19/2026 at 9:42:08 PM

> Here's my five minute lunchtime hypothesis: it's because the heart is on the left.

Your hypothesis can't possibly be correct, because the only premise is false.

by thaumasiotes

5/20/2026 at 1:11:42 AM

I would think right-handedness is largely reinforced through learning gross motor skills as an infant. If you always use your right, your brain optimises for that.

I wonder whether something simple like being allowed to select and use an object with either hand rather than having it offered to your right hand retains ambidextrous by the time handedness became fixed in the brain around age 4-6.

by dwd

5/19/2026 at 5:53:18 PM

I remember reading that there is evidence that Neanderthals tended to be left handed. Someone else might be able to confirm/debunk this.

by nephihaha

5/19/2026 at 5:39:18 PM

I am curious at what age hand preference develops. And can you exert any influence on that development?

In particular, I would expect the influences to be somewhat counter intuitive. With things like having to use the left hand to hold a caregiver's hand in early walking preferencing the right for accessory use. At infant ages, it would be neat to see if preference of holding a baby on a side influences things.

by taeric

5/19/2026 at 9:12:59 PM

I’m a leftie from a 50% leftie family. Apparently I showed my left handedness as a baby when grasping for things and hardly used my right hand. My mother was also a leftie, but in her generation she was forced to write with her right hand. The net result being she could write equally well with both hands. When I learnt this I tried to copy it.

by markb139

5/19/2026 at 10:20:08 PM

Right, I know that dexterity in a hand is largely a teachable thing.

And, similarly, I don't think this is unique to hands. It is just that most people don't know what their "dominant" foot or eye are. (I'm now curious to know about dominant ears. That is almost certainly a thing?)

My question is largely one of curiosity to know when the dominance fully sets in.

by taeric

5/19/2026 at 6:36:19 PM

The introduction of this article makes reference to a couple of papers (e.g. https://doi.org/10.1038/s41598-017-16827-y ) that handedness is observable in utero but cautions small sample sizes for these studies.

by Technolithic

5/19/2026 at 6:46:28 PM

Right, my question was more meant for how well established that is. And if it is open to influence. My searches made it look like it was not positive that handedness was fixed until a bit later. Still before formal schooling, but not necessarily in babies.

by taeric

5/20/2026 at 2:09:04 AM

Why is there handedness on stringed instruments? If you're right handed, you strum a guitar with your right hand, fret with the left. But both are fine motor skills requiring coordination. Left handed players go out of their way to acommodate doing it the other way around; either finding left-handed instruments (challenge: most things they might like/want are not available in lefty version) or suffer with a flipped right handed instrument (control positions on electrics are wrong, asymmetric cutaways for reach are wrong, nuts are slotted wrong for a mirrored string order).

by kazinator

5/20/2026 at 10:24:11 AM

Strumming/picking requires significantly more (and more frequent) motor control than fretting. Most music will only use a handful of notes/chords, but multiple strumming/picking patterns which need to be performed on precise timings. Your strumming hand is often doing an order of magnitude more precise motions than your fretting hand.

by tso

5/20/2026 at 6:56:16 PM

That provides an explanation only in the following way: beginner guitarists tend to strum more while holding fretted positions. While that goes away for advanced guitar, which requires considerable left hand technique (e.g. legato playing), every guitarist passes through a beginner stage. The beginner stage steers right handed players toward using the right hand for strumming. Only those who find that extremely awkward struggle against it and adjust their instrument so that they strum with the left.

Flat-picked guitar solos (bluegrass, metal, country, ...) keep the left hand as busy as the right, and at times more busy. The left hand can easily outpace the right, which is why there are techniques like triplet 16th notes: playing 24 notes in a 4/4 time measure, while picking as if there were only 16.

Guitar playing is ambidextrous, like piano, at the higher levels of mastery.

But at the beginner stage, like learning to strum chords, that's where right-handedness favors using the right hand for activating the string. That's probably what it is.

It can be learned both ways; e.g. Michael Angelo Batio.

by kazinator

5/20/2026 at 6:20:00 AM

Strength perhaps? I cannot imagine strumming very long with my right hand/arm. I imagine it would get quickly sore. Learning to use a fretboard is hard enough with any hand, might as well use the weakest.

by sph

5/20/2026 at 9:51:44 AM

I think I read somewhere, that your preferred hand is better at staying in rhythm.

by dan00

5/20/2026 at 2:33:56 AM

Fun little nugget, Australian Sulphur Crested Cockatoos almost universally favour their left feet as a holdfast. They're also left eye dominant.

by Mayzie

5/20/2026 at 2:04:15 AM

Here is a funny thing.

