[Paleopsych] Wired: (Flynn Effect): Dome Improvement
ross.buck at uconn.edu
Thu May 5 16:59:48 UTC 2005
Again the notion of heritability is being presented as a meaningful measure of genetic-versus-environmental influence. Most monozygotic twins are monochorionic, sharing the same choroid plexus and therefore the same blood supply in the womb. A minority are dichorionic, with identical genes but a different intrauterine blood supply. Davis, Phelps and Bracha (Schizophrenia Bulletin, 1995, 21, 357-366) investigated concordance of schizophrenia in monochorionic and dichorionic monozygotic twins, and found that while the concordance rate for MC MZ twins was 60% (i.e., if one twin is schizophrenic there is a 60% chance the other will be as well), the concordance rate of the DC MZ twins (with identical genes) was 10.7%. Environmental influences are overwhelming, and they begin at conception: the genes do nothing without environmental influences turning them on and off.
The Flynn effect suggests that the vast media wasteland may actually function as a vast brain playground.
Ross Buck, Ph. D.
Professor of Communication Sciences
Communication Sciences U-1085
University of Connecticut
Storrs, CT 06269-1085
Ross.buck at uconn.edu
From: paleopsych-bounces at paleopsych.org [mailto:paleopsych-bounces at paleopsych.org] On Behalf Of Premise Checker
Sent: Thursday, May 05, 2005 12:27 PM
To: paleopsych at paleopsych.org
Subject: [Paleopsych] Wired: (Flynn Effect): Dome Improvement
First some remarks from
From: Hal Finney <hal at finney.org>
Date: Tue, 3 May 2005 11:03:41 -0700 (PDT)
To: extropy-chat at lists.extropy.org
except that the article is now available:
Wired magazine's new issue has an article on the Flynn Effect, which we
have discussed here occasionally. This is probably my favorite Effect,
so completely extropian and contradictory to the conventional wisdom.
Curmudgeons throughout the ages have complained about the decay of society
and how the younger generation is inferior in morals and intelligence
to their elders. Likewise modern communications technology is derided:
TV is a vast wasteland, video games and movies promote sex and violence.
Yet Flynn discovered the astonishing and still little-known fact
that intelligence scores have steadily increased for at least the
past 100 years. And it's a substantial gain; people who would have
been considered geniuses 100 years ago would be merely average today.
Perhaps even more surprisingly, the gains cannot be directly attributed to
improved education, as the greatest improvements are found in the parts
of the test that directly measure abstract reasoning via visual puzzles,
not concrete knowledge based on language or mathematical skills.
The Wired article (which should be online in a few days) does not have
much that is new, but one fact which popped out is that the Effect has
not only continued in the last couple of generations, but is increasing.
Average IQ gains were 0.31 per year in the 1950s and 60s, but by the
1990s had grown to 0.36 per year.
Explanations for the Effect seem to be as numerous as people who have
studied it. Flynn himself does not seem to believe that it is real,
in the sense that it actually points to increased intelligence. I was
amused by economist David Friedman's suggestion that it is due to the
increased use of Caesarian deliveries allowing for larger head sizes!
The Wired article focuses on increased visual stimulation as the catalyst,
which seems plausible as part of the story. The article then predicts
that the next generation, exposed since babyhood to video games with
demanding puzzle solving, mapping and coordination skills, will see an
even greater improvement in IQ scores.
Sometimes I wonder if the social changes we saw during the 20th century
may have been caused or at least promoted by greater human intelligence.
It's a difficult thesis to make because you first have to overcome the
conventional wisdom that says that the 1900s were a century of human
depravity and violence. But if you look deeper and recognize the
tremendous growth of morality and ethical sensitivity in this period
(which is what makes us judge ourselves so harshly), you have to ask,
maybe it is because people woke up, began to think for themselves, and
weren't willing to let themselves be manipulated and influenced as in
the past? If so, then this bodes well for the future.
--------------now the article:
Pop quiz: Why are IQ test scores rising around the globe? (Hint: Stop reading
the great authors and start playing Grand Theft Auto.)
By Steven Johnson
Twenty-three years ago, an American philosophy professor named James Flynn
discovered a remarkable trend: Average IQ scores in every industrialized
country on the planet had been increasing steadily for decades. Despite
concerns about the dumbing-down of society - the failing schools, the garbage
on TV, the decline of reading - the overall population was getting smarter. And
the climb has continued, with more recent studies showing that the rate of IQ
increase is accelerating. Next to global warming and Moore's law, the so-called
Flynn effect may be the most revealing line on the increasingly crowded chart
of modern life - and it's an especially hopeful one. We still have plenty of
problems to solve, but at least there's one consolation: Our brains are getting
better at problem-solving.
