[Bobylonian]

Maybe. Humans developed their brains mainly because primate ancestors ~3 million years ago started to hunt other animals(including other primates) for meat and eat cooked protein rich meat, which allowed to develop and maintain bigger brains. That affected more diverse gut bacteria of primates - they lost ability to process raw meat more efficiently, because there was no more need for that.

My take is that in overall ASD is next evolutionary change in brain development, where things that were coming from natural animal world are given away - that includes easy and intiutive social interaction that monkeys have, filtering of visual and sensory information that is bombarding our brains, where normally humans ignore 80-90% of information that brain receives and that includes gut behaviour as well. Apparently this brain development change can come together only with prolonged life.

[smt88]

I would wager that autistic people are less likely to have children, which means that humans are evolving away from autism (assuming a large enough hereditary factor).

[akiselev]

The evolutionary benefits of a dominant allele can vastly outweigh the negative consequences of a recessive one, keeping it alive even though it reduces fitness of some individuals. With a spectrum disorder like autism that's likely caused by many factors, we can't even hazard a wild guess.

[Auracle]

My autistic cousin that can’t function on his own would differ, if he had the mental capacity to do so. The spectrum is wide and people on the light side (or that know people that are) have a skewed view of things.