[solarmist]

I think you meant this tongue in cheek, but this seems highly unlikely.

The neocortex handles rational thinking and reasoning, so an increased reliance on it would put autism further from evolutionary predecessors. Also, you would expect the ratios of allistics:autistic to be reversed as well.

Also, as a mildly autistic person, I don't believe autism would be a beneficial trait in the wild. I would probably be fine, but some of my tendencies would lessen my likelihood of survival.

[PeterisP]

If that would be the case, then it would also then manifest in behavioral traits of non-human primates, since they would not yet have this relatively recent adaptation.

[solarmist]

I'll bet it does. We don't have a generic description of what autism means yet. I'm sure what we describe as autism is a cluster of differences.

So it's hard to imagine what it would look like in other primates.

Like these[1] loners in slime mold colonies. We don't even know if these kinds of variation are common or not. Autism-like variations might be like this or it could be human specific.

[1] https://www.discovermagazine.com/planet-earth/slime-molds-sh...