

If Smart Is the Norm, Stupidity Gets More Interesting - tokenadult
http://www.nytimes.com/2012/10/23/health/if-intelligence-is-the-norm-stupidity-gets-more-interesting.html

======
tokenadult
Editing has happened to this comment since the first reply was posted to it.
At first I just shared some links to scholarly articles on genetic influences
on human intelligence, as I was about to go out the door to have a walk with
my son the hacker as this article reached HN's front page. Now I'm back at my
computer to provide some more commentary on helpful background reading for the
newspaper article from today (which I learned about from a researcher on this
issue). Over the years here on HN, I have often seen mistaken conclusions
about "heritability" and its relationship to human intelligence from HN
participants who haven't kept up with the current research literature. I keep
up with the current research literature on human behavioral genetics by weekly
visits during the school year to the Readings in Behavioral Genetics and
Individual Differences Psychology "journal club" (graduate seminar) at the
University of Minnesota.

<http://www.psych.umn.edu/ugrad/pastsyllabi.html>

(One or two past syllabuses of the seminar are available above. The current
course page

<http://www.psych.umn.edu/courses/mcgue/psy8935/>

has log-in authentication to facilitate sharing current journal articles among
seminar participants. The seminar also has an email list from which I learned
about the New York Times article submitted here, just after today's seminar.)

An old-fashioned view of heritability estimates for human intelligence, which
I see repeated frequently on HN, is that heritability constrains
controllability ("malleability") of human behavioral traits. Nothing could be
further from the truth.

Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard Jr., Thomas
(2009). Beyond Heritability: Twin Studies in Behavioral Research. Current
Directions in Psychological Science, 18, 4, 217-220

[http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...](http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Johnson%20\(2009\).pdf)

is an interesting paper by some of the researchers most familiar with research
on human twins, including the director of the Minnesota Study of Identical
Twins Reared Apart, which includes the statement "Moreover, even highly
heritable traits can be strongly manipulated by the environment, so
heritability has little if anything to do with controllability. For example,
height is on the order of 90% heritable, yet North and South Koreans, who come
from the same genetic background, presently differ in average height by a full
6 inches (Pak, 2004; Schwekendiek, 2008)."

Another interesting paper,

Turkheimer, E. (2008, Spring). A better way to use twins for developmental
research. LIFE Newsletter, 2, 1-5

[http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...](http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20\(2008\).pdf)

admits the disappointment of behavioral genetics researchers. Eric Turkheimer,
a leading scholar in the Behavior Genetics Association, points out that the
interpretation often given to "heritability" findings that they somehow
measure genetic constraint on variation in a human trait is wrong.

"But back to the question: What does heritability mean? Almost everyone who
has ever thought about heritability has reached a commonsense intuition about
it: One way or another, heritability has to be some kind of index of how
genetic a trait is. That intuition explains why so many thousands of
heritability coefficients have been calculated over the years. Once the twin
registries have been assembled, it’s easy and fun, like having a genoscope you
can point at one trait after another to take a reading of how genetic things
are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That
looks pretty genetic too. Personality? Yep, that too. And over multiple
studies and traits the heritabilities go up and down, providing the basis for
nearly infinite Talmudic revisions of the grand theories of the heritability
of things, perfect grist for the wheels of social science.

"Unfortunately, that fundamental intuition is wrong. Heritability isn’t an
index of how genetic a trait is. A great deal of time has been wasted in the
effort of measuring the heritability of traits in the false expectation that
somehow the genetic nature of psychological phenomena would be revealed. There
are many reasons for making this strong statement, but the most important of
them harkens back to the description of heritability as an effect size. An
effect size of the R2 family is a standardized estimate of the proportion of
the variance in one variable that is reduced when another variable is held
constant statistically. In this case it is an estimate of how much the
variance of a trait would be reduced if everyone were genetically identical.
With a moment’s thought you can see that the answer to the question of how
much variance would be reduced if everyone was genetically identical depends
crucially on how genetically different everyone was in the first place."

I regret that the recent review article "The neuroscience of human
intelligence differences" by Deary and Johnson and Penke (2010), relating
specifically to human intelligence,

[http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neur...](http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neuroscience_of_intelligence_review.pdf)

has not received more discussion on HN. "At this point, it seems unlikely that
single genetic loci have major effects on normal-range intelligence. For
example, a modestly sized genome-wide study of the general intelligence factor
derived from ten separate test scores in the cAnTAB cognitive test battery did
not find any important genome-wide single nucleotide polymorphisms or copy
number variants, and did not replicate genetic variants that had previously
been associated with cognitive ability[note 48]."

The review article Johnson, W. (2010). Understanding the Genetics of
Intelligence: Can Height Help? Can Corn Oil?. Current Directions in
Psychological Science, 19(3), 177-182

[http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/...](http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/Johnson%20Current%20Directions%20Psych%20Science%202010%20\(G%20and%20E%20in%20IQ\).pdf)

is an article I submitted as a new submission on HN a little while ago. The
article looks at some famous genetic experiments to show how little is
explained by gene frequencies even in thoroughly studied populations defined
by artificial selection.

