Can transgender females ‘destroy’ girls’ sports? What the numbers, science and common sense say

March 3, 2022 11:10 am

LGBTQ flags. (Photo by Getty Images)

A bill that Iowa Gov. Kim Reynolds signed Thursday aims to save Iowans from a society-threatening scourge.

Not COVID-19 or climate change. It’s transgender girls who want to play sports with their friends.

The bill, House File 2416, would prohibit transgender females from playing women’s sports at Iowa high schools and colleges. Only cisgender females ­– ones who have a gender corresponding to the sex assigned at birth – could compete in girls’ and women’s basketball, soccer, track and other sports. Those assigned male at birth must sit out or compete in boys’ and men’s events – no matter what gender they present as or whether they’re transitioning or have transitioned to female.

Many Republicans are sounding the alarm, saying transgender females threaten the very existence of sports for women and girls. Letting them participate “will do away with girls’ sports and it’s just not fair,” Reynolds warned. In the Iowa House of Representatives, Orange City Republican Skyler Wheeler asserted: “This bill is not about discrimination. It’s about protection.”

But a more sober examination employing math, science and common sense finds that Iowans needn’t fear that legions of muscular former males will grab all the trophies and medals.

The math: The Iowa Department of Education’s puts the state’s K-12 enrollment at 484,159 students. Statistics are few, but a 2017 peer-reviewed study in the American Journal of Public Health estimated 390 out of 100,000 Americans are transgender. Applied to Iowa’s school population, that’s about 1,888 students.

The bills, however, apply only to transgender females. Surveys, such as Social Security records and surgical statistics, indicate that transgender males (assigned-at-birth females transitioning to male) are more prevalent than females – perhaps as much as 65% to 35%. For the sake of argument, let’s say half – 944 – of the estimated 1,888 transgender students are female.

But that includes elementary-age students, whose sex-based physical differences are less significant and who aren’t yet playing school-based organized sports. That means the relevant number of transgender students is undoubtedly far less, maybe half again: 472, spread across 327 school districts. So, on average, perhaps one or two students in a district may be a middle- or high-school transgender female.

Obviously, the number will be larger at big schools and perhaps zero at small schools. But it’s still a tiny number that gets even tinier because only some transgender students want to play sports. In any school, there are band kids and theater kids and sports kids.

These few transgender females hardly pose an existential threat to girls’ sports. But if lawmakers continue to insist that transgender females play men’s soccer or basketball, the students also will have to share locker rooms and showers with cisgender boys. Is that what legislators want? Do they really want to humiliate these youths?

The science: For transgender children, the unwanted bodily changes associated with puberty can be distressing, perhaps even deadly with some considering suicide. Loving parents ensure their offspring get treatment, including, in many cases, pubertal blockers – drugs that temporarily delay the onset of adolescence while children clarify their feelings. That means some, if not most, transgender females will forgo the testosterone surge that gives them a theoretical athletic edge.

I say “theoretical” because it’s unclear that transgender females really are physically superior to cisgender females. As Dr. Jack Turban, a fellow in child and adolescent psychiatry at Stanford University School of Medicine, told public radio in May 2021, cisgender men may perform better than cisgender females, “but a cisgender man is not a transgender woman.” The hormone treatments many transgender females receive limit or eliminate any potential testosterone benefit. The rare transgender female who plays sports may have little advantage – or no advantage at all.

California has let students choose whether to play boys’ or girls’ sports based on their self-perception, regardless of their birth gender, since 2013. Nonetheless, in a state with nearly 40 million people, no transgender girls are dominating sports leagues, Turban noted. If they were, transgender rights opponents are sure to say so.

The common sense: Athletes of any gender can have a genetic edge, such as a 6-foot, 1-inch cisgender female volleyball player, a long-legged cisgender female hurdler, or a big-boned cisgender female softball catcher. Athletes everywhere capitalize on genetic differences to win in sports.

But success goes beyond genetics to natural ability, dedication and training, all accessible to anyone. Ask any guy who’s had a woman hand him his head on a basketball court or softball diamond.

So, if the risk of a transgender female dominating an Iowa sport is insignificant, there must be another reason Iowa Republicans want to block them.

I wonder what it is.

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Thomas R. O'Donnell
Thomas R. O'Donnell

Thomas R. O’Donnell is a longtime Iowa reporter, editor and science writer and blogs at He lives in rural Keosauqua.