It occurred to me that aspects of Dr Temple Grandin's brain may perhaps resemble that of the prehistoric cave artist's who often seems to have had a similar understanding of his/her animal subject(s), or perhaps even to that of the shaman while in a trance...

This requires some thought... Hob will tell us that it is left/right hand ability of the brain that gets developed one way or the other. Instinct/intuition is seen as part of the feminine side of things. As autism is a particular condition of the brain, you really can't backtrack it to shamanism or cave art, these things arose from hunting or a need for religion; perhaps it is her 6th sense which has become fully developed and it this she shares with prehistoric man/woman..