Re: Brain size, IQ

Paul Crowley (
Sat, 14 Sep 96 21:35:30 GMT

In article <Pine.SUN.3.95L.960909233511.11048B-10 "Ralph L Holloway" writes:

> Minor differences in our brain sizes seem to have little
> if anything to do with intelligence as far as I can tell.

Surely you should have said: "*Major* differences in our brain
sizes have little if anything to do with intelligence . . ".

> How can we legitimately use those units to discuss
> brain-size-intelligence interrelationships in the fossil record? If we do,
> are we not then more or less hoisted on our own petards to ascribe the
> variation in modern human species' brain weights along the same lines?

I don't think this necessarily follows. One simply has to say
that culture is the dominant factor in determining the success or
failure of races; that brain size is one factor, and a relatively
unimportant one; but, however, it is significant over evolutionary
timescales, and larger brain sizes have, *for_racial_groups*,
provided enough advantages to enable a gradual increase.

Culture can change rapidly. Whatever the ancient Greeks, Romans
or Egyptians had, they have long since lost. The Florentines had
a marvellous period around 1500. They have lost virtually all of
it, and whatever it was, it had nothing to do with brain size.

OTOH culture may change slowly. To be a bit anecdotal, I'm 100%
Celt. We have large brains, but over the last 2,000 years or so,
we've lost out to the smaller-brained germanic tribes and are now
almost a remnant on the western fringe of the continent. The reason
for this was cultural. We were essentially cattle herders and
traders and never really got the hang of farming, especially for
grain. (The difference in Ireland between protestant farms and
catholic ones is obvious to the most casual of observers.)

Or to be even more anecdotal and somewhat speculative: I married
a "germanic" woman from eastern England. We have a son and a
daughter. Our daughter has inherited my Celtic genes insofar as
she's as untidy and as disorganized as I am, and as my parents
were. On the other hand, our son has inherited his mother's
"tidiness genes". He's totally organized and almost passionate
about order and cleanliness. He'll be a success in whatever he
does, although IMO he does lack some qualities that his sister
and father possess.

How about a "tidiness quotient"? It would be easily measurable.
I'd bet it's mostly in the genes.