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The Science of Handedness
Hugh Pickens writes "Representing only 10 percent of the general human population, scientists have long wondered why left-handed people are a rarity. Now a new study suggests lefties are rare because of the balance between cooperation and competition in human evolution and a mathematical model was developed that predicts the percentage of left-handers by sport based on each sport's degree of cooperation versus competition. 'The more social the animal—where cooperation is highly valued—the more the general population will trend toward one side,' says study author Daniel M. Abrams. 'The most important factor for an efficient society is a high degree of cooperation. In humans, this has resulted in a right-handed majority.' If societies were entirely cooperative everyone would be same-handed, but if competition were more important, one could expect the population to be 50-50 because cooperation favors same-handedness—for sharing the same tools, for example while physical competition favors the unusual. In a fight, for example, a left-hander would have the advantage in a right-handed world. The mathematical model accurately predicted the number of elite left-handed athletes in baseball, boxing, hockey, fencing, and table tennis (PDF)—more than 50 percent among top baseball players and well above 10 percent (the general population rate) for the other sports. For other sports like football or hockey where team cooperation is paramount, it is ideal for all individuals to possess the same handedness. For example, in football, blocking schemes are often designed to protect a quarterback's blind side. As a result, it is beneficial for all quarterbacks on the roster to possess the same handedness to minimize variations of the offensive sets. 'The accuracy of our model's predictions when applied to sports data supports the idea that we are seeing the same effect in human society.'"
Why isn't everyone left-handed? That too would be beneficial in a cooperative society (shared tools). Maybe millions of years ago, the left-handed tribes died out. (Maybe they called themselves Neandertals.)
My AC stalker: " I personally agree with your posts most of the time, but that won't keep me from modding you troll"
are like the wolves amongst you right-handed sheep, right!!!!???
I'm not ENTIRELY convinced, what about situations where it is advantageous for people to have opposite handedness for optimal cooperation? There seems to be a built-in assumption here that different-handed assortments of people will always have more problems working together. I'm not sure there's a practical way to test this as a general thing though.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
If this were true then golf would have a lot more left handers, but it doesn't.
Rt handed people who are Left eye dominant are usually more clumsy and less adept at sport than Left eyed Left handed people.
I got to the chocolate box before you, that's why the hard ones have teeth marks.
Stop posting these psychobabble.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
Lefties are combative assholes
cooperation favors same-handedness—for sharing the same tools, for example
I'm struggling here to think of a primitive tool with handed-ness built into it. Anyone?
for example while physical competition favors the unusual. In a fight, for example, a left-hander would have the advantage in a right-handed world.
Doesn't know much about ancient warfare. Good luck running a phalanx or pretty much any massed swords -n- shields combat with some people randomly swapping sword and shield hands. Half your shield protects your buddy to the left, kinda like half of the shield of your buddy to the right partially protects you...
Of course if you're not one of those religious extremist types, the majority of human evolution happened long before ancient warfare kicked in; however, acting as a filter, most lefties would have died out due to the effects of ancient warfare.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Can a right-handed male and female produce a left-handed child?
Can a left-handed male and female produce a right-handed child?
Is there a percentage?
Right + right = right 90% of the time?
Left + left = left 90% of the time?
Or is it that any combination will result in a right-handed child 90% of the time?
I just couldn't get past the error on page1, paragraph 4.
In a perfect world we would all be ambidextrous -- being able to use BOTH hands would make things much simpler.
Just a few years ago, a Canadian study using baseball stats (because they tracked handiness closely) concluded that lefties were far more likely to die, ( http://www.nejm.org/doi/full/10.1056/NEJM199110033251412) this was later shown to have suffered a seemingly paradoxical sampling error (not controlling adequately for those that didn't die). Then there was another study that concluded that left-handedness was likely the result of anoxia in the womb ( http://www.sciencedirect.com/science/article/pii/002839327390050X). It was discounted for similar sampling error problems. Neurological "wiring error"; perhaps a mutation with few consequences; advantages in the mathematical world (presumably via having a screwy mindset); Language disadvantages; Language *advantages*; high proportion of left-handed (possibly suppressed) American presidents http://www.anythingleft-handed.co.uk/presidents.html (Clinton, Bush, Obama ... ). So... run a elaborate predator/prey model applied to sports and see an advantage for the 10% that are different; sounds like rediscovery of Perato distribution to me, http://en.wikipedia.org/wiki/Pareto_distribution I'm just not convinced that there's been a proper scientific approach to this issue to date, and until then i'm still stuck with a twisted spine in most college classrooms.
