We now seem poised for a change: Instead of understanding women and men as two different halves of a binary, we will see them as different points on a spectrum.

“A man can decide to be female, take hormones if required by whatever sporting organization is concerned, win everything in sight and perhaps earn a small fortune, and then reverse his decision and go back to making babies if he so desires,” the former tennis star Martina Navratilova wrote in an op-ed for The Sunday Times. “It’s insane and it’s cheating.”

Navratilova is an out lesbian, a stalwart advocate of LGBTQ rights and, up to the article’s publication, a woman renowned for her liberal sympathies. She has since apologized for using the word “cheating,” but her argument brought immediate rebuke, most defiantly from Rachel McKinnon, a male-to-female (MtF) trans track cyclist, who claimed: “She [Navratilova] imagines a nonexistent cisgender man who will pretend to be a trans woman, convince a psychologist and a physician to prescribe hormone therapy, undertake the process for legal changer recognition, then wait the minimum 12 months of testosterone suppression required by the current IOC [International Olympic Committee] rules, compete, and then change his mind and ‘go back to making babies’?” (Cis relates to people whose sense of personal and sexual identity corresponds with their natal, or birth, sex.)

McKinnon is probably right: Even the most motivated male athlete is unlikely to self-identify falsely as a woman and maintain the masquerade for, say, 20 years (the approximate duration of a sports career) just to win medals and money. To then proclaim that he’ll now go back to being a man seems utterly preposterous.

There is arguably a more relevant objection, which suggests that trans athletes, especially MtF, would be physically advantaged over natal female athletes. The assumption is that trans athletes who were once males have raised levels of testosterone, which confers on them advantages in terms of physical strength and speed. Testosterone is the hormone that stimulates the development of male secondary characteristics and is part of a group called androgens. Estrogens promote the development and maintenance of female characteristics in the body. Here’s where the issue intersects with another contentious situation that’s divided sport.

Elixir of Athletic Success

Caster Semenya is a South African who was born, reared and socialized as a woman, was legally recognized as a woman and competed on the track in women’s events. In 2009, Semenya, then 18, dominated the 800-meter events at the International Association of Athletics Federations (IAAF) world track and field championships, winning by more than two seconds. A fellow competitor called her a man. Pierre Weiss, the general secretary of the IAAF, track and field’s world governing body, said, “She is a woman, but maybe not 100 percent.” Actually she has a condition known as hyperandrogenism that causes an excessive secretion of androgens.

In 2011, the IAAF introduced a policy directed at women who had unusually high concentrations of testosterone: female athletes above the testosterone threshold of 10 nanomoles per liter — considered at the lower end of the male range — faced measures if they wanted to continue competing. Hormone-suppressing drugs and surgical removal of internal testes, which can produce testosterone, were among the unpleasant options.

Testosterone is popularly regarded as an elixir of athletic success. Exogenous testosterone is the most popular performance-enhancing drug and is forbidden in sport. There’s little or no overlap between typical male and female ranges on endogenous testosterone levels. So women who, for natural reasons, have levels of testosterone outside the usual female parameters are considered to hold an unfair advantage. At least that’s what the IAAF concluded. Other naturally conferred advantages — height, increased red blood cell count, low resting heart rate, for example — are not considered unfair, of course.

A complicating factor is that success in sport is not the result of just one physical trait. Sport psychologists never tire of reminding us that mental attributes such as motivation, mental toughness and locus of control are crucial. Add to this environmental influences — cultural as well as geographical — and the role of testosterone becomes harder to discern in isolation. Endocrinologists explain the difference between the sporting performances in men and women by reference to testosterone, but they have no interest in context. Context-sensitive accounts of sporting excellence provide more complex algorithms of social, psychological and physical factors.

On the Basis of Sex

Caster Semenya is understandably aggrieved at being forced to take drugs, which would probably get other athletes disqualified, just to get to the start line. Last month, she took her complaint to the Court of Arbitration for Sport (CAS) in Switzerland. She no longer wants to take testosterone-suppressing drugs in order to compete. If she’s successful, IAAF will have to admit Semenya and other athletes with naturally high testosterone levels — and brace itself for the howls of protest from countless other women who will claim they’ll be disadvantaged.

If the court rules against Semenya, it will be a decision that distances athletics — and possibly sports generally — from the rest of society, which has moved toward self-identification as the main criterion for sex. Rather than being assigned their sex, people can choose how they wish to be addressed and treated. It’s possible that reforms to the UK’s Gender Recognition Act will relax the demand that anyone has to prove they have a diagnosis of gender dysphoria and lived in their preferred sex role for a minimum of two years. Sex would become a matter of self-declaration.

Effectively, if someone expresses a wish to be considered a man, a woman or neither, that will be sufficient, regardless of one’s biology. The military, educational organizations, places of employment, the criminal justice system and other social institutions will be taxed to make accommodations. That includes sport. Some sports have integrated men and women into single events. Ultramarathons, equestrian events, some forms of cycling and sailing are just a few examples. But who can be serious about sport embracing gender fluidity? It has flexed its muscles and reaffirmed its reliance on the traditional binary. The fact remains: Sport will be obliged to change.

Full Circle

Ironically, this may draw us close to a cultural full circle. It seems staggering to think that the division of the species into two kinds — what we now call the binary — is largely a product of the past 350 years. Before then, the stress was on similarities, the female body being just a “gradation,” or nuance of one basic male type. “Medical theory taught that there was but one sex,” wrote Jeffrey Weeks in his 2009 book, Sexuality.

The female body was a kind of an inverted version of the male, a clitoris imagined to be an underdeveloped version of the equivalent structure in men — the penis. The big difference was that women could reproduce children. Anatomists in the 19th century searched for the sources of women’s difference and apparent inferiority. It wasn’t until 1903 that two English biologists discovered a substance produced in the body and carried in the blood to stimulate various cells and tissues into specific actions.

They called the substance hormones. Sex hormones were responsible for differences in development between males and females. Over the next three decades, sex endocrinology created a completely new understanding of sexual differences based on hormones. Eventually, hormonal differences became accepted as natural facts. Women were different to men in most profound, categorical and immovable way.

We now seem poised for a change: Instead of understanding women and men as two different halves of a binary, we will see them as different points on a spectrum. People will be free to identify as they wish, not necessarily as a male or a female, but combinations of both or neither. Under conditions of gender fluidity, there will be no impermeable groups, nor rules that constrain movement between self-assignations.

How will sport respond? We will get a clue later this month when the CAS rules on the Semenya case. Caster Semenya is not trans, but her unusual hormonal makeup raises far-reaching questions about how sport visualizes itself for the rest of this century. Will it change in a way that keeps it consistent with the rest of society? Or will it cling to its traditions and invite more challenges?

The views expressed in this article are the author’s own and do not necessarily reflect Fair Observer’s editorial policy.