Caster Semenya

This essay, on the related but separate debates over Caster Semenya and over transgender athletes, was my Observer column this week. (The column included also a short piece on creating vaccines for low-income countries) It was published on 5 May 2019, under the headline ‘Caster Semenya is a victim of rules that are confusing and unfair’.

Should women with naturally elevated levels of testosterone be able to compete in women’s events? That’s the question with which athletics has been grappling over the past decade. Last week, the Court of Arbitration for Sport (CAS), international sport’s highest court, ruled that such athletes could be banned unless they took medication to reduce their testosterone levels.

The CAS case had been brought by Caster Semenya, the South African Olympic middle distance runner and 800m Olympic champion. From the moment she burst on to the international stage a decade ago, questions were raised about her sex. Semenya is hyperandrogenic – she has a much higher level of testosterone than most women. The IAAF, the governing body of international athletics, defines athletes like her as having ‘a difference of sexual development (DSD)’. And last year, it introduced regulations forcing such athletes to reduce their testosterone levels if they wished to compete in certain events. Semenya challenged this in court.

CAS described the rules as ‘discriminatory’. But, it added, such discrimination is ‘necessary, reasonable and proportionate’.

If that sounds confused, it is.

Most people accept the case for separate male and female categories in sporting events in which physical prowess matters. Defining who belongs to the two categories has, however, created much debate. Different methods have been adopted, from crude physical inspections to genetic tests. All have proved unsatisfactory.

The latest dividing line is functional testosterone. Testosterone levels in women are, in most circumstances, lower than in men. So the IAAF decided to limit the testosterone level that makes women eligible for certain events. The trouble is, while all male elite athletes lie in the high testosterone band and most female athletes fall into the lower testosterone class, a few women, such as Semenya, have elevated levels that take them into the ‘male’ category.

The IAAF suggests that excluding such women, or forcing them to reduce testosterone levels, helps create a level playing field and protects the integrity of women’s sports. That’s why CAS accepted IAAF regulations as ‘necessary, reasonable and proportionate’, even if ‘discriminatory’.

Testosterone certainly aids athletic performance, increasing muscle bulk and the number of red blood cells. Hyperandrogenic women have an advantage over athletes whose testosterone is in the ‘normal’ range.

But why is that unfair? Elite sport, by definition, is an uneven playing field. From Dina Asher-Smith to Lionel Messi, the best athletes are not like the rest of us. That difference is partly due to genetic traits. Why should Semenya not be able to take advantage of her genetic attributes, as every other athlete does?

If the debate about hyperandrogenic athletes has caused controversy, that over transgender athletes is generating an even fiercer storm. Prominent female athletes, from Paula Radcliffe to Martina Navrtatilova have raised fears about transgender athletes similar to those about hyperandrogenic ones.

While the two debates are linked, the contexts are different. Semenya was born and has lived as a woman but happens to have naturally high testosterone levels. Female transgender athletes, such as the cyclist Rachel McKinnon, were born and lived as males but have transitioned to being female.

Many trans activists argue that anyone who identifies as female should be allowed to compete in women’s sport. Critics argue that, given the advantages conferred by a male physique, it would be unfair to allow anyone who has been through male puberty to compete as a woman, even if they have transitioned from male to female by taking hormone treatment.

Neither claim seems reasonable. From the perspective of fairness and justice, it would be wrong simply to allow self-identified women who have the physical attributes of men to compete in women’s events. It would be equally wrong to have a blanket ban on transgender women competing in female sports. There is little evidence either of trans athletes dominating sport (there has not been a single trans Olympian) or of athletes who have transitioned from male to female continuing to have an advantage over those born female.

The latest International Olympic Committee regulations allow transgender women to participate so long as they have taken hormone therapy to reduce their testosterone level to below a set figure for at least a year.

These rules have been criticised from both sides. For some, they place too great a burden on transgender athletes; for others, they make it too easy for athletes not born as women to compete in women’s events. There is a debate to be had over these issues. What seems indisputable, though, is that some such regulations are required. Whereas the IAAF’s hyperandrogenic rules are irrational and discriminatory, regulations allowing transgender athletes to compete under certain conditions do seem ‘necessary, reasonable and proportionate’.



There has been considerable comeback, especially on Twitter to this article. See for instance this tweet by Janice Turner, which set the parameters of much of the discussion. That tweet, and much of the subsequent discussion, contains two key criticisms: First that I failed to mention that IAAF exclusions apply only to ’46, XY’ athletes; and second, that I failed to mention that CAS report describes Semenya as ’46, XY’.

