The Myth of Protection

Sex testing in sport is often justified as a way to “protect women’s sports.” But there is no evidence that these policies achieve that goal.

There is, however, extensive evidence that they:

• Violate human rights

• Undermine athlete dignity

• Reinforce narrow and exclusionary definitions of womanhood

And importantly, there is no consistent scientific evidence that naturally occurring biological variations, whether related to sex development or gender identity, translate into unfair, categorical advantage.

Sport has already tried sex testing

Sex testing in elite sport dates back to the mid-20th century, when international competitions began requiring proof that women competing in the women’s category were “truly female,” as a way to "protect women" and the women's category.

In 1946, the International Amateur Athletics Federation (IAAF, now World Athletics), the international federation for running events, required female athletes to provide medical certificates from their home countries verifying their sex.

In the 1960s, organizations like the International Olympic Committee and international federations introduced mandatory “femininity tests," which included:

• Physical examinations, sometimes referred to as “nude parades”

• Chromosome testing, looking for XX chromosomes as a marker of “true” womanhood

• Later, genetic testing, including screening for the SRY gene (which is what sports organizations are moving back to now)

  
  

Chromosome testing, once considered the gold standard, quickly proved unreliable:

• An estimated 1 in 1,500 to 1 in 2,000 people have natural differences in sex development (often referred to as intersex variations)

• Some women with XY chromosomes develop typically female bodies and identities

• Some women with XX chromosomes may have traits that don’t align with expectations

• No single marker consistently defines athletic advantage

  
  

By the 1990s, even the International Olympic Committee acknowledged the limitations and abandoned universal sex testing. In fact, every major sport body that tried chromosome testing eventually dropped it - not for being too lenient, but for being scientifically wrong. It mainly ended up flagging women who’d competed their whole lives with no idea anything was different. It didn’t work. It failed scientifically. It failed ethically. And it caused harm that many athletes are still living with today.

But, sadly, that wasn’t the end. Instead of testing everyone, sport shifted to targeted suspicion. Athletes were flagged for testing if they appeared “too masculine,” performed “too well,” or didn’t conform to gender norms.

This shift didn’t solve the problem - it made it more discriminatory. It created our current system where:

• Women’s bodies became subject to scrutiny

• Gender expression became grounds for investigation

• Athletes - disproportionately Global Majority athletes and athletes from the Global South - were singled out

Bringing sex testing back isn’t progress. It's repeating a history we know causes harm to women and girls.

A Better Path Forward

Fairness doesn’t come from exclusion. It comes from building systems that are equitable, informed, and humane. If the goal is truly to protect women’s sports, we need to move away from policing bodies and toward:

• Evidence-based policy grounded in actual performance data

• Inclusive frameworks that recognize biological diversity

• Safeguards for athlete privacy and dignity

• Investment in women’s sports at all levels

  
  

Ultimately, sex testing creates conditions and environments that dictate who feels safe, welcome, and able to participate. And this impacts all women and girls.

Targeting and excluding any woman makes all women less safe in sports.

SOURCES:

• The Lancet, “Gender verification of female athletes” — history of chromosome/SRY testing, why it was phased out: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(05)67843-9/fulltext

• The Conversation, “World Athletics’ mandatory genetic test for women athletes is misguided” — written by the scientist who discovered the SRY gene, explaining why it can’t determine biological sex: https://theconversation.com/world-athletics-mandatory-genetic-test-for-women-athletes-is-misguided-i-should-know-i-discovered-the-relevant-gene-in-1990-262367

• Nature, “The unfair fight” — 1996 Atlanta testing data (8 of 3,387 athletes), IOC/World Athletics testing timeline: https://media.nature.com/original/magazine-assets/d41586-021-00819-0/d41586-021-00819-0.pdf

• GLAAD, “Fact Sheet for Reporters: ‘Sex Testing’ in Sports” — modern context on renewed testing proposals and intersex athlete impact: https://glaad.org/fact-sheet-for-reporters-sex-testing-in-sports/

• Scientific American, “Sex Testing in the Olympics and Other Elite Sports Is Based on Flawed Science” — reporting on the 100-year history of sex testing: https://www.scientificamerican.com/podcast/episode/sex-testing-in-the-olympics-and-other-elite-sports-is-based-on-flawed/