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 IOC need to held accountable for this. https://t.co/gVaiZukxch

— Emma Hilton (@FondOfBeetles) August 1, 2024

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:

I could have sworn I included the graphs! Sorry. Here they are. pic.twitter.com/dLXqMaaMYK

— Carole Hooven (@hoovlet) August 1, 2024

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.[8]

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.[9] 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.[5] 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.[9]

Carole also gives a strong recommendation to this free podcast:

“Inclusivity” is given more weight than science, rationality, and fairness and safety for women. ⁦@Scienceofsport⁩ is right on. Give the most recent episode a listen. https://t.co/yY4Gjj37hL

— Carole Hooven (@hoovlet) August 1, 2024

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, external 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

As you may remember, when faced with determining whether trans women should compete against biological women in the Olympics, the IOC threw up its hands and punted, declaring that each separate sport had to make its own rules on the issue. This has led, in the present Olympics, to biological males qualifying to box in the women’s division. The results are predictable, for even men who become transwomen retain a substantial amount of the size, strength, musculature, and other athletic advantages that biological men have over biological women. Hormone suppression doesn’t equalize those athletic abilities.

Nevertheless, according to the NBC News story below, two biological males who identify as women—people who were disqualified from boxing as women in previous competitions—have qualified for the IOC. Note that they both seem to have been raised as women, so they may well believe that they are indeed biological women. Ergo, they may well not think of themselves as having “transitioned”, so I won’t call them “transwomen.” Nevertheless, they are both almost certainly biological men with disorders of sex development (“DSDs”), and their competing against biological women is just as unfair—but not nearly as consciously unfair—as transwomen competing against biological women.

Click to read (the story is by Matt Lavietes):

Excerpts:

Two boxers who were disqualified from competing with women at a global event last year have been permitted to fight in the Paris Olympics, the International Olympic Committee confirmed.

Imane Khelif of Algeria and Lin Yu‑ting of Taiwan failed to meet gender eligibility tests at the Women’s World Boxing Championships in New Delhi last year, prompting their disqualifications. But they have been cleared to compete in the women’s 66-kilogram and women’s 57-kilogram matches in Paris this week, the IOC confirmed in an email Tuesday.

 At the time of their disqualifications, the president of the International Boxing Association, which governs the World Boxing Championships, alleged that the boxers’ chromosome tests came back as XY (women typically have two X chromosomes, while men typically have an X and a Y chromosome).

“Based on DNA tests, we identified a number of athletes who tried to trick their colleagues into posing as women,” the association’s president, Umar Kremlev, told Russia’s Tass news agency at the time. “According to the results of the tests, it was proved that they have XY chromosomes. Such athletes were excluded from competition.”

. . .In an email Tuesday, the IOC said that “all athletes participating in the boxing tournament of the Olympic Games Paris 2024 comply with the competition’s eligibility and entry regulations, as well as all applicable medical regulations.”

The IOC updated its rules regarding athletes’ gender eligibility, including its transgender participation guidelines,  in 2021 to defer to each sport’s governing body. The IOC no longer recognizes the IBA as the governing body over Olympic boxing, and instead refers to the Paris 2024 Boxing Unit — an ad-hoc unit developed by the IOC — for its eligibility standards.

In other words, the IOC made up the qualifications, ignoring what the International Boxing Association says. And they made them up on the spot. Why on earth would they do that? The article continues:

Critics in the United States, where the issue of whether trans women should be permitted to compete in women’s sports has been hotly debated in recent years, condemned the inclusion of Khelif and Lin in this week’s competition. Some questioned whether their participation was fair to other female competitors, while others directed incendiary language toward the boxers. [JAC: Check out the “incendiary language”, which isn’t incendiary at all, and comes from Riley Gaines.]

Khelif is scheduled to compete against Italy’s Angela Carini on Thursday, and Lin is scheduled to fight against Uzbekistan’s Sitora Turdibekova on Friday.

Here’s Khelif from the Wikipedia article, which adds some details (below):

From Wikipedia:

In March 2023, Khelif was disqualified for failing to meet eligibility criteria shortly before her gold medal bout at the 2023 IBA Women’s World Boxing Championships. The Algerian Olympic Committee said Khelif was disqualified for medical reasons. It later emerged that the disqualification was due to high levels of testosterone.^[7][8]

The International Olympic Committee (IOC), using different rules to the IBA, cleared Khelif to compete in the 2024 Summer Olympics in Paris, confirming that she complied with all necessary eligibility and medical regulations for the event,^[8][12] without detailing what these eligibility rules were.^[10] The IOC noted that Khelif was a woman according to her passport and that this was not a “transgender issue“.

