Olympic boxing and disorders of sex development

August 2, 2024 • 10:30 am

There was a bit of confusion yesterday involving my post about the defeat of Italian female boxer Angela Carini by Algerian boxer Imane Khelif, who in all likelihood is male but identifies as female. The bout was over in 42 seconds after Khelif delivered a few powerful blows to Carini’s head. She then refused to shake hands with Khelif, cried, and then explained that she was fighting for her late father (she later apologized for the unsportswomanlike gesture of not congratulating her opponent).  Most of the videos that accompanied the tweets have been taken down by the Olympics for copyright reasons, but I found one on Emma Hilton’s site:

The first thing I’d like to clear up is my use of the word “transwoman” to refer to Khelif. I meant it to refer to the big brouhaha in sport and gender, which refers to the contested presence of genuine transwomen (i.e., natal males who transition to a female gender identity) competing against women in women’s sports. I kept using the term when applying it to Khelif, but Khelif may indeed have assumed that he/she was a biological female since birth, since Khelif was raised as a female from birth in Algeria.  If that’s the case, then Khelif didn’t really “transition”.  If you use the “trans” term loosely, I suppose you could say that Khelif transitioned from the biological condition of being a male to having the identity of a woman, but since this wouldn’t have been a conscious transition, I thus gladly retract the use of the term “transwomen” for Khelif.  One could, I suppose, call Khelif an “intersex” person, but those afflicted with disorders of sex development (DSDs) prefer the term “person with a disorder of sex development”. Also, definitions of “intersex” vary among researchers.

But that’s a semantic issue. The main question is this: was Khelif a biological male, went though male puberty, and then wound up with the strength, size, speed, and punch-strength advantages that go along with male puberty—advantages that do not go away fully even with testosterone-suppression?  All evidence points to “yes”, and my judgment was based on the fact that Khelif had an XY karyotype, the physical appearance and size of a man, and had previously failed testosterone tests and, on that basis, was denied the opportunity to box women.

Now the only way to ascertain for sure what Khelif’s sex was is to do an ultrasound or some kind of noninvasive examination to see if there are ovaries (making a female) or testes (making a male) or both (making a very rare hermaphrodite).  This hasn’t been done, but the conclusion of those with more expertise than I is that it’s probable that Khelif was a biological male with a DSD and had gone through male puberty, thus having the same advantage against biological women as either a transwoman or, in Khelif’s case, a male afflicted with a DSD who has suppressed his testosterone. If this is the case, the Olympics screwed up in its last-minute method of determining whether an athlete can compete against biological women (the IOC has said that each sport should make its own rule). At the bottom I say what I would judge to be necessary and sufficient tests to determine whether a person is qualified to compete against biological women.

Let’s look at someone who knows the ins and outs of this: Carole Hooven of Harvard University, author of the well known book T: The Story of Testosterone, the Hormone that Dominates and Divides Us. There is a chapter on sports and gender, too.  It’s an excellent book and I recommend it highly.

Hooven issued a long tweet yesterday explaining Khelif’s likely condition. And yes, Khelif appears to be a male with a DSD. Go to the tweet to read the whole thing:

Here’s an excerpt from the long tweet (my bolding). Note that it’s all about one particular DSD, suggesting that this is what Hooven thinks that Khelif has:

First: People living with DSDs should be treated with compassion and understanding, and receive any heath care they need. These can be challenging conditions for individuals and their families. But when male athletes have DSDs that give them an advantage over females, and they compete in the female category, this raises concerns about safety and fairness, and forces discussion of the relevant physical traits.

Athletes with XY DSDs who have testes (usually internal), XY sex chromosomes, male-typical levels of testosterone, and functional androgen receptors are often described as females with “hyperandrogenism,” i.e., abnormally high levels of testosterone. They experience physical benefits of this high testosterone during puberty, which translate into athletic advantages over females. The issue for sports is that athletes with the XY DSD 5-alpha reductase deficiency (5-ARD), may be socialized as female, may be legally female, and may live and identify as female; but they are male.

These individuals are usually born with female-appearing genitalia, which can lead to being sexed as female. Here’s why. 5-ARD is caused by a mutation in the gene that codes for the enzyme 5-alpha reductase, which converts testosterone into a more potent androgen, DHT. This androgen interacts with the androgen receptor, like testosterone, and is necessary for the typical development of male external genitalia (penis and scrotum) and the prostate. Without DHT, female-typical external genitalia develop. At the end of this monster post is a graphic of the relevant steroid production pathway, from my book T: The story of Testosterone.

DHT is also responsible for male-pattern baldness and dark, coarse facial hair, which is why people with the condition have smooth skin that can give a feminine appearance.

