On the eve of the new year, my Twitter feed and an academic listserv I frequent lit up with arguments about biology and society. Some people had a lot to say about scientific matters—birth sex, assigned sex, genes and chromosomes—while others appealed to social ones: employment rights, free speech, and gender diversity. I could tell that transgender rights lay at the heart of the matter, but why were the people who tagged me on Twitter raging at one another about biological truth? And why were the professionals on my listserv raising disturbing questions about free speech and material reality while also trying to relitigate the meanings of sex and gender?

How do scientific facts get made in the first place?

This essay is for the reader who feels as buffeted and perplexed by the arguments as I sometimes do. The first thing to say is that these disputes have real consequences. I fully support the rights of transgender people to live free from the fear of violence, to use public facilities as they wish, to participate in competitive sports, and to enjoy fair and equal education and employment opportunities. At this historical moment, however, these rights often remain aspirational. Resistance to their achievement is widespread. If, as a society, we want to make progress, it is important to sort through the charged appeals to abstract notions such as scientific truth, material reality, and freedom of speech.

I will examine three events in turn: a Twitter banning, a denial of a work contract, and a contested scientific publication. Since I am a scientist whose work has been invoked—on both sides—in debates about equality for sexual and gender minorities, my reflections on these events has led me back to some basic questions about how scientific knowledge gets made in the first place. What I have come to conclude is that despite the fact that disputants on both sides wield claims about natural truths, the science we have now cannot settle the matter. Indeed, the science of sex and gender will not settle itself until we, as diverse societies, settle the substantive social questions.

On December 11, 2019, Twitter locked the account of an organization called 4thWaveNow, accusing it of violating Twitter’s Hateful Conduct Policy. The group had tweeted that a trans woman had no standing to comment on a young lesbian’s experience, because the lesbian belonged to a “population” the trans woman “neither advocates for…nor understands from personal experience, being a natal male.” Many trans individuals consider the phrase “natal sex” to be an insult, preferring language such as “assigned male (or female) at birth.” Twitter concluded that the use of the term fell under its Hateful Conduct Policy.

4thWaveNow responded that the tweet used accepted medical terminology. For example, the current American Psychiatric Association (APA)’s Diagnostic and Statistical Manual V uses the phrase “natal sex” in its consideration of gender dysphoria (though it also speaks of “assigned sex”). By contrast, the World Professional Association for Transgender Health’s (WPATH)’s Standards of Care for the Health of Transsexual, Transgender, and Gender Nonconforming People for the most part uses “sex assigned at birth.” After arguing with Twitter for three weeks, 4thWaveNow deleted the offending tweet, and Twitter unlocked the group’s account.

Contemporary arguments pit a tidy world of facts against the so-called lies of political correctness.

We should understand this incident within its larger context. Social media contains a never-ending fount of insults and slurs aimed at trans people. This is one reason that Twitter changed its hateful conduct rules a year ago to include transphobic remarks and slurs. It is not clear that things have changed all that much in the meantime, but reporting tweets that might contain offensive language has become a popular tool in a battle to reshape the sex and gender landscape—or to keep it from changing. Each side reports the other, Twitter locks and bans accounts, and arguments ensue as to whether a particular tweet violated Twitter’s rules or whether Twitter should have the power to ban such speech in the first place.

4thWaveNow describes itself as “a community of people who question the medicalization of gender-atypical youth.” Founded in 2015 by the mother of a teenage girl who—temporarily and, at least from the mother’s perspective, suddenly—socially transitioned to become a trans man, the organization hosts discussions among parents of trans or gender dysphoric children. Recently it highlighted a research controversy over the existence of what has come to be called rapid onset gender dysphoria—the apparently sudden self-naming of dysphoria in teenagers. While 4thWaveNow founders describe themselves as left-leaning liberals, some conservative organizations link to their site, and the group says its members “are open to discussion with people on all sides of the political spectrum.”

The banning happened just before a bigger story broke. In December 2018, in the United Kingdom, a nonprofit think tank called the Centre for Global Development (CGD) did not renew a consultancy agreement for a public policy researcher named Maya Forstater. Forstater alleged her contract was not renewed because of extensive public comments she had made about trans issues, and she filed a complaint under the United Kingdom’s 2010 Equality Act, which protects individuals from discrimination on the basis of the following personal characteristics: age, disability, gender reassignment, marriage and civil partnership, pregnancy and maternity, race, religion or belief, sex, and sexual orientation.