She defeated Angela Carini in 42 seconds at the 2024 Olympics, after Carini withdrew citing intense pain in her nose. Reem Alsalem, the United Nations Special rapporteur on violence against women and girls, tweeted about the match, writing, “Angela Carini rightly followed her instincts and prioritized her physical safety, but she and other female athletes should not have been exposed to this physical and psychological violence based on their sex.”^[14]

And from The Daily Fail, the details of the match between Khelif and Carini:

 A boxer deemed a ‘biological male’ today won against an Italian woman in one of the most controversial Olympic bouts ever.

The fight between Italy‘s Angela Carini and her Algerian opponent Imane Khelif took just 46 seconds, with the Italian throwing her helmet onto the floor as the clash was abandoned, yelling: ‘This is unjust.’

The 25-year-old refused the handshake and fell to the canvas sobbing having received just two punches from Khelif – who had been banned from a major boxing contest before the Olympics.

00:17

02:24

Read More

 

Khelif was thrown out of last year’s world championships after failing testosterone tests carried out to establish gender qualification.

After the match was stopped, the referee raised Khelif’s hand in the air. But a visibly furious Carini yanked her own hand away from the fight official and walked off.

Ignoring the Algerian, the Italian fighter then plunged to her knees and burst into tears as she said she had never felt such strong blows in a contest before.

Speaking after the match, the heartbroken Italian said: ‘I’m used to suffering. I’ve never taken a punch like that, it’s impossible to continue. I’m nobody to say it’s illegal.

‘I got into the ring to fight. But I didn’t feel like it anymore after the first minute. I started to feel a strong pain in my nose. I didn’t give up, but a punch hurt too much and so I said enough. I’m leaving with my head held high.’

A couple of punches to the head and it’s all over. /2 pic.twitter.com/6egSrRj51s

— FairPlayForWomen (@fairplaywomen) August 1, 2024

IOC allowed this male boxer to fight a woman. He won. Fight abandoned after 46s /4 pic.twitter.com/YwUfZQ6ssb

— FairPlayForWomen (@fairplaywomen) August 1, 2024

“None giusto!”.
“it’s not fair!” Says Angela /6 pic.twitter.com/ukqReaRHbP

— FairPlayForWomen (@fairplaywomen) August 1, 2024

And the end, with tears. It’s heartbreaking:

Angela Carini’s Olympic dreams smashed today. She breaks down in tears. /7 pic.twitter.com/CBNK2pNFo4

— FairPlayForWomen (@fairplaywomen) August 1, 2024

The loser’s statement, even sadder:

“I wanted this victory at all costs. Just for my father.”

Italian boxer Angela Carini emotionally discusses winning for her late father after securing a spot at the Paris Olympics.

She just forfeited her match against Imane Khelif, who is male. pic.twitter.com/zypHELjldX

— Steve McGuire (@sfmcguire79) August 1, 2024

I’ve written before (see here and here) that taking testosterone suppressors does not eliminate the athletic advantages of natal men over natal women, especially if they’ve gone through male puberty. You can track down the references by going to the thread of Emma Hilton, a biology professor at the University of Manchester. The thread starts here:

There have been two academic reviews of musculoskeletal changes in transwomen suppressing testosterone.

Both conclude that loss of muscle mass and strength is small, and that strength advantage over females is retained.

Citations to follow.

— Emma Hilton (@FondOfBeetles) March 6, 2021

Here’s the huge difference in punching power (my emphasis) between biological men and women (it will probably be somewhat reduced if the man suppresses his testosterone, but not equalized). The reference is at the bottom of the figure.

It’s manifestly unfair to women to force them to compete against biological males who identify as women.  This might be another question to ask to the Presidential candidates—if they have a debate.

h/t: Luana

It would seem superfluous now to argue that women and men are equally competitive in athletics and thus there should be no sex-spcific categories.  We know that, with puberty, comes differences in may traits involved in athletic success, including muscles mass, bone density, grip strength, throwing speed, and so on. (Equestrian sports may be one in which women have either no disadvantage or even an advantage, but I haven’t looked for the data.)  This intersexual difference in athletic ability is in fact why we have separate men’s versus women’s leagues. I was surprised to find, in the Lundberg et al. paper below, that even before puberty boys have significant athletic advantages over girls, which one has to consider when deciding whether to separate the sexes in secondary-school competitions.

But the International Olympic Committee (IOC), which a few years ago punted in a general policy for its athletes, deciding that each sport has to set its own rules, has led to the publication of the Lundberg et al. paper, reiterating again that there seems to be no physical sport in which men don’t have an inherent, sex-related advantage (largely coming from testosterone), so the Bayesian presumption is that there will be a difference. The paper’s publication was apparently prompted by the IOC’s abandoning standards. As the authors note, “The IOC framework does not provide suitable guidance to sports authorities to protect the female category in sports.”

