Former Olympic champion and candidate for California governor Caitlyn Jenner has faced intense backlash in the past month for supporting a ban on transgender girls in girls’ sports. 

“It just isn’t fair. And we have to protect girls’ sports in our schools,” Jenner said to an interviewer. Jenner’s stance surprised many reporters and athletes, being a transgender woman herself, and many people claim that her sudden negligence of transgender opportunities is a facade to garner Republican votes in her upcoming recall election against current Democratic Gov. Gavin Newsom.

However, regardless of political ulterior motives, examining Jenner’s argument could bring important insight into the status of sports and transgender rights: Do transgender individuals who were assigned male at birth have an unfair advantage in girls’ sports? 

Academic papers on the topic give conflicting conclusions, consistently noting the lack of research in how the athletic performance of transgender women compares with that of cisgender women. Most research papers judge fairness by biological markers of athleticism, such as testosterone levels, hemoglobin levels and lean body mass. Testosterone is a hormone with many impacts on athletic performance, and hemoglobin is a protein that supplies cells with oxygen, especially during exercise. A review of several studies related to sports and transgender people from Springer found that there is currently no consistent research showing that transgender individuals have an athletic advantage at any stage of their transition. Many papers show that after hormone replacement therapy, transgender women see a decline in hemoglobin levels that matches cisgender women. However, another paper published in the British Journal of Sports Medicine found that although hormone replacement therapy decreases strength, lean body mass and muscle area, these values still remain above average cisgender women. Finally, the only paper that actually measures performance, rather than biological markers, observed race times between eight non-elite male-to-female runners before and after their transition. Adjusting for age differences, the study found that their performances were not significantly changed by the transition. In summary, hormone replacement therapy undoubtedly changes many biological markers in transgender athletes, but whether or not these athletes have a significant performance advantage is still uncertain, especially with such limited research.

There are even more gray areas when considering transgender athletes on a case-by-case basis. Every person is different. Not only do individuals have a wide range of hormone levels to begin with, transgender individuals will be at different stages of hormone replacement therapy—if undergoing therapy at all. A blanket ban on transgender girls is blind to the differing cirumstances of each individual. Moreover, many people who support transgender girls in girls’ sports state that some cisgender women have elevated testosterone levels anyway. Should a woman who is born with greater athleticism and elevated levels of testosterone and hemoglobin be banned from competing in girls’ sports? Should Serena Williams be banned from the Grand Slam tournaments for the unrelenting power behind her shots and her muscular frame? Should Lebron James be banned from the NBA for being upwards of 265 pounds while clocking a 4.4 second 40 yard dash?

Differing biological makeup in athletics has never been seen as a looming issue in sports, as genetic gifts play just as important of a role as hard work and skill. This phenomenon is shown to its greatest extent in team sports, where one superstar is seldom enough to win a championship. Given that there’s no definitive evidence that transgender women have a significant advantage in sports, allowing them to compete should not break the game. And this may be counterintuitive, but even if a transgender woman has an overwhelming athletic advantage over other women, a superstar could make the sport more interesting, increase watch time and inspire other transgender women who have struggled to overcome discriminatory bans like the one Jenner proposes.

Finally, banning transgender women from girls’ sports forces them to compete in boys’ sports, which is far more unfair to these athletes. Blatantly misgendering transgender women and forcing them into boys’ sports exacerbates gender dysphoria in individuals who already struggle with the complex relationship between their identity and societal norms. Challenging their identities would create serious health consequences for athletes and prevent them from competing in sports at all––on top of the many barriers against transgender athletes already. Ultimately, denying these athletes the right to compete, exacerbating gender dysphoria and deepening the prejudice against their identities are far greater injustices than some unproven argument about transgender women having an athletic advantage.