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Why is almost everyone right-handed? A new study connects it to bipedalism
- raggi 6mo ago[flagged]
- Freak_NL 6mo ago'Everyone' is treated as singular (aside from 'everyone are' sounding completely wrong).
- 3form 6mo agoI 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.
- shagie 6mo agoDrop 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) 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.
- darenr 6mo agoNo, grammatically "everyone" is an indefinite pronoun. a single collective unit.
- cwnyth 6mo agoConfidently incorrect.
- stackghost 6mo agoIs that a British thing? Nobody in North America uses "everyone are"
- exe34 6mo agoIt's not.
- shagie 6mo agohttps://www.britannica.com/dictionary/eb/qa/Everybody-Has-or-Everybody-Have- 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 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.
- deleted 6mo ago[deleted]
- krater23 6mo agoDidn'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.
- stackghost 6mo agoActual study here: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003771 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.
- PeterWhittaker 6mo agoThey 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.
- Freak_NL 6mo agoSo 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.
- scythe 6mo agoHere'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.
- gpm 6mo agoIf 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?
- Tor3 6mo agoBut it is a thing. That's how it was always explained in school, among other places, when I was a kid.
- yawpitch 6mo agoHere’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.
- stackghost 6mo ago>Here’s my multiple years of anatomy classes response: the heart isn’t on the left. Why is the left lung smaller, then?
- jnakano89 6mo ago"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.
- foofyter 6mo ago[flagged]
- NickC25 6mo agoWhat 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.
- tejohnso 6mo agoIn 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.
- ekaryotic 6mo agosouthpaws 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.
- jvanderbot 6mo agoYou were probably a left-handed person who was taught to write/use tools with their right hand in kindergarten. I got this treatment too.
- bkjelden 6mo agoI'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.
- toast0 6mo agoFWIW, 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.
- hypnodrones 6mo agoI 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.
- yawpitch 6mo agoOne of many articles out there debunking the pop-psych mythology around brain lateralization: https://themindcompany.com/blog/left-brain-right-brain-myth https://themindcompany.com/blog/left-brain-right-brain-myth
- hypnodrones 6mo agoThanks! 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.
- Phemist 6mo agoLeft-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...
- Pay08 6mo agoThat seems like it'd create a rather large hole in the dataset.
- rybosworld 6mo agoIt'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.
- deleted 6mo ago[deleted]
- taeric 6mo agoI 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.
- Technolithic 6mo agoThe introduction of this article makes reference to a couple of papers (e.g. https://doi.org/10.1038/s41598-017-16827-y https://doi.org/10.1038/s41598-017-16827-y ) that handedness is observable in utero but cautions small sample sizes for these studies.
- taeric 6mo agoRight, 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.
- markb139 6mo agoI’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.
- taeric 6mo agoRight, 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.
- adrian_b 6mo agoIt 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.
- Stevvo 6mo agoI 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.
- TitaRusell 6mo agoMy 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.
- moralestapia 6mo agoIn 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).
- mannyv 6mo agoIn many parts of Asia they will 'correct' children who are using their left hands.
- Pay08 6mo ago
- dagi3d 6mo agoI am right handed but left handed for some very specific things such as playing pool or hockey
- AnotherGoodName 6mo agoSame 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.
- deleted 6mo ago[deleted]
- daveguy 6mo agoRe: 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.
- ThrustVectoring 6mo agoGolf 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.
- mannyv 6mo agoMy 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.
- skyberrys 6mo agoThe 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.
- jgord 6mo agowithout reading .. my immediate guess is that one hand is needed for maintaining upright balance, while the other hand grasps something important ?
- dwd 6mo agoAs 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.
- skyberrys 6mo agoThis 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.
- js2 6mo agoThe 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.
- lurquer 6mo agoThe ‘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.
- colkassad 6mo agoI 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.
- ivanjermakov 6mo agoI think skate stance is much more evenly distributed (closer to 50/50) than handedness (about 10% left).
- emil-lp 6mo agoCitation needed
- mmastrac 6mo ago"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-stance/ 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-goofy.html https://azeemba.com/posts/skateboarding-how-many-people-ride...
- hydrogen7800 6mo agoMe 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.
- haunter 6mo agoI 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)
- Magi604 6mo agoI 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.
- sobiolite 6mo agoI 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.
- usef- 6mo agoWith modern controllers the main joystick/thumbstick is on the left side. People are using both hands for fine control in different circumstances.
- Gigachad 6mo agoKeyboard is also both hands equally used. With handwriting less common, I wonder if people are shifting mostly towards using both hands equally now.
- phforms 6mo agoI 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.
- ticulatedspline 6mo agoAs 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.
- Groxx 6mo ago>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-fact-the-lack-of-pirates-is-causing-global-warming/ 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.
- Vachyas 6mo agoAn 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.
- dhosek 6mo agoFor 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.
- xenadu02 6mo agoI 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.
- walterburns 6mo agoMy 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.
- kazinator 6mo agoHere 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!!!"
- Kaijo 6mo agoTo 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.
- Tor3 6mo agoYou'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.
- yzydserd 6mo agoA 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".
- 6mo ago
- kazinator 6mo agoWhy 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).
- sph 6mo agoStrength 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.
- dan00 6mo agoI think I read somewhere, that your preferred hand is better at staying in rhythm.
- tso 6mo agoStrumming/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.
- kazinator 6mo agoThat 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.
- Mayzie 6mo agoFun little nugget, Australian Sulphur Crested Cockatoos almost universally favour their left feet as a holdfast. They're also left eye dominant.
- NetOpWibby 6mo agoI'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.
- ivolimmen 6mo agoExactly 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.
- NetOpWibby 6mo agoThat's awesome! I don't know any IRL lefties. Alas.
- abernard1 6mo agoBabies 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-bias/ https://sites.psu.edu/clarep/2024/04/12/the-left-cradling-bi...
- hufdr 6mo ago[dead]
- sp0ck 6mo agoI 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 ?
- acetofenone 6mo agoAs 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-kangaroos-evolution-animals-science https://www.nationalgeographic.com/animals/article/150618-ka...
- prox 6mo agoAh 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.
- inejge 6mo ago> 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.
- accidentallfact 6mo agoCetaceans 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.
- Nevermark 6mo agoIf 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.
- monooso 6mo agoNot 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.
- theultdev 6mo agoI 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.