But of course the burning question now is whether or not transgender women (natal men), even under testosterone suppression, retain athletic advantages over natal women, and, if so, whether those advantages disappear over time. And Lundberg et al. paper says that advantages remain and do not go away with time. (We’ve had evidence for this for a long time.)

In classifying individuals for athletics, then, “transgender women don’t count as women”, a fact that goes against all the mantras of gender activism. Nevertheless, truth is stronger than mantras, and the data show that, in those sports that have been examined, transgender women have a similar (but smaller) advantage over natal women as do natal men do over natal women.  The authors (and I) see the inclusion of natal men in women’s sports, then, as unfair. But others disagree, thinking that inclusivity trumps fairness. Since all of us think that those who want to compete athletically should have a way to do so, some hard thinking is involved. Should we have “open” categories, in which only a few will compete? Or should trans women compete only in men’s sports? I have no solution, but surely we need to know the facts before we make a decision like this.

I found the Lundberg paper because a reader sent me an article from the conservative Federalist that linked to it. And yes, the Federalist does accurately characterize the paper. You can read the Federalist by clicking below, but if you want a deeper dive in to the data, one with lots of references, click on the second headline too (get the pdf here). All access is free

Excerpts from the link above:

The International Olympic Committee (IOC) developed its 2021 framework on sex and “gender” around the concepts of fairness, inclusion, and non-discrimination. This framework leaves it to each sport’s governing body “to determine how an athlete may be at a disproportionate advantage against their peers.” However, they admonish sports organizations against “targeted testing … aimed at determining [athletes’] sex, gender identity and/or sex variations.” Instead, it’s up to each sport to “[provide] confidence that no athlete within a category has an unfair and disproportionate competitive advantage.”

The IOC’s sophistic gymnastics to deny sex-based categories in sport prompted 26 researchers from around the world to rebut the IOC’s framework. Their paper, published last week in the Scandinavian Journal of Medicine & Science in Sports, is the latest peer-reviewed study providing evidence of the obvious about sex in sports.

The researchers reviewed studies from “evolutionary and developmental biology, zoology, physiology, endocrinology, medicine, sport and exercise science, [and] athletic performance results within male and female sport” to refute the IOC’s position that male athletes warrant “no presumption of advantage” over female athletes based on “biological or physiological characteristics.”

That statement “is ridiculous on its face,” says Kim Jones, co-founder of the Independent Council on Women’s Sports (ICONS). “This is the basic knowledge we all understand and see play out in front of our eyes every day. [This new] paper is brilliant at laying out how clear the differences are between men and women. There are thousands of differences between male and female development in humans across the entire maturity path that result in these huge performance gaps.”

John Armstrong, a mathematician at King’s College London who was not affiliated with this research, highlights this “central flaw” of the IOC’s framework. “To say we should not presume male advantage in a sport unless we have specific data for that sport is like saying that just because most of the apples in a tree have fallen to the ground, one shouldn’t presume the remaining apples are also subject to gravity,” he said.

“There is overwhelming evidence of male advantage from across different sports and there is little to be gained from demonstrating this again and again, sport by sport,” Armstrong noted.

So much for untreated natal men versus untreated natal women. What about when testosterone is suppressed?

But even sports that have copious research into sex differences in performance have permitted males to compete in the female category at all levels of competition and age. One path has been through misguided policies based on testosterone levels.

Over the last decade, various sports governing bodies — including the IOC and USA Boxing — have attempted to define females through testosterone levels. Those organizations relied heavily on a publication by Joanna Harper, a trans-identifying male medical physicist. The paper consisted of eight self-reports by trans-identifying male recreational runners who had suppressed their testosterone pharmacologically and recalled that they ran slower after doing so. Harper excluded the one respondent who said he ran faster and then concluded that males who were suppressing their testosterone could compete fairly in the female category.

Read the paper if you want to see how weak Harper’s evidence was, yet was used to buttress allowing transgender women to run against natal women. The subjects, whose times were self-reported, weren’t even athletes.  But I digress:

Last week’s paper builds on research by lead authors Tommy Lundberg, Emma Hilton, and others who demonstrate the persistence of male advantage after testosterone suppression.

While testosterone suppression decreases various measures of anatomy, physiology, and physical performance, those changes are a small fraction of the differences between men and women on these metrics. A testosterone-suppressed male will have less muscle mass than his former self, but as a category, testosterone-suppressed men remain larger and stronger than women. Further, testosterone suppression does not change attributes like height, bone length, or hip and shoulder width.