The “decision makers” are aware that athletes with 5-ARD are male, and that they experience the benefits of male puberty. The requirement to reduce their testosterone to typical female levels isn’t discriminatory, since these are males who are asking to compete in the female category. But more significantly, all the relevant scientific evidence shows that reducing male T in adulthood does not undo the physical benefits of male puberty.

And the relevant reference:

Here’s more detail about T, DHT, and male advantage in strength and speed.

I’ve been asked if men with the DSD 5-ARD (in which ppl cannot convert testosterone into the more potent androgen DHT) experience the typical benefits of male puberty, that would give them an advantage in strength and speed relative to women. This is relevant to questions about whether male athletes with 5-ARD should be allowed to compete in the female category. This is an excellent question, because it could be the case that DHT is necessary for the development and maintenance of male-typical muscle, lean body mass and strength. If that were the case, then people with 5-ARD might not have a typical male advantage, because the lack of DHT would perhaps lead to a more feminine pattern of fat, lean body mass and strength. I’ve wondered about this myself and have looked into the evidence.

Perhaps the top researcher in this area, Shalendar Bhasin, who is scrupulous in his methods, has examined this very question. The answer appears to be: no, testosterone does not need to be converted to DHT to exert its typical anabolic effects. These findings are reported in his 2012 study, “Effect of Testosterone Supplementation With and Without a Dual 5α-Reductase Inhibitor on Fat-Free Mass in Men With Suppressed Testosterone Production, A Randomized Controlled Trial.” (It is linked to below—and since it’s paywalled, I’ve included the graphs that show comparisons between the placebo and DHT— inhibited conditions, with no difference on the various outcomes.)

The paper is actually free; click on the link below to go to it, and follow the link to “get pdf” or go to the pdf directly here:

The paper shows, as Hooven notes above, that this DSD has its normal effects on the body even though testosterone isn’t converted to the androgen DHT. In other words, 5-ARD males produce testosterone that, even though not converted to DHT, sill has its normal effects on masculinizing the body.

A bit on the condition from the National Library of Medicine:

The presentation of patients with a deficiency of 5α-RD2 can vary. This condition is an autosomal recessive disorder of sex development associated with the mutation in the SRD5A2 gene. No direct association has been seen between the phenotype and the genotype in this disorder. Two individuals with the same gene defects in SRD5A2 can present with completely different phenotypes. This shows that other additional genes probably control the phenotype and the gene under discussion.

The newborns might have genitalia resembling labia majora, which would be unfused labioscrotal folds. The phallus in these children may look more like a clitoris than a penis. At the same time, the internal genitalia in these children include seminal vesicles, epididymis, vas deferens, and ejaculatory duct, and one may not see any Mullerian structures. The testes in these children might be present in the inguinal sac, and very rarely, they can also be found within the abdomen. These children tend to be raised as females until puberty, when they start exhibiting virilization. At puberty, the phallus may grossly enlarge to form a penis, the testes may descend into the unfused labioscrotal folds, the voice deepens, and a beard starts growing. The development of all these secondary sexual characteristics during puberty does not need the presence of DHT but only the presence of testosterone.

Carole also gives a strong recommendation to this free podcast:

So the questions that people are probably asking (my questions and my answers):

a.) Does Khelif have a DSD?  Almost certainly, since the chromosomes, testosterone levels, and physiognamy suggest that Khelif is a biological male, but the genitalia probably are female-like, although we don’t know for sure. At any rate, there was some phenotypic trait that caused Khelif to be raised as a female.

b.) Was the DSD XY DSD 5-alpha reductase deficiency (5-ARD)?  It’s likely since Hooven discusses it at length. This is in fact the same DSD that Caster Semenya had: according to the BBC:

The 2018 rules meant that Semenya could not compete in female track events over this distance without taking testosterone-reducing drugs.

She appealed against World Athletics’ proposal at the Switzerland-based Court of Arbitration for Sport (Cas), but eventually lost in what amounted to a landmark case in 2019.

It was in the Cas ruling that Semenya’s specific DSD was confirmed as 46 XY 5-ARD (5-alpha-reductase deficiency). People with this particular DSD have the male XY chromosomes. Some are assigned female or male at birth depending on their external genitalia.

Semenya told BBC Sport that she was “born without a uterus” and born “with internal testicles” and said: “I am a woman and have a vagina”.

Cas said athletes like Semenya with 5-ARD have “circulating testosterone at the level of the male 46 XY population and not at the level of the female 46 XX population”, which gives them “a significant sporting advantage over 46 XX female athletes”.

Given that Semenya has the equipment (though perhaps not the ability) for making sperm, Semenya is biologically male. So is Khelif, though people are loath to say it or use the pronoun “he” (check their Wikipedia entries).  It’s possible that Khelif has another DSD, PAIS D (partial androgen insensitivity syndrome), but this is less likely based on phenotype; and this condition is rarer.

