Dr. Feigenbaum published this article in 2019 to justify the participation of men as "transgender" women in women's sports:
https://www.barbellmedicine.com/blog/shades-of-gray-sex-gender-and-fairness-in-sport/
It's pure propaganda, despite the apparently scientific approach. Dr.Feigenbaum is clearly an activist for transgenderism. He obfuscates the issue with irrelevant data.
His arguments are basically that:
Let's be clear: There are only 2 sexes and 2 genders. There is no 3rd sex and no 3rd Gender. Sexual reproduction is strictly binary. The cultural Marxist attempt to redefine "gender" is pure nonsense, as gender is not defined by conventions. Every society throughout human history had different dress codes and different social roles for men and women - whether they were patriarchal or matriarchal. The exact expression is fairly irrelevant. The important point is that they all recognized that men and women are very different and they have completely different reproduction strategies.
"8,000 YEARS AGO, 17 WOMEN REPRODUCED FOR EVERY ONE MAN"
"Once upon a time, 4,000 to 8,000 years after humanity invented agriculture, something very strange happened to human reproduction. Across the globe, for every 17 women who were reproducing, passing on genes that are still around today—only one man did the same."
The competitive pressure on men is and has always been much higher. Women do not have to compete to reproduce. Their competition is about getting the best possible male partners - and that competition is between women, based on looks and social rank. Women never had to compete against men.
Even women who lose out in the competition for the best men still can reproduce - there will always been men willing to mate with them. But men who lose out in the competition will never reproduce - the best men will absorb a large number of women, where possible entire harems of women.
Only Men who built up skills, were good fighters or able to earn great status and wealth gained access to women.
Societies that choose monogamy give a majority of men access to women, which makes them much more creative, productive and - as a result - more prosperous.
Societies that allow polygamy, as most Islamic countries, or that destroyed the natural balance between men and women - such as India, where girls were frequently killed at birth due to the high cost of a dowry or communist China with their one-child policy - end up with large numbers of disaffected men who will never have access to a woman. They turn into useless drones or violent criminals. Wars often remove the "excess males".
To claim that gender is defined by "conventions" or "behavior" requires some serious mental gymnastics. Social behavior is downstream from reproductive function. Behavior etc. are adopted spontaneously by men and women to be recognizable as such by the opposite sex. They have different social roles and socialize differently - again, spontaneously, not by any kind of "social pressure", which is confirmed by the fact we observe this across all human societies.
Differences between male and female babies are already observable at the age of 3 months. Girls will focus more on images of faces, boys more on images of toys.
Feminism didn't reduce this gender specific behavior in the least, it even increased it. Women still socialize far more with each other than with men. The metoo movement was instrumental in creating an even more extreme segregation, as now men do not want to take any risks by socializing with women even in a professional context.
If modern feminism proved anything, it is that men and women are not the same. Which is of course why transgenderism attacks feminism.
Chromosomal aberrations are extremely rare and do not represent a 3rd sex or gender. Most of them either cause the carrier to be deformed, handicapped or barely affected at all. Typically, all individuals with 2 or more X chromosomes are female.
The question about whether an XXY individual should be allowed to compete as woman due to higher testosterone is a red herring: if that individual has female sex organs, she competes as woman, even if she has naturally a higher testosterone level. That's not a problem at all. In fact, that's within the natural variability. She's still a woman.
1 in about 400'000 births is a true hermaphrodite with 2 working sets of genitalia and internal organs.
Only in about 1 of 5'000 births a baby has ambiguous sex organs. Only 1.7% at most can be considered in any way "not normal", in terms of sexual organs and reproductive organs. So 98.3% can immediately be sorted into male and female without any ambiguity. Babies are not "assigned" a sex at birth, their sex is observed and recorded.
All of Dr.Feigenbaum's examples are provided without statistics, so they are meaningless. He knows that once he'd put numbers behind those aberrations, it would be obvious that the issue is totally marginal.
Problems arise when a man decides to compete as a woman although he has male sex organs, male bone density, male muscle mass and a male brain - the testosterone level is only a marginal issue, contrary to what Dr.Feigenbaum claims.
The advantages of males over females in all sorts of competitions is enormous.
In short, Dr.Feigenbaum's arguments are incredibly weak.
Mental differences are even more important than biological ones. These affect the drive to compete and win, which is much stronger in men, but also in general problem-solving ability.
