Caster Semenya’s case gives a concrete opportunity to challenge the binary

Anna Lewis
8 min readMay 2, 2019

In their verdict against Caster Semenya, the Court of Arbitration for Sports stated that the “binary division has not been challenged”. Its about time.

“This is not the end of the conversation”. So said Caster Semenya’s team when it was announced that she would have to suppress her testosterone levels to compete in women’s events. Where should the conversation go from here? I outline the case for a multiple category system. Inspired by the Paralympics, the whole competitive sporting world should move towards having event categories. These categories should be designed to capture performance advantages people have as the result of their biology. The debacle that has engulfed Caster Semenya should be taken as an opportunity: the particular events that were under consideration in this case represent a great test bed. It won’t be easy, but it is worth a shot.

What happened?

Athletics South Africa, representing Caster Semenya, had petitioned the highest court for sports (the Court of Arbitration for Sports, CAS) to overthrow a proposed rule that would affect Caster. The rule, proposed by the IAAF (International Association of Athletics Federation), requires women with certain Differences of Sex Development (DSD, restricted to women with a Y chromosome and whose bodies are sensitive to the increased testosterone) to lower their testosterone levels if they wish to compete in International events for races between 400m and a mile.

The two sides in brief

Caster’s team argued that this is clear discrimination. The UN Human Rights Council has called the result “unnecessary, harmful and humiliating”. Her lawyers say that she “does not wish to undergo medical intervention to change who she is and how she was born”. They point out that genetic outliers are integral to the whole international competitive sporting enterprise, and we should be celebrating their unique gifts.

The IAAF, on the other hand, argued that women with the specified DSDs had too large of a performance advantage over women who did not. They argued that their rule is necessary to uphold the values of ensuring “fair and meaningful competition”, where “success is determined by talent, dedication and hard work”, and to be as inclusive as possible, including encouraging a broad range of people to aspire to succeed at the highest levels.

CAS’s ruling

CAS concluded that the rule is indeed discriminatory, but that it nonetheless represents a “necessary, reasonable and proportionate means of attaining a legitimate objective.” They go on to state that “It is human biology, not legal status or gender identity, that ultimately determines which individuals possess the physical traits which give rise to that insuperable advantage and which do not.” In this case, they judge that the performance advantage of women who have many of the biological attributes that males possess is “significant and often determinative.“

CAS go out of their way to stress that this was no easy decision, with direct trade offs. In their own words: “on one hand is the right of every athlete to compete in sport, to have their legal sex and gender identity respected, and to be free from any form of discrimination. On the other hand, is the right of female athletes, who are relevantly biologically disadvantaged vis-à-vis male athletes, to be able to compete against other female athletes and to achieve the benefits of athletic success. The decision is also constrained by the accepted, necessary, binary division of athletics into male events and female events, when there is no such binary division of athletes. That binary division has not been challenged.”

Where could the conversation go from here?

The time is ripe to challenge that binary division, through switching away from the two “men’s/women’s” categories. Instead, categories based on advantages that each athlete possesses could be introduced. (Another approach, which has some advocates, would be to just have one category. I won’t consider the pros and cons of that directly here, but will just state that I am for a world of more prizes, not fewer, and for more opportunities for people to flourish).

Separate categories for sporting events is nothing new. They exist for weight in sports like boxing, wrestling and rowing. In the Paralympics, there are no fewer than 29 100m events. The attempt is to define categories based on physical abilities/impairments that allow for a reasonably level playing field. In Judo, many resisted the idea of weight categories on the basis that the whole point was that you could use your opponent’s weight against them. It took the 6’ 6” Dutchman Anton Geesink, who consistently beat all the Japanese judoist masters, for weight categories to be embraced (source).

One concrete proposal would be to define categories of advantage in much the same way that the Paralympics defines categories of impairment. For example, lean body mass, height, muscle strength, ability of blood to carry oxygen, lung size, etc. Each sporting event would be assessed for which type of advantage was relevant, and event categories would be defined based on this. Athletes would be scored based on the advantages they had. Unlike the Paralympics, the aspiration would be to not use male/female as part of this scoring, but instead to capture the advantages that males typically have in the scoring.

