During a recent conversation on here, I was pointed to some resources about transgenderism that I found very interesting. I thought I'd share my understanding of what they say.
Typical male and female brains have physically different structures.
These two studies identified physical differences between how men's and women's brains are structured on average. The first paper's authors, at least, are very careful to point out that it does not mean that either one is better than the other, just that they are different.
That doesn't mean that there are two types of brain
There are many differences between the brain types, and just because some features are more pronounced in more men than in women, that doesn't mean you can sort them into two categories.
To make an analogy, it would be like trying to distinguish between men and women based on a person's strength. Yes, the strongest man will be stronger than the strongest woman, and the average man will be stronger than the average woman, but trying to draw a line like "men can lift over 100kg, women can't" is doomed to failure. It's even harder to draw a line if there are more variables (lifting, throwing, running, swimming, endurance, etc.), there can never be a case where all women are on one side of a divide, and all men are on the other.
Transgenderism is NOT a choice
Those previous papers (and, presumably, others), lay down a baseline for an average male brain and an average female brain without which this third paper would not make sense.
Brain activity and structure in transgender adolescents more closely resembles the typical activation patterns of their desired gender, according to findings to be presented in Barcelona, at the European Society of Endocrinology annual meeting, ECE 2018. These findings suggest that differences in brain function may occur early in development and that brain imaging may be a useful tool for earlier identification of transgenderism in young people.
In other words, there really are people with brains that physically don't match the typical structure for their body. ("A woman trapped inside a man's body".)
That's not to say that there aren't people around who are perfectly satisfied with their body, even if it doesn't match the average brain type for that sex, but it does show that we need a richer language for how people identify themselves, and be less keen on forcing unscientific labels on people.
As usual, I've disabled anonymous comments, in the vain hope that any conversation will remain civil.