IQ And Disease:  The Curious Case of the Ashkenazi Jews

The slow liberation of the
Mainstream Media from the deathgrip of political
correctness accelerated last week with startlingly
courageous coverage in The Economist and the
New York Times
of the potentially epochal scientific
paper by Gregory Cochran, Henry Harpending, and Jason
Hardy entitled

The Natural History of Ashkenazi Intelligence

[PDF file].

The Economist headlined its
anonymous article:

"Natural
Genius? The evolution of intelligence: The high
intelligence of Ashkenazi Jews may be a result of their
persecuted past.
" (
June 2, 2005).

And in "Researchers
Say Intelligence and Diseases May Be Linked in
Ashkenazic Genes
,"
[
June 2, 2005] the
NYT`s redoubtable genetics reporter

Nicholas Wade
reported

"`It
would be hard to overstate how politically incorrect
this paper is,` said

Steven Pinker
, a cognitive scientist at Harvard,
noting that it argues for an

inherited difference in intelligence between groups
.
Still, he said, `it`s certainly a thorough and
well-argued paper, not one that can easily be dismissed
outright.`"

The high average intelligence of
the

Ashkenazi
Jews (essentially, Jews from Northern
Europe whose

ancestors
spoke Yiddish, ancestors of the great
majority of Jewish Americans) has had an

enormous impact
on the modern world.

(Jews from the

Muslim world
score somewhat lower than Ashkenazis,
which leads to a sizable social gap within Israel.)

The Economist reported:


"Ashkenazim generally do well in IQ tests, scoring 12-15
points above the mean value of 100…"

Which is not an enormous gap.
Assuming a 12 point difference between Ashkenazis and
white gentiles, it suggests that the median Ashkenazi
scores somewhere around the 80th percentile among all
whites. Many gentiles have higher IQs than many Jews.

But this difference in median
intelligence does lead to large differences at the far
right edge of the

bell curve.

For
example, some back-of-an-envelope math suggests that
Ashkenazi Jews are roughly an order of magnitude more
likely than white gentiles to have IQs above 145.
Roughly one in 70 Ashkenazi Jews score above 145
compared to one in 700 white gentiles. There are about
30 times as many white gentile adults as Ashkenazi Jews
in the U.S. So that implies one-fourth of white
Americans with IQs above 145 are Ashkenazi Jews.

Ashkenazi levels of

real world accomplishment
are

impressive
and thus support the IQ studies. Jewish
Americans make up no more than three percent of the U.S.
adult population. But in the 1995 book

Jews and the New American Scene
, the prominent
social scientist Seymour Martin Lipset, a Senior Scholar
of the

Wilstein Institute for Jewish Policy Studies
, and
Earl Raab, Director of the Perlmutter Institute for
Jewish Advocacy at Brandeis University, pointed out

"During
the last three decades, Jews have made up 50% of the top
two hundred

intellectuals
, 40 percent of American

Nobel Prize Winners in science
and

economics
, 20 percent of professors at the leading
universities, 21 percent of high level civil servants,
40 percent of partners in the leading law firms in New
York and Washington, 26% of the reporters, editors, and
executives of the major print and broadcast media, 59
percent of the

directors, writers, and producers
of the fifty
top-grossing motion pictures from 1965 to 1982, and 58
percent of directors, writers, and producers in two or
more

primetime television series
."
[pp 26-27]

Interestingly, the Ashkenazi
cognitive advantage seems to be mostly in verbal and
numeric, rather than visual, skills. For example, in
Hollywood, fewer top

cinematographers
are Jewish compared to
screenwriters or agents.

Ashkenazi intelligence is one of
those facts that are obvious, important, and
interesting, yet, is largely unmentionable in polite
society… at least until this week.

The Cochran-Harpending theory may
turn out to justify the audacity of The Economist
and the NYT in breaking this taboo. If validated,
it would prove a landmark in the fields of medicine,
population genetics, IQ research, and even history.