"Together, however, the developmental natures of GCA [that is, IQ] and height,
the likely influences of gene–environment correlations and interactions on
their developmental processes, and the potential for genetic background and
environmental circumstances to release previously unexpressed genetic
variation suggest that very different combinations of genes may produce
identical IQs or heights or levels of any other psychological trait. And the
same genes may produce very different IQs and heights against different
genetic backgrounds and in different environmental circumstances."

The brand new review article

Chabris, C. F., Hebert, B. M., Benjamin, D. J., Beauchamp, J., Cesarini, D.,
van der Loos, M., ... & Laibson, D. (2012). Most reported genetic associations
with general intelligence are probably false positives. Psychological Science.

[http://coglab.wjh.harvard.edu/~cfc/Chabris2012a-FalsePositiv...](http://coglab.wjh.harvard.edu/~cfc/Chabris2012a-FalsePositivesGenesIQ.pdf)

is especially important for discussing social science implications of what
genetic studies have shown for years now. Social scientists are still catching
up with how little certainty attaches to genetic studies of human intelligence
--except for the certainty, as reported in today's article, that most genetic
influences on IQ are small in effect.

"At the time most of the results we attempted to replicate were obtained,
candidate-gene studies of complex traits were commonplace in medical genetics
research. Such studies are now rarely published in leading journals. Our
results add IQ to the list of phenotypes that must be approached with great
caution when considering published molecular genetic associations. In our
view, excitement over the value of behavioral and molecular genetic studies in
the social sciences should be tempered—as it has been in the medical
sciences—by a recognition that, for complex phenotypes, individual common
genetic variants of the sort assayed by SNP microarrays are likely to have
very small effects.

"Associations of candidate genes with psychological traits and other traits
studied in the social sciences should be viewed as tentative until they have
been replicated in multiple large samples. Failing to exercise such caution
may hamper scientific progress by allowing for the proliferation of
potentially false results, which may then influence the research agendas of
scientists who do not realize that the associations they take as a starting
point for their efforts may not be real. And the dissemination of false
results to the public may lead to incorrect perceptions about the state of
knowledge in the field, especially knowledge concerning genetic variants that
have been described as 'genes for' traits on the basis of unintentionally
inflated estimates of effect size and statistical significance."

I beg the pardon of the first participant to reply, who was annoyed by my
submitting full journal citations with links to full text and relevant
quotations of the article conclusions. In my own personal opinion, sometimes a
Hacker News comment that links to sound research literature is more useful to
participants here than expressions of personal opinion based on individual
anecdotes. But reasonable minds can differ on such an issue, and I'm happy to
add the commentary here that I once had a much different view of the genetic
influences on human intelligence (the first popular articles I read on the
subject, back in the 1970s and 1980s, were by Arthur Jensen and the late
Richard Herrnstein) but I've had opportunity to learn about new research over
the last twenty years, and I now know, and like to tell my friends on Hacker
News, about the current consensus view that intelligence is largely a trait
fixed in the genome of Homo sapiens, linked to hundreds of genes each of weak
individual effect, and that most variance between one individual and another
in IQ comes from poorly understood gene mutations and environmental influences
that may be much more powerful than was once supposed.

~~~
niels_olson
I see your edit, thanks[1]. But there are better[2] ways to cite in a forum
[3].

\--

[1] citation 1

[2] citation 2

[3] citation 3

~~~
beefman
Why is this better?

~~~
niels_olson
Because it is the universal standard, from when the internet protocols
involved mail carriers and the packets involved sheets of paper. It is the
universal standard because it interrupts the flow of thought as little as
possible. If I decide I want read their articles, I will.

------
pg
It could be even more complicated than that. Intelligence could be a question
of proportion, like beauty.

~~~
tokenadult
_Intelligence could be a question of proportion, like beauty._

Could you expand on that a little, please? How would a working scientist test
the hypothesis you advance here?

~~~
pg
In the simplest case, imagine that there are genes that determine quality x,
and others that determine quality y, and intelligence depends on how close x/y
is to some constant c.

If intelligence were determined by genes in that way, you wouldn't find it by
looking for ("smart") genes whose presence was correlated with intelligence,
or ("stupid") genes whose absence was.

I used beauty as an example because it seems unlikely that there is a single
"beauty" gene whose presence makes human faces beautiful, but rather that
beauty is a product of the interaction of multiple genes that control the
dimensions of the face.

~~~
thewarrior
I would like to elaborate on that idea by saying that there is a feedback loop
between the persons environment and his innate tendencies . I'm specifically
referring to the feeling of satisfaction you get as you become better and
better at something . It is that feeling of satisfaction and the inner drive
that would provide the impetus needed to continue working harder and harder to
master the discipline . However if all the components aren't in "proportion" ,
this feedback loop between practice -> improvement -> satisfaction -> urge to
practice more gets broken .