I can walk a bicycle perfectly just by holding nothing but the saddle with my right hand. I can pick some spot on the ground ahead, call it, and hit it with the front wheel accurately.

Switch to my left hand and the bike's front wheel starts having a mind of its own.

"No, don't veer that way, Bike; you're not reading my mind, like you do through my right hand!!!"

by kazinator

5/20/2026 at 2:35:45 AM

To drain pasta or noodles quickly, I put it in a colander, hold it above my kitchen sink, and swirl it around in quick circles. I realized about a month ago my circles are always counterclockwise, and very efficient, but that I can't keep a clockwise spin going for more than a few cycles before messing up. Since then I keep trying to spin my pasta clockwise (such are the small excitements and adventures of my wfh life), starting with very slow movements, but I just can't do it. There's something weird about this motor skill specifically that eludes me. I'm left-handed but my right-handed writing is reasonable and I play piano with matched abilities in both hands. Maybe one day, with enough practice, my pasta will go clockwise.

by Kaijo

5/20/2026 at 5:22:49 AM

You're right-handed, right? It is more natural to move your hand in counter-clockwise circles than the opposite. People who have never swirled pasta or anything like that will feel the same if you ask them to make swirling motions with their hands. Inwards is easier - clockwise with your left hand, counterclockwise with your right hand.

by Tor3

5/20/2026 at 7:12:57 AM

A literature search didn't turn much evidence of this at all, let alone conclusive evidence. Any sources? I swirl right hand clockwise. I also draw circles clockwise. One article said circle drawing direction was likely cultural or linked to handwriting systems, not which was more "natural".

by yzydserd

5/20/2026 at 7:08:46 PM

The right hand is associted with clockwise motion. Screws are "righty tighty"; if not they are called to be opposite threaded or left threaded. I suspect most right handed people, if given a string and bobbin, such that they hold the bobbin with their left hand, will use their right hand to wind the string clockwise onto the bobbin.

A four-legged animal's right front paw makes clockwise circular with respect to the sagittal plane of its body, as it walks.

On a recumbent bicycle with hand pedals, the right hand crank goes clockwise. It would be weaker the other way.

For all kinds of motions, it's better when the hand is coming down in the extended-arm position, working with gravity.

Extreme example: if you are hammering something with your right hand, of course, you raise the hammer and extend your arm, let it fall and then retract your arm. That creates a clockwise motion. Counter-clockwise hammering something upward from below is awkward. You also wouldn't want the workpiece close to you so that you are raising the hammer with your extended arm, bringing it it in and dropping it with closed arm. It's bad leverage: raising with the extended arm is harder.

This hammering motion applies when doing something like winding a rope onto a bobbin. You have to raise your right hand and forearm against gravity and that is better when it is closer to your chest. Then drop it down slightly away from your chest. Clockwise winding has compellingly better ergonomics for the right hand.

by kazinator

5/19/2026 at 4:34:28 PM

What does it say for mixed-handed folks like myself (different skillsets per hand - in other words, throw and write with different hands)? What about cross-dominance (different body parts differ on dominant side - in other words, a right-handed person being left-foot dominant)?

I've been told that it's effectively a mental illness if discovered during childhood (as is ambidexterity). Yet I can't help but think that it is not a mental illness, but rather something else.

by NickC25

5/19/2026 at 4:47:41 PM

In order to present it as a mental illness there would have to be some kind of negative effect, wouldn't there? These differences you mention don't stand out as harmful or even disadvantageous.

by tejohnso

5/19/2026 at 10:12:16 PM

southpaws are more common where at least one parent has schizophrenia. i believe it to be caused by an epigenetic change, where damage to the brain in a parent leads to the parent rewiring their brain to use the opposite hemisphere. In short, it's hardly an illness, more of an antibody to one.

by ekaryotic

5/19/2026 at 5:04:09 PM

You were probably a left-handed person who was taught to write/use tools with their right hand in kindergarten. I got this treatment too.

by jvanderbot

5/19/2026 at 5:06:19 PM

I'm otherwise a lefty but I use computer mice right handed, because when I first started using a computer in elementary school all of the computer labs were set up right handed.

