

Our Brains Are Shrinking. Are We Getting Dumber? - srean
http://www.npr.org/templates/transcript/transcript.php?storyId=132591244

======
korl
Whatever, idiocracy-like event occurred thousands of years ago, I think the
one happening now will dwarf it. At least in most western countries and Japan
where successful people have less children. It's almost like an anti survival
of the fittest, if you are successful, less people in the next generation will
carry your genes.

Brain size might or might not be related to intelligence. In any case, this is
what Wikipedia has to say "In general, these studies have reported that East
Asians have on average a larger brain size than whites who have on average a
larger brain size than blacks."[1]

If you ignore who is having children among whites (successful people or not),
you still have the white population rapidly declining with a birth rate below
replacement levels, I believe that this coupled with mass immigration and the
high birth rates of immigrants, specially in Europe, in addition to race
mixing in other places like the US, will ensure that brain size in these
places decreases at a fast rate. Unless we have mass immigration from East
Asian countries, like Vietnam.

In the "racist" comment above, I didn't lie, I didn't insult anybody and I
didn't say that one race is more intelligent than the other. I agree that my
opinion might not be politically correct.

[1][http://en.wikipedia.org/wiki/Race_and_intelligence#Brain_siz...](http://en.wikipedia.org/wiki/Race_and_intelligence#Brain_size)

~~~
olalonde
In case you are right, the good news is that this "survival of the dumbest"
phenomenon can only be sustained as long as there are enough smart people to
take care of the dumb ones. This trend will inevitably be reversed one day.

~~~
artmageddon
Not that I read so from your post, but that's not something to take much
comfort in. To be fair, we saw this coming a _long_ time ago... or at least
The Onion did:

CHICAGO-In a report with dire implications for the intellectual future of
America, a University of Chicago study revealed Monday that the nation's
uneducated are breeding twice as fast and twice as often as its educated. "The
average member of the American underclass spawns at age 15, compared to age 30
for the average college-educated professional," study leader Kenneth Stalls
said. "America's intellectual elite, as a result, are badly losing the genetic
marathon, with two generations of dullards born for every one generation of
cultured literates." Added Stalls: "At this rate, by the year 2100 there will
be five smart people on Earth, swallowed whole by more than 12 billion mouth-
breathers incapable of understanding the binary exponentiation that swamped
the Earth with their like." High-school dropout Mandi Drucker, 16, said of the
findings, "All I know is, we're in love."

May 14, 1997 | ISSUE 31•18

[http://www.theonion.com/articles/study-uneducated-
outbreedin...](http://www.theonion.com/articles/study-uneducated-outbreeding-
intelligentsia-2to1,4282/)

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bradleyland
No mention of surface area or number of folds. It is believed that the vast
majority of our intellectual ability resides in our cerebral cortex. I know
that anthropologists estimate brain size based on the size of the skull and
the brain cavity, but I don't know if they can tell us much about the actual
make-up of cro-magnon brains? The question mark is there because I don't know.
Can anyone offer any insight there?

It would stand to reason that since the cerebral cortex is the home of our
higher-thinking abilities, an overall reduction in brain size might not equate
to a reduction in intelligence, were there an increase in the number and depth
of the "folds" on the surface of the brain.

~~~
joeyo

      > It would stand to reason that since the cerebral cortex 
      > is the home of our higher-thinking abilities ...
    

Not only that, but the prefrontal cortex (PFC) is one particular cortical
region that has become enlarged in humans with respect to other great apes.
PFC is generally implicated in "higher" reasoning, metacognition, and other
executive functions. It's possible that cro-magnon brains were larger but that
additional volume was allocated to other functions (balance or smell, for
example) and that they still had smaller frontal lobes.

------
lukev
In response to all the comments referencing "Idiocracy" - I can't believe so
many of you are taking that movie seriously.

1\. Even if the effect it claims is true, it wouldn't result in an "everyone's
stupid" society, it would result in a split society with an even more distinct
intellectual upper and lower class. Not desirable, to be sure, but not
necessarily dangerous to the human race as a whole.

2\. What we arrogantly see as the "stupidity" of the lower classes is almost
entirely caused by social and environmental factors. Genetically, they're not
necessarily inferior at all. Even if genetic drift COULD occur within just a
few generations, which I doubt, genetic effects would be entirely dominated by
environmental factors such as education, nutrition, and socialization.

If you pulled a healthy baby from the worst white trash family at birth,
raised it well and gave it an education, there's no reason to think it would
be any less intelligent than you.

