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Chimpanzees Shed New Light on Hand Preference
An anonymous reader writes "'Language skills are associated with the left side of the brain, and many scientists have said early humans developed a preference for their right hands when they acquired speech,' but Emory University's Yerkes National Primate Research Center has a new study that links hand preference to the motor skills area of the brain rather than the language part of the brain. 'That means lefties have probably been around much longer than believed -- at least 5 million years, when scientists say humans and apes branched on the primate family tree. And evolution has purposely kept them.'"
Obviously there is no disadvantage for being left handed, why should there be a selection against it?
if lefties has a better channce of using the brain's motor neurons, then why did evolution choose to have 2/3 righties in the chimp population. doesn't it goes against darwin's theory?
So, essentially what they've proven is that the motor skills part of the brain may effect the development of our motor skills?
Man, I can't wait until I get my Ph.D.! This research scientist stuff is going to be a piece of cake!
When things get complex, multiply by the complex conjugate.
*extends left hand*
i fact just about every creature in nature and everything in nature has "handedness"
only a "scientist" could attribute this to something recent like language skills.
http://slashdot.org/~GuyFawkes/journal
You Sinistromanualist, you...
More seriously the, errr, granparent post is referring to this happening to his grandfather. Minus the beating, this was still happening to me when I was at school in the eighties (UK). An English teacher made a concerted effort to force me to be right-handed, and it completely messed up my writing. You can see a clear difference between the schoolbooks I had before her 'teaching', and those I wrote afterwards.
For the worse, of course.
Cheers,
Ian
Since when has evolution* purposely chosen to do anything
*In case there are any Americans reading, so as not to offend I'll include the standard disclaimer that evolution is just a theory and it's equally likely we were created out of mud 6000 years ago and fossils are the result of God's sense of humour.
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nor am I a member of Mensa unforunately
Actually we had a poll on the members only section of our local mensa chapters website regarding this exact question - the conclusion being that we didn't have an unusually high (or low for that matter) number of lefties.
-- A good compromise leaves everyone mad. --Calvin and Hobbes
Perhaps left-handedness doesn't have any advantages, but no drawbacks detrimental to survival either. That too would allow it to remain in the 'gene pool'.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
Yeah, well it's BUSH'S fault that he can't READ.
stuff
Nothing to do with handedness, that's just the way wome are. You'll realise that as you get to know more of them :-)
No but, yeah but, no but...
...must be difficult to find lefthanded bananas
D.
To suggest that left handedness is genetic is a socialist lie. It is condemned in the Bible, like being crippled and eating shellfish. Everyone knows that left handedness is a choice, a sinful lifestyle promoted by Satanic liberals. Even the scientific term, sinister, reveals it's Luciferian origin. Concerned parents must act now to stop children being taught to be left handed in schools, and to stop the media being overrun by positive depictions of left handedness. Would you want your child to be fondled by a left handed pedophile coming home from a sickening Sinster Pride march?
Order a copy of "What Liberals Don't Want You to Know about the Left Handed Agenda", by Salvation Publications, for only $99.99. Comes with guaranteed promise of Heaven and a free shotgun.
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This is an interesting study but I'm not sure how relevant it is.
Humans have several areas of the brain where structure and therefore function differ vastly from other primates. Specifically the areas of the brain dealing with speech (Broca's and Wernicke's areas) and the connection between the two (arcuate fascicus). These areas have a definite correlation to handedness as a right-handed person has a 97% chance of having these speech structures on the left versus the right while in a left-handed person has a 50-50 chance of this (if my neuroanatomy is correct). This is why speech mapping must be performed on patients who will undergo neurosurgery near possible speech centres, for example in a temporal lobectomy.
Thank you, science monkey!
One strange thing I've noticed when teaching and attending Emergency Medical Services (read 'ambulance service') classes is that there are a higher number of lefties then the general population.
At the station in my town 4 out of the 9 EMS workers are left handed.
There's no place like
I'm ambidextrous. I'm better than both of you.
I am TheRaven on Soylent News
I'm ambidextrous, and I'm in MENSA. Admittedly I was forced to learn to use my left hand while taking several years to recover from an injury to my right hand, so it's not 100% natural. Does that count?
;)
It's fun to be writing something in front of someone who doesn't know, and switch hands and continue perfectly. The look on their faces is priceless
I think it's more likely that only those of us with our brains in backwards could ever see fit to sit through an entire course of Prolog.
--
Try Nuggets , the natural-language SMS search engine. Answers to your questions per SMS in 10 seconds.
Interesting article though I disagree with the statement about LH persons being less analytical.
I'm a third gen lefty (tree: PGM, F, myself). My eldest son fell from near my side of the family tree and he (now 6) has only ceased to be ambidexterous in the last two months. He went to the dark side and uses his right hand to throw and write. Still bats and kicks left however so maybe he'll make it to the major leagues yet. Still holding out hope for the newborn daughter.