by bkjelden

5/19/2026 at 6:02:20 PM

FWIW, I'm a righty, but relearned to use a mouse left handed for ergo benefits at my first real job; now I left mouse for work and right mouse for home. I prefer ambidextrous mice anyway, but it's really hard to find a left hand mouse if you want that. Even the ambidextrous mice often have thumb buttons for the right thumb. It's not to hard to learn to use a pointer with either hand; IMHO as someone who can't do a lot of complex motion with my non-dominant hand. I think there's a lot of convenience gained by accepting right mousing, although it is a longer reach if you have a keyboard with stuff to the right of your letters.

by toast0

5/19/2026 at 9:33:25 PM

Weirdly enough, I don't know why I use the mouse right-handed. I was forced into doing it in any particular way, and beside the fact that I was already an adult when I learned of the existence of left-handed mice, I can't think of any reason why I'd naturally gravitate towards right-handed mouse use.

by Pay08

5/19/2026 at 5:20:46 PM

When was that? I know it used to happen, but I haven't heard of or seen that in my lifetime, I'm nearly 60.

by SoftTalker

5/21/2026 at 2:24:18 PM

It happened to me, and I'm 60. I lived in a rural area, maybe that's why.

by godshatter

5/19/2026 at 5:22:53 PM

Probably because it didn't happen to you, or kindergarteners don't know better and just play along. I only remember it because I was a little shit and got into a big fight about it. It would have been late 80s.

by jvanderbot

5/19/2026 at 5:41:20 PM

An elementary school teacher of mine had this happen to her (this was in the early '90s, so her experience I'm guessing would have been in the late '60s).

One day she wrote her name twice on the whiteboard and asked us to identify the difference between the two; visually they were identical, but she wrote one with her left hand and one with her right. She said as a kid she was made to use her right hand when she started showing signs of left-hand dominance.

by Hotdogsteve

5/19/2026 at 5:39:37 PM

I didn't know what difference it made and there was one left handed scissors so it went to the kid who knew. I'm left eyed and often wonder if I should have learned to write left handed.

by bluGill

5/19/2026 at 9:09:07 PM

wait, you just gave me an extreme epiphany about my significantly worse right eye myopia. the divergence definitely snowballed from the "use it or lose it" thing and me not wearing my glasses as much as possible

by mrsvanwinkle

5/19/2026 at 10:07:28 PM

Every study in scientific examination that concept says that for myopia and such things use it or lose it does not apply. Use it or lose it does apply to some things but not that case.

by bluGill

5/19/2026 at 5:46:24 PM

it happened to me, and when my parents found out they flipped out.

i found out about my parents reaction like everyone else,, suddenly there was a bunch of screaming profanity and acoustic violence coming from the principals office

by rolph

5/19/2026 at 5:57:17 PM

My parents generation is maybe a bit older than you, one of my mom's siblings was forced to right handedness. My mom is left handed and says they tried a little with her, but it only took for some things.

by toast0

5/19/2026 at 7:00:47 PM

I don't know - my grandmother (father's mom) was fully left handed. My dad writes left handed but everything else right handed.

I am left handed for fine motor skills (writing, fork/knife) but throw righty and play single handed sports with my right (except for table tennis which i can do either hand at a good level). I can play two handed sports (hockey, lacrosse, golf) pretty much with either hand with little issue. Right footed, but can kick with my left pretty confidently.

by NickC25

5/19/2026 at 8:56:55 PM

Hey SAME! but pre-K, trained at home by cousin who used to be a lefty as well.

by mrsvanwinkle

5/19/2026 at 5:40:52 PM

I'm sorta here too. I'm right handed, no external pressure to use one hand or the other in early age. Mother is a lefty, father is a righty. As a result I often used the computer mouse on either side as a kid, really wherever it was left by the last user.

Learned to shoot a bow as a kid but only learned as an adult I'm left eye dominant, and to take advantage would require re-learning the bow in my left hand(many many strikes on my arm sent be back to a righty). Shooting guns is a similar situation, but I'm a fairly good shot regardless. It definitely makes using sights weird.

I'm semi-ambidextrous too, with enough focus I can somewhat cleanly write with either hand, and I'm generally good with my hands in fine tasks, with only a minor preference to pick up a tool with my right hand.

I wonder how common this is. People seem surprised when I demonstrate my left handed writing.

by MSFT_Edging

5/19/2026 at 6:05:57 PM

> I've been told that it's effectively a mental illness if discovered during childhood (as is ambidexterity). Yet I can't help but think that it is not a mental illness, but rather something else.

https://en.wikipedia.org/wiki/Handedness#Types: “Mixed-handedness or cross-dominance is the change of hand preference between different tasks. This is about as widespread as left-handedness.”

