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From: geb@cadre.dsl.PITTSBURGH.EDU (Gordon E. Banks)
Newsgroups: comp.ai
Subject: Re: Inheritance of IQ
Message-ID: <3095@cadre.dsl.PITTSBURGH.EDU>
Date: 20 Jul 89 18:42:17 GMT
References: <5453@pt.cs.cmu.edu> <2061@cbnewsh.ATT.COM> <5480@pt.cs.cmu.edu> <458@edai.ed.ac.uk> <602@visdc.UUCP> <3072@cadre.dsl.PITTSBURGH.EDU> <603@visdc.UUCP>
Reply-To: geb@cadre.dsl.pitt.edu (Gordon E. Banks)
Organization: Decision Systems Lab., Univ. of Pittsburgh, PA.
Lines: 46

In article <603@visdc.UUCP> jiii@visdc.UUCP (John E Van Deusen III) writes:
>In article <3072@cadre.dsl.PITTSBURGH.EDU> geb@cadre.dsl.pitt.edu
>(Gordon E. Banks) writes:
>>
>> If populations are separated from each other, is it not conceivable
>> that evolutionary pressures in one environment might not differ from
>> those in another, thus producing a differential effect?
>
>Can you suggest what one of the "differential evolutionary pressures"
>might be?
>
It's hard to do this without risk of seeming to suggest a particular
people might have evolved to have more or less intelligence than another, but
I'll give it a go:  Suppose one tribe lives in
an environment where the food supply is plentiful (coconuts and
bananas dropping off the trees, etc.) such as a nice tropical
island, few preditors, no inclement weather, etc. vs. another tribe
that lives among hostile neighbors in a difficult environment and
has to live day by day by their own wits.  Might not the dumber
members of that tribe be eliminated much quicker than the first?
Even social and cultural conventions might produce a selective
advantage, for example suppose one tribe values scholarship, professional
and priestly classes (making them more marriageable), while another
has celibate scribes and priests and allows the largest warriors
polygamous mates.  I don't think it is unreasonable at all to
suppose differences may show up, and rather quickly, actually.

>I again want to state that all humans have essentially the same genetic
>compliment.  No one race of humans has "evolved" beyond the others, if
>evolution is defined to be the assimilation of a positive random genetic
>mutation.  What exists among humans is only variation in the expression
>of a common pool of genetic information.
>
>The levels of genetic intelligence within a population fit a standard
>probability distribution; that is, 95% of the population is within two
>standard deviations of the mean.


Of course, we're all of the same species.  And I agree that 
variations between (at least the larger) populations are small compared
to the variations of individual within each population.  What we can't
say is the the mean of each population is the same, or how different they
really are.  It would just be somewhat amazing if they all were exactly
the same, wouldn't it?  But of course, that is what our current American
culture insists upon maintaining, not only with respect to intelligence,
but even athletic prowess.  Suggestions to the contrary are met
with charges of racism and often loss of employment.