A new brain study was released that shows human brains are a mosaic of male and female structures. A few people have tried to use this study to discredit all the other studies that have identified specific differences in male and female brains, and how transgender people have brains that are more like the gender with which they identify than the gender assigned at birth.
Let’s remember this slide for a moment, ok? Don’t lose sight of this image on this slide.
The new study, The brains of men and women aren’t really that different, study finds, does not say that male and female brains are identical. It says they are extremely similar and that any male or female brain has a large mix of more male or more female structures. In addition, this study looked at the overall brain, at the topology of the total brain to reach its conclusion.
Now interestingly, this study actually reinforces the existing neurobiological research into transgender brains thus far. How can it do that? Because it shows how similar male and female brains are, and what that means is you don’t have to have a “completely female” brain to be an MtF trans woman or a “completely male” brain to be an FtM trans man.
Instead, this study further enhances that it is only a few small critical structures, just like the BSTc in the slide previously that which is tiny! It’s inside the hypothalamus, which itself is about the size of a peanut. And then it’s inside the stria terminalis, which is a small structure inside the hypothalamus itself. And then the difference is in the bed nucleus, which is inside the stria terminalis which is inside that tiny hypothalamus. And we already know from other studies that this region of the brain appears to be linked to gender identity and somewhat also towards sexual orientation.
So the studies done to date do not contradict the neurobiological thesis for being transgender. In fact, this study further enhances that work by showing how small the changes can be that lead one to feeling gender identity dysphoria.
When people try to argue that this study disproves a biological basis for being transgender, refer them to my comments here. This study reinforces the neurobiological model.
I will add here, a diagram from the TED Talk of one of the scientists involved in this study. The brain itself is neither male nor female. It’s always a mosaic of structures. But the mosaic consists of a mixture of male and female structures. And every human brain is like this. So rather than having a “female” brain or a “male” brain, what matters are those few individual structures that control sense of gender identity.