Wade reported in the NYT:

"A team
of scientists at the University of Utah has proposed
that the unusual pattern of genetic diseases seen among
Jews of central or northern European origin, or
Ashkenazim, is the result of natural selection for
enhanced intellectual ability. The selective force was
the restriction of Ashkenazim in medieval Europe to
occupations that required more than usual mental
agility… Ashkenazic diseases like Tay-Sachs, they say,
are a side effect of genes that promote intelligence."

Wade goes on to note that this
theory was anticipated by Jared Diamond, the celebrated
author of the Pulitzer Prize-winning

Guns, Germs, and Steel
(here`s my

review
). Diamond pointed out in 1994 that one
possible explanation for these Ashkenazi hereditary
diseases is:


"selection in Jews for the intelligence putatively
required to survive recurrent persecution, and also to
make a living by commerce, because Jews were barred from
the

agricultural jobs
available to the non-Jewish
population."

In their brilliant
cross-disciplinary

essay
, which will appear soon in the

Journal of Biosocial Science
, the three
University of Utah researchers show that from about 800
to 1700 A.D., Yiddish-speaking Jews were almost
completely confined to cognitively-demanding occupations
such as finance, fields in which intelligence pays off
more than in peasant farming.

They cite records showing that
wealthy Jews had more children survive to adulthood than
poor Jews. Moreover,

medieval Jews
were sufficiently endogamous (marrying
within the ethnic group) to prevent gene flow from the
gentile population, which might have diluted the effects
of this selection mechanism.

Contrary to the layman`s assumption
that Darwinian selection can only putter along at
geological speeds, the authors mathematically
demonstrate that the 35 generations during these nine
centuries offered enough time for mutations conferring
greater business acumen to spread widely among the
Ashkenazi.

Sadly, however, there haven`t been
enough generations for natural selection to refine away
the downsides to some of these intelligence-boosting
mutations.

Cochran, Harpending, and Hardy cite
evidence that the victims of three hereditary diseases
that primarily afflict Ashkenazis tending to be smarter
than even other Ashkenazis. For example, a study of
patients with torsion dystonia, which until recently put
10 percent of its victims in wheelchairs, found their
average IQ was 121.

Tay-Sachs and several other
Ashkenazi sphingolipid neurological diseases could be
analogous to sickle cell anemia, which is the snag in
nature`s initial attempt to provide genetic protection
against the horrendous tropical killer,

falciparum malaria
.

That mosquito-borne disease appears
to have only become a devastating threat a few thousand
years ago, when agriculture began in Sub-Saharan Africa.
Enough generations have since gone by for the sickle
cell mutation to emerge and spread in tropical Africa
and other warm places ravaged by this most deadly of
malarias. If you inherit a copy of the sickle cell gene
from one of your parents, you are more likely to survive

falciparum malaria.
But, unfortunately, if you
inherit copies from both of your parents, you will die
in infancy—unless you get modern medical care.

The sickle cell gene increases
until the benefit it provides in surviving malaria is
equaled by the toll it takes in sickle cell anemia.

The Ashkenazi sphingolipid
disorders could be similar. In the great tradition of
Einstein`s paper on the

General Theory of Relativity,
the Utah authors have
proposed a straight-forward test of one part of their
theory: people with one copy of the genes that cause the
Ashkenazi sphingolipid diseases should have higher IQs
than their siblings who have no copies.

If validated, the implications of
this discovery would be extraordinarily broad.

With luck, it could lead to better
treatments of victims of these diseases.

It could also aid understanding of
the genetics of intelligence, which in turn might lead
to "smart pills" or genetic engineering to boost
IQ.

Whether or not that would be a good
thing for the human race is difficult to say at present.
But allowing the honest study of the social impact of
existing genetic differences would help us

make better informed decisions
about whether we want
to permit bioengineers to create new genetic disparities
in the lab.

The savage persecutions suffered by
Jews suggest that high intelligence can generate
resentment among the masses. No doubt there will be some
who will suggest that the Cochran-Harpending paper
should have been suppressed to prevent awareness of the
secret of Ashkenazi intelligence from seeping out.

