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.
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.
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.
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.
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.
The article didn't really help me understand what it was about bipedalism that resulted in a right handed preference. Also in my family left hand dominates, we are a cluster of left handed people. My theory is if any child wants help with fine motor control the help is provided by a left hand to a left hand.
The original paper is titled "Bipedalism and brain expansion explain human handedness". It doesn't seek to explain why we have a right-handed preference specifically (vs left-handed), but rather why humans have such a strong handedness preference compared to ancestors who had only a mild right-handed preference.
IOW, why handed vs ambidextrous, not so much why left-handed vs right-handed.
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?
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.
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.
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)
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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...
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.
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.
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.
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.
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.
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).
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.
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.
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.
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).
"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.
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.
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.
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.
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.
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.
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.
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.
> 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”.
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.
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.
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."
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.
> 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.
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.
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.
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.
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.
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.
[delayed]
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.
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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.
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.
I think skate stance is much more evenly distributed (closer to 50/50) than handedness (about 10% left).
Citation needed
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What does "face left" mean? Left foot front? That's regular.
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.
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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.
Oddly enough, a lot of my "nerd friends" are left handed, and I'm also left handed. /shrug
The original paper is titled "Bipedalism and brain expansion explain human handedness". It doesn't seek to explain why we have a right-handed preference specifically (vs left-handed), but rather why humans have such a strong handedness preference compared to ancestors who had only a mild right-handed preference.
IOW, why handed vs ambidextrous, not so much why left-handed vs right-handed.
> why handed vs ambidextrous
Did it even explain that? I'm ambidextrous, I have no handedness bias, so whichever I pick up to first learn something is the hand I use. So I'm a mix of left-handed and right-handed depending on the task. And yet I didn't really understand why that's odd because of my bipedalism?
without reading .. my immediate guess is that one hand is needed for maintaining upright balance, while the other hand grasps something important ?
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.
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.
With modern controllers the main joystick/thumbstick is on the left side. People are using both hands for fine control in different circumstances.
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)
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.
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.
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.
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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
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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?
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.
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> 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.
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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.
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I remember reading that there is evidence that Neanderthals tended to be left handed. Someone else might be able to confirm/debunk this.
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.
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.
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.
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.
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.
I am right handed but left handed for some very specific things such as playing pool or hockey
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.
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.
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.
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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.
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.
Same! I am specifically left handed for pool and cannot figure out how to play it right handed - absolutely zero coordination.
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...
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.
One of many articles out there debunking the pop-psych mythology around brain lateralization: https://themindcompany.com/blog/left-brain-right-brain-myth
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.
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.
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.
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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.
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).
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.
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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.
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)
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%)
In many parts of Asia they will 'correct' children who are using their left hands.
It was pretty common practice in the rest of the world too until a few decades ago.
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.
In my own personal and subjective experience, the correlation between left handed people I know and "edginess"-level is almost 1.
I am inclined to believe this is a learned trait rather than an innate one (excluding the obvious reasons why one would be left-handed only).
I would suspect the causation (if such a correlation does exist) goes in the other direction (or more likely, has a common cause), given how early handedness tends to appear (and how it can be quite resistant to pressure to conform).
What?
"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.
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.
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.
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.
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.
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.
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.
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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.
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Hey SAME! but pre-K, trained at home by cousin who used to be a lefty as well.
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.
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.
> 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”.
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
"Left-footed and right-handed"
Same as Mickey Dolenz who drummed for the Monkees. Very unusual combination.
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.
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.
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.
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'Everyone' is treated as singular (aside from 'everyone are' sounding completely wrong).
Drop the "every" part and you can see the word that needs to be agreed with.
This also applies with "some"
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.
The quantifier does not change the grammatical number of the subject.
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.
Confidently incorrect.
No, grammatically "everyone" is an indefinite pronoun. a single collective unit.
Is that a British thing? Nobody in North America uses "everyone are"
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.
It's not.
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.