Unless you happen to think the very notion of IQ is bunk. Anyone who has read
Stephen Jay Gould's The Mismeasure of Man or Howard Gardner's work on multiple
intelligences or any critique of The Bell Curve is liable to dismiss IQ as
merely phrenology updated, a pseudoscience fronting for a host of racist and
elitist ideologies that dare not speak their names.
These critics attack IQ itself - or, more precisely, what intelligence scholar
Arthur Jensen called g, a measure of underlying "general" intelligence.
Psychometricians measure g by performing a factor analysis of multiple
intelligence tests and extracting a pattern of correlation between the
measurements. (IQ is just one yardstick.) Someone with greater general
intelligence than average should perform better on a range of different tests.
Unlike some skeptics, James Flynn didn't just dismiss g as statistical tap
dancing. He accepted that something real was being measured, but he came to
believe that it should be viewed along another axis: time. You can't just take
a snapshot of g at one moment and make sense of it, Flynn says. You have to
track its evolution. He did just that. Suddenly, g became much more than a
measure of mental ability. It revealed the rising trend line in intelligence
test scores. And that, in turn, suggested that something in the environment -
some social or cultural force - was driving the trend.
Significant intellectual breakthroughs - to paraphrase the John Lennon song -
are what happen when you're busy making other plans. So it was with Flynn and
his effect. He left the US in the early 1960s to teach moral philosophy at the
University of Otaga in New Zealand. In the late '70s, he began exploring the
intellectual underpinnings of racist ideologies. "And I thought: Oh, I can do a
bit about the IQ controversies," he says. "And then I saw that Arthur Jensen, a
scholar of high repute, actually thought that blacks on average were
genetically inferior - which was quite a shock. I should say that Jensen was
beyond reproach - he's certainly not a racist. And so I thought I'd better look
This inquiry led to a 1980 book, Race, IQ, and Jensen, that posited an
environmental - not genetic - explanation for the black-white IQ gap. After
finishing the book, Flynn decided that he would look for evidence that blacks
were gaining on whites as their access to education increased, and so he began
studying US military records, since every incoming member of the armed forces
takes an IQ test.
Sure enough, he found that blacks were making modest gains on whites in
intelligence tests, confirming his environmental explanation. But something
else in the data caught his eye. Every decade or so, the testing companies
would generate new tests and re-normalize them so that the average score was
100. To make sure that the new exams were in sync with previous ones, they'd
have a batch of students take both tests. They were simply trying to confirm
that someone who tested above average on the new version would perform above
average on the old, and in fact the results confirmed that correlation. But the
data also brought to light another pattern, one that the testing companies
ignored. "Every time kids took the new and the old tests, they did better on
the old ones," Flynn says. "I thought: That's weird."
The testing companies had published the comparative data almost as an
afterthought. "It didn't seem to strike them as interesting that the kids were
always doing better on the earlier test," he says. "But I was new to the area."
He sent his data to the Harvard Educational Review, which dismissed the paper
for its small sample size. And so Flynn dug up every study that had ever been
done in the US where the same subjects took a new and an old version of an IQ
test. "And lo and behold, when you examined that huge collection of data, it
revealed a 14-point gain between 1932 and 1978." According to Flynn's numbers,
if someone testing in the top 18 percent the year FDR was elected were to
time-travel to the middle of the Carter administration, he would score at the
When Flynn finally published his work in 1984, Jensen objected that Flynn's
numbers were drawing on tests that reflected educational background. He
predicted that the Flynn effect would disappear if one were to look at tests -
like the Raven Progressive Matrices - that give a closer approximation of g, by
measuring abstract reasoning and pattern recognition and eliminating language
altogether. And so Flynn dutifully collected IQ data from all over the world.
All of it showed dramatic increases. "The biggest of all were on Ravens," Flynn
reports with a hint of glee still in his voice.
The trend Flynn discovered in the mid-'80s has been investigated extensively,
and there's little doubt he's right. In fact, the Flynn effect is accelerating.
US test takers gained 17 IQ points between 1947 and 2001. The annual gain from
1947 through 1972 was 0.31 IQ point, but by the '90s it had crept up to 0.36.
Though the Flynn effect is now widely accepted, its existence has in turn
raised new questions. The most fundamental: Why are measures of intelligence
going up? The phenomenon would seem to make no sense in light of the evidence
that g is largely an inherited trait. We're certainly not evolving that
The classic heritability research paradigm is the twin adoption study: Look at
IQ scores for thousands of individuals with various forms of shared genes and
environments, and hunt for correlations. This is the sort of chart you get,
with 100 being a perfect match and 0 pure randomness:
The same person tested twice: 87
Identical twins raised together: 86
Identical twins raised apart: 76
Fraternal twins raised together: 55
Biological siblings: 47
Parents and children living together: 40
Parents and children living apart: 31
Adopted children living together: 0
Unrelated people living apart: 0
After analyzing these shifting ratios of shared genes and the environment for
several decades, the consensus grew, in the '90s, that heritability for IQ was
around 0.6 - or about 60 percent. The two most powerful indications of this are
at the top and bottom of the chart: Identical twins raised in different
environments have IQs almost as similar to each other as the same person tested
twice, while adopted children living together - shared environment, but no
shared genes - show no correlation. When you look at a chart like that, the
evidence for significant heritability looks undeniable.
