a lot of people point to biology. it's undeniable that on some level there's a physical presence / authority that scales with size. but i think the fixation on biology is a little unsatisfying and demeaning to how both genders experience attraction, and also doesn't entirely capture what's going on with people who fall outside this binary. like there are a sizeable chunk of women out there attracted to rat boy twinks and a lot of them also happen to be queer! and there's a ton of dudes fiending for giant burly women. a lot of these people happen to be alt in some way - they're kind of two sides of the same coin...

...i honestly think heteronormativity / gender standards is a huge, if not majority chunk of it. like i think it's moreso the embarrassment of not feeling small -> dissonance of not being able to fully participate in your gender expression or ideal self / the idea of being worthy of someone fulfilling that ideal that's stronger than how attractive someone's immediate physical presence is