~~~
pohl
The movie actually did depict a split society. At the top was President Dwayne
Elizondo Mountain Dew Herbert Camacho, who operated at a much higher cognitive
plane than Frito the lawyer, who operated at a much higher level than the
masses - for example the woman operating the Fischer Price diagnostic panel at
St. God's Hospital, where Dr. Lexus was clearly high-functioning - presumably
well above his undepicted & "tarded" ex-wife, a pilot.

~~~
lukev
But everyone was still sub-average by "normal" standards.

If this actually happens, you're likely to see an intellectual upper class
that is _more_ intelligent than the current average. Selection works both
ways, and even if the intelligentsia reproduce more slowly, they still
reproduce (mostly) within their own group, leading to ever-smarter offspring.

Assuming genetic factors dominate intelligence anyway.

~~~
pohl
_But everyone was still sub-average by "normal" standards._

You mean that everyone was sub-average by _todays_ normal standards. But what
was normal in the year 1435 is very different from what is normal in the year
2011, and again very different from what the norm will be in the year 2505.

Had Trevor and Carol been able to produce offspring, they (and the rest of
their class) might have been able to bolster the norm. Alas, Trevor tragically
met his demise with a heart attack whilst masturbating to produce sperm to
artificially inseminate her.

Meanwhile, Clevon kept cleaving on, appreciably moving the needle on what
'norm' means.

 _Edit:_ We didn't get to see much inside of the Brawndo corporation, where
all of the power was concentrated, so we can't be sure that President Camacho
was the brightest around. All we got to see was the CEO, who may not have been
the brightest bulb in the drawer. The descendants of the medical researchers
bent on curing hair-loss and prolonging erections probably work in the bowels
of that - or some other - corporation.

------
Symmetry
The fact that people are getting smarter over time is the firm scientific
consensus and I'd think that most science writers should know that:
<http://en.wikipedia.org/wiki/Flynn_Effect>

Brain volume contributes to a lot of things. It might be that we're getting
clumsier, or that we're less visually perceptive than our ancestors were. But
we can be sure that IQs aren't going down.

~~~
dspeyer
The Flynn effect has been observed over less than a century. Extrapolating it
to 20k years is a stretch.

~~~
wzdd
Not at all. This article cites a gain of 0.3 points per year and postulates
(admittedly without drawing any conclusions) that the average person in the
early part of this century had an IQ of 80:

[http://www.americanscientist.org/issues/id.881,y.0,no.,conte...](http://www.americanscientist.org/issues/id.881,y.0,no.,content.true,page.1,css.print/issue.aspx)

If we continue to extrapolate, we can conclude that 300 years ago people had
an IQ of 10. Not very bright, but a significant improvement over their great-
grandparents, who would have had an IQ of -20.

------
jacquesm
No, that's just Moores law, with the higher integration levels of the brain we
are now seeing more power efficient and smaller brains. It's that new .1 nm
process that they're using.

~~~
dawgr
I know it's a joke and you might be right, but I don't think the need to
reduce brain size would be such a huge evolutionary pressure to see a decrease
of 10% in just 20,000 years, that's relatively little.

Granted that the bigger the brain, the more energy it needs, but if the brain
uses 25% of our energy, 0.25*0.1= 2.5%. Even if that's wrong by a few percent,
it doesn't sound like such a big advantage to cause that decrease in so little
time and as it's been pointed out, it actually started happening when more
food/energy was available from agriculture or whatever.

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lkrubner
"the actual make-up of cro-magnon brains"

There seems to be no agreement about what the word "cro-magnon" refers to.
Possibly the phrase should be disused? I have frequently read that cro-magnon
refers to the first homo sapiens who arrived in Europe. With that usage, "cro-
magnon" is just a way of referring to us, a synonym for homo sapiens. But the
phrase has other uses. Some writers continue to refer to "cro-magnon" as if it
refers to some distinct species, different from us. But then, the question
arises, which species are we talking about? Who is it related to? Why does it
need a unique name?

As far as I know, the most exhaustive coverage of the various human species is
in Ian Tattersall's book, Extinct Humans:

[http://www.amazon.com/Extinct-Humans-Ian-
Tattersall/dp/08133...](http://www.amazon.com/Extinct-Humans-Ian-
Tattersall/dp/0813339189/ref=sr_1_1?ie=UTF8&qid=1294160996&sr=8-1)

Tattersall is among those who refer to cro-magnon as homo sapiens, and
therefore makes the phrase "cro-magnon" largely meaningless. One might say,
with greater clarity, "Early homo sapiens in Europe."

Having said that, I should add, there is no doubt that Neanderthals (I'm using
the spelling suggested by the Google Chrome auto-suggest, which may be out of
date) were a distinct species, and that they had larger brain cases that homo
sapiens. There is no evidence they were smarter than us. They never showed
much advance toward abstract thought, which gives us reason to assume they
were dumber than us, at least using traditional (habitual) notions of "smart"
and "dumb".

