Intersexual Politics

Check the Facts: How Common Is Intersex? And Why Does It Matter?

In March 2023, Liam Morrison was an eighth-grader on the honor roll at John T. Nichols Middle School in Middleborough, Massachusetts. One day, Liam wore a t-shirt to school emblazoned with the message, “There are only two genders.” Only a few minutes after arriving at school, Liam was removed from his classroom. The principal told Liam that he must remove his t-shirt because it was offensive. Liam refused, so the principal sent Liam home.1

Liam had violated the fundamental orthodoxy of contemporary gender ideology: namely, that biological sex is a continuous spectrum, not a male/female dichotomy, and that any claim to the contrary is bigoted and harmful. “Human sex is not binary,” Scientific American informs us.2 “Sex is not binary,” agrees a recent article in American Scientist.3 According to an article in The Atlantic, the notion that humans are either male or female reflects “a fundamental misunderstanding about the nature of biological sex. Science keeps showing us that sex also doesn’t fit in a binary, whether it be determined by genitals, chromosomes, hormones, or bones.”4 Secretary of State Anthony Blinken earlier this year issued a memo to all employees of the State Department, warning them to avoid use of the gender binary.5 Blinken’s cable, sent on February 5, 2024, advised employees to “avoid using phrases like ‘brave men and women on the front lines’”; a better choice would be “brave first responders.” Likewise, staff were advised to replace “mothers and fathers” with “parents”; “husband or wife” should be scrubbed in favor of “spouse”; better to use “everyone” because “ladies and gentlemen” is no longer acceptable.

The Nonbinary Assertion

What is the basis for the assertion that human sex is not binary? The phenomenon that proponents most often cite is intersex: individuals who are both male and female, or who do not fit neatly into either male or female categories. A classic example of true intersex is an XX/XY chimera: an individual who is an amalgam of female and male. Such individuals often have ambiguous genitalia—not quite male, not quite female—and they may even have an ovary on one side and a testicle on the other side. An XX/XY chimera can arise as a result of simultaneous fertilization of a single ovum by both an X-carrying sperm and a Y-carrying sperm. Documented human XX/XY chimeras are exceedingly rare, with only a handful of cases reported in the literature worldwide.

How common is intersex? According to the Washington Post, “nearly 2 percent of the population—roughly the same percentage of people born with red hair—is intersex.”6 The United Nations Human Rights Office likewise claims that “being intersex [is] almost as common as being a redhead!” (exclamation point in original).7 According to an ACLU web page, “up to 1.7% of the world’s population is intersex, making it almost as common as having red hair.”8 And if the Washington Post, the United Nations, and the ACLU all say it’s true, then it must be true, right? And if it’s true that intersex is as common as red hair, then Liam Morrison’s t-shirt is simply wrong and human sex is not binary.

But what if intersex is actually very rare? Conjoined twins—what we used to call “Siamese twins”—are rare, fewer than one in 100,000 live births. We don’t create theories of personality based on the norm of two heads sharing one body, because two heads sharing one body is a rare pathology, not a normal variation. If intersex is a normal variation, akin to red hair, then our understanding of gender needs to accommodate that fact, and we must indeed replace the male/female binary with a continuous spectrum. But if intersex is exceedingly rare, closer to conjoined twins, then intersex conditions are better understood as uncommon pathologies, not as normal variations, and the male/female binary remains valid. That’s why it’s important to know: is intersex as common as red hair? Or is it uncommon, or indeed rare?

Intersex Defined & Redefined

Where does that figure of 1.7 percent, or “nearly 2 percent,” come from? That figure comes from a single source: a paper published in 2000 by Anne Fausto-Sterling, a now-retired professor of biology at Brown University. Fausto-Sterling had long been interested in intersex. In her 1993 essay “The Five Sexes,” she defined “intersex” as referring either to individuals who have XY chromosomes with predominantly female anatomy, or to individuals with XX chromosomes with predominantly male anatomy, or to individuals with ambiguous or mixed genitalia.9 That’s a reasonable definition of intersex. But how common is it?