In her complaint, heard by a tribunal judge, Forstater argued that CGD discriminated against her because she believes that biological males, even trans women legally recognized via the United Kingdom’s system of Gender Recognition Certification, cannot become women. Forstater argued that her belief deserved protection under the 2010 Equality Act. In his decision, issued in December 2019, the judge found that “The specific belief that the Claimant holds . . . is not a philosophical belief protected” by the act. Rather, he argued, Forstater used arguments about immutable biological sex to bolster her “belief in the importance of single sex services, support for single sex education,” and so on:

I conclude from . . . the totality of the evidence, that the Claimant is absolutist in her view of sex and it is a core component of her belief that she will refer to a person by the sex she considered appropriate even if it violates their dignity and/or creates an intimidating, hostile, degrading, humiliating or offensive environment. The approach is not worthy of respect in a democratic society.

The legal logic spelled out in the twenty-six-page judgment is worth reading, but it also helps to compare it to U.S. law. Thanks to a landmark Supreme Court ruling in 2014, the crafts store chain Hobby Lobby, for example, is fully entitled to fire an employee who, outside of work, advocates for birth control or abortion. In fact, in much of the United States, a non-government business or organization can fire someone merely for being homosexual or transgender. In other words, in both countries, it is legal for a person to be fired, in effect, for speech made outside of the workplace. For my own part, I would welcome laws that extended freedom of speech to non-workplace political advocacy, but note that, in this example, it is a pro-business legal system rather than transgender activism that limits free speech. Indeed, the prevailing jurisprudence on the First Amendment sees it as protecting individuals against censorship by government actors, not by private companies such as Facebook and Twitter.

This is not to say there are not legitimate concerns about freedom of speech and thought. Having grown up in the McCarthy era, I understand this worry. I have seen family friends prevented from earning a decent living by employment blacklists and even a few imprisoned for their beliefs. But two things are worth noting. First, the freedom-of-speech outcry often comes from conservative quarters under the banner “leftists are totalitarian,” and yet the same people who insist on the right to use language about sex and gender that people in the LBGTQ community find hurtful are the last to speak up when a leftist professor is fired or silenced. In the United States, specific anti-trans arguments that traffic in the freedom of speech trope come from contributors to groups such as the conservative magazine The Federalist and the conservative think tank The Heritage Foundation; they have attacked the transgender rights movement as “a vehicle for censorship and state power” or have framed the study of gender in the academy as “political correctness vs. the truth.”

Well-funded U.S. right-wing organizations also sometimes collaborate with a small group called the Women’s Liberation Front (WoLF). WoLF’s point of view resembles one developed in the late 1970s in a particularly heinous anti-trans screed by Jan Raymond. In Great Britain anti-trans sentiments among erstwhile feminists are widespread. Feminist theorist Sophie Lewis links its currency in England to the history of British feminist alliances with colonialism and the empire, which imposed policies “to enforce heterosexuality and the gender binary, while simultaneously constructing the racial ‘other’ as not only fundamentally different, but freighted with sexual menace.” And second, speech suppression is a two-way street. Sex-diverse people remain legitimately fearful of firing or of physical attack should they speak out in the workplace or in public settings.

The Forstater decision stoked an already-raging conflict between gender-diverse activists and a category of feminists that we in the United States have always called cultural or essentialist. In the United Kingdom such activists usually identify as “gender critical” feminists, while their opponents often call them TERFS: trans exclusionary radical feminists. The conflict regularly includes complaints about the suppression of free speech and invokes appeals to the biological truth and material reality.

If the tribunal decision stirred the embers of ongoing conflict, J.K. Rowling, the creator of Harry Potter, poured on the gasoline. On December 19, Rowling aimed several offensive remarks at trans people before tweeting, “But force women out of their jobs for stating that sex is real? #IStandWithMaya.” Within ten days her words had been retweeted over 37,000 times. My feed lit up with people citing me as an authority in support of the tribunal judge’s decision and also with people furious because they felt that my ideas about sex as non-binary harmed “real, biological” women. Indeed, the tribunal quoted from an op-ed I published in the New York Times in 2018, arguing that biological sex is multilayered and complex, rather than simply dichotomous.

What are we to make of these disputes? Sometimes people frame their arguments as a matter of science versus anti-science—biology is scientific truth but some deny it for political reasons, they say, pitting a tidy world of facts against the so-called lies of political correctness. On the science side of this rhetorical opposition, the “truth” about sex is frequently presented in terms of X and Y chromosomes and reproductive biology. One example I see frequently on Twitter is the suggestion that sex type is binary in that the only options are male or female. This formulation suggests that intersex people (those people with disorders of sexual development) suffer from abnormalities that do not alter their “true,” chromosomal biological sex. Such a view harks back to the 1950s view—discussed at length in my book Sexing the Body (2000)—that nature has an “intended” sex that medical scientists need merely unearth. This contrasts starkly with the current international treatment consensus, which calls on medical personnel to work with parents and children to assign a felt or desired sex, rather than nature’s “intended” one.

