Strange headline. Whether nature or nurture, it's all biological by definition.

It is interesting to see some physiological differences, but I'm not convinced there is a distinctive "trans brain" as they assert. They talk about a study showing that a few brain characteristics of trans people averaged closer to the values associated with their identified gender than their biological sex. Perhaps somebody who has the actual citations can confirm this, but I'm guessing all those characteristics are statistically distributed through broad spectrums in both men and women with some overlap between the sexes. So some men are more effeminate in by some metrics than some women, and vice versa.

It is not surprising that m-to-f trans people would be on the effeminate side of the biologically male spectrum of characteristics, when compared against the male average. But what about cisgender gay men, or just cisgender straight guys with some effeminate tendencies? There are two big questions I haven't see answered: 1) Is there also some percentage of happily cisgender men whose physiology is similarly effeminate to m-to-f trans people? 2) How many other aspects of their brain morphology match a biologically male versus female brain? Do they just have some effeminate characteristics, or are they really fully female or much more female than male?

Without better answers to these questions than I've seen (although perhaps I've missed them?), I'm still not convinced of the current social dogma that trans men really are men and trans women really are women. We should certainly let these people live whatever lifestyle they want without facing discrimination, but the demands their advocates are placing on society are a bit unnerving. When did we all decide that pronouns are based on psychological gender instead of physiological sex? Why should institutions that have been segregated by sex because of anatomical differences, such as showers and airport screenings, suddenly make exceptions to those sensible policies because of psychological differences? How are we supposed to simultaneously respect a diverse definition of femininity including a variety of natural body forms (i.e. flat-chested) and personalities (i.e. rugged badass lumberjacks) in empowered women, while also congratulating m-to-f trans people for trying to show that they're women by getting fake boobs and parading around in tight dresses and heavy make-up, i.e. reinforcing old superficial stereotypes of what "women" are all about?

And I also worry about cis men with some effeminate characteristics and cis women with some masculine characteristics feeling pressure from a pro-trans society to interpret these characteristics as signs that they're trans, when really they're just cis people with characteristics off toward one end of a smoothly varying spectrum. The large cultural disparities in anonymously reported trans identification would seem to support this interpretation; it could be that trans people in these places are afraid to speak up, or it could be that many of them don't "know" they're trans and were perfectly happy living and identifying as cis despite having some mannerisms or interests more commonly associated with the opposite sex. Clearly, this isn't everyone, and there are some people who feel a deep affinity with the opposite sex from a very early age.

However, I'm still not convinced there's anything wrong with viewing this clear-cut gender dysphoria as a psychological disorder, whose victims suffer from the delusion that they actually belong to the opposite sex. There are almost surely physiological bases for these delusions, just as there are for other psychological conditions, and the patients deserve compassion for sure -- but what I am not convinced they deserve, because it has never been afforded to any other class of deluded people -- is for society to fully play along with their fantasies. For example, we are not expected to address someone with multiple personality disorder by their preferred name or gender of the day. So unless there is better scientific proof that they are not deluded and really are what they identify as, I think there must be room to be compassionate in a way that stops short of participating in their delusions.