ATLANTA — The women on the Princeton University swim team spoke of collective frustration edging into anger. They had watched Lia Thomas, a transgender woman who swam for the University of Pennsylvania, win meet after meet, beating Olympians and breaking records.
On Jan. 9, the team met with Robin Harris, executive director of the Ivy League athletic conference.
The swimmers, several of whom described the private meeting on condition of anonymity, detailed the biological advantages possessed by transgender female athletes. To ignore these, they said, “was to undermine a half-century fight for female equality in sport.”
Ms. Harris had already declared her support for transgender athletes and denounced transphobia. In an interview, she said that she had replied that she would not change rules in midseason. “Somehow,” a swimmer recalled, “the question of women in sport has become a culture war.”
The battle over whether to let female transgender athletes compete in women’s elite sports has reached an angry pitch, a collision of competing principles: The hard-fought-for right of women to compete in high school, college and pro sports versus a swelling movement to allow transgender athletes to compete in their chosen gender identities.
Although the number of transgender athletes on top teams is small — a precise count is elusive as no major athletic association collects such data — disagreements are profound. They center on science, fairness and inclusiveness, and cut to the core of distinctions between gender identity and biological sex.
Echoes of those debates ripple outward from pools to weight lifting rooms and tracks, to cycling courses and rugby pitches, and to the Olympics, where officials face a fateful decision on how wide to open the door to transgender women.
Sebastian Coe, the Olympic champion runner and head of the International Association of Athletics Federations, which governs world track, speaks of biological difference as inescapable. “Gender,” he said recently, “cannot trump biology.”
The American Civil Liberties Union offers a counterpoint. “It’s not a women’s sport if it doesn’t include ALL women athletes,” the group tweeted. “Lia Thomas belongs on the Penn swimming and diving team.”
The rancor stifles dialogue. At meets, Ms. Thomas has been met by stony silence and muffled boos. College female athletes who speak of frustration and competitive disadvantage are labeled by some trans activists as transphobes and bigots, and are reluctant to talk for fear of being attacked.
Ms. Thomas herself has chosen silence. In March, after winning the 500-yard freestyle in the N.C.A.A. women’s championship in Atlanta, she skipped a news conference. She has of late spoken only to Sports Illustrated, saying, “I’m not a man. I’m a woman, so I belong on the women’s team.”
Even nomenclature is contentious. Descriptive phrases such as “biological woman” and “biological man” might be seen as central to discussing differences in performance. Many trans rights activists say such expressions are transphobic and insist biology and gender identity are largely social constructs.
Some trans activists try to silence critics, whom they derisively call TERFs, which stands for trans-exclusionary radical feminists. A spokeswoman for a gay rights group urged a reporter not to “platform” — that is not to quote — those she said held objectionable views, including Martina Navratilova, the retired tennis legend, a champion of liberal and lesbian causes. Ms. Navratilova argues that transgender female athletes possess insurmountable biological advantages.
“So I’m a ‘TERF’ — OK, that’s the way you want to go?” Ms. Navratilova said in response. “I played against taller women, I played against stronger women, and I beat them all. But if I faced the male equivalent of Lia in tennis, that’s biology. I would have had no shot. And I would have been livid.”
Former allies are split so bitterly as to make reconciliation a distant prospect. Half of Ms. Thomas’s University of Pennsylvania team sent a letter to the school, released by a lawyer, saying the swimmer had “an unfair advantage.” Brooke Forde, an Olympic silver medalist with Stanford, however, supported Ms. Thomas. “Social change is always a slow and difficult process, and we rarely get it correct right away,” she stated.
50 Years of Title IX
The landmark gender equality legislation, which was signed into law in 1972, transformed women’s access to education, sports and much more.
Griffin Maxwell Brooks, a trans nonbinary diver at Princeton who competes on the men’s team, released a TikTok video accusing “cisgender women” of leveraging “misogyny to perpetuate transphobia.”
Not long afterward, a Princeton eating club barred a female swimmer from joining, saying her “transphobia” might bring it disrepute, according to a Princeton swimmer.
Finally, inescapably, America’s hyperpartisan politics has electrified this debate. Librarians have been told to remove books with transgender themes from shelves. And Republican-dominated legislatures in 18 states have introduced restrictions on transgender participation in public school sports in recent years, according to data from the Human Rights Campaign, an L.G.B.T.Q. advocacy group.
A few Republican leaders resisted crackdowns. Gov. Spencer Cox of Utah vetoed a ban on transgender girls competing in girls’ sports; the Legislature overrode his veto.
In Texas, Gov. Greg Abbott demanded agencies investigate parents and doctors who assist children in transitioning, which he termed “child abuse.” In Florida, Gov. Ron DeSantis said he would “reject lies” and refused to recognize Ms. Thomas as the winner of the 500-yard freestyle championship.
Governor DeSantis’s declaration carried no legal power. But it underlined that a difficult conversation is near lost to the shouting.