How do we transform controversies into “real,” settled science?

Arguments that the actual biology of sexual development is not so neatly dichotomous as many presume have been met in my Twitter feed with responses such as “that’s ridiculous” and it’s “propaganda posing as science.” But it is a rare actor who is actually anti-science; I certainly am not. The science versus anti-science epithet-hurling really tracks differing interpretations of the facts of anatomical and physiological development. Rowling and Forstater argue that “sex is real”—“that there are only two sexes in humans.” In the Forstater ruling the judge cited my work to counter this viewpoint. He wrote that “morphology is not simply a question of what genes a person has, but also of which ones are being switched on, to what extent, in what combinations and how they interact.”

Trans activists also sometimes contest scientific findings. In 2018, for example, a U.S.-based scientist named Lisa Littman coined the term rapid onset gender dysphoria (ROGD) and published an exploratory study on the topic. Littman’s article met with an immediate and forceful outcry. Trans advocates and other medically knowledgeable allies argued that she used language that pathologized trans people, that the science was poorly executed, the conclusions ill-founded, and the results directly harmful to trans adolescents. In response, the journal withdrew the paper, had it re-reviewed, and then republished it after rewrites in which Littman addressed some of the criticisms. The World Professional Association for Transgender Health (WPATH) reminded everyone that ROGD was a proposed but not-yet-accepted clinical phenomenon, and urged restraint in the use of any terms that might lead to limitations of treatment options for transgender youth.

Research biologists, medical doctors, and psychiatrists used to decide the facts. A confluence of political movements disrupted this direct line to scientific authority.

As part of the tempest, Littman lost a consulting job that had provided her a major source of income. Unlike Forstater, Littman had not previously been involved in any public denunciation of trans people, but had, instead, been trying to put anecdotal claims of the sort 4thWaveNow has made on a sounder footing. As in Forstater’s case, however, the law did not protect her from being fired over an outside scientific controversy.

Neither Forstater’s deployment of the facts about sex, the Tribunal judge’s response, nor Littman’s publication are scientifically flawless. There are raging controversies about whose science is correct, or whether a particular scientific finding is “good science.” But the scientific arguments raise an even more fundamental question: How do scientific facts get made in the first place? How, in other words, do we transform controversies into “real,” settled science? Answering this question leads us back to the political disputes that lie at the heart of the matter.

My work has been cited both to defend and to oppose trans rights. In the Forstater case, the judge used my writing to emphasize the complexity and non-binary nature of sexual development. In contrast, in a case now before the U.S. Supreme Court, WoLF joined forces with well-funded right-wing organizations to file a friend-of-the-court brief opposing workplace protections for a trans woman fired for wearing dresses to work. This brief also argued that sex is a simple binary, but via a critique of one of my scientific articles, cited my statistics on the high frequency of internally consistent male and female births. The linguistic twist offered on these data was that, “In reality, sex is observed and recorded (not ‘assigned’) at birth by qualified medical professionals (emphasis added).”

While the contrasting uses of my writings is bemusing, the important lesson is about how facts come to exist in the first place. The fact that incommensurate beliefs about the definition of sex draw from the same scientific well means that the science itself remains unsettled. And the science is unsettled because as a community—lay people and scientists alike—we are at loggerheads about the politics of sex and gender. In one of my favorite books, Science in Action (1987), the sociologist Bruno Latour imagines science as Janus-faced, caught between the authority of the past and the revisions of the future. Looking left, “accepted science” exhorts us to “just get the facts straight” and says that “once the machine works, people will be convinced.” Looking right, “science in the making” says that we should “get rid of all the useless facts” and that “the machine will work when all the relevant people are convinced.”

This brings us to the crux of the problem: exactly who the “relevant people” are has been in flux for some time. Until fairly recently, authority for deciding what the facts were and how they most effectively explained sex, gender, sexuality, and identity rested squarely with research biologists, medical doctors, psychologists, and psychiatrists. Once the practitioners in these fields reached consensus, the facts about sex and gender stabilized, guiding medical practice and psychological treatment.

