Why Human Sex Is Not Binary

> Some worms produce both. Some fish start producing one kind and then switch to the other, and some switch back and forth throughout their lives. There are even lizards that have done away with one type all together.

Ok, so we can't abstract every species in the same way...

> Among our fellow mammals, which are less freewheeling because of the twin constraints of lactation and live birth, there are varied connections between gametes and body fat, body size, muscles, metabolism, brain function and much more.

Ah, so we went from overlapping gametes to the relationship of gametes and physical features... so this means mammals are binary in regards to their gametes, right?

> Producing ova or sperm does not tell us everything (or even most things) biologically or socially, about an individual’s childcare capacity, homemaking tendencies, sexual attractions, interest in literature, engineering and math capabilities or tendencies towards gossip, violence, compassion, sense of identity, or love of, and competence for, sports.

Why does it need to? It's only purpose is to draw distinct categories based on sexual reproductive strategies. We see two distinct strategies, therefore two categories.

It seems to me we're arguing whether sex has clear boundaries, and we find exceptions to make these boundaries blurry and therefore change or erase the category. Despite blurry boundaries, the categories still exist (if it's blurry only at the boundaries). To make this short, I think the only way sex would not be binary is if the Y chromosome is completely useless (since it must produce some male features).

Gender is nullable-binary. Sex is multifaceted.

https://dspace.mit.edu/handle/1721.1/128358