. . . which leads us to the next question:

c.) Is Khelif a man?  if he has 5-ARD and went through male puberty, producing testosterone at higher male levels (these don’t overlap with female levels), levels that require suppression to meet sports standards, the answer is yes. Female-like genitalia don’t make someone a biological woman if they have testes (see above).

But there is one last question, and the most relevant one.

d.) Should Khelif be competing in women’s boxing?  Given what we know of his size, strength, and performance, as well as his XY status and what must have been high testosterone, the answer is, at present, no. Suppressing testosterone in his case will not eliminate any athletic advantages Khelif accrued by going through male puberty. But further investigation would be useful (see below).

e.) How should sports organizations determine if someone has a sex-based athletic advantage? Ideally, it should be a three-part test. First, are there testes or ovaries? If there are testes, that’s already a sign of male advantage, particularly when accompanied by an XY karyotype.  Further tests can examine testosterone levels and exposure as well as sequencing of the DNA to see if there are genetic mutations causing DSDs. But there’s already enough information from Khelif’s obvious athletic advantages and his XY karyotype to mandate banning him/her from boxing until these other issues are examined.

Finally, let me add that most people having DSDs are not athletes in the limelight, and in fact have to deal with medical, emotional, and social issues that arise in conjunction with having DSDs.  These people should not be regarded as freaks, have the same moral and legal equality as the non-afflicted, and should be treated with empathy

h/t: Carole Hooven for discussion and clarification

83 thoughts on “Olympic boxing and disorders of sex development”

    1. We’ll have that printed on a hat for you. How ’bout it? You can head up the MWFA movement.

  3. Yes – excellent – bravo.

    As discussed here and as PCC(E) found literature on, 1/5200 – the edge of coin flip result -is the approximate frequency of the “intersex” conditions, which I’m thinking needs a more accurate term. But that frequency is unforgettable.

    I am wondering still how many “intersex” athletes have been competing over time. It seems relatively new beginning with Semenya.

    1. It’s also a little less likely than being dealt four of a kind in a five-card poker hand. But much more likely than a straight flush. Most people have a hard time imagining a coin landing on its edge — the p(edge) comes from computer modeling — but rare poker hands are intuitively obvious, coming directly from perms and combs.

      1. +1

        BTW Leslie, a while ago for a number of reasons I changed my pseudonym ThyroidPlanetto my real first name (last name upon request).

        Just sayin’ – Cheers.

          1. Errmm yes.

            I’m gonna use this comment to express appreciation to the readership here and PCC(E) especially. I hope everyone sees it. This ability to think/write things out and put them up is important – for better or worse.

            A quote :

            “Pooh began to feel a little more comfortable, because when you are a Bear of Very Little Brain, and you Think of Things, you find sometimes that a Thing which seemed very Thingish inside you is quite different when it gets out into the open and has other people looking at it.”

            The House At Pooh Corner
            A. A. Milne & Ernest H. Shepard
            1928 by E. P. Dutton; copyright renewal, 1956, by A. A. Milne

          1. XKCD wrote a comic about a method to generate useful passwords. The example was horse battery staple. I thought that was brilliant so I added Sam Harris’ impossible idea of a piece of uranium the size of Jupiter, and sprinkle in a little Monty Python.

            It did not work as expected.

            Reader Stephen B. (Biro?) noted that Thyroid Planet means shield-shaped wanderer, which I thought was brilliant, because it does.

  4. A lot of reporting on the 46 second bout between Khelif and Carini seems inaccurate and (in part) misleading. I’ve seen headlines about Carini being “brutalized,” etc. which suggests a long bout of many punches. Even here on WEIT, Coyne reports multiple blows. I saw the video from several sources yesterday, and here is how it played out. The boxers were dancing around for about twenty seconds. Khelif then made one attempt at a blow to the face, and succeeded. Carini stepped back (or staggered a little bit), considered her options rather quickly, and then made a signal she is quitting. It took one blow to the face to convince her not to continue. She was not knocked down. I’ve read somewhere she might have gone into the fight, knowing in advance she would quit/refuse to fight Khelif. That’s not incompatible with how these first 3/4 of a minute played out. Whatever her intent, the one blow to the face convinced her to quit. The fact that she apparently refused a friendly/closing handshake when Khelif offered it – this is visible in the videos I saw – suggests to me a somewhat premeditated refusal to fight. I’ll assume that going into the Olympics, the women boxers know the fact that Khelif was banned from fighting women in an earlier (championship) contest.