Seven years later, in 2000, Fausto-Sterling supervised five of her undergraduate students in writing a paper titled, “How sexually dimorphic are we?”10 The objective of the paper was to determine how common intersex is by adding up all the different intersex conditions. But in deciding what conditions to include, she didn’t use her own definition of intersex from her 1993 essay. Instead, she invented a completely new definition, one never before used or suggested by anyone: according to Fausto-Sterling and her five students, an individual is intersex if that individual “deviates from the Platonic ideal of physical dimorphism at the chromosomal, genital, gonadal, or hormonal levels.” That greatly expanded definition allowed Fausto-Sterling and her students to classify men with XY chromosomes and normal male internal and external genitalia, as well as women with XX chromosomes and normal female internal and external genitalia, as “intersex” because they depart from the “Platonic ideal of physical dimorphism.”

Armed with her new definition, Fausto-Sterling and her students were able to conjure a figure of 1.7 percent of the human population qualifying as intersex. Most of that 1.7 percent—more than 88 percent, to be precise—comes from just one condition: late-onset congenital adrenal hyperplasia (LOCAH). Fausto-Sterling and her students asserted that 1.5 percent of humans have LOCAH, and they classified LOCAH as an intersex condition.

Spurious Reasoning

So what is LOCAH? Individuals with LOCAH have a deficiency in one of five enzymes that metabolize adrenal hormones, most often the enzyme 21-hydroxylase. As a result of the resulting hormonal imbalance, individuals with LOCAH often have severe acne; women with LOCAH are more likely to miscarry, although the rate of miscarriage can be greatly reduced if the obstetrician checks for LOCAH and prescribes the appropriate treatment, an inexpensive oral pill. But because such individuals deviate “from the Platonic ideal” with regard to “hormonal levels,” Fausto-Sterling classifies them as intersex. Indeed, of the five most common conditions she and her students classify as intersex in the 2000 paper, none meet the basic criteria for intersex that Fausto-Sterling herself had set forward in 1993.

It’s worth emphasizing that individuals with LOCAH simply are not, by any stretch of the imagination, intersex. Men with LOCAH have normal XY chromosomes and a normal penis, prostate, and testicles. They look like men. They are men. Women with LOCAH have normal XX chromosomes and a normal vagina, uterus, and ovaries. They look like women. They are women. Fausto-Sterling and her students appear to have recognized that if their definition of the intersexual as “an individual who deviates from the Platonic ideal of physical dimorphism” was to have any plausibility, then at least some patients with LOCAH must at least occasionally have problems which are intersexual in nature. Accordingly, she and her students asserted that “when late-onset CAH occurs in childhood or adolescence and causes significant clitoral growth, it is quite possible that surgical intervention will ensue.” There is no shred of evidence anywhere in the scholarly literature to support this claim. Fausto-Sterling and her students did provide one citation in support of this remarkable assertion: a first-person account in the women’s magazine Mademoiselle. However, the article in Mademoiselle—titled “Am I a Woman or a Man?”—describes an individual with XY chromosomes but complete androgen insensitivity syndrome: in other words, a classic case of true intersex meeting Fausto-Sterling’s 1993 criteria, in this case an individual who appears to be a woman but who has male chromosomes.11 The article in Mademoiselle never mentions LOCAH or anyone who has anything like LOCAH. Fausto-Sterling and her students cited an article about complete androgen insensitivity syndrome in support of a claim they made about LOCAH, an unrelated condition.

