Lia Thomas made a very good point about what makes a woman, whether you like it or not

Unlike her critics, transgender swimmer Lia Thomas has been largely silent since placing first in the 500-meter freestyle at the NCAA women’s swimming championship in March. Earlier this week, though, she sat down with Good Morning America’s Juju Chang to give her side of the story. Describing a childhood spent feeling bewildered and depressed by a body that betrayed her, Lia told a story that is similar to those of many trans people — including my own. Lia discussed how swimming helped her cope, and how the fear of losing her ability to compete led her to put off medically transitioning until her sophomore year at UPenn.

Asked by Chang whether the contested possibility that a testosterone-fueled puberty may leave “legacy effects” on a trans woman’s body after medical transition that should disqualify her from competing in elite sports, Lia answered, “I’m not a medical expert, but there is a lot of variation among cis female athletes. There’s cis women who are very tall and very muscular and have more testosterone than another cis woman, and should that then also disqualify them?”

And herein lies the heart of the issue: What makes a woman, and who gets to decide that? Is it chromosomes? Hormones? Genitalia? The ability to become pregnant?

Many of those who would like to see Lia lose her championship title argue that Title IX policies were meant to protect women and girls in collegiate sports. They ignore the fact that Title IX protects all students from discrimination based on sex, sexual orientation, and gender identity. Implying that trans women aren’t “real” women, they weaponize transphobia and widespread misunderstandings about sex and gender to justify draconian and discriminatory policies. And, as the dark history of sex-testing in women’s sports shows, this is a real concern. These policies not only encourage women to view one another with unnecessary suspicion but pander to harmful and outdated ideas about what femininity should look like.

Take Ewa Klobukowska, Polish track star and the first to fail the International Association of Athletics Federation’s (the governing body now known as World Athletics) chromosome test. Three years after Ewa won gold and bronze medals in the 1964 Tokyo Olympic Games, the IAAF ruled that an extra chromosome disqualified her from competing as a female, publicly shaming her as a “male imposter” and stripping her of both medals and dignity. The next year, Ewa got pregnant and gave birth to a son. A medical journal later published the results of the test that upended her life — XX/XXY — one outcome of a condition called mosaicism that occurs when a person has two or more genetically different sets of chromosomes. Ewa, now 76, completely removed herself from the public eye after a failed suicide attempt. The IAAF has never formally apologized or restored her medals.

Forty years later, the IAAF would administer another chromosome test to Santhi Soundarajan, a young Indian woman from the “untouchable” caste who had seen track and field success. Slated to represent her country at the upcoming Olympics after winning a silver medal at the 2006 Asian Games, her joy was upended when she was sent home, bewildered, the very next day. Initially told she had failed a routine doping test, Santhi learned several days later — via national news — that she had actually failed a “sex test.” Born with complete androgen insensitivity syndrome, Santhi has XY chromosomes, female genitalia, and internal testes that produce testosterone, but her body lacks the androgen receptors that would allow it to use any of that hormone. Even if she shows levels in the typically male range, therefore, it expresses no physical effect on her body.

More recently, 18-year-old lesbian Dutee Chand was subjected to a series of tests after winning two gold medals at the 2014 Asian Junior Athletics Championships. Several athletes, she would later be told, thought she didn’t appear feminine enough, so suspected she might be male. IAAF doctors tested her testosterone levels and gave her an ultrasound, chromosome analysis, MRI, and physical examination that included “measuring and palpating the clitoris, vagina and labia, as well as evaluating breast size and pubic hair.” The IAAF officially replaced chromosome testing with testosterone testing in 2011 after another lesbian runner, Caster Semenya, was found to have naturally high levels, a move that would later inform the NCAA’s own policy on transgender athletes. Dutee was later told that she had “hyperandrogenism,” and would be disqualified from further competition unless she wanted to undergo unnecessary medical treatments to lower her levels.

In a 2013 issue of The Journal of Clinical Endocrinology & Metabolism, a group of French researchers record the IAAF-recommended “treatments” performed on four female athletes who, like Dutee Chand, were diagnosed with hyperandrogenism. Any internal gonads were removed, estrogen replacement therapy (like that undergone by Lia Thomas) began, and female genital mutation — including clitoridectomy for size reduction and “feminizing vaginoplasty” for labial fusion — was performed, even though none of these conditions pose any health risk to women and the interventions themselves can cause a multitude of issues.

Assigned female at birth, I lived more or less unsuccessfully as a woman for nearly 30 years before making the decision to transition. When I finally found the doctor that would prescribe my first rounds of hormone replacement therapy, she asked how long I’d been “self-medicating,” insinuating that I’d been doping myself with anabolic steroids. I was confused — I’d never tried a drug stronger than dark beer — until she commented that my testosterone levels were high enough to get me booted from elite sports.

I didn’t have PCOS, amenorrhea, hirsutism, or XY chromosomes (though, admittedly, plenty of men don’t). I’d given birth and wasn’t particularly athletic. Genetic tests I underwent while pregnant with my daughter, years later, suggested mosaicism, but randomly testing the genetic material from all over my body would have been prohibitively expensive without much payoff. Those who would label me a confused, mentally ill woman seemed unlikely to be swayed by such truths. Still, under the IAAF’s policies, I would have been classified male, and many of those same people would support that.

While being transgender isn’t currently classified as a disorder of sexual development, many endocrinologists and biologists who work and research in the fields of sex, gender, and genetics believe that gender identity is at least partially — and possibly wholly — biological, and studies seem to show that trans women lag behind cis men in physical strength and body mass even before undertaking hormone therapy. If this is the case, and Lia Thomas was never truly or fully male to begin with, then we must admit that she’s just one more victim of a harmful system that could force any accomplished female athlete to lose her identity, hard-earned medals, and even part of her clitoris, based on measures of sex that seem increasingly arbitrary. And when we allow this to happen to any woman, all women lose.