    1. Please don’t call me “Coyne” on this site, as it’s very impersonal. “Jerry” is okay. But what you’ve “read somewhere” is not very convincing and, in fact, might be just as “misleading and inaccurate” as how you say people described the fight. I might have said there were multiple blows because I saw multiple videos from different angles.

      UPDATE: I just looked at the whole clip that Sastra posted below, and there are at least five or six punches to the Italian woman’s head. So you’re just wrong. In fact, your whole description of the fight is wrong.

      At any rate, it clearly was a physical mismatch, and you seem to have missed the point of this post, which was that the mismatch was likely caused by Kheif having a DSD, which I consider extremely likely from the evidence. For some reason you would rather spread the rumor that the woman didn’t really want to fight Khelif. The mismatch was apparently, and was probably due to gender-related issues. In fact, I find it invidious that you would rather accuse the woman of cowardice for not wanting to fight a biological man than realize that she shouldn’t have been paired with what is likely a biological male

      1. Khelif has been beaten several times by other women. Is it really fair to call this a mismatch?

        1. Yes, because (as Jerry noted) – individuals with the disorder (5-alpha reductase deficiency – https://medlineplus.gov/genetics/condition/5-alpha-reductase-deficiency/) that this person likely has are male, and males as a group have an advantage over females. As an analogy, if I entered a 10 year and under track meet, I might very well get beat in a sprint by multiple children. However, it would not make it appropriate for me to enter that category as I am 58.

        2. Strength and endurance are not the only elements to such sports. I suspect many of the women in the competition are much better trained and may have more experience than the gentlemen in question.

          I saw something similar repeatedly in the military. Young women would often arrive very fit, having spent a lot of time running and lifting weights before enlisting. They were stronger and faster than some of the young men who had apparently prepared themselves for the experience by eating donuts and playing video games.
          However, after a couple of months, the guys could be reliably predicted to overcome that deficit.
          Soon, the guys would be taking turns carrying the packs of the women in mixed-sex squads to ensure they could remain competitive and to ensure the women did not injure themselves trying to keep up.

          Generally, there is not a lot of performance overlap between men and women, if they are equally trained and motivated. At least in sports or activities where strength and endurance are important.

          Or that has been my personal observation.

      2. Jerry: sorry I am unfamiliar with blog etiquette about how you should be addressed/referenced, no disrespect intended. Also, I did not intend to weaken your argument, that men should not be competing against women. My intent was to show how conflicting information gets out into media, and it seems I’ve succeeded! Thanks to Sastra for the link to a more complete video; I feel a bit duped, and should have been more careful drawing conclusions.

    2. I’ve seen the clip you describe numerous times, but I did come across a more complete, longer clip which showed the fight from the beginning. There was more to it. It wasn’t a long match so i think it’s strange that just the snippet at the end went viral.

      Here’s the full fight (or most of it) — it gives a better idea of what happened:

      https://youtu.be/SHCYCmF4wXs?si=39q4-FQb7bUGFbxj

      1. Granted I have not watched many women’s boxing matches, but if you were to ask any reasonable person if the fight was A) two women boxing; or B) a man boxing a woman, I think most would answer B. Look at the difference in musculature, limbs, and movement.

        I will say that I don’t know how Carini would look vs whomever is the top-ranked women’s boxer, so it’s possible that she would still look weaker in comparison against other fighters as well.

        There will be unfair competition in a tournament like this where the top ranked athletes take on the lowest ranked candidates, so my beef isn’t with mismatches in this type of tournament, but rather with ensuring females at least have a somewhat standard field in terms of natural upper bound to their potential. Inclusion of males into female sport introduces a higher bound to the level of physical ability that no actual female can ever achieve.

        1. There’s also the issue of some nations taking advantage of a loophole to cover themselves in Olympic glory by deliberately finding and training DSD-affected male athletes to compete against female athletes. Given the sorry example of how East Germany engaged in doping female athletes for the Olympics back in the 1970s it’s likely to happen if it’s allowed to.

        2. You would need the counterfactual experiment, in which you show a match with two random female olympic boxers and ask onlookers the same question as a control. Implying to people one of the two might be male is going to get a lot of positive replies, regardless of whether it’s actually true. This is especially true because Boxers are, for obvious reasons, on the “masculinized” edge of typically female secondary sex variation. So any female boxer is more likely to be mistaken for male than a random female from the population.

          1. Jojoz, I completely agree. I don’t know if Laila Ali (the only female boxer I know the name of) had a similar physique difference vs. her opponents.

            In the photos and videos that I’ve seen of other instances of males competing against females in other sports (track, swimming, cycling), the males have noticeable physical differences vs. the females they compete against, so this seemed to me to be part of that pattern.