A Fraudulent Figure Gone Viral

After the 2000 paper on intersex appeared, Fausto-Sterling published a book titled Sexing the Body: Gender Politics and the Construction of Sexuality,which drew heavily on the claim that 1.7 percent of humans are intersex. The book made a huge splash. “Instead of viewing intersexuality as a genetic hiccup,” went the review in the Washington Post, “[Fausto-Sterling] points out that its frequency mandates a fresher look. In one study, intersexuality typically constitutes 1.7% of a community.”12 The New England Journal of Medicine applauded Fausto-Sterling’s “careful and insightful book. . . . She [Fausto-Sterling] points out that intersexual newborns are not rare (they may account for 1.7% of births), so a review of our attitudes about these children is overdue. . . .”13 “Most people believe that there are only two sex categories,” went the review in American Scientist.“Yet 17 out of every 1,000 people fail to meet our assumption that everyone is either male or female. This is the approximate incidence of intersexuals: individuals with XY chromosomes and female anatomy, XX chromosomes and male anatomy, or anatomy that is half male and half female.”14

This reviewer, like most reviewers, appears never to have read Fausto-Sterling’s 2000 paper, but only the press release. The reviewer reasonably assumed that Fausto-Sterling was using the usual definition of intersex, the same definition of intersex Fausto-Sterling herself had endorsed in 1993. But the five most common conditions cited by Fausto-Sterling and her students in their 2000 paper don’t meet the criteria the American Scientist reviewer outlined: they are not individuals with XY chromosomes and female anatomy, they are not individuals with XX chromosomes and male anatomy, nor do they have anatomy “that is half male and half female.”

Political Advocacy Masquerading as Science

Fausto-Sterling was acting not as a scientist but as a political advocate. When she was interviewed on this topic in 2001 by The New York Times, she said, “My point is that there’s greater human variation than supposed. My political point is that we can afford to lighten up about what it means to be male or female. We should definitely lighten up on those who fall in between because there are a lot of them” [emphasis added].15 In order to deconstruct the male/female binary, Fausto-Sterling recognized that she had to show that “there are a lot” of people who don’t fit the binary. So she twisted the facts to suit her political agenda, reclassifying men and women with hormonal imbalances as intersex, in order to inflate the number of intersex individuals by a factor of 100.

That’s right: when you remove the five most common conditions cited by Fausto-Sterling in her 2000 paper, none of which meets the criteria for intersex as she herself defined it in 1993, the frequency of intersex drops by a factor of roughly 100, from almost two in 100 births to fewer than two in 10,000 births. That’s the true incidence of actual intersex: fewer than two in 10,000.

I wrote a peer-reviewed scholarly paper, published in August 2002 by the Journal of Sex Research, titled “How Common Is Intersex? A response to Anne Fausto-Sterling.”16 In my paper, I showed that Fausto-Sterling was boosting the numbers of “intersex” individuals by including people, such as men and women with LOCAH, who don’t come close to meeting any sensible definition of intersex. I revealed the many dishonest and misleading prevarications Fausto-Sterling and her students had fabricated in order to swell the numbers of intersex people by two orders of magnitude.

Male & Female

Try Googling the question “How common is intersex?” Among the top twenty hits, you will find two numbers in answer to that question. The first number is 1.7 percent. About as common as red hair! When you dig, you will find that every web page citing the 1.7 percent figure is getting that figure from Fausto-Sterling’s 2000 paper, or from her 2000 book Sexing the Body, or from some other source citing Fausto-Sterling. The other figure you will find, on the other web pages, is 0.018%, or just under two in 10,000, the figure which I provided in my 2002 scholarly paper. And every one of those web pages cites my 2002 paper, directly or indirectly.

You have to choose: whom are you going to believe? Anne Fausto-Sterling or me? I hope you will read both of our papers and then decide for yourself.

Intersex is not a normal human variation. It is not analogous to red hair. It is a rare pathology. And please remember: recognizing a condition as a medical pathology has no moral connotation. I have high blood pressure. That doesn’t make me a bad person. But if I don’t treat my high blood pressure, bad things may happen. An intersex individual has a rare health condition which warrants appropriate and caring treatment. That doesn’t mean intersex people are bad people, and it certainly doesn’t mean that they need surgical intervention. Most do not. In her book Sexing the Body, Fausto-Sterling rightly notes that throughout the twentieth century, many surgeons sought to “correct” the ambiguous genitalia of babies born intersex, often with disastrous results. So I agree with Fausto-Sterling that the care of intersex individuals should be done with the utmost respect and caution.

