My take on it is that, during all of the time when our evolution was taking place, we lived in little tribes of about a hundred people. Each tribe would have at least one autistic person who would serve as a counterbalance to the chief. We were a second loci of power built around respect for our ability to see differently, and that was tied in with a lot of gender nonconformity in a great many tribal peoples before the Christians exterminated them. The result was that the chief led the way most of the time, but the medicine woman would recognize when the chief was leading the tribe off a cliff, and step in to intervene. Producing greater long term survival for the tribe as a whole.