⇒ about 20% of the population is not strictly right-handed. That’s not a majority, but I think the word to use for that is “normal”.

by Someone

5/19/2026 at 5:22:09 PM

Left-footed and right-handed. I find my "handedness" follows where the activity is driven from (upper/lower body).

Soccer, snowboarding, batting, golfing: lefty

Writing, throwing, tennis, pool: righty

by liquidise

5/19/2026 at 5:50:12 PM

"Left-footed and right-handed"

Same as Mickey Dolenz who drummed for the Monkees. Very unusual combination.

by nephihaha

5/20/2026 at 10:31:29 AM

true, with snowboarding, I still don't know which leg to lead with...

by rimworld

5/20/2026 at 4:53:54 AM

I'm a lefty but do everything else with my right hand. My earliest memory of using lefty scissors was in 5th grade and they were metal and super uncomfortable to use. Meanwhile, the other kids were given modern scissors with the hard plastic molding. I don't remember if I felt discomfort with those but I sure didn't want to use old rusty scissors so I stuck with it.

I kick with my left foot too. I feel more comfortable throwing with my right. If I'm holding a bat, I do so the "normal" way (idk terminology there).

When my son was learning to write I was super excited that it looked like he would be a lefty but a week later he favored his right hand for scribbling.

by NetOpWibby

5/20/2026 at 5:00:31 AM

Exactly the same for me. I am very used to using my right hand so most thing I can do with both hands. When I played baseball (Even though I am Dutch) I could swing with my left and my right. I do catch with left though.

Weird thing is; lefties are rare. I have a very old group of friend that I know since I was 15. We are all lefties and one friend even married a left handed woman so the lefties are in the majority.

by ivolimmen

5/20/2026 at 3:36:48 PM

That's awesome!

I don't know any IRL lefties. Alas.

by NetOpWibby

5/19/2026 at 4:17:31 PM

"Handedness" is two traits, not one. The paper finds bipedalism explains strength (how strongly someone prefers a hand); brain size explains direction (which one). Most coverage conflates them.

Australopithecus was already strongly lateralized — committed handers — long before the rightward consensus emerged. Two traits, evolved separately by millions of years.

by jnakano89

5/20/2026 at 9:41:56 AM

If our hands are intended to have complementary roles, then consistent specialization to one side makes sense, because there isn't a useful continuum - a strong developmental preference would be more reliable.

But since the middle of the continuum, i.e. no-preference, would presumably be the worst situation, it would be developmentally unstable and any tilt to either side would quickly become dominant.

One possible "motive" for a particular left-right lopsided bimodal skill pattern.

by Nevermark

5/19/2026 at 10:31:32 PM

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.

by Magi604

5/19/2026 at 11:53:17 PM

As a lefty I never had any problems adapting to a right hand mouse and actually find the keyboard to be better suited as a "left hand" activity and would have a hard time switching it up.

by ticulatedspline

5/20/2026 at 12:49:25 PM

I'm a lefty, but always mouse on my right (keyboard left). This has made me exceptionally good at using hotkeys, to the point where a friend at a LAN party called me a hot-key whore. He wasn't (and still isn't) wrong. After using any program for a while, I will figure them out, including how many times to press tab to get to a field.

by theandrewbailey

5/20/2026 at 3:01:08 AM

Living with laptops with touchpads for a couple of decades as a righty, I can use a touchpad perfectly fine with either hand, but a mouse is still right handed for me.

by evilduck

5/20/2026 at 12:03:00 AM

[dead]

by threwrfaway

5/19/2026 at 10:35:44 PM

I mouse right-handed because it’s convenient, but I still naturally default to doing any novel task left-handed. It’s not a matter of fine motor skills, you can learn to do anything with either hand if you decide to, it’s just an unconscious preference.

by sobiolite

5/19/2026 at 11:50:21 PM

I have switched between left and right mouse every few years when I was younger, just to see what works best for me. I could adapt to both, even though I can only write and draw with my left hand. I have settled with left-hand mouse because I feel like I can be a bit more precise for graphical works and shooters.

