"On nearly every continent, and for all of recorded history, thriving cultures have recognized, revered, and integrated more than two genders. Terms such as “transgender” and “gay” are strictly new constructs that assume three things: that there are only two sexes (male/female), as many as two sexualities (gay/straight), and only two genders (man/woman)...Most Western societies have no direct correlation for this tradition, nor for the many other communities without strict either/or conceptions of sex, sexuality, and gender. Worldwide, the sheer variety of gender expression is almost limitless." There's a map.
Interactive Map: Gender-Diverse Cultures
If I'm honest, I knew of some of these (the Indian examples) but not all. I've no way of knowing how accurate it is. My understanding is that sex is binary; gender is a spectrum. Sex is biological; gender is cultural.
But could you not then say, for argument sake, that the annoying parts of
Heteronormativity is the instance [insistence?] that everyone use the same vernacular? It's still trying to force your ideals and beliefs onto another and make them behave in a manner you find acceptable.
Surely it works both ways?