The earliest most popular publication that posited that "sex is a social construct" might be Butler's Gender Trouble. This article is a pretty good overview on

The earliest most popular publication that posited that "sex is a social construct" might be Butler's Gender Trouble. This article is a pretty good overview on the evolution of the discourse on this topic: https://plato.stanford.edu/entries/feminism-gender/#SexGenDis https://plato.stanford.edu/entries/feminism-gender/#SexGenDi... (I linked straight to the section on sex as a social construct, but the whole article is worth a read.)