The Debate Over the Science
Michael J. Joyner, a doctor at the Mayo Clinic in Rochester, Minn., studies the physiology of male and female athletes. He sees in competitive swimming a petri dish. It is a century old, and the sexes follow similar practice and nutrition regimens.
Since prepubescent girls grow faster than boys, they have a competitive advantage early on. Puberty washes away that advantage. “You see the divergence immediately as the testosterone surges into the boys,” Dr. Joyner said. “There are dramatic differences in performances.”
The records for elite adult male swimmers are on average 10 percent to 12 percent faster than the records of elite female swimmers, an advantage that has held for decades.
Little mystery attends to this. Beginning in the womb, men are bathed in testosterone and puberty accelerates that. Men on average have broader shoulders, bigger hands and longer torsos, and greater lung and heart capacity. Muscles are denser.
“There are social aspects to sport, but physiology and biology underpin it,” Dr. Joyner noted. “Testosterone is the 800-pound gorilla.”
When a male athlete transitions to female, the National Collegiate Athletic Association, which governs college sports, requires a year of hormone-suppressing therapy to bring down testosterone levels. The N.C.A.A. put this in place to diminish the inherent biological advantage held by those born male.
Ms. Thomas followed this regimen.
But peer reviewed studies show that even after testosterone suppression, top trans women retain a substantial edge when racing against top biological women.
When Ms. Thomas entered women’s meets, she rose substantially in national rankings. Among men, she had ranked 32nd in the 1,650-yard freestyle; among women, she ranked eighth and won a race this season by a margin of 38 seconds.
She had ranked 554th in the men’s 200-yard freestyle; she tied for fifth place in this race in the women’s 2022 N.C.A.A championship.
And she ranked 65th in the men’s 500-yard freestyle but won the title as a female.
“Lia Thomas is the manifestation of the scientific evidence,” said Dr. Ross Tucker, a sports physiologist who consults on world athletics. “The reduction in testosterone did not remove her biological advantage.”
Testosterone levels are crucial but do not invariably predict performance in every sport. Chris Mosier is a 41-year-old elite athlete who transitioned to male in 2015 and had no testosterone-fueled developmental advantage. Yet he has beaten elite racewalking biological men.
“Athletic performance depends on a lot of factors: access to coaches and nutritionists and technical skill,” Mr. Mosier said. “We are making broad generalizations about men being bigger, stronger, faster.”
Most scientists, however, view performance differences between elite male and female athletes as near immutable. The Israeli physicist Ira S. Hammerman in 2010 examined 82 events across six sports and found women’s world record times were 10 percent slower than those of men’s records.
“Activists conflate sex and gender in a way that is really confusing,” noted Dr. Carole Hooven, lecturer and co-director of undergraduate studies in human evolutionary biology at Harvard University. She wrote the book “T: The Story of Testosterone.” “There is a large performance gap between healthy normal populations of males and females, and that is driven by testosterone.”
The sprinter Allyson Felix won the most world championship medals in history. Her lifetime best in the 400 meters was 49.26 seconds; in 2018, 275 high school boys ran faster.
Renée Richards was a pioneer among transgender athletes. An ophthalmologist and accomplished amateur tennis player — she played in the U.S. Open and ranked 13th in the men’s 35-and-over division — she transitioned in 1975 at age 41. She joined the women’s pro tennis tour at age 43, ancient in athletic terms. Ms. Richards then made it to the doubles final at Wimbledon and ranked 19th in the world before retiring at 47.
Ms. Richards has said she no longer believes it is fair for transgender women to compete at the elite level.
“I know if I’d had surgery at the age of 22, and then at 24 went on the tour, no genetic woman in the world would have been able to come close to me,” she said in an interview. “I’ve reconsidered my opinion.”
Joanna Harper, a competitive transgender female runner and Ph.D. student studying elite transgender athletic performance at Loughborough University in Britain, agreed that testosterone gives transgender female athletes some advantage.
But she spoke of inexorable emotional and psychological pressures on transgender athletes.
“Is it so horrible,” she said, “if a handful of us are more successful than they were in men’s sports?”
Reka Gyorgy, a 2016 Olympian and a swimmer at Virginia Tech, offered a response of sort. She placed 17th in the preliminaries for the 500-yard freestyle in the N.C.A.A. championships — a slot short of making the finals. She wrote an open letter, affirming her respect for Ms. Thomas’s work ethic.
She was less forgiving of the N.C.A.A.
“This was my last college meet ever and I feel frustrated,” she wrote. “It feels like that final spot was taken away from me because of the N.C.A.A.’s decision to let someone who is not a biological female compete.”
That decision prevented her from qualifying for All-America honors.
Title IX and the Fight for Equality
To wander the stands last March at the women’s swim championships at Georgia Tech and ask about Ms. Thomas was to draw shakes of the heads from parents and grandparents, sisters and brothers of swimmers. Many emphasized that transgender people should have the same right to housing, jobs, marriage and happiness as any American.