And the part below surprised me, as I always thought athletic differences became significant almost entirely after puberty, which could justify having only a single league for younger kids. I’m not so sure now, but remember that winning may not be as important for younger kids than for high-school, college, or professional athletes, so combined leagues may still be considered “fair” in, say, elementary or some secondary schools.

Even before puberty, though, males outperform females in athletic competitions. Greg Brown is an exercise physiologist at the University of Nebraska at Kearney and was a co-author on the Lundberg paper. Brown recently published research based on national youth track and field championships. He found that by age 8, the boys ran faster in their final rounds than the girls did in theirs, at race distances from 100 meters to 1,500 meters.

Again, click to read:

Here’s the paper’s abstract with the IOC’s unjustified conclusion and the data from transwomen (my bolding). Note that what they consider most fair is disallowing transwomen from competing against natal women.

ABSTRACT

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC’s recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC’s “no presumption of advantage” principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC’s concept of “meaningful competition” is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports.

Finally, the data on transwomen athletes.  I’ve left the references in showing the plethora of studies concluding that testosterone suppression doesn’t eliminate male advantage. Bolding in the text is mine

4. TESTOSTERONE SUPPRESSION POST-PUBERTY DOES NOT NEGATE MALE PERFORMANCE ADVANTAGE:

The IOC framework suggests that testosterone concentrations could be investigated as a means to mitigate performance in transgender women. However, no study has demonstrated that transgender women with suppressed testosterone levels after puberty reach biological or physical parity with females. Conversely, numerous studies have shown that biological differences persist after testosterone is suppressed,^25, 44, 46 with physical performance implications. There is no plausible biological mechanism by which testosterone suppression could reduce height and associated skeletal measurements (e.g., bone length and hip or shoulder width) that may confer a discipline-dependent performance advantage. Consequently, no study has reported reductions in skeletal advantages in transgender women who suppress testosterone after puberty.²⁵

Twelve controlled longitudinal studies^44, 47–57 collectively following more than 800 untrained or moderately trained transgender women have shown that testosterone suppression for 1 year induces only a 5% loss of pre-transition muscle mass/strength. This loss accounts for only a fraction (one-fifth or less) of typically observed male versus female muscle mass and strength differences.^25, 26, 58 For example, in the study by Wiik et al.,⁴⁴ thigh muscle volume differences of 39% between transgender men and women were reduced only marginally with 1 year of testosterone suppression, and 83% percent of the initial male advantage was retained. The result is higher levels of muscle mass and strength in transgender women compared to females for at least 3 years after testosterone suppression (i.e., the longest sampling duration of current longitudinal studies), with male advantage still evident in cross-sectional studies of transgender women who suppressed testosterone for up to 14 years.^59–61

Note, however, that factors affecting endurance performance, like supermarathon running, have not been tested sufficiently to come to any conclusion. It may turn out that in these endurance sports transwomen are on par with men. But certainly this isn’t the case for marathon running.

The effects of testosterone suppression on biological factors underlying endurance performance are less well explored than those of strength and power. Nonetheless, untrained or moderately trained transgender women who have successfully suppressed testosterone after puberty achieved female-typical hemoglobin concentrations within 3–6 months.^44, 46 In contrast, the effect on hemoglobin mass, which, unlike hemoglobin concentration, is strongly related to VO_2max,^39, 62 is unknown, and other factors related to endurance performance, such as work economy and fractional utilization, have not been studied.

We argue that the existing literature on physical changes induced by testosterone suppression constitutes the most robust dataset currently available, and is relevant for elite athletes, because it confirms the principle of persistence of biological characteristics even in the absence of training. These longitudinal studies are then complemented by studies in which testosterone suppression in males has been accompanied by exercise training, which demonstrate that training can partly, or even completely, attenuate reductions in muscle mass and strength.^63, 64 Therefore, a rational hypothesis based on current evidence would be that retained male advantage would be larger, not smaller, in highly trained transgender women if they continued to train during testosterone suppression, compared with untrained or moderately trained individuals. This hypothesis is also supported by the observation that sex-specific differences in athletic performance are at least equally pronounced in elite athletes compared to untrained or moderately trained individuals.²⁶

The findings documented in the scientific literature, and the hypothesis that retained male advantage would be larger in athletes, predict that the relative ranking of transgender women in competitive sports would improve significantly after they switch from the male to the female category. This is illustrated by a case study of an American transgender swimmer, who achieved significant National Collegiate Athletic Association (NCAA) ranking improvements (from middle to top) across a range of events after switching from the male to the female category.⁶⁵ This occurred as a result of performance decreases that were significantly smaller than male versus female performance differences, supporting the retention of male biological advantage and illustrating the resultant unfairness.

