Transgender people aren’t the monolithic community we may appear from the outside. For every MTF transsexual who insists that she was always a woman inside and she corrected her male body to match her brain, you can find someone who questions whether categories like “man” and “woman” are absolutes after all. (I’ve been reading Undoing Gender by Judith Butler, which is by far her most readable book, and has taken my breath away several times. She attacks the idea of gender as a social construct from a new, ingenious standpoint, by showing how our personhood — and hence our gender — can be “undone” by grief or loss or social crap.) But the woman-brain-in-a-man-body school of thought (or its reverse, for FTMs) remains the mainstream view of trannies. And it’s won the support of some very iffy Dutch science:

[I]nvestigators from the Netherlands Institute for Brain Research in Amsterdam reported preliminary evidence that transsexuals may be inherently different, after all. Their study of six male-to-female transsexuals showed that a tiny structure deep within a part of the brain that controls sexual function appeared to be more like the type found in women than that found in men. If confirmed, the study seems likely to challenge long-held beliefs about what it takes to make someone a man–or, a woman.

The facts: the researchers dissected the brains of six (just six!) post-op transsexuals. They compared them with brains of straight and gay men, and women. The region of the hypothalamus that the researchers claim is different in MTFs than in men (the central subdivision of the bed nucleus of the stria terminals) is “smaller than a pinhead” and you can’t even see the differences using an MRI. The researchers claim, with absolute confidence, that they know the “bed nucleus” “controls sexual function.” The scientists say the “bed nucleus”

measures about 2.6 cubic millimeters, about the size of the colorful, spherical head of a pushpin. In women, it averages 1.73 millimeters, and in transsexuals the average figure is 1.3.

Some other experts were skeptical, the article linked above says. All of the TSs who were dissected had taken estrogen for years, and maybe that changed the size of this region of the hypothalamus. Or maybe the stress of living as a trans person changed the size of their “bed nucleus”. And then there’s this:

Dr. S. Marc Breedlove of the University of California at Berkeley, who wrote an editorial that accompanies the new report, said that the function of the bed nucleus in human behavior, sexual or otherwise, remained “a complete black box.”

So we don’t even know what it is, or what it does. Or what its size signifies.
The reason this research bugs me has very little to do with me and my fellow trans people. It’s more my fear that we’re being used as wedge to push an essentialist agenda. It’s not too far from saying “transsexuals have women’s brains” to claiming “men’s and women’s brains are totally different.” And from there, to claiming that women have less good spatial sense than men. And from there, to claiming there’s an innate biological difference between men’s and women’s math abilities, says Richard Francis, author of Why Men Won’t Ask For Directions:

Evolutionary psychologists assume that it’s biological, that there are hormones involved, that testosterone somehow makes men better spatial navigators. But, the evidence for that is extremely weak. In fact, I spent much of the time writing this book having to read that kind of literature. Whereas there’s ample evidence that social-cultural factors play an enormous role in this. And also this spatial cognition story extends to sex differences in mathematics. For example, the sex differences are most pronounced in the United States, even in the Western world. In some cross-cultural studies, they’ve shown that in African-Americans and Hispanics that females are superior in mathematics, and in Asian-Americans it has been found that the sex difference is quite small. And, then there’s evidence that these sex differences are disappearing over time, which you would expect given the new educational opportunities available to females. And, this does not accord well with a biological explanation, much less an evolutionary explanation.

My new favorite blog Mad Science Mama has an amazing post about scientists who tweaked a gene in fruitflies that seemed to govern sex-specific behavior. And what did altering this gene change? The fruitflies’ fighting styles, of course:

The gene called “fruitless” is known for its role in male courtship… The same gene directs another sex-specific behavior — fighting patterns, the new study shows. Female fighting, for example, largely involves head butts and some shoving. Males prefer lunges; they rear up on their back legs and snap their forelegs down hard – sometimes nailing an opponent that is slow to retreat.

The flies undergo a major role reversal when the male and female gene versions are switched. With a feminine fruitless gene, male flies adopt more ladylike tactics, mostly the head butt and some shoving. With the masculine fruitless gene, females instinctively lunge to the exclusion of their usual maneuvers.