I've been thinking about this connection for a long time, and it finally struck me: Autistic people are probably more likely to be trans because we sort of...Idk not overanalyze everything but at least in the way I think, gender just never made sense to me? Like, the idea of body=gender is just so backwards to me, because by and large, societies had multiple genders. It's historically verifiable, and in the modern world, as well.
It's not like "Oh we're super logical", but I feel like we have that higher likelihood because we question things by nature. We sort of go "wait this doesn't make sense" when something's just nonsensical. I don't know how else to describe it because it's always just been a thing for me and a lot of other autistic people I know. Like, yes, we take things literally, but also when something makes zero sense we question it.
I know I'm kinda rambling, but I just feel like because we examine the world in different ways than neurotypicals, that's how we arrive at the conclusion that gender isn't our bodies.