Anyway, I'm PhD physicist, my Dad (LH) is a very talented mechanical designer/engineer. Grandmother was a puzzle wizard. If you look at PhD level scientists you will find more than the nominal 10% LH... which does not support the "less analytical" assertion. On the other hand (pun?) perhaps we LH are less analytical but in return we are given better gifts to see analytic tasks as in a more wholistic light. Maybe this is why Maxwell's Equations, classical E&M, the Standard Model Lagrangian and GR are as beautiful as Sunday Afternoon by Seurat or as magnificent as DaVinci's David to me.
"One strange thing I've noticed when teaching and attending Emergency Medical Services (read 'ambulance service') classes is that there are a higher number of lefties then the general population."
It's a lot harder to run with left-handed scissors than the general populace realizes.
"Derp de derp."
...as good as one hand can get, I'm sure there are evolutionary good reasons to also have a good second hand. That'll keep left and right fairly equal, and then the "gap" to flip it around and use left as your primary and right as your secondary isn't that big.
I think many people misunderstand evolution as a process towards a "superbeing", one obviously better than the last in every respect. It is just as much about providing a flexibility so that a species may adapt to changing circumstances. Being able to throw a left punch in a right-punch world. Or to live in a colder / warmer / drier / wetter / whatever climate. Dinosaurs excelled as the circumstances were. They changed, and the dinosaurs couldn't adapt.
Hell, I could talk about modern-day life. Those who can adapt to the stress, instant communication and almost constant hustle and bustle do well, those that don't do less well. Could evolution adapt to that in the span of decades? No way. But it has given each of us different capabilities, some of which will be more useful, some less. To adapt is much more important than being 0.3% stronger than the last generation.
Kjella
Live today, because you never know what tomorrow brings
I'd give my left arm to be ambidextrous!
Quite practical while playing a game of pool. I don't have to play those odd balls behind my back which everyone always misses. I just switch to the other hand.
I was dyslexic until I tought myself writing properly at the age of 29. I had two mental breakdowns at the age of 11 and 22. It's still lurking around the corner and can only be held at bay by strong discipline. And I'm a typical case of asperger.
So yes, the results don't surprise me at all.
Although people generally agree I am very intelligent it won't help me since I have none of the skills that are required for material or social success.
Personally I think you are all a cruel bunch who never speak clearly and are only interested in personal gain.
I do feel like I come from another planet sometimes, at least I am treated that way.
I'm a leftie. The reason I think left handness exists is specialisation. Darwinian theory doesn't mean we will all be the same exact highly optimised beings. What happens if the environment changes? Evolution would not be able to react fast enough. Instead sucessful groups of our ancestors, the ones which survived, emerged from the jungle and ultimately produced us, had group members with different strengths, different abilities. It's like any game, for example it red alert or d&d. If you only have spell casters in a party, or one type of unit in an attack, you will not be as successful as a mixed group.
Evolution is not a god that sits on a mountain somewhere. It's the theory that those forms that have the greatest tendency to propagate in a given environment gradually become more frequent in that environment(*).
Seriously, this kind of bizarre 'science as voodoo' thinking is why to a lot of people creationism doesn't sound so stupid -- "God wanted there to be left handed people for his own ineffable plan" sounds about equivalent to "Evolution has kept left handed people on purpose".
It sucks and requires a certain amount of discipline, but it's better to keep science as science, a methodology for choosing between theories, than to let it become just another set of beliefs, like a religion.
(*) I know this is not a good or rigorous definition of evolution in general or biological Darwinian evolution in particular, but throw me a frickin' bone here.
Whence? Hence. Whither? Thither.
Evolution hasn't purposely done anything. For whatever reason, there is not sufficient evolutionary disadvantage to being left handed for it to have died out amongst humans. Conversely, any advantage there may be to being right-handed is sufficent to make it dominant, but insufficient to wipe out left-handedness.
Evolution is a name for a process, not a thing, it doesn't do anything, on purpose or not.
For a geek/tech site, we're very loose with our terminology and language at times...
It's official. Most of you are morons.
The list goes on here.
And to all those who read into this too far; are righties really too different than lefties? My mother was a lefty "beaten" to be a righty and therefore ambidextrous. She can write with both hands. One of the more smarter individuals I've met. I myself am a righty and I find no challenge in thinking right-minded or left. So really, in the end, does it make a difference?
While helping my girlfriend with her lab on the common Fiddler crab (Uca pugilator) I decided to do some side-research of my own*. I found that approximately 1/3rd of Fiddler crabs in our population (of about 20) were left-handed (in that their left claw was freakin' huge). This would lead credence to an earlier post talking about handedness being a surprise to rivals.
It is interesting to see, however, that the Scientific American article covering the same subject seemed to focus more on the study whose results found similarites in the limbic system asymmetry between primates. The handedness study (which of course waters down easier for the average person) seemed to be second fiddle.