            The hormone & steroid doping by USSR, East Germany, and other communist bloc countries inspired a very famous April 1976 National Lampoon cover (I don’t have the link, you’ll need to search for it).

    3. Italian here.
      I for one reported (on this very website on the previous post) that there are people accusing Carini of having premeditated forfeiting the match. Of course it’s not impossible. But I think it’s pretty unfair to assume malign intent when
      – there is no proof of the allegations
      – afterwards, she apologized for not shaking hands, and also said that she bears no grudges against Imane Khelif
      – there are alternative explanations, one being that feeling the strength of the punch made her reconsider the risks (it seems she was hit at least two times, even though there is one where she is hit right on the face).

      As an Italian, reading the lips in this case is pretty clear and she says “it hurts too much” and “it’s not fair” before giving up. She went to her coach two times before finally retiring.

      I think she was under extreme psychological pressure. The days before the match the Italian press was almost depicting Khelif as a monster, as well as incorrectly calling her (him) a trans woman. Several politicians (of the far right coalition that holds the govern) weighed in calling the situation unfair and asking Carini to refuse to participate in the match. As her coach said after the events, it would have been easier to listen to them and avoid entering the ring altogether; they could have even found an excuse if they didn’t want to make it appear as a protest (she had an infection to a tooth just days before). She chose to try and fight. I think only the athlete has the ultimate word if she wants to continue fighting or one strong blow is enough.

      Now the (Italian) press has almost switched side, everybody is explaining Khelif is not a trans woman but probably has a DSDs (as if it wasn’t the same press who was responsible for mis-information, when it was always pretty easy to check and see this was not the case); they are downplaying the physical differences (as if Caster Semenya never happened); and they are depicting Carini as if she had done something horrible, there wasn’t any risk and she just knew she would lose; they are practically calling her a clown. Let’s not contribute to this climate please.

      (And thank you Jerry for making this new post clarifying things)

  5. Thank you for shedding light and trying to reduce the heat on this difficult situation. I followed some of the exchange about this on Twitter yesterday (some of it specifically in response to your tweet). Most of the comments fell into one of two camps: the “of course she’s a woman, how can you be so hateful?” side and the “of course he’s a man, how can you be so stupid?” side, neither of which do much to address the overall issue.

    There’s another competitor from Taiwan in a similar situation that hasn’t gotten nearly as much attention. I wonder what’s going on there, and how their case compares to the Algerian’s.

    2. I don’t know if Lin Yu‑ting has fought in the 2024 Olympics yet.

      She was banned from IBA competition last year for the same reasons as Khelif.

      Khelif is getting a lot of attention because of the match with Carini and the obvious mismatch in size and physique and Carini’s refusal to participate in such a match. IMO, these are exactly the kinds of brave acts (Carini) needed to highlight the unfairness of not carefully protecting women’s sports from biologically male competitors.

  6. This is a heartbreaking case in that the competitor, Imane Khelif, was (to the best of my knowledge) thought to be female at birth, thought of herself as female, was socialized as female, and identifies as female. So, she (presumably) never thought of herself as anything other than a female. Yet, at the karyotype level and physiologically, she has many of the characteristics of having passed through male puberty. Most relevant is that she has the upper body strength of a male boxer. The risk here is that she has a good chance of landing a blow that could kill one of her opponents. Yes, the opponents know that their sport carries significant risks, but the opponents did not anticipate that the risk would entail boxing against an opponent who has the attributes of a biological male. This may be why Angela Carini simply gave up after 42 seconds; she realized the magnitude of the mismatch and wisely chose to save her own life.

    This is a rare corner case but, of course, all athletes who make it to the Olympics are corner cases—amazing and rare specimens of humanity. That said, in the case of boxing, the gap is so large that it shouldn’t be allowed. Someone will be killed!

    1. It’s an uncommon condition (1 in a few thousand) but if it confers regular male levels of strength, such people may gravitate to sports, becoming over represented.

      1. The condition occurs more frequently in small communities that are isolated from other communities, so over time, everyone in the village is closely related to others in their community. Think of small villages in the mountains where it is unlikely that marriages will take place outside the group. This can happen in Amish communities as well. The book “Middlesex”, by Jeffrey Eugenides, released in 2002 is a good read on this subject.

    2. In February, Imane Khelif came for a boxing tournament here in Bulgaria. A Bulgarian boxer, Joana Nweamerwe, later said:
      ‘[Khelif] liked to approach suddenly and say: “I’ll smash you now because I am a man. But to the others, I am a woman. Now you’ll taste my male strength”… While sparring, he smiled and showed tongue. He was behaving arrogantly.’

