
Genetics and intelligence differences: five special findings - tokenadult
http://www.nature.com/mp/journal/vaop/ncurrent/full/mp2014105a.html
======
FD3SA
I never understood why the politically correct crowd happily accepts that
athletic ability is heritable, yet when it comes to intelligence suddenly all
bets are off.

As soon as we accept reality for what it is, we can begin adapting our
societies and policies to maximize opportunities for individuals with the
knowledge that our talents and limitations vary quite drastically.

~~~
ap22213
It's not that I don't believe that intelligence is heritable. I do. It's more
that I don't believe that it's all that important to be intelligent in order
to be a good Human.

People have a natural attraction to those similar to them. In history, the
over-emphasis of particular and possibly unimportant (who knows?) traits has
often been the cause for wars, genocides and all sorts of other evils.

Further, I don't think that relative Human intelligence has all that much
magnitude. That is - a 'really intelligent' Human is not all that different
from a 'non-intelligent' one, taken in the context of other species. And,
those non-intelligent ones may have particularly interesting genetics that
make them important to the species, in other ways.

Humans have done pretty well as a species with lots of diversity. Why ruin a
good thing? And, do you really want Humanity to be comprised of near clones?

~~~
jiggy2011
Probably because the jobs traditionally done by the less intelligent are being
shipped overseas or done by machines leaving these people in poor economic
circumstances. Intelligent people would not have to be clones, smart people
can be quite different from each other in terms of personality, areas of
interest etc.

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gliese1337
You can probably guess it from context, but I had to look this up to be sure,
so for the benefit of others: assortative mating is when you have kids with
other people similar to you, rather than selecting mates randomly. In other
words, in this case, people with high intelligence tend to marry other people
with high intelligence, and people with low intelligence marry other people
with low intelligence. This causes the variance in the distribution of
intelligence to steadily increase, rather than everybody evening out over a
few generations.

~~~
phkahler
And if a society values intelligence, they should encourage smarter people to
reproduce and offer as much birth control as possible to less smart people.
Following this line of reasoning and policy is sure to ignite all kinds of
flame wars ;-)

~~~
tjradcliffe
There is an interesting and much-neglected corollary to the heritability of
intelligence, which is that we are part of the least intelligent generation of
humanity that has ever lived.

This follows from the two conditions:

1) intelligence is at least somewhat heritable (empirically true, according to
the article)

and

2) intelligence is positively correlated with reproductive success (plausible
give humans seem to have been selected for it)

The conclusion follows from the way world population has exploded in the past
250 years, increasing roughly ten-fold in twenty or twenty-five generations.
That increase equates to "zero selective pressure": basically anybody could
breed successfully, and they did (including my ancestors, some of whom
occupied the more stagnant and brackish depths of the gene pool...)

So up until 1750 or so intelligence was being selected for, generation after
generation. After that time, there was no pressure and the many small effects
that this article documents as underlying the heritability of intelligence
(with no single gene showing as much as a 1% effect on the overall outcome)
would happily carry us all on a random walk across the landscape, creating
engineers in some parts and political partisans in others.

This realization makes particularly funny the various organizations that have
at times promoted Nobelists etc as pinnacles of intelligence (William Shockly,
inventor of the transistor, was heavily involved in this kind of thing).
Nobelists are certainly bright, but it seems more likely you'd find the most
intelligent people amongst still-extant stone age tribes, whose pre-industrial
life-style would still subject them to selective pressures long released in
the more-developed world.

~~~
jostmey
Reminds me of the recent study where Chimps beat humans in a simple strategy
game.

~~~
vikiomega9
Do you remember the name?

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hackuser
Would someone decode what Nature means by "open" and "expert review"? What is
"open" about it? Is this settled science, one person's hypothesis, or
something in between?

~~~
w1ntermute
1\. Open = free (no subscription required)

2\. Expert review = exactly what it sounds like (as opposed to original
research)

3\. Something in-between

~~~
gwern
Is it really 'something in-between'? This is
[https://en.wikipedia.org/wiki/Robert_Plomin](https://en.wikipedia.org/wiki/Robert_Plomin)
\- if there's a greater living behavioral geneticist, his name escapes me.

~~~
hackuser
> Is it really 'something in-between'? This is
> [https://en.wikipedia.org/wiki/Robert_Plomin](https://en.wikipedia.org/wiki/Robert_Plomin)
> \- if there's a greater living behavioral geneticist, his name escapes me.

That is a valuable piece of information for us lay people. Do non-geneticists
studying the issue generally agree with him?

------
tormeh
It's kind of trite and obvious by now, but can we please kill the "Everyone
gets what they deserve" line of thinking?

