Megan McArdle is a Bloomberg View columnist. She wrote for the Daily Beast, Newsweek, the Atlantic and the Economist and founded the blog Asymmetrical Information. She is the author of "“The Up Side of Down: Why Failing Well Is the Key to Success.” Read more opinion SHARE THIS ARTICLE Share Tweet Post Email

Photographer: Jasper Juinen/Bloomberg Photographer: Jasper Juinen/Bloomberg

"Why can't a woman be more like a man?" asks Henry Higgins in "My Fair Lady." Women might point out that, since too many men seem to trust a mysterious toilet paper fairy to change out the forlorn tube of cardboard, it makes more sense to ask: "Why can't a man be more like a woman?"

But regardless of how we ask it, the question is a good one: Why can't members of the sexes be more alike? Why do so many irritating differences persist? Feminists' answer has been: cultural and structural sexism. Societies train women to take second fiddle to men in work and relationships -- and then punish them for trying to break out of their assigned roles. No, say traditional conservatives: Women and men are different, and cultures reflect those differences.

The conservatives may now be getting some support from a surprising source: transgender men.

It's not news that women's and men's brains aren't exactly the same. But why they aren't the same is a matter of some dispute. We know that training can actually change the physical structure of your brain. London cab drivers famously have more gray matter in the area associated with spatial recognition, perhaps developed through their work navigating the metropolis. In the same way, women's brains might be different from men's because they have been trained to be different, in ways that show up in the distribution of their brain cells over time.

A small but very interesting study was recently done on transitioning female-to-male transgender subjects, who receive high doses of testosterone. After just four weeks, images of their brains recorded significant changes.

Obviously, I do not want to overinterpret the results of one study with a small number of subjects. But since I'm sure we'll see more studies like this in the future, with a range of results, I think it's worth asking some uncomfortable questions this raises: What if some of the disparity between men and women -- for instance, in the workforce -- never goes away? What if the gaps are, at some level, indelible because men's brains are simply better wired for success in that environment?

This study doesn't prove anything like this. Such a small study doesn't prove anything. And when we have enough data to draw big conclusions, we might conclude that the differences that actually exist don't matter for career success. Or that women have the biological advantage. On the other hand, the scientific process might prove the traditional conservatives were right. Ish.

When evaluating scientific findings, I always remind myself: "The universe is not here to please you" and "nature doesn't care about fair." It can be true that women are less likely to have astounding math or engineering abilities, even though that's unfair as heck, and I don't like it. In the world of science, things do not become more true just because we'd be better off if they were.

And when it comes to gender, it's clear that nature is completely uninterested in fairness. All nature cares about is that you a) survive and b) reproduce. Justice is a human value, not a natural condition. Male orb spiders are more likely than not to end their romantic interlude as dinner for their mate. This is rather harder on the spiders than anything most female humans have to endure, but it seems to make for healthier kids, so the males have to take one for the team. What if nature, with its infinite disregard for our wishes, simply declined to deliver the raw talent for women to ever gain equal representation at the top of many fields?

Well, it seems worth pointing out the things this wouldn't prove:

It wouldn't prove that women belong back in the kitchen. Women are already in the workforce in large numbers, doing all kinds of jobs. Obviously, women can do those jobs. So we know that the old way of doing things was, in fact, holding a lot of women back from doing things they'd be good at. It wouldn't prove that sexism is no longer an issue. Male and female brains can be systematically different, and women can still be unfairly discriminated against in the workforce. One thesis does not disprove the other. It wouldn't prove that we can stand pat even if we've realized that we've reached a place where female and male brain differences are accounting for most of the difference in workplace outcome. If male brains do a better job at certain things -- say, competition or negotiating -- then the answer might be "we need to restructure the economy so that it better rewards female talents." Science can tell you what is. It cannot tell you what ought to be. And after all, gents, we are the majority. Fair is fair. It wouldn't prove that any individual woman is unsuited for a job. Averages are just averages. There are women who are great at math, and men who are great at nursing, just to name two historically gendered activities. Even if group averages are different, you can't infer anything about individual ability by looking at their group memberships.

What this would do is greatly complicate the attempt to infer sexism by looking at differences in outcomes. Unfortunately, outcomes are the best data we have. It's pretty easy to count how many women are in the C-suite. It's nearly impossible to monitor the thousands of daily internal decisions that add up to a discriminatory barrier, or don't.

So if we find out that women's brains really are different from men's, in ways that are driven not by the environment in which they are raised but the hormones suffusing their brain, we're going to need to start by rethinking the ways that we identify sexism in the first place -- and then start thinking about what sort of remedies might be appropriate. This is going to be an even longer, messier negotiation than the one we're having now.

Especially if science tells us that women are just better at understanding complicated stuff like science. Men, the benighted darlings, will just have to trust us.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

To contact the author of this story:

Megan McArdle at mmcardle3@bloomberg.net

To contact the editor responsible for this story:

Philip Gray at philipgray@bloomberg.net