Conflicting values, implicit norms, and flawed evidence: a critical review of World Athletics’s eligibility criteria to compete in the women’s category from 2009 to 2024

In Mokgadi Caster Semenya v. International Association of Athletics and Athletics South Africa v. International Association of Athletics, the Court of Arbitration for Sport (CAS) ruled that World Athletics’ Differences of Sex Differentiation (DSD) regulations are appropriate measures to level the playing field in sport. In this paper, we historically contextualize the rules and regulations that have been applied, and continue to function, to limit athletes with DSD conditions’ eligibility to compete in women’s sporting events without pharmacologically lowering their testosterone levels. Recognizing that fairness and unfairness remain difficult and selectively used constructs in sport by both policymakers and arbitrators, we argue that fairness in competition could be operationalized on the basis of the principle of fair equality of opportunity and attainability of advantage within a given category. We then review the available evidence regarding performance advantages with which athletes with DSD may compete in order to address the ethical and epistemological challenges related to the level of evidence considered sufficient by CAS for the implementation of DSD regulations.