This fracas has confirmed my feeling that while physical anthropology is a science, cultural anthropology is, by and large, ideology devoted to buttressing progressive social narratives.

As I reported in September (see here and here), the American Anthropological Association (AAA) and Canadian Anthropological Society (CASCA), in their annual meeting in Toronto, had decided to cancel a panel on sex (“Let’s talk about sex, baby: why biological sex remains a necessary analytic category in anthropology”). As I wrote at the time:

As I said, the proposal was accepted by the AAA and CASCA for the meeting. But then they has second thoughts—and rejected it (see below).  I suspect that the main issue was [Elizabeth] Weiss’s talk, which maintained that “skeletons are binary”, which is true, but not something that cultural anthropologists, at least, would find comfortable. THERE IS NO BINARY IN WOKEWORLD!

Of course sex in humans is binary, with the proportion of exceptions to the male/femake definition based on gamete size being only about 0.018/%, or one in 5,600 people. Now if you’re a Pecksniff, and I’ve had many of these, you’ll say, “well, 1 in 5,600 doesn’t mean an absolute binary.” Okay, fine, I can respond, “For all practical purposes, it is a binary.” After all, if you toss a nickel in the air, the chance it will land on its edge is also about 1 in 5600, but when the Pecksniffs toss a coin, even they don’t say, “Heads, tails, or edge?”.  The reason for asserting that sex is a spectrum, of course, is that the binary of sex in nature doesn’t match the more spectrum-like nature of gender. But gender is not sex.  The assertion of binary sex in all animals and vascular plants also, for some reason, is said to offend transsexuals and gender activists, although of course the very nature of transexuality—transitioning from male to female morphology or vice versa—presumes a sex binary.  It was this twisted attempt to force nature into a Procrustean bed of ideology that led the anthropology societies to cancel the meeting (it was held elsewhere). As the societies said in their letter of rejection (or, rather, of deplatforming); emphasis is mine:

We write to inform you that at the request of numerous members the respective executive boards of AAA and CASCA reviewed the panel submission “Let’s Talk about Sex Baby: Why biological sex remains a necessary analytic category in anthropology” and reached a decision to remove the session from the AAA/CASCA 2023 conference program(me). This decision was based on extensive consultation and was reached in the spirit of respect for our values, the safety and dignity of our members, and the scientific integrity of the program (me). The reason the session deserved further scrutiny was that the ideas were advanced in such a way as to cause harm to members represented by the Trans and LGBTQI of the anthropological community as well as the community at large.

Yes, the idea of a sex binary was said to be “unsafe” “harmful,” and “undignified.” That the binary was true apparently didn’t matter. Such is cultural anthropology.

Now Kathleen Lowrey, who organized the panel, wrote an analogy between the canceling of the panel (and a letter from The Offended) and medieval bestiaries that tended to affix human traits on imaginary animals. The centerpiece of her article is a letter from three anthropologists adamantly maintaining that sex in humans is NOT binary, using an example from orangutans that involves, yes, binary sex.

Click below to read the piece from Reality’s Last Stand.

Involved in this fracas as an opponent of binary sex is the omnipresent Agustín Fuentes, a Princeton anthropologist who always shows up when a dose of wokeness is needed in anthropology (see all I’ve written about his missteps here, which include accusing Darwin of misogyny and promoting genocide). Lowrey’s statements are indented:

In September, several colleagues and I were pre-emptively booted from the 2023 joint meetings of the American Anthropological Association and Canadian Anthropology Society in Toronto. Our panel, titled “Let’s Talk about Sex, Baby: Why biological sex remains a necessary analytic category in anthropology,” was scheduled for Sunday, November 20. I have already detailed this regrettable situation elsewhere, so I won’t repeat it here.

Instead, I want to focus on a specific point about why our panel was said to fly in the face of the “settled science” in anthropology: the contention that evidence from orangutans demonstrates that the great apes, humans included, are not sexually dimorphic species. In a joint letter, three anthropologists—Kathryn Clancy from the University of Illinois, Agustin Fuentes from Princeton, and Robin Nelson from Arizona State University—wrote, “We see three forms of the adult orangutan. Does this represent a sex binary?” They proffer this rhetorically, expecting the reader to assent that the answer can only be “no.” I am indebted to my co-panelist, Elizabeth Weiss, for sharing and discussing the relevant literature on this with me.