------
47uF
Why is the idea of innate IQ still taken seriously if there's so little
evidence for it? If intelligence is just the ability to think in a structured
abstract way, doesn't it make sense to think of it as a skill developed over
time? I mean, it's not hard to think of spending most of your time in a
different mode of thought. I'd say that for most people their normal day to
day tends to require concrete or social/emotional information processing.

If it seems that intelligence (specifically abstract structured thought) seems
to stabilize early in life, maybe it's something that starts developing even
earlier. A strategy for prioritizing, filtering, and processing information
from a world of endless stimuli (of which abstract/structured would be only
one such strategy) would start developing the moment we're born. By the time
you're 10, you'd already have 10 years of "practice".

~~~
lumberjack
You are confusing things.

First and foremost you don't need evidence to look for evidence. A hypothesis
is enough.

Secondly, there is evidence that IQ is at least in part genetic. There is no
other way to explain geniuses, child prodigies, and mentally retarded
individuals whose environments vary greatly.

~~~
Evbn
Sure there is: chemical exposure balance or random variation in the uterine or
infant environment.

Fetal alcohol syndrome reliably retards kids, and it isn't genetically
inherited. Hypothetically, maybe something like adderall works in utero with
lifelong effects.

Also, hypothesis formation should be motivated by data, or else you are
wasting time searching through an exponential space with 0 probability of
finding a correct one.

------
guylhem
Serendipity - just the other day I was replying to a comment about education
and IQ and explained I didn't believed in ethnic differences of IQ, but also
in IQ altogether - <http://news.ycombinator.com/item?id=4680279>

At least looking for "dumb genes" is more plausible, because if IQ is an
aggregate of multiple functions, some functions could be separately damaged

Copy paste:

 _The current perspective of IQ and ethnicities show that while there might be
slight differences, they are dwarfed by the differences in the education
process.

Regarding IQ:

First, I don't believe that IQ exist as a measurable quantity - IQ is too many
things thrown together in a single bad. Tests group together various things
which may be handled by different subsystems in the brain. If there is
something called IQ, it's an aggregate.

Anyway, if there was such a unique quantity, actual data shows a progression
of IQ scores in time - therefore if the tests are considered accurate and
unbiased, it must be a "quantity" that can evolve based on the society a
person lives it. It should then be considered not as a value, but as a
function depending on a variable called society.

I do not know if studies have tried to measure the accuracy of repetitive
measurement in low education adults enrolled in a learning program. If there
are such studies and if they show inconsistent result (ie any change of IQ),
then IQ should be considered as a function of 2 variables : f(society,
personal experience).

Now, even if we consider that at a time t it could be accurately measured and
that societal bias could be removed, considering how other qualities (such as
determination, work ethic, consistency, creativity, competitiveness...)
influence the outcome of any human activity, it seems foolish to rank people
based on just one quality - especially if we don't know the other values, and
their individual ponderation in the end result.

This ponderation could also be different depending on the activity, and IQ
provide an absolute advantage in some activities (rhetoric?), but say
determination would give an absolute advantage in other activities
(startups?)._

~~~
lumberjack
>Anyway, if there was such a unique quantity, actual data shows a progression
of IQ scores in time - therefore if the tests are considered accurate and
unbiased, it must be a "quantity" that can evolve based on the society a
person lives it. It should then be considered not as a value, but as a
function depending on a variable called society.

Seriously? Couldn't it just be the subjects getting used to the tests? That's
not the point though. It doesn't mean subjects are getting smarter. It just
means they are learning, which is natural. However if we have two subjects and
subject A gets 115 IQ points the first time while subject B gets 104, 111,
113, 115 IQ points after four consecutive test respectively, it's clear that
subject A is superior intellectually in that they can achieve more in less
time.

~~~
guylhem
That's not exactly the idea. See <http://en.wikipedia.org/wiki/Flynn_effect>

Maybe a full society is getting used to the tests, or maybe the tests are
biased.

Even with you example (considering repetitive test at the same time on 2
person from the same society), it could show many things: a) that the
measurement is flawed b) that you should retest A to see if he also get better
scores c) failing that, A has a fixed IQ score while B can improve d) if A
improves too what's the limit?

Finally, "it's clear that subject A is superior intellectually " - even if B
would get say 120 on its final test while A ends with 118??

------
dschiptsov
Which seed will grow better depends not just of its genes, but also of
environment, weather and of how much it was fertilized.

This, for example, is one of the answers why _rich getting richer_. The
difference in environment + variety of experience matters much more than
difference in genes, in cases where there is no inherited disorder.

By changing environment, behavior and altering mental models (unlearning the
learned helplessness, for example) it is possible to improve even IQ scores.

This is how the Flynn effect works - it is effect of the environment + variety
of experience.

------
niels_olson
During commencement at our medical school, one of the second-years on stage
said "I know what you're all thinking: you were expecting all sorts of crazy
intellectuals and artists. But everyone is so . . . normal."

~~~
mb_72
'Real' crazy intellectuals and artists don't study medicine, they study the
Humanities or don't study at all. The rigor and discipline required of medical
students and doctors would actually favour those being 'normal'; I wouldn't,
personally, have expected anything else.

