Ask Vest Christiansen
Aarhus University
In their recent feature article “Regression, Not Progress: A Response to World Athletics’ Return to Sex Testing,” Lindsay Parks Pieper, Jaime Schultz, and Jörg Krieger critique World Athletics’ decision to reinstate genetic screening in women’s athletics as a regressive and harmful measure (Pieper et al., 2025). They argue that such policies, rooted in a long and troubling history of sex verification in sport, continue to stigmatize female athletes and reinforce negative gender norms. While the authors rightly highlight past ethical failings – such as invasive physical examinations and breaches of confidentiality – their critique of sex verification do not address crucial scientific, procedural, and ethical distinctions between past and present practices. The authors thus do not consider key points – recently published in the Scandinavian Journal of Medicine & Science in Sports (Lundberg et al., 2024; Tucker et al., 2024) – on how to find viable solutions to the central question: if the women’s category is to remain protected from male advantage in elite sport, how can this be achieved without some form of objective criteria? To ensure fairness for female athletes in the present, we cannot be guided only by the unethical practices of the past, but instead must consider modern, non-invasive screening protocols.
In this comment I argue that World Athletics’ (WA) new approach represents a necessary and ethically justifiable effort to protect the integrity of women’s sport.
Framing the Core Issue
The underlying question is: how can female athletes be ensured fair competition if eligibility for the women’s category is left undefined or wholly self-declared? In their response, Pieper, Schultz, and Krieger criticize WA’s screening initiative but leave this central question unanswered. However, if we believe the women’s category should be preserved as a sex-based category, we need to have a clear idea on how we define and enforce its boundaries.
In the absence of objective criteria, athletes become vulnerable to rumour and racialized suspicion, rather than protected by clear and consistent policy.
As this issue is foundational, we must tackle the question of how the category is to be safeguarded. The importance of this became clear during the Olympic boxing scandal in Paris in 2024, when the Algerian Imane Khelif and Lin Yu‑ting of Chinese Taipei (Taiwan) won gold. Both had been barred from competing at the 2023 world championships by the International Boxing Association after failing sex tests but were allowed to take part in Paris by the IOC, because the IOC explicitly stated self-declaration and gender stated in athletes’ passport as the criteria for which category to compete in (International Olympic Committee, 2021; IOC Media, 2024). The subsequent widespread speculation about the two boxers’ eligibility for the women’s category were not just media fabrications; they emerged precisely because the IOC – who had taken over the control of the Olympic boxing tournament – has no transparent, confidential, systematic, and biology-based procedure in place to address eligibility concerns before they reached public view.
In the absence of objective criteria, athletes become vulnerable to rumour and racialized suspicion, rather than protected by clear and consistent policy. Even if the cases erupted under different regulations, the issues were similar with Namibian runners Christine Mboma and Beatrice Masilingi in Tokyo, 2021. And if we go back to the 2016 Rio Olympics, the women’s 800 meters podium was occupied by three athletes – Caster Semenya, Francine Niyonsaba, and Margaret Wambui – who all were either confirmed or strongly suspected to have differences of sex development (DSD), most likely of the 5-ARD or PAIS type (I will return to these conditions below).
This does not mean these athletes are at fault. On the contrary, they were competing under the rules provided. But it does signal a systemic failure to ensure that the women’s category remains protected from male advantage. Since 2021 IOC has intentionally disregarded biological reality in favour of an ideological standpoint of inclusion (Christiansen, 2023). The physiological differences between men and women, which are the result of the exposure to testosterone during male puberty, cause performance difference of between 10 and 60 percent between the sexes (Lundberg et al., 2024). The consequence hereof is that if there were no protected category for women there would be no female winners in sports where power, strength, speed, and endurance affect performance. This is why we have categories for the two sexes. And when we have opted to have categories, they must be policed and protected. Otherwise they become futile (Parry & Martínková, 2021).
Indeed, when presenting the organisation’s ambition to introduce the new screens, World Athletics President Sebastian Coe reaffirmed the organization’s commitment to maintaining fairness in women’s sport, stating: “We will doggedly protect the female category, and we’ll do whatever is necessary to do it” (Ingle, 2025).
Coe is not alone with this perspective. After the boxing scandal in Paris, a group of more than 30 scholars – sport scientists, philosophers, sociologists – proposed a solution akin to what WA is now introducing. The conclusion stated:
It is crucial that sports federations in sex-affected sports are empowered to protect female athletes and ensure fair competition. […] Rather than “policing female bodies,” screening followed by comprehensive follow-up in the rare cases that require extra consideration, with emphasis on the duty of care to every athlete, will ensure preservation of the female category for fair and safe sport (Tucker et al., 2024).
This points to another issue that could have deserved more consideration in Pieper and colleagues’ contribution.
Mischaracterization of the SRY Screen
One of the central claims in Pieper, Schultz, and Krieger’s piece is that World Athletics’ use of genetic screening – specifically for the presence of the SRY gene – represents a scientifically flawed and ethically dubious attempt to police women’s bodies. They write that “WA’s test will likely be used to disqualify transgender women and women with DSDs, even though there is no definitive link between the SRY gene and athletic talent” (Pieper et al., 2025).
