Katelyn Burns is an essayist and a trans woman. She lives in Maine with her two young children.

High school junior Mack Beggs is transgender. Texas rules require him to compete against girls. (Michael Stravato for The Washington Post)

Last week, a Texas court dismissed a lawsuit that sought to ban Texas transgender high school wrestler Mack Beggs from wrestling in the girls division. Beggs was assigned female at birth and has been taking testosterone to raise his hormone levels to that of any other teenage boy as part of his medical transition. Since the University Interscholastic League has explicitly stated that Texas athletes must only compete in the gender divisions of their birth certificates, Beggs wrestles against girls and dominates his competitions.

The policy in Texas is unfair to cisgender (non-trans) female athletes, who are forced to wrestle against boys like Beggs, as well as to transgender girls who were assigned male at birth but are on hormone replacement therapy.

Texas’s policy, along with the six other states that define high school athletic gender divisions according to the gender on birth certificates, has no basis in scientific reality when it comes to how hormones work. The difference in musculature between men and women comes entirely from the difference in how efficiently our sex hormones build muscle. Testosterone, the primary sex hormone in cisgender males, is better at building muscle more quickly, which is why men have larger muscles than women, on average. Having more muscle also helps burn fat faster, which is evident when you hear the common lament from women how “it’s unfair that men lose weight faster.”

When transgender boys like Beggs medically transition, they get testosterone injections to bring their hormone levels in line with cisgender boys and reap the athletic rewards of doing so along the way. You can see this very clearly by examining Beggs’s dominance against female competition, as well as just looking at his muscular development. The lawsuit that was dismissed claimed that by taking testosterone, the boy was effectively taking a performance-enhancing banned substance.

When those assigned male at birth take additional testosterone, the resulting increase in muscular development also comes with significantly dangerous side effects, including liver, kidney and heart damage, impotence and suffering from “‘roid rages.” This is why taking testosterone to raise T levels above the normal range for cisgender boys and men is banned, both legally and in sporting contexts. It should be noted that cis men who have been diagnosed with low T are also prescribed the same testosterone injections as trans men. By taking just enough of the hormone to move his levels into the normal boy range, Beggs is not seeking a performance enhancer; he’s just trying to live a normal life as the boy he really is. So why would Texas go to the lengths that they do just to ensure that Beggs plays in his birth-assigned gender category? The true answer lies on the other side of the gender spectrum.

There’s a common societal perception that trans women and girls are really men, and with athletes, this perception translates into an assumption that trans girls and women have a permanent advantage from birth. That’s wrong. When trans girls medically transition, they need two separate hormone treatments, one to block testosterone production, and then an estrogen regimen, which brings their levels in line with those assigned female at birth. Because trans girls hormonally become indistinguishable from any other female athletes, requiring them to compete in the boys’ division would be unfair. Opponents of trans girls’ participation in female athletics often point to other advantageous physical traits such as height as reason enough for a wholesale ban. But that ignores the natural variance that cis women have in height and dismisses the fact that height is not an advantage in sports such as gymnastics.

The larger debate surrounding trans rights makes clear what’s really going on in the disputes over school sports. If those who seek to keep trans women out of women’s rooms are forced to admit that trans women are hormonally woman enough to compete in women’s athletics, then their scaremongering tactics around the bathroom and public accommodations debate begin to crumble. It’s a harder argument to force some female athletes to use a locker room that’s separate from the teammates who they already play with.

By overzealously and erroneously attempting to ban so-called “boys” (trans girls) from taking over girls’ sports, Texas officials have managed to create a situation where an actual boy (Beggs) has taken over a girls’ sport. If it really wants to be fair, Texas should look to other states, the NCAA, the International Olympic Committee and the many other sport governing bodies that make accommodations for trans teens going through medical transitions to bring its policy into alignment with science.

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