"IOC bans biological males from women's sports" headlines driving me bonkers. These headlines don't tell me what they banned, because "biological male" isn't a kind of person.
They banned people with the SRY gene.
The SRY gene is typically found on the Y chromosome, although occasionally it appears on an X chromosome. People with an SRY gene may or may not have a testosterone-based puberty. They may or may not have a Y chromosome. They may or may not have a penis. They may or may not be amab. They may or may not be men. It is not scientifically reasonable to say that "biological male" and "SRY positive" are equivalent.
Sexual dimorphism in humans means there are clusters of traits that tend to appear together in two groups. Sperm vs egg production. Low vs high voice. Presence vs absence of Y chromosome. Presence vs absence of SRY gene. More facial hair vs less. Tall vs short. Longer vs shorter penis/clitoris. High vs low androgens. Low vs high estrogens. Et cetera.
On average, someone who has some traits that look more like the first than the second in these pairs will also likely have other traits that look more like the first than the second in these pairs. Traits that are correlated in this way are considered primary and secondary sex characteristics, and we call one of the correlation classes "male sex characteristics" and the other "female sex characteristics."
But, while it can be useful to refer to individual sex characteristics by their correlation class name (as in, male hormones, female genitalia, et cetera) it does not make sense to refer to an individual human person as male/female. Because all human beings come with a mix of primary and secondary sex characteristics. I would argue that the vast majority of people do not have every single one of their primary and secondary sex characteristics present as clearly solidly in the same correlation class, especially since the correlation is much weaker when it comes to many secondary sex characteristics. That doesn't mean the majority of people are intersex, although "just what mixtures of traits count as intersex?" is a question that doesn't have a clear cut answer. I will not pretend to have an answer for it.
The point is, though, that presence of SRY gene is not any more valid of an idea of "biological male" than using any other single sex characteristic. I'm not sure exactly what percentage of people have an SRY gene but suppose it's 49.8%. I could come up with a testosterone threshold that cuts the population at 49.8%. I could come up with a height threshold that cuts the population at 49.8%. I could come up with a variety of tests on a variety of sex characteristics that cut the population at 49.8%. Or any other percent. And they would not produce the same partition of the population. There would always be some people who land on one side of some tests and the other side of others. And none of them would be a good test of "biological male" because no single sex characteristic defines the "male" correlation class. It is defined by its rough correlation of characteristics.
People have to stop writing headlines (or anything else) with the nouns "biological male" and "biological female" in them as if those mean something. Those literally don't mean anything.
The IOC banned people with an SRY gene from participation in women's Olympic sports. They banned people with that specific male sex characteristic. There are cis and trans men, cis and trans women, and nonbinary people who have that gene. And who lack it. They did not ban "biological males." They are not permitting "biological females." There are no such things. We have to stop pretending there are.
