Mike Smith relays an interesting possible explanation for the observed
statistical fact that American and European Jews have a mean IQ a
standard deviation higher than Caucasian gentiles:
During the period from ancient times to modern times, there was a
constant phenomenon of Jews converting to Christianity (there were
many social pressures to do so). In a nutshell, the idea is that the
lower-IQ Jews were statistically more likely to convert, as it freed
them from having to learn to read Torah. During the Middle Ages, it
was not worth the effort for most people to become literate; the
payback was not worth it. Books were rare and expensive, and learning
to read was no guarantee of getting ahead in life. Of course, people
like to do what they’re especially good at, and the higher-IQ’s among
the Jews did not find learning to read to be such a burden. As such,
they were statistically less likely to convert (and statistically more
likely to become fathers of many children in a culture that valued
intelligence.) It is worth noting that in ancient times, Jews were not
stereotyped as especially intelligent; that stereotype arose in the
Middle Ages.
This is a special case of one of my favorite Damned Ideas, originally
developed by John W. Campbell in the 1960s from some speculations
by a forgotten French anthropologist. Campbell proposed that the
manhood initiation rituals found in many primitive tribes are a
selective machine designed to permit adulthood and reproduction only
to those who can demonstrate verbal fluency and the ability to override
instinctive fears on verbal command.
Campbell suggests that all living humans are descended from groups
of hominids that, having evolved full-human mental capability in some
of their members, found the overhead of supporting the dullards too
high. So they began selecting for traits correlated with intelligence
through initiation rituals timed for just as their offspring were
achieving reproductive capacity; losers got driven out, or possibly
killed and eaten.
Campbell pointed out that the common elements of tribal initiations
are (a) scarring or cicatricing of the skin, opening the way for
lethal infections, (b) alteration or mutilation of the genitals,
threatening the ability to reproduce, and (b) alteration of the mouth
and teeth, threatening the ability to eat. These seem particularly
well optimized for inducing maximum instinctive fear in the subject
while actually being relatively safe under controlled and relatively
hygenic conditions. The core test of initiation is this: can the
subject conquer fear and submit to the initiation on the basis
of learned (verbal, in preliterate societies) command?
Campbell noticed the first order effect was to shift the mean of
the IQ bell curve upwards over generations. The second-order effect,
which if he noticed he didn’t talk about, was to start an arms race in
initiation rituals; competing bands experimented with different
selective filters (not consciously but through random variation).
Setting the bar too low or too high would create a bad tradeoff
between IQ selectivity and maintaining raw reproductive capacity. So
we’re descended from the hominids who found the right tradeoff to push
their mean IQ up as rapidly as possible and outcompeted the groups
that chose less well.
It doesn’t seem to have occurred to Campbell or his sources, but
this theory explains why initiation rituals for girls are a rare and
usually post-literate phenomenon. Male reproductive capacity is
cheap; a healthy young man can impregnate several young women a day,
and healthy young men are instinct-wired to do exactly that whenever
they can get away with it. Female reproductive capacity, on
the other hand, is scarce and precious. So it makes sense to select
the boys ruthlessly and give the girls a pass. Of course if you push
this too far you don’t get enough hunters and fighters, but the right
tradeoff pretty clearly is not 1-to-1.
(This would also explain why humans are designed for mild polygyny,
1 to 3 sexual partners per male. You can spot this by looking at
where human beings are on various physical characteristics that
correlate with degree of polygyny in other primates — disparity in
average size between males and females, for example, is strongly
correlated with it.)
What Campbell did notice is that this theory of selection
by initiation would neatly explain one of the mysteries of human
paleoanthropology — how human beings got so smart so fast. The
differences between H. Erectus and H. Sapiens are not large in
absolute genetic terms (they can’t be, we share over 94% of our genome
with chimps) but they’re hard to credit given normal rates of
morphological change in mammals and only two million years to work
in. Something must have been putting hominids under
abnormally strong selective pressure — and Campbell’s idea
is that we did it to ourselves!
Now, I’m not sure I believe Jews bootstrapping themselves up a
whole standard deviation in less than 2000 years, but if you apply
a similar idea to a longer timeframe it begins to look pretty
reasonable. (And Campbell did suggest that the Jewish practice of
infant circumcision had originally been a manhood rite.)
Within my lifetime, I expect we’re going to have the ability to do
germ-line enhancement of human intelligence. I strongly suspect that that
will set off another arms race — because cultures that suppress
that technology will be once again doomed against cultures that do. And
this time, we’re smart enough to know that in advance…