I hope I'm not breaking any rules for posting this in non-Adult section.
To be honest, I think that the reason of having higher proportion of homosexuals among autistic people is their tendency to feel sort of detached from the general population and in consequence being less likely to subscribe to the current cultural perception of sexuality.
The older I am the more I think that the current cultural perception of sexuality (which is based on the Bible and Christian traditions) that treats sexuality as a categorical variable (e.g. you're either het, homo, bi, pan, demi, whatever, etc.) as a bit ridiculous and fundamentally flawed.
I think most of people have sort of non-straight tendencies, even though they would vehemently deny it and feel uncomfortable about it (hence the saying that the biggest gay-haters are those unsure about their own sexuality). I think human sexuality is more like a radar-chart thing composed of various different elements, than a categorical variable.
Look at men in Ancient Greece. They had wives and a lot of them engaged in pederasty at the same time. Were they straight, gay or pedophiles? I think if you were to ask them that, they wouldn't have a clue what are you talking about.
To conclude, I think autistic people tend to have a more objective view of their own individual sexuality and as such tend to get categorized as non-straight by the rest of the population more often.
But it's just my speculation.
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2011: Your Aspie score: 139 of 200. Your neurotypical (non-autistic) score: 67 of 200. You are very likely an Aspie.
2021: Your broader autism cluster (Aspie) score: 106 of 200. Your neurotypical (non-autistic) score: 121 of 200. You have both broader autism cluster and neurotypical traits.
I'm getting better at this stuff!