By the way, the actual studies are found here (in 300-500KB PDFs):
Asymmetries in the Hippocampus and Amygdala of Chimpanzees
Handedness in Chimpanzees (Pan troglodytes) Is Associated With Asymmetries of the Primary Motor Cortex but Not With Homologous Language Areas
* I had previously determined that the bisque turned out a bit stringy and that scampi was preferred. This, sadly, derailed the other, more "important" research.
Small potatoes make the steak look bigger.
Hi there.
d ec ember_2004/bne1186.html
I got sent a link to your post from a friend who knows I do some research into hominid handedness and laterality. I was interested in reading the articles and managed to find them through the power of the internet, so I thought you might want the link:
http://www.apa.org/journals/bne/press_releases/
Cheers, Lisa
[Sigh] And it's use by the mediaeval church is why it means 'evil'. In fact although the parent was satire (not troll) as all good satire it was very close to the truth. The church has long used 'left' to mean 'evil' - left-handers really were persecuted in times past. We still use the phrase cack-handed. And a lot of the modern left-wing demonisation by the right is very religiously inspired.
--
USA: home of the world's largest terrorist training camp.
But chimp research would have to null out the contributions to handedness that might be made by any number of OTHER differences in brain development between humans and the rest of the primates before these scientists, let alone a bunch of
- The timeline of human brain development from birth to adolescence is hardly one of linear increases in all capabilities and is not the same as chimps
- the LACK of parity between LH and RH dominant individuals is complex: the numbers are not evenly distributed but that is obscured, as serveral posters reported, by cultural enforcers that mask biologicaly determined behavior. We might even be seeing the reports of apparent intellectual advantages in a few lefties because our culture has beaten the lefthandedness out of a larger subset of the population with only the more gifted and adaptable surviving the brainwashing.
...These areas have a definite correlation to handedness as a right-handed person has a 97% chance of having these speech structures on the left versus the right while in a left-handed person has a 50-50 chance of this (if my neuroanatomy is correct)....[bloodredsun's comment] is particularly interesting since it implies there are yet other dimensions to the asymmetry between LR and RH dominance, these are not distributions of capability that are anatomically just mirror images of each other but distinctly different wiring.- I have not read every comment but so far there is no report of data correlating extent of corpus collosum [CC:the bridge between L and R hemispheres. nearest analog to a computer bus you will find in brain anatomy] to handedness. The CC is [if memory serves] is better developed in women than men ON AVERAGE and women [perhaps as a consequence] have [on average] less rigid specialization of functions to particular brain regions. This is why [on average] women recover more fully from strokes then men do.
- someone probably trotted out the stat that lefties have more accidents and I just missed it. Its a whole other debate about whether that is due to strong tendencies to put the saftey/kill-switch/brakes/etc on dangerous equipment where a RH person would expect them or due to other considerations but its not likely to be attributable to language skills...differences between LH and RH persons that don't stem from language either support or don't repute the findings of the article so I guess this one is a point for the sciencists.
- Is there any study or known correlation between handedness and [_]dyslexia, [_]ADD or ADHD, [_]Stuttering, [_] other developmental anomalies, e.g. autism?
But, of course, I have my anecdotes too;)My mom reports that she was probably a lefty but growing up in the 30's in a Missouri village where the dogs barked in German and you were either a Luthern or a Methodist, she had that bad habit beaten out of her. One of my boys writes [illegibly] with his left hand but throws [and I mean quite athletcally: he's an ultimate frisby player] righty.
and PLEASE, if you can't read or react in an informed and rational way concerning the general fact that there are differences between men and women, please exit the conversation NOW!.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
...definitely has its advantages if you're used to using a mouse with your right hand. I can surf and take notes at the same time. Also, I'm better at finding the really ripe fruit.
As far as I know the number of left-handed in the Middle East (and Asia for that matter) is equivalent to the number in the west, so I don't think this has got anything to do with the direction of writing. Is seems to be mostly a coincidence. An interesting point is that all people "read" pictures the same way - left to right - no matter how they are used to reading letters.
-- A good compromise leaves everyone mad. --Calvin and Hobbes
Pick up any child development book (like any college book) and it will tell you that whatever side you lie on in the womb determines if you are left or right handed. And it makes perfect sense, too. If you are lying on your left (as many obviously do) your right arm is free to move and start developing motor skills. And if you lie on the right, you have to use your left arm to move all about. And there is really nothing you can to about it. That's why natural selection hasn't just "threaded" them out, because there has been no way to. Just because your parent's are both lefties dosen't mean you will be, because you prob won't.
There are some studies that link brain lateralization to personality in birds and mamals, which provides an explanation of the survival benefits of having both left and right handed members in a species: http://www.abc.net.au/catalyst/stories/s1139554.ht m/
(Ask yourself - who do the marmosets remind you of??)
Someone else did a game theory analysis of how predation could lead to lateral specialisation in prey as a survival strategy, but I don't have the link.
For the profoundly right lateralized(~LH), you might appreciate these marmosets also:
http://www.rathergood.com/moon_song/