What? Now we have orangutans showing that sex isn’t binary, alongside clownfish (which of course do show binary sexes)?  Yes, that’s what it says in the letter by the three misguided anthropologists, and I quote from that letter

• Implicit in the session abstract and several of the individual abstracts is the assumption that sex is a biological binary; a concept that is rejected by current biological anthropology and human biology, and highly disputed across contemporary biology.

So much the worse for biological anthropology. But wait! Here come the orangutans! (my emphasis in the letter):

As anthropologists who work in biological anthropology and human biology, we are aware that definitions of sex can be made using pelvic girdle shape, cranial dimensions, external genitalia, gonads, sex chromosomes, and more. Sex, as biological descriptor, is not binary using any of those definitions. People are born with non-binary genitalia every day – we tend to call people who fall into this group intersex. People are born with sex chromosomes that are not XX or XY but X, XXY, XXXY and more, every day. The same is true with gonads. What’s more, someone can have intersex genitalia but not intersex gonads, intersex chromosomes but not intersex genitalia. These bodily differences demonstrate the massive variation seen in sex physiology across vertebrate species. Looking beyond humans, we see three forms of the adult orangutan. Does this represent a sex binary? Significant percentages of many reptile species have intersex genitalia. Are we still trying to call sex a binary? The binary limits the kinds of questions we can ask and therefore limits the scope of our science.

Clearly the implied answer to the rhetorical question of Fuentes et al. is “Hell no! Orangutans clearly demolish the sex binary.”

Except that they don’t. What the three sweating anthropologists are doing here is conflating sex-related traits like chromosome and genital appearance with biological sex itself, which is defined as whether you have large, immobile gametes (females) or small mobile gametes (males). There are no other types of gametes, so there are just two sexes. Further, the binary nature of gamete size has led to all kinds of advances in understanding nature—for example, how sexual selection works. Turtles don’t have sex chromosomes, but they have sexes—two of them—sex being determined by rearing temperature.  As Luana and I wrote in our Skeptical Inquirer paper:

Natural selection has independently produced diverse pathways to generate the sexes, but at the end there are just two destinations: males and females. And so we have an evolved and objectively recognized dichotomy—not an arbitrary spectrum of sexes.

Back to Lowrey, who handily and quickly dismantles the “orangutans-have-three-sexes” argument:

Clancy, Fuentes, and Nelson are referring to a phenomenon observed among male orangutans whereby junior males will not always develop secondary sexual characteristics if a dominant senior male is present. While these junior males are reproductively capable, and will impregnate female orangutans when the opportunity arises, they do not develop the larger body size, heavy jowls, and “laryngeal sac” that produces the loud, resonant calls typical of dominant males. Consequently, female orangutans are much less willing to mate voluntarily with these developmentally arrested junior males than with dominant senior males.

The mechanism that induces developmental arrest in junior males in the presence of a dominant senior male is unknown. Initially, it was hypothesized that this was a stress response. However, dominant males produce more stress hormones than developmentally arrested junior males. This suggests that the lack of mating opportunities for junior males might be offset by a significant reduction in violent conflicts with other males. Dominant senior males are relatively tolerant of developmentally arrested males but engage in aggressive combat during encounters with other mature males, resulting in injuries and sometimes premature death. This behavior may be a canonical example of what evolutionary biologists have termed the “sneaky fucker” gambit, observed in many species, where some males monopolize mating opportunities with females through aggression, forcing unsuccessful males pursue alternative strategies that avoid direct male-male competition. The arrested development observed in some male orangutans may be a particularly highly developed example of this strategy.

Are orangutans, then, a trimorphic species proving that primate sex is not binary? This species exhibits three adult body forms; however, two of these are male, and one is female. Consequently, orangutans, like humans, have only two sexes. The alternate male body forms likely represent reproductive strategies evolved to access the limiting factor for the production of orangutan offspring. This limiting factor is the bodies and capacities of female orangutans, including their large sessile gametes, uteruses for gestating baby orangutans, mammary glands for nourishing young over extended juvenile periods (orangutan offspring can be breastfed for up to eight years), and the devoted care from orangutan mums necessary to rear orangutan offspring to maturity.

The story of the trimorphic orangutan, therefore, doesn’t hold up under scientific scrutiny as a slam-dunk example that refutes the sex binary. Instead, it serves a different purpose. It contributes not to scientific literature but to the evolving canon of a postmodern bestiary.