But they talked of the thousands of hours the young women put into their sport. From early childhood, they swam hundreds of laps daily, nursing injuries and watching nutrition. Why, having reached the pinnacle, should they race against a swimmer who retains many biological advantages of a male athlete?
“We have a biological male taking over women’s sports,” said one mother. “I don’t understand why those on the left politically are not supporting cis women.”
Equality for women in sports followed decades of struggle. Fifty years ago, President Nixon signed Title IX, which banned discrimination in higher education. This opened doors to previously all-male classes and led to many more female teams and scholarships.
In 1972, one in 27 girls played sports; today two in five do so, according to the Women’s Sports Foundation. The 1972 U.S. Olympic team featured 90 female athletes alongside 339 male athletes. Last year’s American team in Tokyo had 284 male athletes and a record 329 female athletes.
Some trans activists are challenging aspects of Title IX, specifically its implicit acknowledgment of biological difference. And supporters, not least the Biden administration, say transgender girls should be permitted on girls’ sports teams. They have pushed for a federal Equality Act, which would prohibit discrimination based on sexual orientation and gender identity in housing, education, employment and credit.
It potentially places biology and gender identity on the same footing in sport. Dr. Doriane Lambelet Coleman, a Duke University law professor and former top track runner, supports legal protections for transgender people but foresees havoc in the arena of sports. The legal rationale for keeping women’s sports sex-segregated would fall away. “We are bringing a male body into a female sport,” Dr. Coleman said. “Once you cross that line, there’s no more rationale for women’s sport.”
Some trans activists and academics welcome that. Nathan Palmer, a lecturer at Georgia Southern University, wrote in Sociology in Focus: “Nature loves diversity, but humans love simplicity. Separating males from females may be socially useful, but when the dividing lines limit and oppress, we have to acknowledge they are social constructions.”
Anna Posbergh, a doctoral candidate at the University of Maryland, is a former pole-vaulter who studies the mechanics of human movement and gender and athletes. She sees notions of gender disadvantage in sports as rooted in culture and an outdated view of what women can achieve.
“I’m beginning to question the idea of sex segregation in sport,” she said. “We need to learn to sit with discomfort.”
This strikes some feminists and scientists as a walk into strange territory. Kathleen Stock, a British philosopher whose work is often grounded in her feminist and lesbian identity, has carved out positions on transgender rights that have made her a lightning rod. She has written “Material Girls: Why Reality Matters for Feminism,” and argues against the insistence that one’s gender identity is all. That is to miss, she said, the profound importance of the lived experience of being born a biological female.
“We are caught up in this fever dream,” she said in an interview. “How could it be that a social construct and not the material reality of being a woman is guiding our thoughts and our physical performance?
“I find it incredible that we have to point this out.”
Search for Solutions
Lia Thomas was not the only transgender athlete to swim at the N.C.A.A. championship. Iszac Henig, a transgender man, swam the 100-yard women’s freestyle for Yale and attracted little attention. Yet his story challenges the argument that transgender athletes should swim under their gender identity.
Mr. Henig finished in a tie for fifth in the 100-yard women’s race with a time of 47.32 seconds. Had he chosen to swim against men, Mr. Henig would not have qualified for the championship.
Mr. Henig and Ms. Thomas swam in the race in which they had the greatest advantage. Every decision, a scientist noted, comes adorned with moral thorns.
In Britain, Emily Bridges, a record-breaking male cyclist, recently declared her intent to race as a woman. This has drawn passionate objections from the top women in cycling, who fear losing races and much prize money.
By way of solution, some point to golf, where in amateur competitions, a superior golfer takes a handicap — docking herself strokes — when competing against lesser players. Applied to swimming, a panel might examine Ms. Thomas’s race times and subtract seconds and let her swim.
The Macdonald-Laurier Institute, a policy organization based in Ottawa, argues for an “open category” for men, transgender athletes and biological females, anyone who cares to try her/his/their hand.
An exclusively female category would remain for biological women. This solution would forestall the need for transgender women to take hormone-suppressing drugs.
Some transgender activists argue such distinctions would be insulting, notwithstanding the decision of those such as Mr. Henig to race in their former gender.
The solution, a balance of gender and biology, looks distant. And yet, no end of anguish accompanies the status quo.
In Atlanta, a father, who declined to give his name, sat in the stands and watched Ms. Thomas in the 200-yard freestyle. She was, he noted, far taller than her competitors, with long legs and arms, big hands and broad shoulders. A day earlier his daughter had lost to Ms. Thomas in the 500-yard race, and nothing about that race felt fair to him or his daughter.
The father was polite as Ms. Thomas was announced and clapped twice.
Ms. Thomas lost by a broad margin. She slipped out of the pool, picked up a towel, sidestepped embracing swimmers and walked out, a solitary figure.
The father watched and shook his head.
“In fairness to Lia,” he said, “the emotional toll.”
He added: “I look at her and see the pressure she’s under. And I think: She’s a 22-year-old kid.”