Science has a gender issue — and it’s not a lack of women

Caster Semenya, a South African runner, took the Olympic gold medal for the women’s 800 meters in 2012 and 2016. She was marked as a girl at birth and identifies as a woman, yet on Wednesday, the international Court of Arbitration for Sport ruled that she can’t compete as one — unless she lowers her natural testosterone levels.

Semenya isn’t alone. Dutee Chand, an Indian sprinter, was forced to undergo “gender testing” in 2013. She was barred from competition when her testosterone came back at a level track and field officials ruled unacceptably high. But the current testosterone cutoff (5 nmol/L) is arbitrary and not backed by research, according to an editorial published last month in the British Medical Journal. The typical female range is 0.4 to 2.0 nmol/L (and the male range is 8.8 to 30.9 nmol/L), yet there’s insufficient evidence that naturally high testosterone boosts women’s athletic performance, according to the editorial.

Chand was authorized to compete again in 2018 because of new technicalities regarding what events the hormone cutoff applies to. But after Wednesday’s ruling, Semenya’s future in track and field remains uncertain.

The surface-level issue here is that women’s bodies are understudied, leading to ideology-fueled assumptions about how they work, for example,  for example, varying levels of sex hormones. But the bigger, foundational problem is the public — and scientific — misunderstanding of sex and gender.

Chand’s “gender testing” sounds reasonable at first, but “gender” isn’t actually what’s examined by the test, which is overseen by the International Association of Athletics Federations (IAAF). In reality, the test measures testosterone, which is a sex hormone — not a gender hormone.

You can plead semantics, but the difference is real. Gender is based on how people act and the roles they take in particular social and cultural contexts, according to the National Institutes of Health. Sex, on the other hand, is biological and usually assigned at birth based on genitalia, though it’s comprised of a range of “sex characteristics” like genetics and hormones.

Most people identify with the gender typically associated with their sex; people assigned to the female sex, for example, usually identify as women. This isn’t the case for transgender and non-binary folks who, for instance, womanhood just doesn’t fit.

Since 2013, the IAAF has caught onto the difference, no longer referring to testosterone evaluations as gender testing. But does this nitpicky distinction even matter? In everyday language, sex and gender are used almost interchangeably, after all.

In short, yes. To be inclusive of the trans community, it’s necessary to differentiate between sex and gender. But even for cisgender (non-transgender) people, accounting for sex and gender as two separate but related variables can be crucial.

Talia Young is an ecologist and postdoctoral fellow at Princeton University studying commercial fishing. “I went to lots of talks on the gender of fish,” she says, but gender is largely, if not entirely, unique to humans.

In animals, “I don’t think it’s the most important thing,” says Young, who wrote a primer on the differences between sex and gender for Public Library of Science, a scientific journal, earlier this year. But it’s an easy mistake to fix, and using the correct term is more precise. “It’s science,” she says. “We put a lot of stock in language and precision.”

Mixing up these phrases is more harmful in human-centered research. The muddling often happens when scientists “lump everything under gender,” says Cara Tannenbaum, the scientific director of the Institute of Gender and Health at the Canadian Institutes of Health Research and the author of the cutoff-challenging editorial.

The reason for the lumping? It could be modesty in the workplace. Both Tannenbaum and Young have heard that scientists are averse to saying “sex” because of the, well, sexual connotations.

Not only are sex and gender different, but they also affect health in different ways. Of the 10 prescription drugs pulled from the U.S. market from 1997 to 2001, eight posed greater health risks for women than men — four for sex reasons and four for gender reasons.

On the sex front, Seldane and Hismanal (antihistamines) and Propulsid (a gastrointestinal drug), can lengthen the time between heart contractions and disturb cardiac rhythm, sometimes to fatal effect. These dangers are more pronounced in the female sex for two reasons. First, the length between heart contractions is naturally longer in this sex. Second, hormones like testosterone blunt the effect of these drugs on the heart.

On the gender side, two appetite-suppressants, Pondimin and Redux, cause valvular heart disease the same way in both men and women, with no sex differences at play. The majority of people that took these drugs, however, were women. This reflects “the institution that says women have to be skinny, skinny, skinny,” says Tannenbaum.

While researchers were able to tease apart sex and gender in these drug cases, some scientists argue that it’s often not possible to distinguish between the two. For this reason, Daphna Joel, a neuroscientist at Tel-Aviv University in Israel, prefers the composite term “sex/gender,” popularized by gender researcher and writer Anne Fausto-Sterling in reference to how sex and gender mutually affect one another.

Joel likes the term because it recognizes that sex and gender are not interchangeable, yet are sometimes impossible to tease apart. “We cannot disentangle sex and gender effects in humans because there is no way to control for either of them,” she says.

Joel has a point. Everyone has both a sex and gender, so the two can’t be measured separately, like studying a mouse with a gene and a mouse without it. So even if we find a difference between men and women, we can’t be sure whether it’s due to sex (biology) or gender (culture).

But that doesn’t mean we’re doomed and should give up trying to parse the two altogether. “I don’t think you can just say, ‘They’re indistinguishable; let’s throw our hands up in the air,’” says Londa Schiebinger, the director of the Gendered Innovations project at Stanford University, which promotes sex and gender analysis in scientific research.

Schiebinger’s persistence is admirable. But, assuming scientific research is based on cisgender people (which almost all research is), why wouldn’t sex and gender always be correlated with the same outcome? If female sex and womanhood are paired together, why aren’t they tied to the same cancer rates or heart attack risk?

It turns out that many facets of gender matter in science, and gender identity is only of them (and measures of gender identity are more complex than just male, female, or non-binary). For instance, according to Tannenbaum, much of the scientific research that’s out there focuses not on gender identity (or an internal feeling of gender), but on gender roles — how people act based on societal norms associated with their gender and sex.

That’s not to say that gender identity isn’t important, as she adamantly points out. But for the types of outcomes health researchers analyze, it’s usually more effective to measure gender roles than identity. In a study of exposure to household chemicals, for example, scientists may be more curious about who cleans the house — often based on gender roles — rather than how masculine or feminine a person is.

Gender doesn’t stop at roles and identity. It also includes gender relations, or how people interact with the world based on their actual or assumed gender. There’s also institutionalized gender, which is based on power differences in society (and what Tannenbaum was alluding to when she described the pressure on women to be thin).

Tannenbaum is hopeful about the future of sex and gender in science. Since 2010, Canada has required all health researchers applying for public funding to detail their plan to measure both sex and gender. Canadian research hasn’t stalled, proving that it’s possible to analyze sex and gender — and to require doing so as widespread policy.

“I’m personally very pleased by the progress being made,” Tannenbaum says, “though it’s not as fast as I would like it to be.”

One of the reasons scientists are paying more attention to sex and gender might be that more scientists are women. Women have climbed from 23% of all workers in science and engineering in 1993 to 47% in 2015, according to the National Science Foundation. And female researchers in medicine analyze sex and gender more often than men, according to a study by Stanford’s Schiebinger.

“It’s not only about women in science, but science for women,” Tannenbaum says, “so the benefits of research apply equally across sex and gender.”