The swimmer referred to above is certainly Lia Thomas. At any rate, 12 women athletes are suing the NCAA for forcing them to compete against trans women. You can read about the suit at the Free Press, by clicking the link below. Again, Lia Thomas seems to have been the spur for this suit (article archived here). The unarchived piece has a YouTube discussion of the lawsuit by two of the plaintiffs, Riley Gaines and Réka György:

Why are men better than women at chess?

This is the question that Carole Hooven, author of the excellent book Testosterone: The Story of the Hormone that Dominates and Divides Us, takes up in a new article in Quillette. What I like about the article is that it appears to consider every available hypothesis, and uses a scientific approach to finding evidence that either supports or weakens many of them. She tentatively settles on one that may be evolutionary in its origin, but I’m getting ahead of myself. Click below to read:

I believe Hooven got interested in the question when FIDE, the international chess federation, recently decided that transwomen would not be permitted to compete in their official chess events that were limited to natal women. Since transwomen are natal men, this implies that there is some advantage in being a natal man when it comes to winning at chess. Of course this move by FIDE could be considered transphobic, as it already has been, but in fact the evidence is that, regardless of cause, men are much better than women at chess.

How do we know this? Because, although some chess tournaments are limited to people of one sex, there are also mixed-sex tournaments in which women play against men. And those show a result similar to that in tennis: rankings based on those tournaments show that the top women chess player would probably rank below the top 200 or 300 men.

But why is this? After all, in tennis and other sports, men outdo women because there is an inherent athletic advantage associated with the male body: more muscles, higher bone density, greater grip strength, and so on. These advantages become prominent at puberty because they’re associated with the higher testosterone of males. (This does not mean, of course, that no woman can ever beat a man in mixed-sex sports; it is a difference, and a big one, in averge performance.) Likewise, transwomen, biological men who assume the identity of a woman, also retain these athletic advantages over natal women, especially when they transition after puberty. That’s why several sports associations have banned transwomen from women’s athletics.

But chess?  None of the athletic advantages I mentioned should obtain for chess, which involves only moving light pieces of wood or plastic around a board. So why are men so much better at playing chess?

Hooven lists a number of hypotheses, which I’ve divided into the following categories in bold (my words). Carole’s text is indented.

a.) More males take up chess in the first place. If this is the case, then regardless of average performance, the top players will be weighted with more men, simply because even if the average performance is the same, a bigger curve for men (frequency versus score) means that the upper tails of high performance will contain more men.  This will be the case regardless of the variation in performance itself, and simply reflects the fact that at every performance level, there will be more men than women.

This is a reasonable hypothesis, but one Hooven thinks is weak because of Scrabble and bridge, which more women than men take up but ultimately the championships are heavily dominated by men:

In a game of Scrabble, as most readers will know, two competing players earn points for creating words using one or more of the seven lettered tiles in their inventory, which they place on a grid-spaced board. Like chess, Scrabble uses a version of the Elo rating system. But unlike in the chess world, women dominate the recreational ranks of Scrabble, accounting for about 85 percent of all recreational players. Even at the competitive level, women generally outnumber men (which isn’t that surprising given that Scrabble is all about words, and verbal ability is one area in which women tend to outperform men). So if the participation-rate hypothesis were correct in this context, then women should be dominating the elite Scrabble ranks.

But they’re not. Instead, men dominate Scrabble’s upper tiers, as they do in chess. And the same goes for Bridge, another game that’s dominated at the recreational level by women.

Scrabble tournaments usually feature separate divisions, which are classified according to Elo ratings. Players with the highest ratings compete in the first division, in which there are few women. As the skill level goes down, the proportion of women increases, until you get to the lowest level, where women vastly outnumber men. No woman has ever won a national or World Scrabble Championship. (However, just last year, Ruth Li from Toronto did win the North American Championship in the High School division, becoming the first female to ever win any such regional championship.)

Of course, Scrabble and chess are different games that require different skills, and lessons from the former may not cleanly translate to the latter. But even if one confines one’s focus to chess, the participation-rate thesis doesn’t present a convincing explanation for the observed sex differences in performance.

In addition, over the last few years women’s participation in chess has increased substantially, but the average gap between men and women hasn’t narrowed much, though it has a bit in some places. Overall, though, this hypothesis seems weak.

