<< (..) the prevalence of (human) sacrifice increased with the degree of social stratification: it occurred in 25% of cultures with little or no stratification, 37% of those with moderately stratified societies, and 67% of those that had a pronounced hierarchy. And by mapping the evolutionary relationships between cultures, the team suggests that human sacrifice and social hierarchy co-evolved. >>
<< Human sacrifice seems to have been largely the privilege of priests or others who claimed religious authority. Watts and colleagues say that their results therefore disclose a “dark side” to the social role of religion. >>
Philip Ball. How human sacrifice propped up the social order. April 4, 2016
Joseph Watts, Oliver Sheehan, et al. Ritual human sacrifice promoted and sustained the evolution of stratified societies. Nature http://dx.doi.org/10.1038/nature17159 (2016).
<< The scientists (..) found that ritual sacrifice may have spurred the transition of smal, egalitarian societies to large, stratified ones. The study examined 93 traditional Austronesian cultures (speakers of a family of languages in parts of Africa, Asia and Oceania). >>
Tatiana Schlossberg. Why Some Societies Practiced Ritual Human Sacrifice. April 4, 2016.
more (an hypothesis of a funny approach inside modern societies): Elio Petri. La decima vittima (movie, 1965)