  7. Thank you for addressing this issue. It’s been frustrating to see the discourse on this the past few days. What constitutes the male sex (contributing small mobile gamete to the reproductive process) and the female sex (contributing large immobile gamete to the reproductive process) has been confused and obscured by the inclusion of numerous other criteria: genitals, self-perception, what it says on passport, hormone levels, personal history, etc. And I think the term “intersex” has also led many people astray, thinking it’s like a third, in-between sex. But unless people want to argue that the two sexes, male and female, should never have been segregated in sports (I’ve seen some argue this), I don’t see a good reason for including males in female categories of sports. What you end up with is someone like Caster Semenya, who has fathered two children, being considered a female in athletic competition.

    1. Hold on. You say that Caster Semenya has “fathered” two children. Is it known that Semenya is the biological father? What I read is that Semenya’s partner became pregnant through artificial insemination. As far as I know, the couple never stated that Semenya was the sperm donor. Is it known that someone with Semenya’s DSD can, at least sometimes, produce reproductively capable spermatozoa? Can anyone clarify this?

      1. This is a rumor/accusation which has been around for a long time but as far as I know there’s no proof that she (Semenya) is the biological father.

  8. That was a beautiful presentation, yours and Carol Hooven’s.

    The rubric for determining sex eligibility should be applicable to all competitors in female events, not just the suspicious ones. One reason why the Olympics abandoned sex testing was that some activists resented women being subjected to the kind of intrusive examinations that would determine if they had ovaries or testes. Asking every women to submit to a pelvic exam or an ultrasound in order to compete would be a big ask, especially the former for a woman with an intact hymen or history of sexual assault. As a supplementary procedure to resolve uncertain cases it makes sense, certainly.

    For screening all female athletes, the first test is a testosterone level because it is checked (repeatedly) to detect doping. But because the logic is easier for me to explain starting with genetics, I will. The first test could be either a gene analysis for SRY or the genes specific to the Y chromosome. (The technical issues of preferring one over the other are out of scope here.). An athlete with a Y chromosome can be DQ’d on the spot (without any genital examination), with the published exemption for those who can show they have the gene mutation that causes CAIS. A doctor needs to attest that the athlete has the “complete” form. Partial sensitivity would be an exclusion. (It’s this part where doctors get involved that annoys the activists.). Athletes with a Y chromosome but low testosterone are either super-rare Swyer syndrome (no gonads, which examination and ultrasound will establish), or, far more likely, are taking estrogen to suppress testosterone production, as openly trans people are allowed in some sports. Because we now know suppression of T after male puberty doesn’t ablate male advantage, the Y chromosome by itself should be a DQ. (Of course, a man who admits he was “assigned male at birth” but now wants to compete against women would be DQ’d without any testing at all.)

    The important point I make here is that the DSD called 5-ARD in an XY person who looked female at birth is disqualifying but the DSD called CAIS in an XY person who also looked female at birth is compatible with competition in a women’s event. Both will have high testosterone levels at puberty. One is masculinized at puberty, the other not. In both conditions the mutated gene is known and can be tested for. It should be easy to tell them apart without excessive “policing” of women’s bodies. But the screening tests should be applied to all women, to avoid bad-faith motivated challenges that spitefully draw attention to women who look different.

    1. This makes a great deal of sense. Not only is there the importance of maintaining fairness in sport, there is also the risk of serious injury or even death for female athletes who compete against those who have been masculinized at puberty.

    2. Excellent post. It is I think likely the individuals in question have 5-ARD but we don’t actually know for sure. They could possibly have CAIS or Swyer. And people are jumping to conclusions in every direction based on their own prior assumptions.

      1. In the case of Swyer’s, the individual would not produce the high levels of testosterone measured.
        In the case of CAIS, the individual would not develop the masculine-appearing bone and muscle structure observed.
        Mild or partial AIS remains a possibility I guess.

        1. As far as I am aware we do not know for sure that both T levels and XY status were tested. The actual results of tests or even the tests used were not confirmed.

          An official in comments said that they were found XY but the same official/ statements seemed to imply that XY = man in all cases, which isn’t true, which makes me think he might not have known what he was talking about. I saw No statements specifically mentioning male T levels were tested. It’s definitely possible, but we don’t know.

          1. I don’t think a testosterone level would be necessary if the athlete appears substantially masculinized. That proves a testosterone effect during puberty, regardless of what the level might be now (through suppression with estrogen, say.) The Y chromosome (or SRY gene assay) clinches it, subject to appeal if the athlete thinks he deserves an exemption.

            I honestly can’t think of any circumstance where a person who is XY in every body cell — thus excluding chimeras and mosaics — could be a woman, i.e., be capable of making large immobile gametes. XYs could be non-masculinized or even become feminized due to various genetic defects we’ve been talking about and they could then compete fairly with women, but they can’t be women.