Second, over the last 50 years or so, female participation in chess has increased measurably around the world—a fact that should, according to the participation-rate hypothesis, lead to a narrowing of the sex gap at the highest levels of play. And in a few cases, that has happened. In France, for example, the female participation rate increased from 6 percent to 15 percent from 1985 to 2015, and the sex gap in ratings also significantly narrowed. But overall, the evidence is mixed. In the mid-1940s, the Elo difference between the world’s highest-rated male and female chess players hovered around 150 points. Eighty years later, that figure hasn’t really changed. (Note that such comparisons are based in part on retrospectively calculated Elo ratings, as FIDE didn’t start using them until the late 1960s.)

b.) Sexism: women are driven out of chess or don’t take it up because of misogyny in the game. Sexism can manifest itself in many ways: simple harassment of women (which is reported), not taking women seriously, which can lead to a lack of self-confidence, lowered expectations, and a higher dropout rate.  This should be mitigated to some degree by the existence of all-women’s leagues and tournaments.  But Hooven doesn’t think that this is an important hypothesis because reduced sexism over time hasn’t narrowed the performance gap:

Such reports [of sexism] should, of course, be taken seriously. But I’m far from convinced that sexism and harassment are the main reasons why men outperform women at chess. We’ve already come a long way in battling sexism during my lifetime. And yet, even as women have made great strides in such areas as medicine, law, engineering, and academia, the sex gap in chess has barely budged since second-wave feminism took off in the 1960s. This all suggests there’s something else going on.

c.)  Men and women have the same average performance, but men have greater variance, manifested as relatively more players in both the highest and lowest tails of the performance distribution. Hooven calls this the “greater male variability”, or GMV, hypothesis. The variability can involve many traits possibly involved in chess success: spatial ability, drive to win, willingness to practice, and so on. The key here is that there need be no average difference between men and women, but still the greater variation of men ensures that in the upper tails, where the champions reside, will be mostly populated by men. (The hypothesis can still hold even if there are some differences in means.) GMV may be the case for intelligence, as the average performance of men and women on IQ-related tests are about the same, but men are more variable. But again, this doesn’t seem to be telling for chess, though it could be important in STEM fields:

The GMV hypothesis is the explanation often given for sex differences in STEM fields, particularly the “hard” sciences such as physics. The idea is that even if there’s no male-female difference in average math or physics ability, there would still be more men at the very high (and low) end of the ability spectrum. These are the extreme outliers who are most likely to earn prestigious faculty positions, file many patent applications, and win career achievement awards. And there is, in fact, strong evidence supporting the hypothesis; many traits do tend to be more variable in men than in women.

But if the greater male variability hypothesis explained the male advantage in chess, then we should observe that Elo ratings [these are measures of chess proficiency involving games won as well as the quality of the opponent] for males would be more variable than those for females. That is, we would expect more male grandmasters not because males are better at chess, but simply because there would be fewer females at both the high and low end of performance.

But in most populations of chess players, that statistical pattern isn’t reflected in the distributions of Elo ratings. Those for males are not more variable than for females. In many cases, in fact, the variability among female ratings is actually higher.

d.) Males are innately better in traits that lead to success in chess.  These involve average differences in traits and not just variances, and could include spatial ability, degree of aggression, drive to win, other aspects of cognitive ability, dedication to the sport so that one practices a lot more, and so on. Note that “innately” implies the differences don’t result from socialization or sexism, but are the same kind of differences that gives men advantages in “regular” sports. Of course these innate differences could interact with other factors, as the phenotype here (chess performance) always involves an interaction between genes and one’s environment.

Ultimately, Hooven considers this the best explanation because there is independent evidence that men excel in the kind of motivation, competitiveness, and “obsessive passion” that leads to monomaniacal focus not just on winning, but on practicing:

 A more promising explanation for male dominance in elite chess involves motivation. A large body of research strongly suggests that the sexes differ in their preferences for competition. As both Kasparov and Repková have intuited, men are simply more competitive—that is, they have a stronger motivation not just to compete, but to win, in formal physical and non-physical competitions of all kinds.

Men are more likely to choose games that involve direct, one-on-one competition, in which the result is a clear winner and loser—such as chess. Women are less competitive even when interacting anonymously—for example, in online arenas such as massive multiplayer role-playing games. This applies even when players interact using avatars of the sex opposite to their own; situations in which social expectations and stereotypes should have a reduced influence on in-game behavior. Women’s performance and enjoyment tends to suffer when the competition intensifies; that is, when the stakes are highest or time pressure is applied. For example, the average male-female sex difference in “blitz” chess games, which allocate ten minutes or less for each player to make all of their moves, is greater than that observed in standard chess, in which each player has at least an hour and a half. Moreover, relative to men, in experimental and real-life conditions, women tend to opt out of tournament conditions.

