Oooooooooooooh. I'm not surprised at the human sacrifice stuff. Any books or papers you can point me to?

but when we look for a rationale behind its early manifestations, it is not at all pleasant. It's homicidal.
Terry Pratchett taught me this! It irks me sometimes how fairy tales and folklore and superstitions get whitewashed or handwaved away as silliness--our society places such an emphasis on rationality that it's sometimes hard to remember that "superstitions" were things that people lived and died by.