I have examined the ways in which scientists take social categories such as “woman” and “man” and attempt to turn them into fundamental truths. For as long as scientists have been trying to figure out the biological basis of sex and gender, nature has presented divergences from their theories. (“Sex” refers to biological characteristics; “gender” refers to social roles and identification.)

The question here is if all other kinds of athletic competitive advantage are allowed, for example, Why should swimmer Michael Phelps's low lactic acid production (which helps stave off muscle fatigue) or the late NBA player Manute Bol's uncommon height be rewarded while Semenya's somewhat higher testosterone level is disqualifying?

Why can’t higher levels of testosterone then be considered as just another natural athletic advantage and not be used as a tool to restrict people from performing?

Biology alone is too limited a tool to tell us how to divide up the athletic field—but it can help us gain a greater understanding of natural human variation. Particularly in a domain as convoluted and controversial as sex and gender, science often uncovers more ambiguity than it resolves. And if science does not inform the issue of intersex women in sports, we can still revert to the values of diversity, inclusion and acceptance that make elite women's sports so extraordinary in the first place.