But a confluence of political movements disrupted this direct line to scientific authority. The Stonewall rebellion gave voice to gay and trans people. The women’s liberation movement and LGBTQ activism drew inspiration from the civil rights movement. Gradually, formerly voiceless patients pulled their chairs up to the science and medicine conference table. With the publication of Our Bodies Ourselves in the late 1960s, the Boston Women’s Health Collective claimed authority over women’s bodies and health care. In 1973 under increasing pressure from gay activists, the American Psychiatric Association (APA) removed homosexuality from its list of mental illnesses.

By the late 1990s AIDS activists had wrested the medical authority to collaborate in producing knowledge about HIV from the unitary grasp of physicians and scientists. As more trans people insisted on having their points of view considered in the making of psychiatric diagnoses, the pronouncements and classifications about transsexuality and gender dysphoria in the DSM shifted. By 2007 the Harry Benjamin International Gender Dysphoria Association, formed in 1979 and dominated by physicians trying to help trans patients, had changed its name to the World Professional Association for Transgender Health, and opened its membership to a broad range of health care professionals. In 2007 law professor Stephen Whittle became the first non-medical, trans person to head WPATH.

Gone are the days when only medical experts define sex, gender, and sexuality. As social movements disrupt a previously comfortable scientific consensus, traditional scientific groups grapple with questions of authority. Who, in this new world, speaks for science, and for whom does science speak? The answer is both unsettling and unsettled. Furthermore, without a new social contract it will remain unsettled. The daily issues are urgent. Take physical safety, for example. One of the great accomplishments of women’s liberation movements was to highlight the unacceptability of violence against women. In the United States rape crisis centers and battered women’s shelters proliferated. Responding to organized pressure, states changed sexual assault laws to make it easier to bring criminal charges against assailants. But, at the same time, street assaults against gay men, lesbians, and trans men and women remain a serious threat.

We could start with public accommodations for which one can imagine simple solutions that do not appeal to particular scientific facts.

And then there are bathrooms. In the United States there used to be special travel guides that would let people of color know where they could safely stop as they traveled through segregated areas of the country. For lesbians the Gaia’s Travel Guides provided safety information. But still today, even in major airports, trans and gender non-conforming people face challenges and physical assault by other patrons when they try to use the bathroom. If, as local, regional, national and international communities, we really mean for all types of people to be visible and exist in public spaces, then we could plausibly start with public accommodations for which one can imagine simple solutions (e.g. closed stalls) that are not based on an appeal to particular scientific facts.

Still, it is easy to understand why people turn to biology to settle disputes about LGBTQ rights. In legal arguments, advocates often use the idea that rights accrue because a particular trait is biologically immutable. On this question I have been convinced for some years by the brilliant and careful legal arguments of former Georgetown Law Professor and Equal Employment Opportunity commisioner Chai Feldblum. It is a tactical and legal mistake, Feldblum contends, to argue that minority populations be treated fairly because they cannot change who they are. Instead, she proposes that government, generally, and more specifically, law made under the umbrella of the U.S. Constitution, must promote what she calls “statements of moral understanding.” In particular, she argues that “it is good for human beings in society to feel safe, to feel happy, to experience and give care, and to live a life of authenticity.” What we require at this historical moment, she believes, is to combine “a robust positive rights discourse” with a new social moral assessment of transgender people on the part of the majority. The social uproar that this current essay explores reflects the process, however uncomfortable and uneven, through which the majority—on its own and through the vigorous push by transgender advocates—lumbers toward Feldblum’s notion of moral neutrality.

Let me end by returning to the use of scientific authority in political argument. In her book Who Speaks for Nature?: On the Politics of Science (2017), the political scientist Laura Ephraim proposed that “a politics of world-building is responsible for constituting the authority of those who speak for nature.” Fifty years ago, biologists and doctors spoke for the nature of sex, but political movements have disrupted this consensus. To riff on Ephraim, as local, national, and international communities build new social and legal structures, people who had been voiceless about their own bodies and psyches now insist that what they have to say about themselves is as authoritative as anything doctors and scientists can muster.

Debates that appear to be about science are really part of the for-the-moment unsettled process of world-building.

Debates about whether one is born with a pre-existing sex or assigned one at birth, as well as the legal disputes about whether sex is fixed and binary or complex and changeable, appear to be about scientific truthiness. But they are really part of the for-the-moment unsettled process of world-building. It is not yet clear how to build a world in which sex-diverse and sexually diverse people can live with the same expectations of physical safety and economic opportunity as majority-bodied and gender-identified people. My optimistic interpretation of our adversarial moment is that this is what we are in the midst of attempting. If, after battling our way through questions of safe spaces and equal employment, we find a way to accommodate a variety of bodies and identities, then a new science of sex will stabilize, and the war of words that induced me to write this essay will slow to a crawl.