So it’s not surprising that females, being less focused (on average, as usual) on crushing an opponent in some future tournament, might be less motivated to go in for the kind of hardcore practice that’s necessary to develop elite skills (“deliberate practice,” as it’s called, as distinct from simply practising by playing).

. . . . If your instinct tells you that males will be disproportionately drawn toward this kind of intense practice style than females, you’re correct. Studies show that boys and men are more likely to exhibit a “rigid persistence in an activity,” by which “the passion controls the individual” (“obsessive passion” in the literature). In anecdotal terms, we are talking here about the man who drops everything to become, say, a 16-hour-per-day videogamer, or a day-trader, or chess addict. Yes, some women take on these kinds of fixations. But men do it more often, and with greater intensity.

It’s long been known that measures of risk-taking, competitiveness, persistence, and aggression are higher in men than women, so this may be a key factor in the explanation.  But are these differences due to evolution or socialization? After all, men are expected to be aggressive and behaviorally conform to a “male stereotype”.  On the other hand, that stereotype itself could reflect behavior instilled by natural selection more in one sex than another, so it’s seen as the norm.

Hooven comes down on the evolution side, and I pretty much agree with her given these arguments as well as others (e.g., socialization should differ among human societies but the average behaviors don’t; our closest primate relatives, who aren’t socialized, show similar difference in aggression and competition, there are biological reasons to expect higher competition in males, and these traits begin to manifest themselves at a young age, presumably before much socialization can take place).  Luana Maroja and I discuss similar sex differences in behavior (and their possible evolutionary roots) in our Skeptical Inquirer paper on ideology and biology.

Hooven:

That said, I don’t see evidence for the idea that socialization alone explains the stronger male tendency to focus obsessively on doing whatever is necessary to win, even at board games. And there are good reasons to think that this tendency has an evolutionary basis: In the animal kingdom, males tend to devote more time, energy, and risk to status competition, since this tends to pay more reproductive benefits for males than females. So it’s not unreasonable to suspect that boys and men have some kind of biological advantage—possibly underpinned by higher lifetime exposure to testosterone—that helps explain their over-representation in tournament-level competition in general. (While this particular brand of competitiveness may have a strong evolutionary explanation, it is unlikely to be the wisest reproductive strategy in today’s world.)

If this is the case, what about FIDE’s decision to ban transwomen from their women’s chess tournaments? (Some countries, including England, Germany, France, and the United States, don’t uphold this ban in their national tournaments.)  In the end, since Hooven concludes that biological factors play a key role in men’s dominance in chess, for the time being FIDE’s ban makes sense:

Ultimately, sex differences in complex behaviors and skills are always a product of interactions between biology on the one hand (that is, our genes and their relatively fixed effects, such as hormone levels and body size) and our environment on the other (that is, factors such as our family circumstances, social dynamics, and cultural norms). Interactions between the two shape not only our skills and abilities, but also any emerging group differences. But none such complicating factors change the fact that the sex gap in chess is real and persistent. Given the circumstances that led to the creation of the female category, and the fact that many girls and women appreciate what this category offers, FIDE is correct to take the steps necessary to protect its integrity.

Of course the data we really need are the chess performance of transwomen playing against biological women, and as far as I know we don’t have that kind of data.

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

A coda:  Perhaps the thinnest book I own is called “Jewish Sports Heroes”, given to me by a Jewish relative. It’s thin because Jews are not usually among the best baseball, soccer, football, or basketball champions we can think of (Sandy Koufax is a notable exception). I’m not going to hypothesize about this religious lacuna, but what amuses me is that the last chapter in the book, and the longest one, is on chess, as Jews have always excelled in chess. If the writers wanted to produce a book of reasonable length then, they simply had to add chess as a “sport” coequal with sports like football and basketball.

The new Kiwi government under Christopher Luxon is weighing a rule that women’s sports will remain women’s spaces—at least in publicly funded sports, which clearly includes those in schools. But there’s a lot of pushback, as you can see from reading this piece in the New Zealand Herald (click to read):

Excerpts are indented:

The Government is threatening to withhold millions of dollars of public funding from New Zealand sports bodies if they do not comply with a push to separate transgender athletes from grassroots competitions.

The hardline and potentially divisive policy from the Government sets out the agenda to “ensure publicly funded sporting bodies support fair competition that is not compromised by rules relating to gender”.

The policy is led by New Zealand First, whose sport and recreation spokesman Andy Foster says it is “about fairness and safety in sport for women”

. . . .While previous Governments have left sporting organisations to work through the vexed transgender space at arm’s length, the National-led regime intends to tackle the issue head-on.

International sporting bodies, including cricket, rugby league and swimming among others, have banned transgender women from their respective elite female codes.