This of course requires a management procedure that lives up to all appropriate standards of confidentiality and medical ethics.
This framing is problematic for two reasons. First, it inaccurately describes what the SRY protocol entails. Second, the suggestion that the screen assumes a direct link between the SRY gene and athletic talent is a misunderstanding.
First: If an individual has the SRY gene – that is, the Sex Determining Region on the Y chromosome – they have the gene that leads to male development. Therefore, in a population of women, those who are positive on the screen will either be a trans woman (trans identifying male), or individuals with 46XY DSDs. While there are a few DSD conditions, there are two common DSDs in sport (Handelsman, 2024). The first is Androgen Insensitivity Syndrome, or AIS. The other is 5-Alpha Reductase Deficiency, or 5-ARD. The first can be categorised as either Partial Androgen Insensitivity Syndrome (PAIS) or Complete Androgen Insensitivity Syndrome (CAIS). Because these individuals are XY they have testicles, or testicular tissue (and not ovaries) and they therefore produce testosterone in the male range. But CAIS individuals have no testosterone receptors (or non-functioning) and therefore cannot utilise the testosterone they have, they are insensitive to it. CAIS individuals therefore have not experienced androgenisation during puberty and thus have no male advantage. The Spanish hurdler María José Martínez Patiño, whom the authors mention, who competed in the 1980s, has this condition. In the meantime, science has progressed and a thorough medical follow up would identify cases like hers, and they are therefore eligible for female events on the WA rules (World Athletics, 2023).
On the other hand, DSD individuals with PAIS or 5-ARD will not be eligible to compete in the women’s category, as they experience androgenisation during puberty, and acquire the physical advantages associated with this. They produce testosterone in the male range, they can utilise the testosterone and thus have male advantage (Handelsman, 2024). As mentioned above, examples of athletes with these conditions are Caster Semenya, Christine Mboma and (most likely) Imane Kahlif.
Second, obviously, the SRY gene does not say anything about athletic talent – only that the person has male category advantage. Also, DSD cases are not false positives of the SRY gene. They have correctly been identified as having that gene, and in WA’s new protocol, follow-up medical testing will then have to demonstrate whether they have one of the relevant DSD conditions (PAIS or 5-ARD) or one that is not relevant. This of course requires a management procedure that lives up to all appropriate standards of confidentiality and medical ethics. If the athlete in question do not have one of the relevant DSD conditions, they are free to compete in the women’s category.
DSD is a very rare condition. However, while the prevalence of DSD in the general population is estimated to be somewhere between 1 in 20,000 and 1 in 40,000, it has been estimated that 46 XY DSDs are 140 to 200 times more frequent in elite female competition than in the general population. As leading sport endocrinologist David Handelsman has stated, this “is striking evidence of the selective advantages of male-bodied athletes with female gender identity in female events” (Handelsman, 2024, p. 6).
Finally, it may be a semantic point – but it is an important one – what WA proposes is a screen and not a test, that must only be done once in an athlete career. The screen is simply a first pass that indicates whether further testing is necessary. It is not sport’s purpose to test people’s sex, but to screen for eligibility. Therefore, the screening proposed by WA is not in itself a disqualification mechanism. It is an initial, non-invasive method used to identify cases that may warrant further, confidential medical evaluation. The fact that it is a screen and not a test is a distinction that is both medically and ethically significant. The screening is not a diagnostic tool. It is designed to flag cases where more precise diagnostic tools – administered under strict medical and ethical oversight – can determine whether a particular DSD (such as 5-ARD or PAIS) is present and relevant.
Most scholars, athletes and fans recognize that biological sex differences are relevant to competitive fairness.
Scientific and Ethical Progress
Pieper, Schultz, and Krieger devote considerable space to recounting the painful history of sex testing in sport: nude parades, chromosomal screening, public outing, and medical disqualifications based on insufficient understanding of sex development. It is true that sport did not handle this well. Whether it was the IOC, WA or other governing bodies they were not equipped to both identify and then medically manage these cases. This mishandling resulted in a lot of pushbacks, and by the late 1990s sex testing was abandoned.
But here again we must acknowledge key improvements in genetic testing and clinical follow-up procedures. Like we would not dismiss contemporary drug testing because early doping controls were poorly administered, we also cannot reject modern screening for sex based on past failures. One can only argue that a return to genetic screening “revives one of sport’s most damaging regulations” if one does not recognize this progress.
The Problem of Non-Testing
Most scholars, athletes and fans recognize that biological sex differences are relevant to competitive fairness. Thus, if women’s sport is premised on recognition of sex-linked physiological differences, then we cannot reject all forms of eligibility verification without offering viable alternatives. The assertion that any screening constitutes harm, should also acknowledge the potential harm of not screening.
If eligibility for the women’s category is left unregulated – or dependent on self-identification as per the current IOC policy (International Olympic Committee, 2021) – then it becomes impossible to enforce meaningful boundaries. Relying on self-identification opens the door to public speculation, accusation, and discrimination, as the media hype around the participation of Algerian boxer Imane Khelif in the 2024 Olympic Games clearly illustrated. If we want to avoid future Khelif or Semenya-style controversies, we must be willing to engage with the necessary task of defining who the women’s category is for – and how that determination is made. A system with screen-then-test can remove the burden of suspicion from individual athletes and prevent the kind of media circus that often surrounds high-profile cases.