It’s weird how people who purport to be scientific will use the example of three forms of orangs, two of them indisputably male and one of them female, to argue for the existence of three sexes. It’s as if people observed that there are dwarf men and women, big outliers in height, to claim that humans have four sexes.

Lowrey, of course, knows that this fallacious “appeal to nature argument”, which claims that what we want to see in nature is what we must see, is purely ideological:

When gender ideologues rifle the annals of animal science in hope of rumbling a plausible tale about white-throated sparrows or bearded dragons, they are looking not for evidence but for allegories. Tracking down their sources is like asking Aesop if foxes ought to eat grapes even if they are within easy reach (they definitely should not, by the way). Such narratives are not aimed at advancing animal ethology or biology, but at telling humans how to behave and what to believe about their own natures.

. . . What kind of morality is enjoined by the parable of the trimorphic orangutan? A creed that says giving kids drugs that erode their bones is groovy. One that urges us to free our minds, man, about where and with whom Marina Volz should be housed. An ethos that claps like a trained seal every time WPATH issues new “settled science” from on high.

WPATH is the World Professional Association for Transgender Health, which has been repeatedly criticized for promoting “standards of care” for trangender health that aren’t safe, and for making statements that aren’t true. You can look up Marina Volz for yourself.

Fortunately, biologists have clarified the cases of the white-throated sparrow and clownfish, both mistakenly said by ideologues to demonstrate a “spectrum of sexes.” Now we have a takedown of the stupid orangutan example as well.  Really, cultural anthropology, which used to be more respectable, has become somewhat of a swamp.

Here’s a demonstration of the two types of MALE orangutans from Wikipedia. Note the caption:

UPDATE: Two tweets on the amount of meat procured by male vs. female hunters (see also tweets at bottom of this page):

(The previous numbers of hunters don't quite add up because some records include 1 or more assistants)

Average per hunter per trip:
M: 9.5 kg
F: 1.4 kg

rstats data package: https://t.co/36XbiZqQ1U

From the SI, warning against doing what I did. Caveat emptor. 2/2 pic.twitter.com/IB1mpSKgP5

— Ed Hagen (@ed_hagen) June 30, 2023

***************

Recently I criticized a speculative paper giving weak data that, in the past, women were hunters along with men, a paper that attacked the division of labor scenario that women gathered and men hunted in early societies. I stand by that criticism, as the paper was weak, but now there’s a paper that shows a larger role for women hunting in hunter-gatherer societies than I envisioned.  While men still do most of the hunting in this sample, women do a considerable amount of hunting too, largely small game but it’s still hunting. And they often go along with men to hunt, and take their babies with them or put them in the hands of other women while they’re foraging.

So, to the extent that I implied that ONLY men hunted in either ancient or modern hunter-gathere societies, though I don’t think I implied that, I retract such an implication.  Although these data hold for modern hunter-gatherer societies, it’s reasonable to assume that they held for earlier societies as well, and the authors cite more archaeological findings of female skeleton buried with weapons.

Click the title below to read (the paper is in PLOS One), and you can find the pdf here.

Some suggestive earlier work (quotes from the paper are indented; I’ve omitted reference numbers):

One of the most prominent discoveries recently includes a 9,000 year old burial located in the Andean highland area of Wilamaya Patjxa in Peru. The burial included an adult female alongside a hunting toolkit consisting of stone projectiles as well as animal processing equipment. Researchers typically presume that stone projectiles buried alongside males are hunting tools but are less persuaded when projectiles are associated with females; the specific assemblage clearly evidenced hunting in this case. In their own review of the literature, Haas et al.  examined burials in the Americas from the Late Pleistocene to the Early Holocene period, identifying eleven females from ten sites who were associated with big-game hunting tools. By using a probability analysis of all twenty-seven sites which had evidence of big-game hunting, Haas et al. determined that females made up a “nontrivial” amount of big-game hunters across the Americas. In fact, their analysis suggested that females represented up to fifty percent of big game hunters from the Americas prehistorically.

In this case, the authors looked at 61 modern hunter-gatherer societies where they could get data from anthropological descriptions about whether women participated in hunts or hunted on their own. Here’s a map with the authors’ caption:

Besides using data from the literature about women hunting, they took data on whether women were purposefully hunting (going out deliberately to hunt) or spontaneously hunting, taking game when they found it on their perambulations. They also categorized game taken as small, medium, or large, and whether women took their children with them when they hunted.