With the trackpad on my Laptop, I switch quite frequently and haven’t yet noticed any difference in precision. The movement is very different than mouse or pen control though and comes more from individual/multiple fingers instead of the whole hand or arm, so I guess that explains it.

by phforms

5/20/2026 at 11:09:09 AM

At one point I used to have two mice plugged in and would use either one depending on which hand was free.

by jcarrano

5/19/2026 at 10:48:31 PM

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

by usef-

5/20/2026 at 2:14:02 AM

Keyboard is also both hands equally used. With handwriting less common, I wonder if people are shifting mostly towards using both hands equally now.

by Gigachad

5/20/2026 at 12:37:52 AM

I used right all the time. Got RSI. Now I use left at work all day, and right at home when gaming.

At work, I don't use a left handed mouse. Just those cheaper but common symmetrical ones. And I don't bother changing handedness. I just pick up the mouse and put it to the left of the keyboard.

shrug It works.

by _carbyau_

5/19/2026 at 6:55:06 PM

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 students.

by Stevvo

5/19/2026 at 8:48:31 PM

Left-to-right writing systems are optimized for right-hand use. Two examples:

* if you're left-handed, your hand smudges over the ink before it dries. There are various contortions that some left-handed people do (hover the hand or wrap it around from above) - right handed ones don't need any of that.

* stroke patterns, as usually learnt in school, result in pushing away if left handed, vs drawing to, if you're right handed. This results in less ideal strokes, and if you're working with a sharp pencil/pen on a sensitive paper, this can tear the paper. If you're working with a felt-tip pen, the line width/pressure suffers as well.

That said, if you really make an effort, you can have a pretty decent handwriting if you're left handed. And if you are forced to use right hand when learning handwriting, you can still have a pretty decent handwriting.

I'm not familiar with details of chinese handwriting (what's easier/better if you're left vs right handed), wouldn't be surprise the constraints are similar.

So I guess your remark about messy handwriting is related to the strict standards for the students (which includes expectation they must write with right hand).

by senko

5/19/2026 at 9:00:50 PM

Right-to-left languages don't make writing much easier. It certainly helps, but at least anecdotally, it's overstated how much more easy (how much easier? English is confusing) it is.

by Pay08

5/19/2026 at 9:48:06 PM

Chinese was traditionally written top-to-bottom, and I can see that making it more a matter of taste which hand you painted with.

Today it's always left-to-right, though.

by thaumasiotes

5/19/2026 at 8:51:49 PM

Due to a broken right-hand, I had to write with my left for 3 months and noticed that our alphabet is made for right-handedness. That's why I agree with your take that writing with the left hand is basically unnatural. But since typing is more important than writing nowadays (or am I in a bubble?), I don't think students should be guided to write with their right hand.

by Tarsul

5/19/2026 at 10:47:56 PM

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)

by ticulatedspline

5/19/2026 at 8:46:01 PM

In many parts of Asia they will 'correct' children who are using their left hands.

by mannyv

5/20/2026 at 5:29:14 AM

As the sister comment said - this was common in the past a lot of places. Maybe everywhere. My left-handed father was forced to learn to write with his right hand.

by Tor3

5/19/2026 at 9:03:02 PM

It was pretty common practice in the rest of the world too until a few decades ago.

by Pay08

5/19/2026 at 10:56:53 PM

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%)

by rcxdude

5/19/2026 at 7:32:50 PM

My father was left handed like me and he got in trouble from teachers.

It's possible that Chinese will one day obtain individuality and freedom and they can write left handed. That would kill the one last advantage the West has.

by TitaRusell

5/20/2026 at 9:10:44 AM

It was the same in communist Poland. You were not allowed to be a lefty -- all the citizens had to be homogenous. My father was born a lefty and forced to write with his right hand in primary school. He ended up learning how to write upside down too, just for fun.

by odiroot

5/19/2026 at 8:22:46 PM

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).

by moralestapia

5/19/2026 at 10:59:27 PM

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).

by rcxdude

5/19/2026 at 9:01:47 PM

What?

by Pay08

5/20/2026 at 1:34:41 AM

My first thought was, "language". The Broca's area is on the left side of the brain, which is the center of control for logic, language and the right hand. It makes sense to me that an evolutionary feedback loop would develop between the hands and complex language development. So it's not odd that the average human brain would develop -somewhat better control over the right hand than the left.

by walterburns

5/19/2026 at 4:36:15 PM

I would be interested in studies into impact of left hemisphere importantce on the right hand usage, possibly the more sophisticated and "logical" usage of our hands pressured it as well.

by hypnodrones

5/19/2026 at 4:43:57 PM

One of many articles out there debunking the pop-psych mythology around brain lateralization: https://themindcompany.com/blog/left-brain-right-brain-myth

by yawpitch

5/19/2026 at 5:55:09 PM

It's true that the creative vs. logical side of the brain is mostly a myth.