        2. This twitter thread, by the author of the piece that broke the news in the first place, confirms that T levels were not tested.

          https://x.com/Slatzism/status/1819427537740558848

          Apparent “masculinization” of someone based on their appearance alone is not a reasonable proxy for T levels experienced during puberty, because in general boxers are on the “masculinized” edge of female secondary sex variation. You will get a lot of false positives.

          Clearer rules are needed. If we think excluding every XY athlete is the way to go, we can. But I think it’s more reasonable to test for specific conditions once someone is determined to be XY, so as not to explicitly exclude individuals who are in every way except their fertility biologically female. You could test for SRY gene, that way Swyer individuals would be eligible, but then you still miss CAIS women.

          1. This is why you have an appeals mechanism. There are genetic tests for CAIS and 5-ARD, which can rule in either diagnosis. I’m not sure off the top of my head if analysis of the SRY gene can rule in gonadal dysgenesis with acceptable accuracy. (A genetic assay may explain the mechanism of a disease without necessarily being an accurate diagnostic test.). It’s too rare to have ever got on my radar screen. It would be excluded by an ultrasound showing gonads instead of fibrous streaks. With a Y chromosome the gonads have to be testes. The external phenotype is female, so there would be no scrotum to examine. Masculinization of the clitoris/phallus (which occurs at puberty in 5-ARD) could be observed directly and does not occur in female athletes unless they are taking testosterone to dope. At this point we’d let the “stop-policing-women’s-bodies” cadres slug it out with the “protect-women’s-sport-from men” revanchists and do whatever the winner dictated.

            My guess is the two boxers decided not to pursue their appeals and make things public because they knew that they would be proved to be males with 5-ARD and that would be the end of it. This way they can claim to be these mysterious women rumoured to have Y chromosomes and get a trip to the Olympics and maybe medal….and more to the point, perhaps, go back to their communities and continue to live as women. In five years, no one will remember who they are.

    3. I can’t evaluate the scientific basis for the tests, which I would leave up to physicians and other scientists. But your statement that all women must be tested (at least for imitial screening), and avoiding pevlic exams and other intrusive screening is absolutely necessary. Women athletes’ humanity and dignity need to be protected in any solution to eliminate bio men from competition.

  9. As a long time reader, I was surprised at the certainty in your initial post, given that prior posts by you have shown more nuance and consideration of multiple perspectives on this issue. Specifically, as I recall with regard to Caster Semenya’s case. And in other instances on the use of pronouns to match sex vs. gender presentation.

    I think in this case, we know much less than with Caster’s case or the case of transwoman Lia Thomas. It is theoretically possible with the limited information that we have, that Khalif could have been disqualified incorrectly by the IBA. The organization is a bit sketchy and has only revealed that Khalif and the other boxer are XY, but not what condition(s) they may have. I am not confident that they have the condition that Carole Hooven posits, though it certainly seems plausible. The IOC also have not confirmed what, if any, criteria they used.

    XY individuals who have an SRY deletion are intersex but physiologically female, similar to XO females, so probably should be eligible for female competition. XY individuals with complete androgen sensitivity (CAIS) have underdeveloped testes but in terms of secondary sex characteristics are well within the typical-female range, so too could be eligible for the female category. Maybe we should exclude them and make a clean XY/XX break, but it is not obvious.

    Because we don’t know in this case, calling them transwomen or a man seems premature – to me at least.

    1. The most accurate way to interpret this situation. Thank you for your comment. The author of the article seems to have decided the conclusion they wanted to arrive on before gathering all the necessary information, you are not making that mistake.

  10. I agree but would also like to note two things:
    1.we don’t really know the gender status of this athlete as the federation that banned him/her hasn’t released the test. The IOF needs to have such tests and have clear guidelines.
    2. Less important but still interesting is I think he/her competed last Olympics and doesn’t have a remarkable record in women’s boxing as these things go.

  11. Somewhat related: I’ve heard that boxing can cause brain damage (chronic traumatic encephalopathy). Anyone know if this is true?

    2. Even one serious head injury can cause health problems later in life. I have read it is a risk factor for dementia. The phrase “punch drunk” has been around for a long time. Recently there has been pressure on the NFL to protect their players from head injury. Yes, getting punched in the head repeatedly can cause brain damage.

  12. Thank you for this clarification post. So much conflicting information out there as well as secrecy.

    I feel for Khelif who seems to have been raised female and surely considers herself a woman. This attention and challenge to her sense of self must be painful. This is why people with DSD arouse more sympathy from me than transwomen who want to compete as women. Yet, biological males should not compete with women. That must be the basis for solutions.

