This looks like it could have been a good book.

Updated Title: New York Review of Reviewed Books, issue 1

Research on sex differences in mind and brain is an important and interesting field, which is often badly served by those pursuing it. Over at Metapsychology, there is a review up of a new book that describes research done attempting to correlate exposure to testosterone in utero with rates of eye contact at 12 months, and language ability at 18 months and four years of age. One promise of this sort of research is that it can separate out different components of biological sex and the different physical causes of those components. The sexes can be divided anatomically, hormonally or chromosomally (do you have a penis? Do you have a lot of testosterone? Do you have a Y chromosome) and each of these traits can vary independently and allow for middle ground (for instance, XX babies exposed to a lot of testosterone in utero can develop a rudimentary penis.)

Science should be able to identify the different causes of different biological aspects of sex. We already know that fetal hormones, not the sex chromosomes per se, are the agents of genital development. We also know that the brain is sexually dimorphic. Men's brains are on average more lateralized, and this may have something to do with the much vaunted male ability to mentally rotate three dimensional objects. So it would be nice to know if the roots of neurological sexual dimorphism are genetic or hormonal.

Unfortunately, if the reviewer is to be believed, what this book gives us is a few weak statistical inferences, tantalizing rhetoric about the power of testosterone, and a blurb from Stephen Pinker, the current king of using mid level science to reinforce crappy stereotypes. It looks a lot like the research Helen Longino criticized fifteen years ago which purported to show that fetal testosterone turns girls into great big lesbos.