Moreover, biologically speaking, "men" and "women" may be better
thought of as continuum, rather than two separate categories that are
opposite to each other in all things, as many sociobiologists have it.
Thanks for pointing that out. I have trouble with the basic category error in all these studies, namely, that the "male brain" and "female brain" are recognizably different entities from the start. The terms "male" and "female" have been agreed to describe differences in physical biological equipment and in specific chromosomes, but have they been shown to (a) unequivocally describe physical differences in brain tissue? or (b) any proven one-to-one correspondence of such physical brain differences to sexual or DNA differences? If some murderer removed my brain and divided it into, say, half a dozen chunks, of which one were subsequently recovered, would the forensics folks be able to say at a glance -- as for instance, with my pelvic bones -- oh, yes, these physical remains are almost certainly those of a female? (And as I recall from my physical anthropology, without large reference collections, even "sexing" individuals from pelves is only about 75% accurate.)
Thus, to attribute the property of sexuality to people's brains seems meaningless to me, as brains are not reproductive organs. Are there such things as "black" brains and "caucasian" brains? For that matter, are there "gay" brains and "straight" brains? The assumption that there are only two kinds of humans, male and female, seems another gross overgeneralization, as Yoshie points out.
Granted, I've read only the NYT and a few other reports on the article ('says lead author, Matthias R. Mehl, University of Arizona psychologist, "Our paper puts to rest the idea that the female brain evolved to be talkative and the male brain evolved to be reticent."'), so I have no idea what conceptualization they are short-handing with their talk of "male brain"/"female brain". But my sense is that their main goal is simply to level the playing field that was badly tilted by scientifically unsupported "urban legends" by insisting, through such studies as this, that demonstration of difference must precede hypotheses for cause. Speaking rates have countless other possible correlations besides gender, both internal to subject (eg ethnicity, economic class, cultural group, academic major) and external (conversation types, gender/class/ethnicity/etc of others).
I read this thread just after my Amer.Soc. Assoc. 'Animals & Society' newsletter, and a different but related question pops into my mind:
When scientists use mice/rats/monkeys/rabbits etc., in behavioral and neurobiological experiments, do they always use only-male or only-female mice because it has already been proven that the sexes of mice/rats/monkeys etc. are so profoundly different in "male brain" and "female brain" that each sex would have significantly different test results? Or do we generally take male & female non-human animals to be effectively the same in the anatomy of their brains, while holding open the question for human sexes?