I think of “sex” as the physical act, so it is not something I would associate with babies (except as an explanation for their existence).
Now I will have to go see the article at Slate. I’m wondering how readers over at Slate receive the article.
"Sex" is our biological dimorphism, male and female.
Not surprising that "Slate" doesn't allow comments. Surely even some of their regular readers would think this is crazy.