  13. There was an article not long ago in Free Inquiry in which the author argued that there should be a third athletic category for trans-females rather than there competing against biological females. Although not included in the article, I would think that individuals like the boxer in question should be included in this category as well. It is absurd and inequitable for him to be pitted against a biological female. While I am not happy with the prospect of certain athletes having to demonstrate their biological sex, I can see no way around this requirement in questionable instances like the present one.

    1. I understand the sympathy to open up sports to all, there are many issues to a separate classification proposal.
      1. There seems to be a wide definition of what constitutes a transfemale, ranging from just changing one’s pronouns to full medical transition. Do you create multiple categories within the group for different types?
      2. One argument I make against this is that trans people are a very small segment of the population, so the talent pool is correspondingly small. Therefore, you’re rewarding winners who have bested a much smaller complement of competitors. Beating a half dozen trans NCAA swimmers is not the same as being better than a couple thousand males or females at the same level.
      3. If you do offer equal prizes (especially money) you create incentives for men to declare as trans in order to escape the harder competition of non-trans males. See Lia Thomas’s ranking as male vs as female. He’d probably also be near the top if in a trans-only segment.
      4. The end effect would be to double the categories in which males can compete, shutting out born-female competitors. No transmale (i.e., female identifying as male) will ever win. Nikki Hiltz is a great American middle distance runner who identifies as transgender and nonbinary. She’s not stepping up to male competition to compete as a man. She is keeping her levels within the female range and competing against her birth sex cohort as she can’t be successful on an elite level beyond that classification.

      The solution is to say “sorry, you can only compete as a male” not to add a classification for a tiny minority of individuals. Or someone can start their own games for trans people and set up the rules themselves – it’s a free world.

    1. hmmm, so there never was a testosterone measurement. This obviates some of what I said above.

    1. …and another has written a very interesting memoir: ‘Inverse Cowgirl’ (2023) by Alicia Weigel, which outlines vividly the challenges of being ‘intersex’.
      Also, accounts of her life can be found on youtube.

  17. If it could be measured objectively, the difference in punch strength between Khelif and the XX female boxers would be informative. Based on the fantastic graph in yesterday’s post showing the difference between males and females in punch strength, one would expect to see a significant difference between the XX and XY(DSD) athletes. Unfortunately, it would be too easy for XY(DSD) boxers to ‘pull their punches’ during such a test if it were to be used as an exclusionary test.

  18. Great explanations Jerry, and good sources. This will be a post I can point people to for a well-thought-out approach. It actually gives me hope that these controversies over sports can be a positive source of useful definitions and better communication. For instance, explaining that development of testes (even if hidden) is what gives a person athletic advantage helps a lot to defuse the questions of who should be allowed to compete in certain arenas, and thus defuses the question of whether a trans person is “authentic.” It’s not that a person is somehow “merely cosplaying being female” or somehow delusional. This kind of case demonstrates that even someone who thought of themselves as female from birth might in fact be wrong when we are talking about biology. They can both be authentically mentally female (partly learned, partly due to hormonally determined brain structure—and we aren’t able to separate that quite yet!) and biologically male for sports and possibly reproductive purposes.

  19. I’m having a generally worthless Facebook conversation with some folks who obviously don’t understand biology and aren’t interested in learning. I linked this post to try to enlighten, but one response was “this is not a reputable site.”. I responded that Jerry would be pleased 😁

    1. Wow. “Not a reputable site”, unlike Facebook comments by the scientifically illiterate general public, which are extremely reputable! Sigh.

      1. And now in classic fashion by the ultra woke, I was told to get lost and to stop spreading misinformation. It’s pretty sad when folks’ ideology blinds them to facts. The best admonition was telling me that I was a science denier 😅

        1. It’s “The Emperor’s New Clothes” out there! I was told today that the “magical and mystical” y chromosome doesn’t determine “gender”. I said no, but it does determine sex!

    2. >a generally worthless Facebook conversation

      Isn’t that rather a tautology?

  20. It is the male body that beats a woman up in a boxing ring, not the genitalia.
    Someone posted on twitter that some non-developed countries actively seek out 5-ARD males and give them incentives to get into running because it is the cheapest bang-for-the-buck way of getting an Olympic medal for the country.

  21. As a Urologist, all I want to talk about is the fascinating biology of 5 alpha reductase deficiency and how a cluster of such people discovered in the Caribbean resulted in the development of drugs for benign prostatic enlargement and prostate cancer. The fact that I can still remember how to draw the testosterone steroidogenesis pathway from memory is likely why I can’t remember where I left my keys.
    Also flashback to residency during pediatric Urology rotation. The most difficult consult you will ever get is to the newborn ward for ambiguous genitalia (difficult in terms of family interaction, not the clinical part)

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