To the best of my knowledge the Sumerians, Egyptians, Indians, and even the vikings, and Mayans sacrificed people as part of their funerary rites. The Zoroastrians didn't do this, nor is there any physical evidence that the Persians did although Herodotus claims a certain Persian Amestris did. Why did people perform these sacrifices? And is the implication of a society that did not perform these rites? What changed?