Oh no, more sexual dimorphism of the brain!

Tue, 21 Feb 1995 13:06:57 CST

I have been following with interest the debate over the study of the
sexual dimorphism of the human brain. When I first read the article
in the NYT I saw what appeared to me to be an obvious flaw in the
conclusions drawn from the research. Perhaps the conclusions were
more those of the journalist than of the researchers, or perhaps the
flaw is in my own reasoning. Let me put forth my question and wait
for the response of my peers.

Given that the human brain develops neurological pathways as a
result of experience, isn't it possible that the differences found in the
cognitive patterns between men and women in the study is an artifact
of their life experiences? If females and males are trained from birth
to attend to certain stimuli in their environment, are encouraged in
some ways of processing information and discouraged from others,
etc., mightn't the female and male brains develop differently? I don't
believe that the observed differences in brain functioning patterns
proves that the patterns are genetic, which is what the article, if not
the authors, implied, only that the brains of males and females, by
the time that we are adults typically function differently in dealing with
some ways of processing information.

I have no objection to the idea that men's and women's brains might
function differently in managing some tasks, in fact, I personally
suspect that this is indeed the case. Still, I don't see how this study
proves or disproves a genetic difference between female and male

Mr. Holloway, who first wrote about this article, noted that it would be
interesting to see a study like this done cross-culturally. I suggest
that the *only* way to study this question is to study it
cross-culturally (or possibly to study infants), at least if one wants to
conclude that there is some evolutionary process that has resulted in
males and females necessarily processing information differently.

Just one additional tidbit and that is that I wonder what the use of
such research information might be. Why, exactly, does it make a
difference if a statistical majority of males use a different part of their
brains to process information than do a statistical majority of
females? Also, is it necessary to think of males and females as
existing in two discrete categories? I'm well aware of the genetics of
sexual differentiation, but I'm also aware that we are discovering
more and more about the "other" factors that go into determining
sexual difference. For example, the recent study indicating that the
brain of male homosexuals is structurally different from the brain of
heterosexual males demonstrates that what might initially appear to
be a case of binary oppositions (male or female) might very well be a
more complex, more continuous sort of difference.

O.k. that's more than enough. Thanks for sticking with me. If anyone
wishes to comment on any of the above, I would be interested to get

Lynn Nordquist
University of Minnesota