Recently I was reading "Seven Million Years, the Story of Human Evolution" by Douglas Palmer and I came across this interesting statement about cave art. Palmer is talking about cave art in France dating back 32,000 years and says "The sophistication of the images and their technical accuracy show that the Cro-Magnon people who made them could just as easily depicted human faces if they had wanted to--but apparently this did not interest them. There are no pigmented pictures of human faces here, and very few outlines with any degree of sophistication until several thousand years later."
Palmer then goes on to say that the sense of "self" emerged about 27,000 years ago, when stencils of human hands (not faces!)started to appear alongside the painted animals on the cave walls. Elaborately carved and decorated human figurines began to show up around that time as well.
Palmer makes no mention of Aspergers or autism in his book, but given our well-known aversion to eye contact and our sometimes poor sense of self, I am wondering if these and other ASD traits are a hold-over from that long-ago era. In other words, at one time we were the norm for the human race and the NT's were the odd ones out.