The NZ First-National policy agreement, however, applies to the amateur end of the spectrum by targeting participation in community sports.

Are community sports different from school sports? I don’t know, but I don’t think so. Rather, I think that the government is leaving professional sports to work out their own rules. But the government is clearly of the mind that it’s unfair to have trans women participating in women’s sports, something I agree with. But the issue is inflammatory (much of NZ is still woke), and so the government is also a bit timorous:

Sport and Recreation Minister Chris Bishop was uncomfortable discussing the coalition agreement.

“New Zealand First are very keen to make sure we have an inclusive environment and atmosphere for everybody – and that rules relating to gender don’t get in the way of that,” Bishop told the Herald.

“It is a tricky one, a thorny issue. There’s strong views on both sides of the debate. I’ll work through that with the relevant sporting bodies.

“Ultimately it’s got to go over to sporting bodies to make sure that we have fair competition.”

They’re very careful in dealing with such an inflammatory issue, but they’re going in the right direction:

Next year, Sport New Zealand will invest $9.3 million in 38 sports at the community level.

Pressed on whether sporting bodies that objected to the separatist policy would find their funding frozen, Foster said: “If a code says ‘We don’t want to do that’, that’s their choice but they shouldn’t then expect the taxpayer to say we’re delighted to support you doing something which we see as unsafe and unfair.

“That’s the policy.”

. . .Foster, a former Wellington mayor, outlined the rationale for attempting to separate trans women from female community sports.

“It’s about fairness and safety in sport for women in particular,” he said.

“Looking at some of the debate that’s been across different sports codes around the world about transgender people who have transitioned from male to female, particularly after puberty, and the evidence around the advantages that happen in weight, speed, all those sorts of things, it compromises fairness in competitions and in some cases safety as well. We’re saying, for publicly funded sports bodies, we think it’s really important for women to have a clear line in the sand drawn.

“With rugby, athletics, boxing, you can see why power, weight and speed become a real issue. If there’s a teenage girl against a former teenage boy, your child is going to get hurt.”

Foster suggested the policy would not apply to all sports, citing equestrianism as an example of men and women competing in the same field.

That’s fair enough. Foster is right about the athletic advantages of post-puberty trans women who have had surgery and puberty blockers, but if data show no inherent advantages of trans women over women in horsey sports, it’s fine to have them compete.

A lot of the article is devoted to criticism from trans women athletes and others about the policy, but the criticisms mostly aren’t workable. For example:

However, transgender athlete and two-time national champion mountain biker Kate Weatherly fears it will lead to athletes being forced into men’s competitions or sidelined completely.

. . . . Given the minimal number of trans women competing in amateur sports, Weatherly fears it could lead to their exclusion from the grassroots arena.

The “small number” argument fails because if a trans women wins because of the advantages she has from male puberty, it is unfair to any number of women or girls who can’t win.  There may be few winners, but there are plenty of losers.

Here’s another from Weatherly:

“Sports are inherently unfair. It’s so heavily dependent on money, where you were born, access to coaches, support networks. There are so many factors that determine how successful you are at sport.

Sports are inherently unfair, she says, so it’s okay to add a big source of unfairness to the mix. Nobody doubts, and it’s clear from recent results in sports, that trans women have a palpable advantage over women in nearly every sport in which they participate.

And there’s the inclusivity argument as well:

Former sport minister Grant Robertson condemned the policy’s intention.

“It’s incredibly sad the government is undermining the work done to make grassroots sports more inclusive,” Robertson said. “We should be doing everything we can to encourage people to participate in sport and recreation. Chris Bishop should be ashamed to be facilitating this nonsense.”

New Zealand Cricket is the first sport to publicly resist the policy – even if that means losing its $425,000 allocated government funding next year.

“Our position is that we’ll continue to prioritise inclusivity and accommodate transwomen in women’s cricket at community, amateur, social level,” NZ Cricket spokesperson Richard Boock said.

Sport New Zealand chief executive Raelene Castle indicated its focus remained on inclusion.

“We have developed a set of transgender guiding principles for the sector, to help organisations develop their own policies for the inclusion of transgender participants in community sport.

Now this is an argument that can’t be dismissed: trans athletes want to compete, and isn’t it unfair to say they can’t? There are various solutions to the problem, including an “other” category for trans people, or allow “men’s sports” to include trans athletes. That may seem unfair to trans women, but, as they say, “sports are inherently unfair.” (I am just using their own argument against them; I do think the problem should be considered seriously.)

Finally, there’s this argument, which was suggested, I believe, by Neil deGrasse Tyson as well:

h/t: Jez