A recent, well-reviewed book that deals with the issues that Claudia raises is Melissa HInes, Brain Gender (Oxford  U.P., 2005).

There's a review here: http://www.psychservices.psychiatryonline.org/cgi/content/full/56/10/1325



New in Paperback! How important are biological factors, such as hormones, in shaping our sexual destinies? This book brings a social developmental, as well as a biological and clinical psychological, perspective to bear on the factors that shape our development as male or female, and that cause individuals within each sex to differ from one another in sex-related behaviors. Topics covered include sexual orientation, childhood play, spatial, mathematical and verbal abilities, nurturance, aggression, dominance, handedness, brain structure, and gender identity. This original and accessible book is of interest to psychologists, neuroscientists, pediatricians, and educators, as well as the general public. It is also used in graduate and undergraduate courses on the psychology of gender and on hormones and behavior.

". . . The book has many pluses. It is clearly written, preserving important and nuanced research findings in a style that can be appreciated by both the established investigator and lay person . . . This timely piece of work cuts through the well-described 'cognitive schemas' of many researchers and theorists in the fields of sex and gender differences and brings these areas of inquiry up to more modern realities..." --JAMA

"[This book] serves as an excellent text for senior undergrad or graduate level courses on this topic." JINS

". . . a remarkable book, a wonderful resource that belongs on one's bookshelf for frequent reference to the many times gender, sex, and brain questions come to mind . . . well written, easy to read . . . Tucked within the pages of this fascinating book are intriguing observations . . . The author has done an excellent job of getting us to think about some of the most fundamental questions in the science of reproduction." --The Journal of Nervous and Mental Disease

"Brain Gender is a fascinating book, clearly written and well organized...The most satisfying aspect of Hines' work is her emphasis on the many ways in which sex and gender research can go wrong and her insistence on recognizing the complexity of the subject...Her book is well worth reading."--Psychiatric Services

"Brain Gender contains much thoughtful and measured information in a readable and interesting manner...This book will make a much-needed contribution to the fields of psychology as well as gender studies."--Feminism and Psychology
Product Details
336 pages; 13 halftones, 20 line illus.; 6-1/8 x 9-1/4; ISBN13: 978-0-19-518836-3ISBN10: 0-19-518836-5
About the Author(s)
Melissa Hines, Professor of Psychology and Director, Behavioural Neuroendocrinology Research Unit, City University, London

At 9:46 AM -0700 7/6/07, Claudia Hemphill Pine wrote:
On 7/6/07, Yoshie Furuhashi <[log in to unmask]> wrote:

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?