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Our Brains Are Shrinking. Are We Getting Dumber?
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ProfessorF
What's a life?
Joined: Thu Apr 23, 2009 7:56 pm Posts: 12030
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 |  |  |  | Quote: Our Brains Are Shrinking. Are We Getting Dumber? by NPR STAFF
Today's human brain is about 10 percent smaller than the Cro-Magnon brain from more than 20,000 years ago.
When it comes to brain size, bigger doesn't always mean better. As humans continue to evolve, scientists say our brains are actually getting smaller.
The downsizing of human brains is an evolutionary fact that took science writer Kathleen McAuliffe by surprise.
"I said, 'What? I thought it was getting bigger!'" she tells NPR's Jacki Lyden. That was the story up to 20,000 years ago, she learned. Then, the brains of our ancestors reversed course and started getting smaller — and they've been shrinking ever since.
Cro-Magnon man, who lived in Europe 20,000 to 30,000 years ago, had the biggest brains of any human species. In comparison, today's human brain is about 10 percent smaller. It's a chunk of brain matter "roughly equivalent to a tennis ball in size," McAuliffe says.
The experts aren't sure about the implications of this evolutionary trend. Some think it might be a dumbing-down process. One cognitive scientist, David Geary, argues that as human society grows increasingly complex, individuals don't need to be as intelligent in order to survive and reproduce.
But not all researchers are so pessimistic. Brian Hare, an anthropologist at the Duke University Institute for Brain Sciences, thinks the decrease in brain size is actually an evolutionary advantage.
The Domesticated Brain
"A smaller brain is the signature of selection against aggression," Hare tells Lyden. "Another way to say that is an increase in tolerance."
Hare says when a population selects against aggression, they can be considered to be domesticated. And for a variety of domesticated animals like apes, dogs or turkeys, you can see certain physical characteristics emerge. Among these traits are a lighter and more slender skeleton, a flattened forehead — and decreased brain size.
Hare's studies focus on chimpanzees and bonobos. In evolutionary terms, they are much like humans, but are physically quite different from one another. Bonobos have smaller brains than chimpanzees — and are also much less aggressive.
While both have the cognitive ability to solve a given puzzle, Hare says, chimpanzees are much less likely to accomplish it if it involves teamwork. Not so with bonobos.
"If the food is quite sparse and it's not easy to share, [bonobos] can solve the problem," Hare says. "Chimpanzees, in that same context — where there's not much food and it's not easy to share — they just refuse to work together. They can't solve the problem, even though they know how."
Hare does admit that the shrinking human brain could signal an evolutionary dumbing-down, but more important is what the phenomenon tells us about ourselves. Comparing our evolution to that of other animals enriches our understanding of the human condition.
"The nice thing about studying animals and human nature," Hare says, "is that it helps us design or think of some strategies that deal with our darker sides." |  |  |  |  |
http://www.npr.org/2011/01/02/132591244/our-brains-are-shrinking-are-we-getting-dumber
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Mon Jan 03, 2011 11:37 pm |
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Amnesia10
Legend
Joined: Fri Apr 24, 2009 2:02 am Posts: 29240 Location: Guantanamo Bay (thanks bobbdobbs)
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Well the mice have trained us very well. I mean they had this planet built to find the answer to life the universe and everything so do not want us destroying it.
_________________Do concentrate, 007... "You are gifted. Mine is bordering on seven seconds." https://www.dropbox.com/referrals/NTg5MzczNTkhttp://astore.amazon.co.uk/wwwx404couk-21
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Tue Jan 04, 2011 3:08 am |
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cloaked_wolf
What's a life?
Joined: Thu Apr 23, 2009 8:46 pm Posts: 10022
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I thought the smaller size may mean greater efficiency. A big brain has never meant a more intelligent brain.
Sometimes I wish we could step into the past, even as passive observers, and see what humans were like then. They definitely would have been stronger and faster than now.
_________________ He fights for the users.
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Tue Jan 04, 2011 5:59 am |
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belchingmatt
I haven't seen my friends in so long
Joined: Fri May 15, 2009 3:16 am Posts: 6146 Location: Middle Earth
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Size doesn't matter, it's what you do with it. So what about grey/white matter ratios and grey matter convolutions or surface area. I'm pretty sure I was told in GCSE biology that these are more important factors than brain size when determining intelligence.
_________________ Dive like a fish, drink like a fish!
><(((º>`•.¸¸.•´¯`•.¸><(((º> •.¸¸.•´¯`•.¸><(((º>`•.¸¸.•´¯`•.¸><(((º>
If one is diving so close to the limits that +/- 1% will make a difference then the error has already been made.
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Tue Jan 04, 2011 8:06 am |
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forquare1
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 6:36 pm Posts: 5161 Location: /dev/tty0
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It could mean a dumbing down, just go out into most towns and see the general public...
Then again in the last 100-200 years we have done some tremendous technical things.
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Tue Jan 04, 2011 8:40 am |
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hifidelity2
I haven't seen my friends in so long
Joined: Fri Apr 24, 2009 1:03 pm Posts: 5041 Location: London
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Not much luck for Zombies then - it now requires them to munch on two people to get a decent meal 
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Thu Jan 06, 2011 4:32 pm |
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dogbert10
Doesn't have much of a life
Joined: Thu Apr 23, 2009 8:23 pm Posts: 638 Location: 3959 miles from the centre of the Earth - give or take a bit
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Given the sort of TV people watch, I'm sure there's a large segment of the population that could manage with less than 10% of what they've got now 
_________________ i7 860 @ 3.5GHz, GTX275, 4GB DDR3
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Fri Jan 07, 2011 12:45 pm |
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Amnesia10
Legend
Joined: Fri Apr 24, 2009 2:02 am Posts: 29240 Location: Guantanamo Bay (thanks bobbdobbs)
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Can we have anyone who watches reality shows banned from breeding? It might help. 
_________________Do concentrate, 007... "You are gifted. Mine is bordering on seven seconds." https://www.dropbox.com/referrals/NTg5MzczNTkhttp://astore.amazon.co.uk/wwwx404couk-21
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Fri Jan 07, 2011 1:37 pm |
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pcernie
Legend
Joined: Sun Apr 26, 2009 12:30 pm Posts: 45931 Location: Belfast
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That's a notion that probably pops into my head more often than it should  , usually followed by, 'That's an awful lot of women!' 
_________________Plain English advice on everything money, purchase and service related:
http://www.moneysavingexpert.com/
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Fri Jan 14, 2011 7:37 pm |
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Amnesia10
Legend
Joined: Fri Apr 24, 2009 2:02 am Posts: 29240 Location: Guantanamo Bay (thanks bobbdobbs)
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Yes you are probably right. 
_________________Do concentrate, 007... "You are gifted. Mine is bordering on seven seconds." https://www.dropbox.com/referrals/NTg5MzczNTkhttp://astore.amazon.co.uk/wwwx404couk-21
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Fri Jan 14, 2011 10:12 pm |
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JJW009
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 6:58 pm Posts: 8767 Location: behind the sofa
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I'm pretty sure my brain shrank last night. It feels like a pickled walnut 
_________________jonbwfc's law: "In any forum thread someone will, no matter what the subject, mention Firefly." When you're feeling too silly for x404, youRwired.net
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Sat Jan 15, 2011 12:20 pm |
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