But the reality is that 99.98 percent of humans are either male or female. Not both. Not neither. The division of the human race into male and female is a hardwired characteristic of our species, as it is for most higher mammals. It is not an invention of the heteronormative patriarchy. Intersex individuals exist, but they are rare. We should not abolish the male/female binary to accommodate intersex individuals any more than we should abolish staircases because some individuals are wheelchair-bound. By all means, let’s provide ramps and elevators for those who cannot walk. But let’s keep the staircases for the rest of us.

The next time you hear someone say, “Intersex is as common as red hair,” I hope you will find the courage to say, “Actually, it’s not. Fewer than two in 10,000 individuals are intersex.”

And if you’re really feeling brave, you might add this: In the image of God he created him; male and female he created them (Genesis 1:27).

1. Alliance Defending Freedom, “Middle Schooler Punished for Wearing ‘There Are Only Two Genders’ Shirt,” (May 26, 2023).
2. Agustín Fuentes, “Here’s Why Human Sex Is Not Binary,” Scientific American (May 1, 2023).
3. Kate Clancy et al., “Biology Is Not Binary,” American Scientist.
4. Alexandra Kralick, “Is Gender Written Into Your Skeleton?The Atlantic (November 11, 2018).
5. Emma Colton, “State Department defends Blinken memo urging staffers to avoid ‘problematic’ language like ‘manpower’,Fox News (February 20, 2024).
6. Karly Domb Sadof, “They were interested in me as if I were a zoo animal. But … I’m a human.’ Intimate images explore intersex identity,” Washington Post (April 21, 2017).
7. Free & Equal United Nations, “Intersex Awareness,” accessed March 28, 2024.
8. Micah Mitchell, “Protecting Intersex Individuals in the Fight Against Anti-LGBTQIA+ Legislation,” ACLU Ohio (June 22, 2022).
9. Anne Fausto-Sterling, “The Five Sexes,” The Sciences, Volume 33(2) (March–April 1993), 20-24.
10. Melanie Blackless et al., “How sexually dimorphic are we? Review and synthesis,” American Journal of Human Biology, Volume 12(2) (March/April 2000), 151-166.
11. Angela Moreno and Jan Goodwin, “Am I a woman or a man?Mademoiselle (March 1998).
12. Courtney Weaver, “Birds Do It,” Washington Post (March 26, 2000).
13. S. Marc Breedlove. “Sexing The Body: Gender politics and the construction of sexuality,” The New England Journal of Medicine (August 31, 2000).
14. Celia Moore, “Sorting by Sex,” American Scientist 88(6) (November-December 2000).
15. Claudia Dreifus, “A Conversation with Anne Fausto-Sterling; Exploring What Makes Us Male or Female,” The New York Times (January 2, 2001).
16. Dr. Sax, “How Common is Intersex?Journal of Sex Research (August 1, 2002).

MD PhD, is a practicing family physician, a PhD psychologist, and the author of four books including Why Gender Matters: What Parents and Teachers Need to Know about the Emerging Science of Sex Differences. More information on Dr. Sax is available at

This article originally appeared in Salvo, Issue #69, Summer 2024 Copyright © 2024 Salvo |


Bioethics icon Bioethics Philosophy icon Philosophy Media icon Media Transhumanism icon Transhumanism Scientism icon Scientism Euthanasia icon Euthanasia Porn icon Porn Marriage & Family icon Marriage & Family Race icon Race Abortion icon Abortion Education icon Education Civilization icon Civilization Feminism icon Feminism Religion icon Religion Technology icon Technology LGBTQ+ icon LGBTQ+ Sex icon Sex College Life icon College Life Culture icon Culture Intelligent Design icon Intelligent Design

Welcome, friend.
to read every article [or subscribe.]