Both criticisms are mistaken. I published a long Twitter thread in response to clear up some of the confusions in the debate, so I thought it might be useful to publish a version of that thread here.

First, the debate is not about Semenya herself but about the IAAF regulations on the ‘Classification of athletes with Differences of Sex Development’.  So, what matters is what the IAAF regulations say. And those regulations do not mention ’46, XY’ once (’46, XY’ refers to individuals with both X and Y chromosomes (which usually defines males) rather than to individuals with XX chromosomes which women usually possess.) The relevant paragraph in the IAAF regulations is 2.2a:

IAAF regulations

Some of the conditions mentioned in section 2.2.a.i pertain primarily to XY individuals, some to XX. (See, for instance, this discussion about ovotesticular disorder).

(The IAAF regulations can be downloaded from the documents section on the IAAF website (though it makes you fill in a form first).  There is also an IAAF press release about the regulations.)

The CAS ruling says that ‘During the course of the proceedings… the IAAF explained that… the DSD covered by the Regulations are limited to “46 XY DSD”’. But that’s not what the IAAF regulations themselves say. I can only assume that this may be IAAF’s intention, and that CAS has accepted that, but the regulations are much looser. If anyone knows about this discrepancy, I’d be grateful for any information.

It’s worth adding here that while males have XY chromosomes, having an XY DSD does not necessarily make you male. As Ross Tucker puts it in this useful summary of the case: ‘A 46XY DSD is not necessarily biologically male – this, indeed, is a point of debate in this issue… The very nature of a DSD is that they are not able to use male hormones in the “typical way” – this is why they exist as DSDs, rather than as men or women, clean and simple.’ It’s one of the reasons that many sports governing bodies have dropped simple chromosome tests for sex verification. Such tests led to anomalous cases, and much unfairness, as with Maria José Martinez-Patino.

Second, the CAS ruling does not say that ‘Caster Semenya is 46, XY’, still less that she is a ‘biological male’. It’s a ruling about the IAAF regulations, not about Semenya’s condition.

Semenya was tested in 2009 for sex verification purposes. She may have been tested since – I don’t know. The results were never officially published. There have been leaks and rumours. But it would be irresponsible to make categorical statements based on rumours and leaks.

Categorical claims based on rumours on leaks also undermine Semenya’s privacy and erode her dignity. She has, it seems to me, shown remarkable poise and grace in the face of a very difficult situation. We should respect her as an individual, her privacy and her dignity. One would have thought that those who wish to defend women’s rights and the ‘integrity of women’s sports’ would be particularly aware of this.


The photo of Caster Semenya is by Kamran Jebreili/AP


  1. I normally agree with you, but cannot here. You say:

    “Semenya was born and has lived as a woman but happens to have naturally high testosterone levels.”

    But therein lies the entire question. She is not just a “woman who happens to have naturally high testosterone levels”, she has an intersex condition such that neither of the neat categories “man” or “woman” is appropriate.

    The intersex condition makes it unfair on women that she compete against women, and yet she also cannot compete fairly against men. So the question is whether such people should compete in the “women” category — which would be unfair to 50% of the population — or whether she should compete in an “open/male” category against men — which is then unfair to about 0.1% of the population.

    I would suggest that the latter, such that people with intersex conditions (and also trans-women) compete in an “open” category, not the “women” category — while not being entirely fair on them — is the more sensible policy.

    • We don’t know categorically what is Semenya’s condition – no official details have been released by the IAAF, nor has Semenya herself released any details. I would not wish to make categorical claims about her condition based on leaks, rumours and inference.

      However, at heart, this is not a discussion about Semenya in particular but about DSD athletes in general. And we can certainly have a discussion about how DSD athletes should be treated.

      Individuals with DSD can be either XX or XY. Even those who are DSD XY are not necessarily ‘male’, precisely because they have DSD. Individuals with DSD are often described as ‘intersex’ but many are born and live as females. Some are even able to have children. XY females able to have children is, of course, unusual, which is why it is in a medical paper. Nevertheless, the point is that there is nothing contradictory in seeing many DSD XY females as females. Nor in such DSD athletes competing in women’s events. Ross Tucker’s discussion of DSD athletes, and of why the IAAF regulations are problematic, is a useful primer on the various issues.

      I have come round to the Martina Navratilova position on this: that there should not be a blanket one-size-fits-all set of rules but rather broad guidelines which allow the authorities to make case-by-case decisions. That seems to me the fairest outcome.

      We should not conflate the issue of DSD athletes with that of transgender athletes. With transgender, unlike with DSD, athletes, there is a category change. So here I do think that a set of regulations about who can compete is useful, indeed necessary.

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