Here are the main results:

Data were compiled from literature on sixty-three different foraging societies across the globe. These included nineteen different foraging societies from North America, six from South America, twelve from Africa, fifteen from Australia, five from Asia and six from the Oceanic region (Fig 1 & Table 1). Of the 63 different foraging societies, 50 (79%) of the groups had documentation on women hunting. Of the 50 societies that had documentation on women hunting, 41 societies had data on whether women hunting was intentional or opportunistic. Of the latter, 36 (87%) of the foraging societies described women’s hunting as intentional, as opposed to the 5 (12%) societies that described hunting as opportunistic. In societies where hunting is considered the most important subsistence activity, women actively participated in hunting 100% of the time

Of the 50 societies that had data on women hunting, then, 79% of them had women sometimes participating in hunts (note, the analysis, using literature data, couldn’t say how often women hunted relative to men). 87% of these, or 69%, showed intentional hunting. Data on game size:

The type of game women hunted was variable based on the society. Of the 50 foraging societies that have documentation on women hunting, 45 (90%) societies had data on the size of game that women hunted. Of these, 21 (46%) hunt small game, 7 (15%) hunt medium game, 15 (33%) hunt large game and 2 (4%) of these societies hunt game of all sizes. In societies where women only hunted opportunistically, small game was hunted 100% of the time. In societies where women were hunting intentionally, all sizes of game were hunted, with large game pursued the most. Of the 36 foraging societies that had documentation of women purposefully hunting, 5 (13%) reported women hunting with dogs and 18 (50%) of the societies included data on women (purposefully) hunting with children. Women hunting with dogs and children also occurred in opportunistic situations as well.

The upshot: 46% of societies with women hunting involved capturing solely small game (presumably rodents and the like), 15% hunt medium game (rabbit-sized creatures?) and 37% hunt either large game or game of all sizes.

And data on women hunting with children:

Of the 36 foraging societies that had documentation of women purposefully hunting, 5 (13%) reported women hunting with dogs and 18 (50%) of the societies included data on women (purposefully) hunting with children. Women hunting with dogs and children also occurred in opportunistic situations as well. [No data are given on the proportion of opportunistic hunting that involved the presence of children.]

The authors’ conclusions:

Here we investigated whether noted trends of non-gendered hunting labor known from the archaeological record continued into more recent, ethnographic periods. The descriptive sample described here is sufficient to warrant the conclusion that women in foraging societies across the world participate in hunting during more recent time periods, a finding that makes sense given women’s general morphology and physiology . The prevalence of data on women hunting directly opposes the common belief that women exclusively gather while men exclusively hunt, and further, that the implicit sexual division of labor of ‘hunter/gatherer’ is misapplied. Given that this bimodal paradigm has influenced the interpretation of archeological evidence, which includes the reluctance to distinguish projectile tools found within female burials as intended for hunting (or fighting) , this paper joins others in urging the necessity to reevaluate archeological evidence, to reassess ethnographic evidence, to question the dichotomous use of ‘hunting and gathering,’ and to deconstruct the general “man the hunter” narrative.

Of the 63 foraging societies with clear descriptions of hunting strategies, 79% of them demonstrated female hunting. The widespread presence of female hunting suggests that females play an instrumental role in hunting, further adding to the data that women contribute disproportionately to the total caloric intake of many foraging groups. Additionally, over 70% of hunting done by females is interpreted as intentional, meaning that females play an active and important role in hunting—and the teaching of hunting—even if they use different tools and employ different acquisition strategies. For example, among the Aka, women’s participation in net-hunting was required, whereas men’s participation was not.

It’s clear from these data that hunter-gatherer societies do not show a strict division of labor, though I’d like to see data on the frequency of hunts in which women participate, not just the frequency of societies in which women hunt.  Men still do most of the hunting and most of the big-game hunting, but this shows only moderate rather than extensive division of labor.