~~~
Nick_C
'cro-magnon' has been out of fashion for quite a while, at least in stuff that
I read. I haven't seen the term in any decent book for, I dunno, say, several
years.

------
ANH
H.G. Wells predicted this in The Time Machine (okay, I'm being slightly tongue
in cheek). He wrote of far future human descendants, the Eloi, who had
undergone severe mental and physical degradation due to no longer being
required to solve difficult physical and societal problems.
<http://en.wikipedia.org/wiki/Eloi>

------
srean
The conversation claims that "humans" have lost an equivalent of a tennis ball
volume of the brain. But perhaps a more revealing measure would be weight of
brain lost in proportion to the body mass.

Elephants have a much larger brain than us, but smaller when compared to their
body mass. (Side note: they are one of the few species that can recognize
itself in the mirror)

~~~
bluedanieru
Neanderthals were bigger and stronger than us, but this transcript only
references us in comparison with Cro-Magnons. They're still Homo sapiens
sapiens so a difference in body mass of 10% seems large (but then so does such
a difference in brain mass).

~~~
Vivtek
Wolves and chihuahuas are the same species, too. Their body mass difference is
well over 10%.

~~~
lkrubner
Not the same species, only the same genus:

<http://en.wikipedia.org/wiki/Canis>

They are related. That does not mean they are the same species.

~~~
Vivtek
Second paragraph of this link: " _Wolves, dogs and dingos are subspecies of
Canis lupus._ " Did you think I just made it up?

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olalonde
If cro-magnons really were smarter than us, it just shows how big of a role
knowledge and culture play in what we perceive as intelligence.

~~~
scotth
Or the humans who make discoveries are anomalous.

------
bhavin
Got the following from an article:

According to one of the theories on the shrinking of brain, “The big heads
were necessary to survive Upper Paleolithic life, which involved cold, outdoor
activities.”

Another theory said, “The skulls developed to cope with a chewy diet of
rabbits, reindeer, foxes and horses. As our food has become easier to eat, so
our heads have stopped growing.”

[http://www.themedguru.com/20110102/newsfeature/shrinking-
bra...](http://www.themedguru.com/20110102/newsfeature/shrinking-brains-
leading-unintelligent-humans-study-86143216.html)

------
chanux
Explains The Sergey-spot <http://popstrip.com/sergey-spot>

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johngalt
Then why do IQ test have to be normalized so often? How would you explain the
Flynn Effect? <http://en.wikipedia.org/wiki/Flynn_effect>

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anamax
(1) Women's brains are typically smaller by about the difference between Cro-
Magnons and Homo Sapiens.

(2) WRT problem-solving ability, bonobo populations are shrinking much faster
than chimps (which are increasing in some places). Perhaps that politically
correct behavior has consequences....

------
substack
I wonder if the decrease in brain size is due in part to infant mortality and
trauma in childbirth. Big brains don't exactly... fit as well coming out,
although it's also not clear how much early brain size influences brain size
later in life.

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stuaxo
Maybe were just outsourcing the knowledge to the rest of society.

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ConceptDog
Much like laundry detergent, they're getting more concentrated.

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bennesvig
Idiocracy wasn't a great movie, but it might be prophetic.

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klbarry
Keep in mind Einsteins brain was especially small, and nodes were closer
together. In addition, women's brains are smaller than mens, but it is fairly
well understood that both genders are equally intelligent.