Purely intellectual activities are not exempt. In chess, the best female players cannot compete with the highest ranking men - only one woman ever managed to place as #10 in the FIDE ranking. This has nothing to do with the number of players or the lack of opportunities, support etc. This study here explains the issue to perfection:
https://en.chessbase.com/post/explaining-male-predominance-in-chess
Same goes for e-sports, where the only all-female team, super hyped and heavily sponsored, did not win a single game:
Apparently, there are significant differences between boys and girls that go way beyond the obvious, which included:
85% of worldwide competitive scrabble players are women and women are supposed to have higher verbal abilities, yet the major competitions are all won by men. So the much lower participation rate does not work against men. Here is a study that examined this gender difference:
"Gender differences in SCRABBLE performance and associated engagement in purposeful practice activities" (https://link.springer.com/article/10.1007/s00426-017-0905-3)
The conclusion is somewhat disturbing:
"we have proposed how large gender differences can be attributed to differences in the methods of skill acquisition as opposed to the capacity for skill acquisition or the rates of skill acquisition. We found that those differences appear to be due to preferences for engaging in certain types of domain-related activities. Future research is required to understand how these preferences originate, and most importantly, how those preferences can be changed by interventions."
They want to find out how preferences emerge? How about they are inborn? Worse: they want change gender-specific preferences. Apparently, it is too hard to admit that those gender-specific preferences might exist for a good reason, based on very different constraints on men and women and that changing them might be a bad thing for the concerned individuals.
It is interesting to see how the popular press represents the study and how the author describes it for the general public:
Why men are better than women at Scrabble
"women were spending more time actually playing Scrabble, an activity that is fun but, in terms of building skills, inefficient. They treated it like an enjoyable pastime where the objective was to be happy, researchers said."
This is exactly what one would expect: women are less competitive because they don't need to be, but socializing is very important. It doesn't matter if a woman is successful or not - her ability to attract and keep a high-value mate is based on very different factors such as her physical beauty, her character, her ability to socialize etc.
However, men took a different approach. Rather than getting together with friends for a pleasant game, they spent their time consciously analysing past games and practising their anagrams. "It is not an innate difference in talent, it is just that women are far less willing to waste their time honing a largely pointless skill," researchers said. "There is not a lot of money in Scrabble; it is not like chess. So why would you even want to be the best Scrabble player in the world? You could argue it does not make sense," Moxley said.
"Pointless skill" - maybe, but that doesn't matter, to men. When they participate in such a game, they see it as a challenge to win. It's really bizarre that the author of this study was able to state:
"It is not an innate difference in talent, it is just that women are far less willing to waste their time honing a largely pointless skill," researchers said"
Without realizing that just skipped over the innate difference that mattered: the desire to compete and win!
The most famous poets, mathematicians and composers are all men, too. Nothing ever prevented women from writing poetry, advancing math or composing music, they even had a lot more time and opportunities than men, especially in upper middle and upper class families. The exceptions make the difference all the more glaringly obvious, e.g. Ada Lovelace and Mary Shelley.
To be a brilliant writer, poet, mathematician or composer requires exactly the same "pointless" dedication as winning scrabble competitions.
So there's a lot more at work than physical differences. Which is why "transgender" women are unfair competitors in women's sports way beyond the physical aspects.
The fact that there is always overlap does not disprove this!
The Internet age revealed how men and women spontaneously chose their own mode of representation: to gain views on social media, women use their physical beauty - no one makes them do that, they choose it themselves. Men who want to get views brag with wealth, cool stunts and "toys".
One "trans" man in a WP article admitted that ‘It now feels as though I am on my own’, i.e. he doesn't get social support anymore as he did as a woman. Any woman who fell for the lie that it's easier to be a man should be aware of this: life is infinitely much easier for women, which is why men work so hard and compete so intensely.
No one, ever, would have said that a tomboy was "not a girl". Behavior has nothing to do with gender.
Contrary to male and female gender and behavior, which are natural, transgenderism is a social construct.
There are a few extremely rare individuals who suffer from actual gender dysphoria, i.e. they suffer from a mental illness that makes them unhappy with their physical body. This is very much like body integrity disorder or xenomelia, the desire to amputate certain limbs and the desire to be disabled:
99% of those who claim to be "transgender", today, are victims of the ideology of transgenderism, which spread exactly like an infectious disease as observed by a study from Brown University - a study the transgender movement tried to censor:
In certain regions of the US, e.g. Los Angeles, up to 15% of adolescents suddenly claim to be "transgender" - clearly a way to "be different" (a fundamental desire among adolescents), which also allows them to gain social status and validation that they could not get otherwise.
Gender matters, in sports. Allowing men to compete in women's sports is blatantly unfair and will lead to the implosion of women's sports.
It's funny how humanity managed perfectly without any of this cultural Marxist nonsense until the 1960s, when the sadistic pedophile Dr.Money started experimenting with "gender switching", which was a horrible crime and resulted in the suicide of his test subjects.
How anyone can advocate giving children hormones for off-label treatment or practice operations on teenagers that mutilate their primary and secondary sexual organs is beyond me.
Children and adolescents are notoriously unable to make long-term decisions, as their brains are not fully developed. They are extremely influenceable by team pressure. Hence the Komsomol, the Red Guard and the Hitler Jugend...
The CCP exploited this by pushing the entire transgender & critical race theory in western universities. Best way to eliminate their competition for the position of hegemon.