Before I go, I’ll call your attention to a series of tweets by Vivek Venkataraman (start here on Twitter), an assistant professor in the Department of Anthropology and Archaeology of the University of Calgary. His university webpage describes his interests:

Dr. Venkataraman is an evolutionary anthropologist who is broadly interested in the evolution of the human diet and food systems, and their relation to life history and behavior. He is assistant director of the Guassa Gelada Research Project ,and also the co-founder and co-PI of the Orang Asli Health and Lifeways Project (OAHeLP)

Venkataraman is somewhat dubious about some of the PLOS One paper’s results, especially the 80% frequency of women hunting among all hunter-gather societies. On the other hand, like me, he applauds any new data that can change our views of biology, and thinks the frequency of hunter-gatherer societies in which women hunt is somewhere between 13% and 80%; but he also thinks that women’s hunting was even more frequent in the past than it is now (see below)

Have a look at these 14 tweets:

 

 

The paper to which  Venkataraman refers is here (click on screenshot):

Let no one say, then, that men hunted and women gathered, nor that there was a strict division of sex roles in such societies—either now or in the past!

h/t: Carole Hooven

Any YouTube video with the title “Orangutan skeltons bust the sex binary” is guaranteed to draw me in, and the very title makes me wary. How can skeletons bust the sex binary of any mammal, given that the definition of sex in mammals involves features (reproductive systems evolved to produce two very different kinds of gametes) that can’t be seen in a skeleton? Sure, you can often identify skeletons (especially of sexually dimorphic species like humans) by various bone traits, like hip-and-leg configuration, but such dimorphism is not 100% diagnostic, nor, more important, the definition of the sex binary.

What Alexandra Kralick has done in the video below, released three days ago,  is show that in orangutans, which have two morphs of males in the wild, give a more or less continuous distribution of bone-size measurements, since one morph of males is intermediate in size between males and females. But a continuous distribution of bone sizes does NOT “bust the sex binary.” What it does do is “break the bone binary”, but that says absolutely nothing about whether sex itself is binary. It’s like showing that the distribution of human heights is not binary and therefore human sexes are not binary!

The video is not only misguided, but is also an embarrassment to the Leakey Foundation, named after Louis Leakey, which sponsors research on human origins and evolution. The Foundation is, in fact, putting its imprimatur on work that purports to show that, in primates (and presumably in humans, since Kralick generalizes her results beyond orangs), sex is not binary. I doubt the Foundation would really agree with that, unless they’re terminally woke (and anti-science).

At any rate, here’s the YouTube introduction to the 48-minute video, which includes Q&A at the end.

Meet Leakey Foundation scientist Alexandra Kralick and learn how orangutan skeletons bust the sex binary in this rebroadcast episode.

Kralick declares that the theme of her work is “casting light on problematic assumptions that permeate scientific narratives of biological sex,” and adds that she’s bringing “a feminist and queer approach to this work to show how biological sex is more complicated than either ‘male’ or ‘female’ but in fact sits on a spectrum.”

One might sense that there’s an ideological motivation behind this work and its conclusion, a motivation that leads to misleading conclusions. One would be right.

Click to listen:

I’ve taken a few screenshots of the slides. The one below argues that “biological sex is not dichotomous” (i.e. “binary”), but she leaves out the one trait that defines sex and shows that it is binary: the reproductive system and the gametes that it makes. To repeat myself, males have a reproductive system evolved to produce small, mobile gametes (sperm), while females have a system evolved to produce large, immobile gametes (eggs). There is no third type of reproductive system, and no other type of gamete. This is the definition of biological sex, not the traits listed on the slide. (Note that the slide depicts humans, not orangutans, showing that Kralick is making a general statement, not one limited to orangs (which of course also fit the sex binary).

In the wild (though Kralick says “not in zoos”), the male orangs have two morphs, “flanged”, with big cheek pads, big vocal sacs, and large body size; and “unflanged”, males who are smaller, though not as small as females, and also lack vocal sacs and don’t have big cheek pads.  Flanged males are behaviorally and sexually dominant over unflanged males.  The two classes of males, of course, are still both male, for both can produce sperm and mate with egg-producing females (the unflanged males in nature may be “female mimics” that deceive females to get mates, but we don’t know).  There are three species of orangs (genus Pongo) that live in different places, and all three have the male size/feature dimorphism. This is what Wikipedia says about them:

Males become sexually mature at around age 15. They may exhibit arrested development by not developing the distinctive cheek pads, pronounced throat pouches, long fur, or long calls until a resident dominant male is absent. The transformation from unflanged to flanged can occur quickly. Flanged males attract females in oestrous with their characteristic long calls, which may also suppress development in younger males.

Unflanged males wander widely in search of oestrous females and upon finding one, will force copulation on her, the occurrence of which is unusually high among mammals. Females prefer to mate with the fitter flanged males, forming pairs with them and benefiting from their protection. Non-ovulating females do not usually resist copulation with unflanged males, as the chance of conception is low.Homosexual behaviour has been recorded in the context of both affiliative and aggressive interactions.