Read Robert Ornstein - The Right Mind.
Also, they need to realize that sports are spacial, and hemispheres tend to have distinct roles in visual and spatial capacities. Pattern recognition plays a role as well.
From TFA: "On the other hand, the number of successful left-handed PGA golfers is very low, only 4 percent. The model also accurately predicted this."
Eh? Golf is a sport where there is no cooperation and where being differently handed should have no benefit in competition with others. One would think that golfers would have the same number of lefties as the general population.
Methinks that cooperation/competition explains part of the situation, it doesn't explain everything.
You can pick who is on your football team, but you can't pick who is in your society. And cooperation stems from empathy, not handedness.
A hockey team needs a good mix of left- and right-handed players. Summary is complete horse-hockey.
TFA even pretty much clearly spells it out in table S1.
Handedness is most likely related to which neural network gain fine grained control solutions first. The "preference" we experience may just be the recognition of this better control.
This is so much crap on so many levels, I can't even begin to enumerate. Half of these blogs shouldn't even be allowed to exist.
So tell me, when you were "in utero" which sports were you most interested in?
and how does this explain the fact that the only thing I do left handed is write with pen/pencil. i'm fairly ambidextrous in a variety of sports but i'm right hand dominant, except for handwriting.
"Representing only 10 percent of the general human population, scientists have long wondered why left-handed people are a rarity." 10% of the population are scientists?
FTA:
Representing only 10 percent of the general human population, scientists have long wondered why left-handed people are a rarity.
Wow, I never knew that scientists made up ten percent of the population. Yay us.
Parity: What to do when the weekend comes.
It isn't a big deal. Most everyday items don't favor one hand or the other. Spears, knives, and even swords pretty much fall into this category, as do quite a lot of other tools. Scissors and similar cutters are sort of an exception. So chances are this wasn't a really large problem. In a pinch you can just use things right-handed (and most lefties are less hand-polarized than righties, maybe do to the convenience of being able to use either hand, for instance I'm perfectly happy doing many tasks with either hand like cutting with scissors).
As for greater cooperation if you have two warriors and one is left handed he can guard the more exposed right flank of his partner and vice-versa. Alexander the Great had a whole cadre of left handed warriors who would take up the far right hand flank of his army (and I'd suspect this was probably fairly standard for ancient armies). The question then is really is there a strong enough difference in cooperation vs competition advantage from different-handedness for it to matter. This study doesn't seem to have addressed that question. At best it can be used like a prior to say "well, maybe it is that way since we DO have 10% lefties." I'm always a little suspicious of that sort of "Bayesian" kind of interpretation since it also leads to such absurdities as the notion that this generation will be the last one in history (do some reading on Bayesian Analysis, lol).
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
If a child learned to type before they learned to write, would they ever consider which "handed" they are?
I'm left handed, but aside from handling pens (which these days don't do on a daily basis) I do pretty much everything with both hands equally. When I was a kid alot of todo was made of getting me a left handed baseball glove, left handed scissors, and even a left handed violin. None of those things were very useful. I can catch, cut, play, even shoot with both hands, more or less evenly. (I actually favor my right hand when shooting.)
Most left handed people I know say the same thing. I'm just guessing, but I'd imagine that a lot of right-handed people are more ambidextrous then they know, but unlike lefties they've never had to think about it.
With writing, handedness makes a huge difference. It's not a simple matter of inversion, forming a letter left-handed is completely different. There is a great deal of "muscle memory" that comes into play. But imagine a generation that grows up typing instead of writing. Would they ever know which handed they are?
Cool art gallery, if you're into that sort of thing.
