I dunno if you want people to post here or on your sub, so I'm posting my comment in both places. Also, I'd imagine this sub gets more traffic so more will see it here:

In the Anglophone world, "sex" - not "gender" - was the word customarily used to mean sex until relatively recently (I first noticed the switch begin to gradually come into use in the USA mainstream press in the early 1990s.)

First and second wave feminism were all about sexism, sex discrimination, sex stereotypes, sex quotas, sexual violence, sexual harassment, sex-based policies, etc. The suffragists spoke of sex. So did the "women's libbers" (and those who opposed them) who came later. Hence, such books as "The Second Sex," "Sexual Politics," "The Dialectics of Sex" and "The Prisoner of Sex." Nobody back then would ever have thought of using "gender" instead of sex in those titles or texts.

Same goes for the law. All the landmark anti-discrimination legislation passed in countries like the USA and UK in the 1960s and 70s - such as the USA's 1964 Civil Rights Act and Title IX, passed in 1972 - prohibits discrimination based on sex, not gender. Gender isn't mentioned. Coz the term "gender" wasn't used as a euphemism or substitute for "sex" back then, and all the concept(s) attached to "gender" nowadays were simply known as "sex stereotypes" and "sexism."

When I was growing up (in the late 1950s, 60s & 70s) and after, the only time I recall anyone in the Anglophone world speaking or writing of "gender" was when studying, teaching or discussing foreign languages. According to Oxford, gender traditionally meant

"(in languages such as Latin, Greek, Russian, and German) each of the classes (typically masculine, feminine, common, neuter) of nouns and pronouns distinguished by the different inflections that they have and require in words syntactically associated with them."

I worked in journalism and as an editor in the 70s, 80s and 90s and wrote tons about feminism and women's issues. Never one did I ever use the word "gender" to mean sex - in fact, doing so would've been counter to the rules explicitly stated in all the style guides in use back then, such as the AP stylebook & Strunk.

It was only in the late 80s, early 90s that the use of gender as a euphemism for sex started to creep into use in ordinary, everyday parlance (as opposed to academia where gender ideology and queer theory had already begun to take over). But even then as now, there were many people who never could get used to the new, less precise lingo - and who objected to it it vociferously.

This letter to the NYTimes from December 27, 1990 summed up the sentiments of many back then:

To the Editor:

The term "gender" is increasingly misused as a substitute for "sex." Does "gender" appear to reflect a greater sophistication, or reluctance to use a term with a possible indecent connotation?

"The Gender Gulf" by Louis Harris (Op-Ed, Dec. 7) misuses the term three times (not counting the headline), including this: "the generation gap is less evident and the gender gap more acute." Among the same day's letters, one ("Sexism on Sesame St.") misuses gender five times including "gender imbalance."

"The Careful Writer: A Modern Guide to English Usage" by Theodore M. Bernstein (New York, 1965) states, "gender is a grammatical term, denoting (in English) whether words pertaining to a noun or pronoun are classed as masculine, feminine or neuter. It is not a substitute for 'sex' (but then, what is?). Indeed, in some foreign languages 'gender' often disregards sex. In German, for example, 'Weib,' The word for woman, is neuter; in French 'plume,' the word for pen, a sexless article, is feminine. To use 'gender' as if it were synonymous with 'sex' is an error, and a particularly unpardonable one in scientific writing."

From Fowler's "Modern English Usage" edited by Sir Ernest Gowers (Oxford, second edition, 1965):

"Gender, n., is a grammatical term only. To talk of 'persons' or 'creatures of the masculine or feminine gender,' meaning 'of the male or female sex,' is either a jocularity (permissible or not according to context) or a blunder."

I can only assume you have elected to permit this misuse, despite a valid and useful distinction between the terms.

SIDNEY WEINSTEIN Danbury, Conn., Dec. 10, 1990 The writer is editor in chief, International Journal of Neuroscience.