The myth of hormones


For a century, talk about testosterone as the “male hormone” has woven folklore into science, so that supposedly objective claims seemingly validate cultural beliefs about the structure of masculinity and the “natural” relationship between women and men.

Labelling testosterone the male sex hormone suggests that it is restricted to men and is alien to women’s bodies, and obfuscates the fact that women also produce and require testosterone as part of healthy functioning. Even the earliest hormone researchers understood that testosterone has wide-ranging effects on metabolism, liver function, bones, muscle, skin and the brain in both sexes.

But because early hormone researchers were fixated on sexual anatomy and reproduction, they gave short shrift to testosterone’s myriad effects, treating it as both oddly narrow — that it is about things men have more of — and overwhelmingly powerful.

Of course, it’s one thing for myths to persist in the public imagination. But what has puzzled us in nearly a decade of research is how these ideas have gained so much traction among the organisations that regulate sports, when the evidence needed to support them is largely absent or contradictory.

Testosterone’s “authorised” biography, with its pat story about how it fuels male-typical athletic performance, is a powerful distraction from the hormone itself, occluding its fascinating, diverse and contingent actions within the body. Testosterone doesn’t drive a single path to athletic performance, nor even a small set of processes that can be linearly traced from more testosterone to more ability.

The idea that testosterone is the miracle molecule of athleticism, and, accordingly, that people with higher levels would obviously perform better, combines several beliefs: That “athleticism” is a kind of master trait that describes similar characteristics in different athletes, that “athletic performance” across different sports generally requires the same core skills or capacities, and that testosterone has a potent effect on all of them.

But that’s simply not true. The problem with trying to flatten athleticism into a single dimension is illustrated especially well by a 2004 study published in The Journal of Sports Sciences. The study analysed testosterone and different types of strength among men who were elite amateur weightlifters and cyclists or physically fit nonathletes. 

Weightlifters had higher testosterone than cyclists and showed more explosive strength. But the cyclists, who had lower testosterone than both other groups, scored much higher than the others on “maximal workload”, an endurance type of strength. Across the three groups, there was no relationship between testosterone and explosive strength, and a negative relationship between testosterone and maximal workload. Though small, that study isn’t an outlier: Similar complex patterns of mixed, positive and negative relationships with testosterone are found throughout the literature, involving a wide range of sports.


International Association of Athletics

Federations has already caused

 immense harm by reinforcing outdated

 and misguided ideas about testosterone 

— and discriminating against athletes 

who have every right to compete

 in their sport without violating

 their bodily integrity


These complexities hold in track and field events, too. Even the International Association of Athletics Federations’ own analysis of testosterone and performance, involving more than 1,100 women competing in track and field events, shows that for six of the 11 running events, women with lower testosterone actually did better than those with higher levels.

In other words, for most sports, testosterone levels do not correlate with superior performance. And yet even in the face of overwhelming evidence, the myths are so deeply ingrained in our assumptions about gender and athletics that the highest governing body in sports believes otherwise.

The obvious result is discrimination against female athletes who have naturally high levels of testosterone. But the harm doesn’t stop there.

The athletics association insists that they can still compete, as long as they undergoes medically unnecessary interventions to lower her testosterone level. But hormonal contraceptives are often not enough to get testosterone down to the arbitrary permissible level. This means athletes must take stronger drugs, and endure chronic, significant side effects.

Nevertheless, the International Association of Athletics Federations president, Sebastian Coe, gave reason for worry when asked whether he would delay the regulations for the 1,500-metre and the mile races — regulated events for which the court said there was no evidence of a difference in performance among athletes with different testosterone levels. Showing a blatant disregard for caution, Coe simply replied, “No,” leaving us to wonder who will monitor the degree of harm, and how will problems be reported and recorded as they arise. How much harm will be acceptable to the court before it reconsiders its position?

The matter of harm cannot be left to sporting bodies, because there are broader issues involved. A United Nations resolution passed in March declared that the association’s regulations violate “international human rights norms and standards”, including the rights to freedom from torture or other cruel, inhuman or degrading treatment or punishment, and the right to full respect for the dignity, bodily integrity and autonomy of the person. The resolution also warned about potential broader chilling effects on the participation of women and girls in sport through reinforcing gender stereotypes.

A growing number of female athletes with lower testosterone levels have argued that allowing athletes with high testosterone to compete is unfair. Addressing that feeling is important. But as the sociologist Madeleine Pape, who once raced against Caster Semenya, has argued, governing bodies like the athletics association have done this in precisely the wrong way, by validating myths and stoking athletes’ fears.

International Association of Athletics Federations has already caused immense harm by reinforcing outdated and misguided ideas about testosterone — and discriminating against athletes who have every right to compete in their sport without violating their bodily integrity.


 Katrina Karkazis is a senior visiting fellow at the Global Health Justice Partnership at Yale University. Rebecca M. Jordan-Young is a sociomedical scientist at Barnard College, Columbia University.