. . . but before there were organized sports, people had to deal with certain personal matters. They also had to physically interact. As one once said, "I don't eat where I shit." Of course, you might argue that, "One hand washes the other." That is true, but every shithole did not come with Purel, a bidet, or even water. There are other practical reasons for using one hand for one thing and the other for something else.
Frankly, I doubt if being left-handed or right-handed is genetic. Perhaps it is hereditary in the sense that you learn from birth based on how others use their hands, and it would be easy to use such behavior to perpetuate a trend. For example, everyone born in a Mandarin-speaking village begins to speak Mandarin without any formal training. Or most people use their hands to eat instead of their feet, which anyone born without hands can tell you is quite doable.
As others have pointed out, society can use commonalities to its advantage, which would re-enforce such trends.
BTW, I typed this with both hands.
The idea that it's beneficial for every player on a hockey team to be same-handed shows quite an ignorance of the game. There is a left-wing position and a right-wing, and being able to either protect the puck from a defender, and/or have the best possible angle to shoot on net, depends very much on whether the player shoots left or right. This is further complicated by players who choose to shoot left despite being right-handed (see this blog post here, I couldn't find a better source)
The results of the study are interesting, and make somewhat intuitive sense, but they should be careful not to generalize to too great a degree.
I haven't RTFA (obviously), but it sounds like those fellas hammered a model onto a data set and attached a nice simplistic explanation on top of it.
The reason many lefties excel in some sports is due to the element of surprise their left-handedness gives them. Finding a simple formula to determine lefties percentage depending on some arbitrary criteria of cooperation/competition, which is an enormously complex subject in itself, sounds like complete nonsense.
For this to have any relevance he'd have to show that handedness was somehow genetic (right-handed parents had right-handed children) or determined soon after birth and influenced by the parents (right-handed parents taught their children to be right-handed unconsciously).
Then those right-handed parents were more successful in the cooperative culture than the left-handed people.
Leading to more right-handed children than left-handed children.
But taking the already existing difference of left / right handedness and then using that to determine their "success" in a synthetic system such as sports ... that's just stupid!
There are no right-handed footballs. Either US or European.
I browsed through the PDF
{blockquote}
In Table S1, the predictions for the fraction left-handed were generated using an estimate of the ideal equilibrium l
for each sport. The appropriate value for l depends primarily on the degree of cooperation c for the sport. This
parameter is dicult to estimate in sports that possess clear cooperative and competitive elements. However, in order
to observe xed points other than l = 1/2, c must exceed a threshold that appears to be relatively high for the
types of transition rates considered in this paper (See gure 1). So, we assumed that l = 1/2 for sports primarily
involving direct confrontations: baseball (batters vs. pitchers), boxing, fencing, table tennis, hockey (defensemen and
forwards)
{blockquote}
I was skeptical when I read "cooperation", then I saw that they used fairly approximate numbers, and the quality of results was not bad
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
I think you mean handegg.
As someone who knows a little bit of mathematical modeling and statistics, I have to point out that they did not predict the percentages, since they already were known! The correct term would be retrodict.
Can this article explain why there are so many left-handed people at my company, especially in IT? I've been in meetings of 8-10 people and noticed that _everyone_ in the room is left-handed (~1000-person company). It seems statistically unlikely.
The model in the paper specifically allows for two possible equilibria: one in which right-handed people dominate, and one in which left-handed people do. We just happen to be in the right-handed equilibrium (by chance).
Perhaps you are confusing evolutionary modelling (a mathematical technique which describes very general processes of information transfer) with theorising about human origins (an empirical investigation which sometimes uses evolutionary models, along with other sorts of models and lots of physical evidence).
This paper is an example of the former, not the latter. It argues that, because there is a process of 'selection' involved in athletic try-outs, it may be possible to apply some evolutionary models to explain the outcomes of that process. It then shows that the data are indeed consistent with the predictions of that model.
It has absolutely nothing to do with cave men, or Neanderthals. Neither does the vast majority of the field of mathematics which we call evolutionary theory.
The article specifically cites evidence for an important genetic component of handedness, and the model is constructed around that evidence. The authors didn't have to 'show' this, as it has already been shown.
I should have been a lefty, but back in 1st grade, my teacher decided that the entire class would only write with their right hands.