But the hemispheres absolutely DO specialize in very predictable ways. Core language faculties are almost always handled by the left hemisphere, for instance.

Face processing is almost universally handled by the right hemisphere.

We know these things from people who have suffered an injury to one of their hemispheres. A person with damage to the right hemisphere has a chance of not being able to recognize faces, but that's almost never seen in an injury that exclusively effects the left-hemisphere.

by rybosworld

5/19/2026 at 9:05:15 PM

For the longest time Iain McGilchrist has been going on about left brain this, right brain that and it all felt very pop-psych stuff.

Not sure if because of that being sort of torn down but recent years he has been clarifying he wasn't talking about a literal left/right device but more an analogy to different modes of thinking.

There is some hemisphere function allocation but it feels far to over played in folks trying to offer easy answers to difficult things.

by HerbManic

5/19/2026 at 4:56:42 PM

Thanks! Although I understand there is still some specialization in each of the hempispheres, which could influence it, but I probably went too strong with my imagination here.

by hypnodrones

5/19/2026 at 5:16:45 PM

Left-handed people are often excluded from participating in MRI studies. To my personal dismay, as these studies often paid 25 euros per hour ~20 years ago, a significant sum for my student self that I could not partake in. It has however given me significant doubts about any strong lateralization claims...

by Phemist

5/20/2026 at 12:29:13 PM

That seems like it'd create a rather large hole in the dataset.

by Pay08

5/20/2026 at 7:42:55 AM

Cetaceans are also strongly handed, sperm whales extremely so. It's possible it has to do with the brain size itself, perhaps it allows to save nutrients for one hemisphere.

by accidentallfact

5/19/2026 at 7:57:15 PM

I am right handed but left handed for some very specific things such as playing pool or hockey

by dagi3d

5/19/2026 at 8:05:27 PM

Same but i feel many sports are weird in that i’ve never been convinced that there’s a particularly natural right or left handedness to them.

Eg. For pool does the more dextrous hand need to push the cue or does it line up and guide the front of the cue? I can see tradeoffs each way and the front hand is certainly not just limp when playing.

Hockey is similar. The top or the bottom hand being the more dextrous probably has tradeoffs but I don’t see either grip as being more or less natural for handedness. I don’t play hockey but play golf and cricket which have similar grips and am similar there to you too.

by AnotherGoodName

5/19/2026 at 8:30:40 PM

Golf and baseball batting have obvious handedness - the muscles that pull your towards your centerline and then across your body and significantly stronger than the ones that push your arm back out away from your body, and the right-handed stance in these two sports uses the stronger muscles in the right arm.

by ThrustVectoring

5/19/2026 at 8:47:13 PM

My dad was a lefty and played golf right-handed. It's a common enough thing.

In golf, strength is overrated until you get to the pros.

by mannyv

5/19/2026 at 8:49:44 PM

phil mickelson, easily the most famous left handed golfer, is right-handed but plays lefty because he would stand across from his dad and mirror his swing as a kid

by daseiner1

5/19/2026 at 8:48:56 PM

fun fact: vs the US, golf stores in Canada carry more left-handed clubs because a right handed hockey player has their right hand higher on the stick which is the same orientation as the grip for left-handed golfers.

by daseiner1

5/19/2026 at 8:19:21 PM

Re: pool, definitely the one pushing needs to be the dominant hand.

It has the most degrees of freedom, and more motion. The one in front has a whole table for stability.

But that's just like my opinion, man.

by daveguy

5/19/2026 at 9:44:22 PM

Same which makes me very poor at sports. I write right-handed. For anything sports related (riding a board, throwing a ball, golf, batting, bowling, etc) I'm leftie. My dad is left-handed, mother is right-handed. I have wondered if I should've been a left-handed writer and was corrected either explicitly or just by the environment to write right-handed.

by js2

5/19/2026 at 8:05:58 PM

Same! I am specifically left handed for pool and cannot figure out how to play it right handed - absolutely zero coordination.

by ar_lan

5/20/2026 at 12:55:33 AM

Interestingly, playing left-handed in "field" hockey is actually illegal for safety reasons and left-handed sticks don't exist.