Four years ago, Flynn and William Dickens, a Brookings Institution economist,
proposed another explanation, one made apparent to them by the Flynn effect.
Imagine "somebody who starts out with a tiny little physiological advantage:
He's just a bit taller than his friends," Dickens says. "That person is going
to be just a bit better at basketball." Thanks to this minor height advantage,
he tends to enjoy pickup basketball games. He goes on to play in high school,
where he gets excellent coaching and accumulates more experience and skill.
"And that sets up a cycle that could, say, take him all the way to the NBA,"
Now imagine this person has an identical twin raised separately. He, too, will
share the height advantage, and so be more likely to find his way into the same
cycle. And when some imagined basketball geneticist surveys the data at the end
of that cycle, he'll report that two identical twins raised apart share an
off-the-charts ability at basketball. "If you did a genetic analysis, you'd
say: Well, this guy had a gene that made him a better basketball player,"
Dickens says. "But the fact is, that gene is making him 1 percent better, and
the other 99 percent is that because he's slightly taller, he got all this
environmental support." And what goes for basketball goes for intelligence:
Small genetic differences get picked up and magnified in the environment,
resulting in dramatically enhanced skills. "The heritability studies weren't
wrong," Flynn says. "We just misinterpreted them."
Dickens and Flynn showed that the environment could affect heritable traits
like IQ, but one mystery remained: What part of our allegedly dumbed-down
environment is making us smarter? It's not schools, since the tests that
measure education-driven skills haven't shown the same steady gains. It's not
nutrition - general improvement in diet leveled off in most industrialized
countries shortly after World War II, just as the Flynn effect was
Most cognitive scholars remain genuinely perplexed. "I find it a puzzle and
don't have a compelling explanation," wrote Harvard's Steven Pinker in an email
exchange. "I suspect that it's either practice at taking tests or perhaps a
large number of disparate factors that add up to the linear trend."
Flynn has his theories, though they're still speculative. "For a long time it
bothered me that g was going up without an across-the-board increase in other
tests," he says. If g measured general intelligence, then a long-term increase
should trickle over into other subtests. "And then I realized that society has
priorities. Let's say we're too cheap to hire good high school math teachers.
So while we may want to improve arithmetical reasoning skills, we just don't.
On the other hand, with smaller families, more leisure, and more energy to use
leisure for cognitively demanding pursuits, we may improve - without realizing
it - on-the-spot problem-solving, like you see with Ravens."
When you take the Ravens test, you're confronted with a series of visual grids,
each containing a mix of shapes that seem vaguely related to one another. Each
grid contains a missing shape; to answer the implicit question posed by the
test, you need to pick the correct missing shape from a selection of eight
possibilities. To "solve" these puzzles, in other words, you have to scrutinize
a changing set of icons, looking for unusual patterns and correlations among
This is not the kind of thinking that happens when you read a book or have a
conversation with someone or take a history exam. But it is precisely the kind
of mental work you do when you, say, struggle to program a VCR or master the
interface on your new cell phone.
Over the last 50 years, we've had to cope with an explosion of media,
technologies, and interfaces, from the TV clicker to the World Wide Web. And
every new form of visual media - interactive visual media in particular - poses
an implicit challenge to our brains: We have to work through the logic of the
new interface, follow clues, sense relationships. Perhaps unsurprisingly, these
are the very skills that the Ravens tests measure - you survey a field of
visual icons and look for unusual patterns.
The best example of brain-boosting media may be videogames. Mastering visual
puzzles is the whole point of the exercise - whether it's the spatial geometry
of Tetris, the engineering riddles of Myst, or the urban mapping of Grand Theft
The ultimate test of the "cognitively demanding leisure" hypothesis may come in
the next few years, as the generation raised on hypertext and massively complex
game worlds starts taking adult IQ tests. This is a generation of kids who, in
many cases, learned to puzzle through the visual patterns of graphic interfaces
before they learned to read. Their fundamental intellectual powers weren't
shaped only by coping with words on a page. They acquired an intuitive
understanding of shapes and environments, all of them laced with patterns that
can be detected if you think hard enough. Their parents may have enhanced their
fluid intelligence by playing Tetris or learning the visual grammar of TV
advertising. But that's child's play compared with Pokémon.
Contributing editor Steven Johnson (stevenberlinjohnson at earthlink.net) is the
author of Everything Bad Is Good for You: How Today's Popular Culture Is
Actually Making Us Smarter.
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