~~~
arethuza
The idea that "they deserve whatever they can get" is one of the criticisms of
modern UK/US culture made by Michael Young who actually coined the term in his
satirical book _The Rise of the Meritocracy_ :

[http://www.theguardian.com/politics/2001/jun/29/comment](http://www.theguardian.com/politics/2001/jun/29/comment)

[Edit: I don't know about the US but here in the UK it is fairly common to
define "merit" in ways that don't actually seem to include "performance" \-
though I think this is a far bigger problem in the public sector than the
private].

~~~
roywiggins
This is basically the "just world" fallacy writ large, right?

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vince_refiti
Q: What is intelligence? A: Thing that is measured with intelligence tests.

Q: What are intelligence tests? A: Things that measure intelligence.

~~~
lambdaphage
This pair of rhetorical questions actually has a non-rhetorical answer, and it
is far more interesting (though less precious) than the one implied here.

This being the internet, the serious answer is a mouseclick away:
[http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29](http://en.wikipedia.org/wiki/G_factor_%28psychometrics%29)

~~~
vince_refiti
It is more correctly circular reasoning. The psychometric measure g does not
break this circle at all. I will never believe in "intelligence tests" until
this circular reasoning can be broken.

~~~
lambdaphage
Why do you think we observe the positive manifold, then?

~~~
vince_refiti
I do not know why the positive manifold is as it is. But it still seems like
it is a precise measure of an inaccuracy.

What I am getting at in a roundabout way is that I cannot find any credible
definition of intelligence that is not dependent on the these tests. If
intelligence were able to measured some other way that corroborated these
tests, then I will be more likely to believe them.

------
tokenadult
Thanks for the interesting comments posted while I was watching my sons play
soccer this evening. To answer some questions that came up in various
subthreads, yes, both Robert Plomin and Ian Deary are mainstream researchers
on the behavior genetics of human intelligence, the authors of well regarded
textbooks (Plomin), popular books (both), and primary research articles (both)
on various related topics. Their joint point of view as expressed in the
review article published today is not the exact point of view of all
researchers in the field, but I thought it would do as a discussion-starter
here on Hacker News.

A crucial detail (Deary and Plomin would both agree about this, but it hasn't
come up in the discussion here yet) is that heritablity has NOTHING to do with
modifiability. It is quite possible in principle that a novel environmental
intervention might be discovered that could boost most people's intelligence.
It is even possible that the most effective intervention might have a gene-
environment (G × E) interaction such that the intervention would most help
people with lowest IQ, and least help people who already have high IQs. No
such intervention that human beings can direct purposefully has yet been
found, but it is clear from the Flynn effect[1] that something in the
environment can have powerful effects in raising average IQ levels of whole
countries, as has happened in the developed world throughout the last century
(for as long as IQ tests have been around).

It is correct that people marry and have children on bases other than just
shared level of intelligence. (But living in the same town, and completing
higher education at similar ages, and pursuing compatible occupations for
marriage, etc. is correlated with IQ.) It is still far too early to say how
rapidly human populations might see noticeable effects from assortative mating
by IQ. It is reasonably clear that often-feared dysenic trends probably are
NOT happening--the lowest-IQ people in the world population don't reproduce at
all, and high-IQ people actually have reasonable numbers of children to
replicate their genes. In any event, the favorable environmental trends have
SWAMPED whatever genetic trends are going on for IQ in the whole human
population, and people are getting smarter all over the world, according to
the research on the Flynn effect.

It is still a hard problem to identify anything at all meaningful and
replicable about how gene differences influence IQ differences, even though it
is now settled wisdom that they do. Human IQ, as the article says, is
influenced by MANY genes, and many of those genes interact with one another in
ways that are not understood at all yet.

[1]
[https://www.ted.com/talks/james_flynn_why_our_iq_levels_are_...](https://www.ted.com/talks/james_flynn_why_our_iq_levels_are_higher_than_our_grandparents)

[http://blog.ted.com/2013/09/26/further-reading-on-the-
flynn-...](http://blog.ted.com/2013/09/26/further-reading-on-the-flynn-
effect/)

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spindritf
_Plominism: The Christian heresy that salvation is neither by faith nor by
works, but 50% hereditary and 50% based on non-shared environment_

[https://twitter.com/slatestarcodex/status/500107441762074625](https://twitter.com/slatestarcodex/status/500107441762074625)

------
socialist_coder
So, it seems to follow that one could take a bunch of fertilized embryos,
measure the genome-wide polygenic score (GPS) of each embryo, then select only
the best one.

The only thing missing is that the genome-wide polygenic score (GPS) for
intelligence has yet to be discovered.

Unfortunately, even when something like this is possible, it would probably be
made illegal even though it would surely be a positive thing for humanity.