by dwd

5/19/2026 at 8:20:52 PM

It happens. I can play hockey with either hand as dominant. Too bad that wasn't really a useful talent like being a switch hitter in baseball. I'm generally left handed, but play musical instruments almost exclusively right handed. I had a friend teach me drums. He was right handed and didn't even think to ask me about my handedness, or didn't want to move stuff around (lefties have to adapt to a right handed world...). It didn't feel awkward though. I don't know why I play guitar right handed. The prevailing theory in my family is that I "learned" by mirroring Kurt Cobain on the TV screen...

by dfxm12

5/19/2026 at 10:31:31 PM

I wish they'd look into footedness as well and if there is some kind of correlation. Like orthodox vs southpaw in combat sports, goofy vs regular in skateboard, or just simply left vs right in football (soccer)

by haunter

5/20/2026 at 6:35:26 AM

I read article and still - there is no answer why it is mostly right hand. It explain why hand specialisation took place but why right is dominant, not left ?

by sp0ck

5/20/2026 at 12:53:16 AM

>Humans sat conspicuously outside the pattern that explained every other primate, but ... once you account for upright walking and a large brain, humans stop looking like an evolutionary anomaly.

>Using the same models, the team was also able to estimate likely handedness in extinct human ancestors. The picture that emerges is a gradient [from less handedness to more as time goes on]

"we explored the data until we found a statistical anomaly and it implies X" may be interesting[1], but there are TONS of those that are NOT true. is there supporting evidence for this, or is it just "hey this math says maybe"? it sounds more like the latter (as it quite literally seems like they're claiming roughly "big arm + big brain = big handedness", both in this site and in the paper itself), in which case they might also be interested in this study that pirates keep the global temperature down: https://www.forbes.com/sites/erikaandersen/2012/03/23/true-f...

1: from skimming the methodology in the paper, I honestly think this may be a fair characterization. it sounds like they combined data columns until one combo came up as P>0.95 and didn't have counter-evidence and said "that means it's probably true". but also some (all?) of that data may have been generated by models they created based on real ape data (I think?), which just sounds even more sus.

by Groxx

5/19/2026 at 6:41:47 PM

It is a very bad choice of words to say that "bipedalism" is a cause for hand specialization.

For hands, it is completely irrelevant how many legs a human has, regardless if a human had used 2, 4, 8, 14 or any other number of legs for walking, the hands would have become specialized.

The reason why the hands acquired specialized roles was that they were no longer used for locomotion, i.e. for brachiation in the trees, like in orangutans or gibbons, but their purpose became holding, controlling and moving various objects from the environment.

It is wrong to say that bipedalism has freed the hands to be used for other activities than locomotion, because the causality was reverse, locomotion became restricted to the hind legs, because the hands were used for other activities, like throwing sticks and stones, so they were no longer available for locomotion.

The strong specialization of the 2 hands has appeared because in most cases when something is transformed with the hands, e.g. bones are broken to get the marrow or stones are knapped to get a cutting edge, one hand must be used to fix in place the object that is processed, while the other hand must move against it, normally with some tool.

For the former role, the left hand became specialized, while for the latter role, the right hand became specialized.

Similar specialization is also seen at other animals where a pair of legs is no longer used for locomotion, but it is used for manipulation, for instance at crabs and lobsters.

So there is no doubt that the specialization of the hands was a necessity when they stopped being used for locomotion. However, it is not known why the right hand became the moving hand and the left hand became the holding hand, and not vice-versa. It could have been a random event or it could have been related to the asymmetry in the locations of the unpaired internal organs, like heart, liver, stomach and so on.

by adrian_b

5/19/2026 at 4:06:10 PM

Didn't I understood the text or is the 'why' not really part of it? I expected more than a vague 'because it slightly existed and then hands are free to do things and brains got bigger'. I miss the point.

by krater23

5/19/2026 at 4:10:09 PM

Actual study here: https://journals.plos.org/plosbiology/article?id=10.1371/jou...

My take is that when they added extra factors to the Bayesian model, the plot was such that humans were no longer outliers.

Whether or not that's scientifically rigorous, or even interesting, I leave to others to determine.

by stackghost

5/19/2026 at 7:02:33 PM

They don't discuss a "why", so much as present data on the "how" and "when". If this work is valid and reliable, then it will be up to later research to propose and test hypotheses as the why.

In a nutshell, the paper basically says that the lateralization that led to the predominance of right-handedness occurred around the time humans became bipedal and around the time of neuroanatomical expansion, possibly related to bipedalism.