But you have to be a true-blue
intellectual to assume that the only way anybody would
ever notice anything as obvious as Jewish brainpower is
if it gets mentioned in the New York Times.
Political correctness doesn`t keep facts from being
talked about—just from being written about in an
intelligent, constructive manner.

On the other hand, the happier
experience of another ethnic minority that may also have
evolved stronger intellectual capacities under similar
urban conditions—the prosperous

Parsis
of Bombay—may offer clues to mitigating envy.

In any case, the Cochran-Harpending
paper offers a fairly new but crucial perspective on the
old nature and nurture question. The researchers have
demonstrated that it`s quite possible for nurture to
change nature
. Culture can drive heredity. Economics
and social customs alter gene frequencies.

Of course, we already knew that
from examples such as

lactose intolerance
. Once, virtually no adult could
easily digest milk. But after some tribes started
herding and milking dairy livestock, one or more
mutations providing lactose tolerance popped up and
spread among them. Thus today, only two percent of Danes
are lactose intolerant, compared to

90 percent of Asian Americans.

There may be many more examples of
the environment molding genes. For instance, I recently

described
how the economics of tropical agriculture,
in which mothers could frequently raise enough food to
feed their children without much help from the fathers,
tend to differ from the economics of temperate
agriculture, where the labor of fathers often made the
difference between their kids` survival or starvation.
This leads to different family structures and different
behavioral tendencies between tropical and Eurasian men
— what Harpending calls the

"Cad vs. Dad
"
pattern of low vs. high paternal
investment.

Are those disparities, which appear
to manifest themselves in the large racial inequality in
illegitimacy rates seen in modern America, cultural or
innate?

Certainly they started out being
cultural. But it`s possible that selection made them
partially inborn over time.

Finally, it`s not surprising that
Henry Harpending and Gregory Cochran came up with such a
stunning

paper
.


Harpending
, who is with the University of Utah`s
outstanding anthropology department, is one of the

leading population geneticists
. Unusually for such a
mathematically-oriented scientist, he has also lived for
42 months in the field with African tribes. Indeed, his
love of Africa is so great that he almost left academia
at one point to become a safari guide.

I stay in touch with some quite
smart people, but even among them, Gregory Cochran is
legendary for the ferocity of his scientific
originality.



The Economist
describes Gregory Cochran as:

"… a
noted scientific iconoclast… He is that rare bird, a
scientist who works independently of any institution. He
helped popularize the idea that some diseases not
previously thought to have a bacterial cause were
actually

infections
, which ruffled many scientific feathers
when it was first suggested. And more controversially
still, he has suggested that homosexuality is caused by
an

infection
."

The Atlantic Monthly`s
February 1999 cover story by Judith Hooper, "A
New Germ Theory
,"
was about Cochran and another
of his research partners, Paul Ewald, and their
Darwinian theory for why more diseases will turn out to
be caused by infections that doctors then expected. This
year, the

American Academy of Microbiology
endorsed
liberalizing

Koch`s Postulates,
which have been the basis for
determining if a disease is infectious since the 19th
Century, along the lines Cochran and Ewald

proposed

The Atlantic

noted
:


"Cochran is a solo player, with an encyclopedic mind (he
is a former College Bowl contestant) and a manner that
verges on edginess."

I can attest that, although a
physicist by education and the leading theorist of
evolutionary medicine by avocation, Cochran also has
memorized almost the entire political and military
history of the human race. (Here`s an

amusing piece
by him in

The American Conservative
showing the
similarities between Bush`s Iraq adventure and
Napoleon`s invasion of Spain.)

When I`m reviewing a historical
film such as

Master and Commander
or

Hero
and I need to pretend to actually know
something about the

Age of Nelson
or China`s

Warring States era,
a call to Cochran will not only
fill me in on what happened, but, more importantly, why
it happened.

All the evidence isn`t in yet. But
it could be that Cochran and Harpending have opened the
door to explaining why some of history`s most important
developments happened—and that, finally, the political
culture is beginning to listen.


[Steve Sailer [email
him] is founder of the Human Biodiversity Institute and


movie critic
for


The American Conservative
.
His website


www.iSteve.blogspot.com
features his daily
blog.]