The History & Harms of Sex Testing in Sports

Sport has always claimed to be about fairness....

But when you look closely at the history of sex testing in women’s sports, a different pattern emerges: one rooted not in fairness, but in fear, control, and a persistent discomfort with women who don’t fit narrow expectations of what a female athlete “should” look like.

Today, as governing bodies move back toward sex verification policies, it’s critical to understand this history, not as a relic of the past, but as a warning for the future.

The Orgins of Sex Testing Began

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.”

In 1946, the International Amateur Athletics Federation (IAAF, now World Athletics), which is 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.” These 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

  
  

These methods were presented as scientific. They weren’t. They were crude, invasive, and fundamentally misunderstood the complexity of human biology.

The Science Was Never There

Biological sex is not a binary switch that can be verified with a single test.

It is a combination of:

• Chromosomes

• Hormones

• Gonadal structures

• Secondary sex characteristics
  

And these don’t always align neatly.

Intersex variations - natural differences in sex development - occur in an estimated 1 in 1,500 to 1 in 2,000 people. That means elite sport was never dealing with a clear binary to begin with.

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

• 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. But, sadly, that wasn’t the end.

From Universal Testing to Targeted Policing

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.

To be clear: this shift didn’t solve the problem - it made it more discriminatory. It created a 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

  
  

High-profile cases, including athletes like Caster Semenya, exposed just how damaging these policies could be.

The Human Cost

Sex testing has never been a neutral process. It has real, lasting consequences that have been detailed by past Olympians and other athletes subjected to these invasive tests. Athletes subjected to testing have experienced:

• Public humiliation and media exposure

• Forced medical interventions, including hormone suppression

• Loss of privacy over deeply personal medical information

• Disqualification and loss of livelihood
  

In some cases, athletes were asked (or in other cases, forced) to undergo medically unnecessary procedures just to compete.

Who Is Actually Affected?

These policies are often framed as being about transgender athletes. However, historically and today, that’s not the full picture.

Sex testing disproportionately impacts:

• Intersex athletes, whose natural biology doesn’t fit binary definitions

• Cisgender women, especially those who are muscular, tall, or don’t conform to gender norms

• Global Majority women, who are more likely to be scrutinized and challenged ("Global Majority women" refers to women of African, Asian, Latin American, Indigenous, and mixed-heritage backgrounds, who together constitute roughly 85% of the world's population. This term shifts the focus from a Western-centric "minority" perspective to a global one, centering the experiences of women who are often marginalized.)
  

And now, with renewed calls for sex verification, every woman in sport is at risk of having to prove her identity.

The Myth of Protection

Sex testing 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.

We’ve Been Here Before

Sport has already tried sex testing. It didn’t work. It failed scientifically. It failed ethically. And it caused harm that many athletes are still living with today.

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

A Better Path Forward

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

  
  

Fairness doesn’t come from exclusion. It comes from building systems that are equitable, informed, and humane.

Why This Matters Now

As new policies emerge - particularly those proposing widespread sex verification - they don’t just affect elite athletes. They set a precedent.

What starts at the international level trickles down to:

• National governing bodies

• Collegiate athletics

• Youth sports, which have already seen lawmaker bans introducing sex testing on children
  

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

What you need to remember is this: this isn’t just about sport. It’s about whose bodies are considered acceptable and who gets to belong.

We should all be vehemently against the testing of women athletes in sport and the policing of women's bodies, on and off the court or field.