In other words, before these two changes, we used all four limbs for locomotion and had no preference for either forelimb for grasping. Then one or two things happened and right-handedness predominated. It seems that that neuroanatomical expansion took over the areas of the brain that previously allowed our left hands to be as capable as our right hands.

I write "one or two things happened" because it wasn't clear to me from the paper whether the neuroanatomical expansion that led to lateralization was necessary to and part of bipedalism, i.e., caused by our locomotion bits taking over other parts of the brain to manage our balance, or whether it was merely coincident with it.

Interesting questions asked and answered, more research needed.

by PeterWhittaker

5/20/2026 at 1:17:37 PM

I don't think being left handed is purely genetic, if at all. Seems like a physical anomaly during gestation.

Twins are slightly more likely to be left handed, might be something to do with crowding in the womb where a specific hand is free more than the other.

by theultdev

5/20/2026 at 6:19:49 AM

Babies sleep better when their head is near their mother's heart. This seems to be the obvious reason for the left-handed cradling bias [1].

If a baby sleeps better, it cries less. If it cries less, it attracts fewer predators and helps both parents sleep better at night and have more energy. It also allows the mother to do things with her dominant hand if she is right-handed.

Given the left-handed cradling bias exists even with left-handers, it means there is something specific with left-handedness and infant rearing. A baby in the left hand and a tool (or weapon) in the right is biologically efficient.

Most studies take this from the perspective of evolutionary advantage of the individual. They should take it from the perspective of evolutionary advantage of the family, without which the baby does not survive.

If the bias confers evolutionary advantages, that is also important for the longer childhood humans have compared to primates, which supports our larger brains. Any differential here would have a feedback effect.

Wouldn't it be interesting if a key reason humans are the way we are is a mother's love ♥?

[1] https://sites.psu.edu/clarep/2024/04/12/the-left-cradling-bi...

by abernard1

5/20/2026 at 6:34:57 AM

[dead]

by hufdr

5/19/2026 at 4:34:24 PM

[flagged]

by foofyter

5/19/2026 at 3:57:54 PM

[flagged]

by raggi

5/19/2026 at 4:00:45 PM

'Everyone' is treated as singular (aside from 'everyone are' sounding completely wrong).

by Freak_NL

5/19/2026 at 5:02:45 PM

Drop the "every" part and you can see the word that needs to be agreed with.

    "One is supposed to do such and such."
    "Everyone is supposed to do such and such."
    "They are supposed to do such and such."
    "People are supposed to do such and such."

This also applies with "some"

    "Someone is supposed to do such and such."

https://en.wikipedia.org/wiki/Quantifier_(linguistics)

Part of the confusion may be that "everyone" is a single word while the example sentence in the Wikipedia article has a non-compound example.

    "Every glass is ..."

The quantifier does not change the grammatical number of the subject.

by shagie

5/19/2026 at 4:46:43 PM

I think that's the case for all the "every <noun>". "Every human is a person", for example. This would make sense, to put it in programming terms - the verb applies to an element in an array of people, not the array itself (which would be plural): for every single human, that human is a person.

by 3form

5/19/2026 at 4:03:44 PM

Confidently incorrect.

by cwnyth

5/19/2026 at 4:03:33 PM

No, grammatically "everyone" is an indefinite pronoun. a single collective unit.

by darenr

5/19/2026 at 4:06:37 PM

Is that a British thing? Nobody in North America uses "everyone are"

by stackghost

5/19/2026 at 4:40:00 PM

https://www.britannica.com/dictionary/eb/qa/Everybody-Has-or...

> The words everybody and everyone are pronouns that describe a group of people, but grammatically they are singular. The last part of each word is a singular noun: body and one.

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

> Though published in the United States since 1901, the Britannica has for the most part maintained British English spelling.

by shagie

5/19/2026 at 4:08:31 PM

It's not.

by exe34

5/19/2026 at 9:22:53 PM

The ‘study’ is fluff.

Paraphrase: Amongst primates there is a correlation between brain size and bipedalism with handedness… (unless you exclude humans, in which case there isn’t.)

That’s like saying: “Alongst animals there is a correlation between height and neck length… unless you exclude giraffes, in which case there isn’t.”

If a correlation disappears when you remove one datapoint, then the correlation was not really a broad pattern across the dataset. It was mostly a story about that one datapoint.

I mean, I get it… you gotta publish something. But, geesh… this is beyond stupid.

by lurquer