This suggests that the unflanged males are indeed either female mimics or males that are non-dominant or of lower fertility, and have to use force to get offspring. Regardless, they’re still called “males”: they are clearly not a third sex!

Here’s a picture of the two morphs of males taken from Wikipedia. First flanged, then unflanged; the differences in vocal sacs and cheek pads are clear. The unflanged male was at the San Diego Zoo, though Kralick says that unflanged males can’t be found in zoos (27:11).

Below is a plot of the “long bone length” of adult (A) and juvenile (J) orangs: flanged male (FL), unflanged male (UFL), and female (F). Note that in each of the five long bones, the unflanged males are intermediate in length between big males and smaller females. Importantly, note that the orangs are classified as either MALE or FEMALE, which Kralick apparently got from the museum specimens that she studied. (The sample sizes were quite small: there were, for example, only three specimens of unflanged males.)

Here are data for the ulna (arm bone), again clearly showing the intermediacy of the unflanged MALES between flanged MALES and normal FEMALES.  But if sex is not a binary, how did they identify the specimens? No doubt the collectors used the presence of a penis or vagina (almost 100% correlated with biological sex in humans) as the identifer of males vs. females, though presence or size of penis is not the definition of “a male”.

You get the same kind of distribution from cross-sectional area of the long bones. Kralick says “These are the results that support the notion that biological sex is a spectrum.” (32:44).

Now where does all this come from? Whence the conflation of sexual dimorphism with the definition and dichotomy of sex itself? You might have already guessed based on the lecture and the fact that at the beginning it’s announced that the Leakey Foundation is collaborating on this with “the American Association for Biological Anthropologists LGBTQIAA group.”

Below is a slide from the talk asserting that these data “subvert the idea of the sex binary as natural and biological, thus altering the discourse that places value on biological causes for gendered social order.” Well, I get the part about subverting the sex binary, but to say that the sex binary is not “natural and biological” is simply wrong.  You know this from the immense irony that although Kralick finds a “spectrum” using bone dimensions, she sees this only by dividing the data by sex: males (two types) and females.  Here she recognizes that there are two classes, and not an intersex. As for its connection with gender, it’s opaque.

Note, though that in the talk Kralick does quote the outdated figure that “17 our of 1000 babies born are intersex” (1.7%), “the same proportion of individuals with red hair”. The intersex figure came from a flawed claim by Anne Fausto-Sterling in 2000, who used a very wonky way to decide who was “intersex.”  (Fausto-Sterling later retracted this claim, but you still see it everywhere).

In fact, developmental variants are very rare, constituting only about one in 5,600 people (0.018 percent), and also don’t represent “other sexes.” This is the same proportion of the time that a tossed nickel will land on its edge rather than on “heads” or “tails”, yet nobody thinks that the results of coin-tossing are “non-binary.” Further, just like coins that land on edge are neither heads nor tails, so an intersex individual, rare as they are, are not “other sexes”, but the results of development gone awry. After all, natural selection has created two endpoints for animal sexes, male and female, though the developmental paths to those endpoints can involve chromosomes, temperature (in turtles), the social environment (yes, clownfish) , or genes. Indeed, the paths are many but there are only two endpoints (males and females); and a deviation from those two goals represents a very rare straying from the path.

Towards the end, Kralick says explicitly that one of her aims is to deconstruct the narrative that unflanged males are “deviant,” which I guess a couple of anthropologists have said (but I bet few would say that today!). The language of “deconstructing”, “subverting”, “undermining”, and “busting” supposedly conventional science is straight out of postmodern discourse.

This slide, which conflates sex and gender again, supposedly gives us lessons about humans, the only species, Kralick asserts, that do have gender.

The goal in this research is apparently to read into nature the spectrum of gender we see in human society, another example of what I call the “reverse naturalistic fallacy”—the idea that “what we consider good in humans must be observed in nature.” It’s a logically unsound way to valorize human identities. The double irony, though, is that Kralick not only affirms the sex binary, or at least accepts it, but also studies something in orangs that has nothing to do with gender.  Unflanged males are variants, apparently frequent, and may represent an evolved reproductive strategy.  Their existence raises a number of interesting and unanswered questions, but this study doesn’t go after any of them. Instead, it tells us what we already know from humans: males and females are of different but overlapping size, i.e., human height falls along a spectrum.

But human sex doesn’t.

h/t: Christopher