>>22866662I think there's a tendency to assume that if any clear categories or distinctions have any sort of "gray" or "fuzzy" areas whatsoever then they must be completely made up and social constructions or whatever.
Usually people will bring up intersex to refute the idea of sex being a binary but intersex is a bunch of chromosomal abnormalities that occur along sex lines, there's no in between hermaphroditic sex that is neither discernably male nor female. And human reproduction has no need of any such "third sex".
You'll also hear the idea that sex is "bimodal" and that there's a spectrum between male and female based on sex characteristics, with most people falling into either the male or female parts of the spectrum. But this categorizes people by sex characteristics and the problems from this are apparent.
For example) is a woman with smaller breasts more "male" than a more feminine woman? Or a hairier body, deeper voice, etc? Is a man with a higher-pitched voice and low-testosterone more "female" than a masculine man? Already this definition of sex based on sex characteristics alone identifying people as "more male/female" or "less male/female" is problematic.