We get the very notion of a “level playing field” from sports. Why not apply this leveling? More individuals would have the chance to aspire to sporting glory. The arguments against such a proposal tend to be practical ones. It would be very hard to get the categories right. It’s a big change with a lot of moving parts (airtime, sponsorship deals, prizes). Athletes have already set their aspirations and are working towards them.

Indeed the prospect of switching wholesale from the system we have today to any such system is daunting. What we need is some circumscribed test ground to experiment. The case of the men’s/women’s division in the 400m — 1 mile races represents just such a test ground. There are athletes whose career is going to be hurt no matter what binary division is upheld, and there has been a lot of gathering of experimental data about which properties tally with success. How about defining, for example, three or four categories based on lean body mass, testosterone, some combination, or something else related to performance? The aim would be to allow athletes like Caster, and like Francine Niyonsaba, who came 2nd to Caster’s 1st in the Rio 800m and who has also confirmed she would be affected, to flourish. It could also give a safe space for M2F women to flourish. (Right now the rule is that M2F women may compete in the women’s category if they have undergone at least a year of hormone replacement therapy, but no-one thinks the last word has been had on this subject either.)

I believe that more categories should be the long term vision for competitive sports at the highest level. What we have in this case is a clear felt need for a change to the system, and a well defined subset of competitions where the need is greatest. This gives a natural, constrained test bed for the future potential of new categories. The introduction of the new categories could be done in a very controlled way, with all parties aware that the boundaries between the categories could change, and indeed that the whole experiment could be judged a failure. Yes a change could be a severe disruption to some those athletes who are competing right now. But this case shows that that disruption is coming anyway. Careful thought would have to be given to how to ensure that those who competed in each category were not disadvantaged. The work that has already been done to try and ensure that female athletes receive comparable opportunities and rewards to male athletes could be drawn upon and extended. It is not an easy path forward but it could end up being the on balance fairest one. It is at the very least worth a try.

Concrete steps that could be taken prior to this attempt would be to study a range of “what-if” scenarios, for example, if we had had such categories in place in the past, what would the podiums look like? How do competitors feel about such categories? How do the public, the consumers of international sports, feel about them? The IAAF, rather than sitting back and celebrating this victory, should spearhead such work. After all, they have been forewarned that this is not the end of the conversation.

Solving wider issues in Sports

The advantages of such a system go beyond DSD and trans individuals, they get right to the core of what sports should be about. Sports is going through a crisis of meaning. What exactly is the “spirit of sport” that bodies such as the IOC (International Olympics Committee) and the IAAF are trying to uphold? The World Anti Doping Agency (WADA) has been trying to pin down what it is that sports stands for, so that they can make decisions about what should count as cheating. They’ve landed on the idea that sports should be about the “dedicated perfection of each person’s natural talents”. But as we learn more about the genetic underpinnings of these natural talents, we will increasingly question why those should be protected. In a public opinion study that my co-author and I carried out, we found evidence that people may not see these genetic advantages as worthy of competitive protection. Note that the “spirit of sport” has already undergone significant revision. As late as the 19th century, training was viewed as a kind of cheating, precisely because it could prevent the person with the most natural talent from winning.

There are thus two massive advantages to introducing categories more broadly. First, it might actually capture “the spirit of sport” in a more accurate fashion, by providing a system that more people would view as fair. And second, with a categories based system in place, you could (optionally) allow athletes to dope, because the advantages that they would achieve would put them in a tougher competition class. With each passing year, we learn more about how pervasive doping is across the full range of sports. A radical new approach might be just what is needed.

Endnote on “Why so much fuss over sports?”

As someone who does not watch sports, and who has hardly done any sports beyond a spot of rowing, I sympathize with the “what’s all the fuss about” and “isn’t it all supposed to be fun and games” attitude. However a) sports is a mega-business, b) sporting figures can act as role models, c) we should support anything that inspires us all to exercise on health grounds. From my perspective though, as someone interested in how our evolving understanding of biology could and should impact society, sports is an institution where values can be explicitly defined, and rules set to achieve those values. It thus acts as a “microcosm” for thinking about issues that we will face in other areas.



Anna Lewis

Bioethics, Genomics, and the Diversity of Human Experience