Chapter 3 – The Real Science Of Transgender Athletics (In One Page)

What you can tell the fearmongers as well as the curious

I've written several posts (five to be exact) so far in my “book serialization,” but without an initial overview that would allow readers to see where it's going and why they should stick with me. I'll now make up for that deficit.

The criticality of the topic hardly needs introduction. The new regime's “executive order” blitz has left no doubt about its obsession with obliterating transgender human beings. Our lives, not just fundamental rights, are increasingly in the balance, and that's how Mike Johnson wants it. Opinions from experts are out there (“There’s no evidence that trans athletes have an advantage over anyone else in sports”), but they're not making much impact on a lot of people, who still think "obviously the males have a big advantage over females.”

We can break it down into three realms: physiology, psychology, and statistics. What's in the popular media is sorely deficient in all. An example of the last is NCAA head Charlie Baker's acknowledgment that there are probably at most 10 transgender athletes among the more than 500,000 total. Fine, but that's just a tiny aspect of what statistics has to say about this topic.

Physiology. The common understanding is that “men are obviously bigger and stronger, and that's the end of that.” Cisgender men are, in fact, bigger than women by about 15%, on average. That average is important. Brittney Griner was six-feet-five-inches tall during her sophomore year, yet a crescendo of complaints about her from the likes of Riley Gaines didn't materialize. Robert Reich was four-feet-eleven then (and still is now, at 78). Were there cries of unfairness that his dream of winning a basketball scholarship was mercilessly squashed by all those six foot two guys?

Distributions are statistics (vide infra); now back to stuff we can touch. The biggest misconception about sex and “strength” (not an SI quantity, by the way) is that men are intrinsically stronger, and this is false. There is no statistically significant difference in the ability to, for example, push or pull a restraining object, per unit muscle cross-sectional area.

The anabolic (tissue-building) hormone testosterone, which is a critical part of every person's metabolism, affects muscle mass (identified more precisely as “fat-free mass”) in complex ways. This mass does not typically decrease to the average of cisgender women when testosterone is suppressed in transgender women (the details vary too much to offer a single reference here). But there is no simple proportionality.

The control of muscle contraction and relaxation is far more direct, on the other hand. One calcium ion is released from a storage sac for every cross-bridge actuator (about 1 every 7 nanometers); then must be sequestered and re-released by the next impulse. And the presence of male-average testosterone concentrations increases the magnitude of this pulse by several fold. This is only the tip of the iceberg of immediate, transient effects that are not detectable by the usual blood tests taken hours if not days before or after the athletic event.

Psychology. The myriad ways in which central nervous system events influence what the peripheral actuators (i.e., muscles) do have gotten less research attention than those muscle fibers, but not due to their lack of importance. It is by no means a given that the gap between cisgender men and women is immutable. In fact it decreased for several decades before coming to what appears to be a plateau in roughly the 1980s. But such observations, however compelling the graphs appear, tell us nothing about underlying causes. The same gender gap existed in the 1980s for Australian nine-year-olds – and no, you're not wrong in thinking that testosterone can play no role in this whatever. Social expectations certainly could, however.

There are many other indications that social expectations play an important role. There is even a small difference in the “home team advantage” between men and women, which becomes smaller the more gender-equal the society. How these factors affect transgender athletes has not been studied, but it is most likely to make them more like their real gender than the one mistakenly assigned at birth.

Statistics. As noted, the oft-cited scarcity of transgender athletes is just one of many relevant numbers, and perhaps not the most significant. The naysayers will always argue that more are coming.

But are they? Consider the 7.6 million high school athletes in the country (as of a decade ago), distributed among 27,727 high schools. There are an average of 26 individuals per team (based on data for colleges), so if the transgender fraction is 1% of the broader population and participates in athletics at the same rate, there are between one and two trans girls per school, and fewer than 0.2 per team. That's insurmountable competition?

The specific number of athletes on any actual team will differ from this crude calculation, of course, but not by an order of magnitude. Clearly there are many, many teams which would have zero trans representation in this “worst case” (for the transphobes) scenario, and equally clearly the likelihood that those people are dominant athletes is far below unity.

We do know empirically that after about 25 years of greater public acceptance of transgender identity, the number of nationally competitive trans athletes can still be counted on a few hands at most, and the margins by which they win would often be losses on another day. I will expand on each of these points, along with others, in future posts. But it is evident from this super-high-level overview that the transmisic claims of the new emperor and his retinue that transgender girls are “destroying women's sports” are absurdly far from reality, and these facts need to be widely publicized.

(The photo of a cheetah at the top is not random, by the way. It turns out that female cheetahs actually run faster than males, yet they’re smaller - less muscle mass. But they have the same concentration of testosterone.)

(Note: updated on 6 Mar 2025 in the third-to-last paragraph: the average number of trans athletes per school was incorrectly stated as the number per team. The latter is in fact much smaller.)