Seems barbaric now, but at the time I sure didn't know any better. This was back in the late 60's though, in a different time.
So, I'm a mix-handed person now. Write & throw balls right handed, shoot, frisbee, archery with the left.
For what it's worth.
Don't believe me. Try this.
First try brushing your teeth every day using your off hand. Do the same with eating and simple things like going to the bathroom or shaving. After a month, practice throwing a ball with your off hand. Start writing after a couple of months start writing with your off hand. After six months you'll be for all practical purposes ambidextrous and able to pick up new tasks very quickly.
Left handed people were persecuted, and rightly so, since their freakish abnormality is an abomination against nature.
Tolerance of their kind can only bring misfortune.
During a brief stint in the US Army I decide that it would be "interesting" if I shot left handed. Well, I did and nobody cared.
My parents are both right handed, and I am left handed.. I cannot reference anyone else I know that has right handed parents and they turned out left handed..
When I was a cook, the kitchen managers mother forced her son to do everything left handed, when he was born right handed. He told me his mother wanted a left handed kid for some odd reason. This guy was not right himself, but I always get stoned and then ask him randomly about his childhood just to hear how crazy his mother really was. It always got a good laugh..
The percentages have to be lower then 10% for right-right to have a left handed child and left-left for a right handed child.
where are you living. What's a quaterback?
oh, american? LOL
Thanks for marking as troll :-)
Atari rules... ermm... ruled.
I'm a left-handed person that spent nearly a year in a cast when I was 7 years old with my left arm which forced me to do some things right-handed. I therefore learned a few things right-handed but I generally always go back to doing them left-handed naturally. I *can* do them right-handed, for example, cutting with scissors. However I default to left-handed mode.
I have a reasonably developed right-hand/arm because of that incident. I can do things with my right arm, I'm very competent with a computer mouse on my right arm, etc. However when it comes to things like typing or writing I'm purely left-handed.
For a long time I tried to teach myself the DVORAK layout for typing. A friend of mine got into it and he said it was great, and all of the 'studies' showed it was awesome. Unfortunately it also has a SEVERE right-handed bias while qwerty has either a left or mixed bias in general. Which means that most of the typing in dvorak is concentrated to the right-hand. I saw some pictures/images on this a while back that explained everything. The images explained why I had such difficulty getting up to speed on the layout which was directly due to my left-handedness. I can type > 120 wpm in qwerty most of the time, use my right-hand as my mousing arm, yet I still had problems here.
Some natural things you can't just overcome easily.
Please mod parent Informative.
I call this BS as my children, all four of them, developed their handedness by age 1 to 1-1/2. This was long before any "cooperation and competition" became significant for them.
How do you define right-handed
This is flat out wrong - you only need to watch hockey for a few minutes to realize that at least 4 of the ten skaters on the ice at any time should be lefty.
While centers and goaltenders can go either way, the left wing and left defense positions are almost always manned by players who are at least left-handed when they are playing that sport.
Left-handed batters have a substantial advantage in baseball: they're two steps closer to first base. This is particularly critical in bunting, where the difference between safe and out is frequently less than half a step.
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If science is what this article is about, I am inclined to evaluate the percentage of scientists in the population to a still much higher value ;-)
Same for writers as it seems...
Isn't it?
Whoever decided that it would benefit hockey to have everyone the same handedness is a flipping buffoon. There's a huge advantage to having people that shoot left/right on different parts of the ice depending on the play.
That being said, hockey is one sport where there are tons of people that usually write right-handed, bat right-handed, golf right-handed, but shoot a puck left handed.
I'm sick of reading this sort of thoughtlessness describing evolutionary biases. If you're going to say that an adaptation gives a reproductive or predatory advantage, then fine, you're talking Darwinian evolution -- survival of the fittest. If you're going to say, "Everybody in chummy societies had the same handedness so they could share tools", then please tell me how the heck that weak-sauce tiny (or effectively zero-magnitude) biological fitness bias is supposed to have produced a genotypic change to an entire species within the known anthropological lifetime of the species. Remember that Darwinism requires that for *your* random trait variation to survive and thrive, at a minimum you have to pass your genes on while somebody else does not.