Most of us would agree that human sacrifice is a bad idea. Yet many ancient civilizations (and some more modern ones) engaged in religious rituals that involved sacrificing people. Why do so many societies evolve a system of human sacrifice, despite the obvious moral drawbacks? A group of social scientists has just published a statistical analysis in Nature that reveals how this grisly practice has fairly predictable results, which benefit elites in socially stratified cultures.
The moral of the story seems to be that you should promptly sacrifice anyone who thinks human sacrifice seems like a good idea.