FEW ATHLETES have been as blessed and cursed as Caster Semenya. All that the 28-year-old South African runner has ever done is run as fast as her legs could carry her—fast enough to win back-to-back Olympic gold medals over 800 metres, and to triumph in each of the last forty 800-metre races that she has entered. But her extraordinary body has also been the subject of ridicule, speculation and censure. In 2009, when she breezed to a World Championship title as an 18-year-old, the International Association of Athletics Federations (IAAF), the sport’s governing organisation, announced that it was investigating whether she might be intersex—an umbrella (and misleading) term for people with a wide range of developmental conditions affecting the genitalia and gonads. To protect her privacy, the IAAF never published its findings. But it has spent the ensuing decade fighting a regulatory battle against Ms Semenya, about whether she must meet certain hormonal criteria to compete as a woman. On May 1st the Court of Arbitration for Sport (CAS), the highest legal body in sport, ruled against her in a decision that will have wide-ranging implications.
How to distinguish between men and women? If sports administrators want to maintain separate competitions for different sexes, any attempt to draw a firm biological distinction between them will miscategorise some people. That leaves them with two options. The first is to pick a binary physical characteristic, such as having—or not having—testes or a Y chromosome, a typical (but not universal) biological marker for males. The second is to pick a physical characteristic that exists on a spectrum, such as endogenous testosterone levels, and to set a threshold.
The first approach might seem more robust. Officials at the Olympics used chromosome testing to verify athletes’ sex between 1968 and 1996. But it turns out that some women who possess both Y chromosomes and testes receive no performance-enhancing effects from them. Maria José Martínez-Patiño, a Spanish hurdler, was kicked off the national athletics team (and shunned by her colleagues and boyfriend) after failing a verification test in 1985. Three years passed before geneticists could prove that her body was insensitive to testosterone, and that her intersex condition thus conferred no athletic advantage. The IAAF subsequently stopped chromosome testing, but not soon enough for Ms Patiño to save her career.
Her case was extremely rare. Various estimates suggest that the share of intersex people in the general population ranges from 0.05% to 1.7%, depending on how broadly the concept is defined. But those figures include conditions that neither raise questions about a person’s biological sex nor confer any conceivable sporting advantage (as in Ms Patiño’s case). Over time, officials have decided that they are unwilling to exclude people who fall into this category. Their approach now is to include people in women’s sports unless they demonstrably have an unfair competitive advantage.
This has led governing bodies to the second option: picking a physical characteristic that exists on a spectrum. Read more via the Economist