Does that brain study really prove what we think it proves? Or, the long arm of Descartes strikes again?

You may have read that having a male brain will earn you more money. Or maybe that female brains are better at multitasking. But there is no such thing as a female or male brain, according to the first search for sex differences across the entire human brain. It reveals that most people have a mix of male and female brain features. And it also supports the idea that gender is non-binary, and that gender classifications in many situations are meaningless.

First thing to consider is that this study may or may not be right. We won't know for certain until a whole lot of checking and challenging is done and that will take, at a minimum, the better part of a decade.

But, just for the purposes of argument, let's take it as read that the study is right. That there are no significant differences between male brains and female brains. What would that prove? And, What wouldn't it prove?

Just this morning, while walking my Schnauzer, I saw a game of Quidditch. It's a pretty silly game played by pretty silly people but, that's okay, because playing games is largely about being silly. Quidditch is kind of like the game in the Harry Potter books except that there is no magic involved, which, come to think of it, means that it's completely unlike the game in the books. But it is a game and an athletic game at that.

It was being played by both men and women and the men were, with one exception, how to put this kindly, not very athletic. All except the one were pathetic, unfit slobs to be honest. The women were in better shape and I would guess that they all go to exercise classes and eat healthy food. I'm reasonably confident in this judgment as the women were wearing skin tight clothing that made it rather easy to assess their bodies. They also ran quickly and smoothly without fatiguing. They were pretty fit. For women. And there's the rub for the men completely dominated the game. And nobody playing seemed surprised or dismayed that this was the case.

What has this to do with brains? Well, did you notice how the above study has a strong rationalist bias embedded in it? The whole argument is framed in a way that the only possible way to define "gender" is in terms of brains. You couldn't say it assumes that our brains do or do not define gender because that wouldn't be nearly strong enough to define the way the study has been framed. The question is set forward in terms that no other conclusion is possible. It does the equivalent of asking, "When did you stop beating your wife?"

But let's try another question: If the brain is not determining gender, could something else be doing the work? Something like, here's a crazy idea, your body maybe? Want to know if you're a man or a woman? Lift the waistband of your pants or skirt and look down.

That runs against one idea of freedom. It was an idea my parents were very fond of. "You can be anything you want to be if you just set your mind to it." Or, "set your brain to it", if you're more physically minded (and this should strike us, there is something decidedly unphysical about wanting to speak in terms of "minds" or "brains" to begin with). But your brain may be irrelevant. You can take the same engine and put it in a car or a school bus and it won't make the car able to carry forty students and it won't make the school bus as fast as the car. You may think that gender is a social construct but you aren't going to make most girls as good at Quidditch as most boys will be.

If we accept the possibility that the same brain may end up functioning in very different ways then we might consider the possibility that it will be very different when we put it into a body with lots of muscle, that is flooded with testosterone and has a penis and testicles as compared to a body that has less muscle, a completely different hormone profile and a vagina and ovaries.

It occurs to just about everyone to wonder, at some point in our lives, what it would be like to inhabit another person's body. What would it be like to "be inside" a body with different sex organs. But notice the move you quietly made without acknowledging it simply by wondering about this "possibility" that is currently impossible and may never be possible. You have assumed that the "you" in this story is something other than your body. You're talking as if your identity was something like the driver of a car and that you could simply get out of one and into another.

The assumption here is that your mind, and not your brain, "mind" meaning the things you experience, believe and remember, is what makes you who you are. But there is no particular reason to conclude that. It might well be that putting your brain in another body would force you to change who you are completely by forcing you to experience, believe and remember completely differently than you now do.

If that's true, and I think it is, then the moral questions arising from gender differences are as simple as figuring out your sex—male or female— and then trying to be as good at being a man or as good at being a woman as you can be.

Come back with me to grade school a moment and let's ask a bunch of fifteen-year-old boys what it would be like to "be" inside a girl's body for a change. One of the boys will inevitably make a joke about how the first thing he would do would be to take his/her clothes off and check out a naked girl. One good thing about it, thinks the heterosexual male, is that you could spend all the time you wanted looking at and touching a girl body. And that may be one of the neat things about being a girl for some girls (have unlimited access to touch a boy's body is a bigger part of the thrill of being a boy than most boys would like to admit). But what if you don't like what you see? As a boy, what you see is a big part of what you like about girl's bodies and some bodies thrill you more than others and some not at all. And, while the average boy or man thinks it's pretty cool to touch breasts, it's different to touch yourself than it is to touch someone else. You're still going to want to touch other people and, well, that's going to take some working out isn't it. And, eventually, you're going to get around to thinking that it would be nice to have other people touch you and there are going to be a lot more boys stepping forward to offer than girls and you just may not find any of the few girls who do step forward appeal to you. And when you're finished working all that out, you might stop being a boy brain in a girl's body and just be a girl al the way through.

Or, you could make yourself miserable and unhappy for the rest of your life by fighting against it.