The harms of past failures do not originate from the existence of screening per se. They arise when there is a lack of clear procedures and a failure to handle eligibility questions discreetly and professionally. A structured screen-then-test pathway, administered confidentially and with medical oversight, is not only more ethical than past practices, but also more protective than the alternative: a climate where every female athlete is a potential target for suspicion.
Moreover, most female athletes support eligibility verification mechanisms. Surveys conducted by sport federations and athlete commissions consistently show that women want clear criteria to protect the integrity of their category. In rowing it is 88% of women athletes who are in favour of sex verification, swimming also has numbers in the 80s, Rugby in the 70s (Tucker & Finch, 2025). And this is not new. A survey among female athletes after the Atlanta 1996 Olympics revealed that 82% supported sex testing, with only 6% reporting discomfort about the test protocol (Tucker et al., 2024).
Conclusion
Pieper, Schultz, and Krieger present World Athletics’ return to genetic screening as a repetition of past mistakes. However, while it is important to recognise sport’s troubled history with sex testing, we also do have to address a viable framework for the present.
In elite sport, fairness, inclusion and safety are paramount, and so policy must be clear and consistent. It must be informed by science, guided by ethics, and attentive to the real-world consequences of both action and inaction. As it is being presented, World Athletics new screening protocol is a solution that is consistent with such a view. Those who oppose it will have to answer: If not this, then what?
Copyright © Ask Vest Christiansen 2025
References
Christiansen, A. V. (2023). The Negligence of Biological Reality. Journal of Olympic Studies, 4(2), 20-30. https://doi.org/10.5406/26396025.4.2.03
Handelsman, D. J. (2024). Toward a Robust Definition of Sport Sex. Endocrine Reviews. https://doi.org/10.1210/endrev/bnae013
Ingle, S. (2025, 25 March ). World Athletics mandates cheek swabs to ‘doggedly protect female category’. The Guardian, 1. https://www.theguardian.com/sport/2025/mar/25/world-athletics-mandates-cheek-swabs-to-doggedly-protect-female-category
IOC Framework on fairness, inclusion and non-discrimination on the basis of gender identity and sex variations, 6 (2021). https://olympics.com/ioc/documents/athletes/ioc-framework-on-fairness-inclusion-and-non-discrimination-on-the-basis-of-gender-identity-and-sex-variations
IOC Media. (2024, 2 August, ). IOC spokesperson Mark Adams reads the IOC statement on the women’s boxing tournament at Paris 2024 Retrieved 24-04-2025 from https://youtu.be/D4HiUIX9o00?si=K8VChxqmMxToEPz8
Lundberg, T. R., Tucker, R., McGawley, K., Williams, A. G., Millet, G. P., Sandbakk, Ø., Howatson, G., Brown, G. A., Carlson, L. A., Chantler, S., Chen, M. A., Heffernan, S. M., Heron, N., Kirk, C., Murphy, M. H., Pollock, N., Pringle, J., Richardson, A., Santos-Concejero, J., . . . Hilton, E. N. (2024). The International Olympic Committee framework on fairness, inclusion and nondiscrimination on the basis of gender identity and sex variations does not protect fairness for female athletes. Scandinavian Journal of Medicine & Science in Sports,34(3), e14581. https://doi.org/https://doi.org/10.1111/sms.14581
Parry, J., & Martínková, I. (2021). The logic of categorisation in sport. European Journal of Sport Science, 21(11), 1485-1491. https://doi.org/10.1080/17461391.2021.1943715
Pieper, L. P., Schultz, J., & Krieger, J. (2025). Regression, Not Progress: A Response to World Athletics’ Return to Sex Testing. idrottsforum.org. https://idrottsforum.org/feature-pieperetal250403/
Tucker, R., & Finch, M. (2025, 27 March). Spotlight: A New IOC President / A New Tool To Protect Women’s Sport / A New Power Metric In The Real Science of Sport Podcast. https://shows.acast.com/realscienceofsport/episodes/spotlight-a-new-ioc-president-a-new-tool-to-protect-womens-s
Tucker, R., Hilton, Emma N., McGawley, K., Pollock, N., Millet, Grégoire P., Sandbakk, Ø., Howatson, G., Brown, Gregory A., Carlson, Lara A., Chen, Mark A., Heron, N., Kirk, C., Murphy, Marie H., Pringle, J., Richardson, A., Santos-Concejero, J., Christiansen, Ask V., Jones, C., Alonso, J.-M., . . . Lundberg, Tommy R. (2024). Fair and Safe Eligibility Criteria for Women’s Sport. Scandinavian Journal of Medicine & Science in Sports, 34(8), e14715. https://doi.org/10.1111/sms.14715
Eligibility Regulations For The Female Classification (Athletes With Differences Of Sex Development), (2023).
Thank you, Ask! This is very good – and clear.
Thank you, Miroslav – I apprecaite that.