There is nothing particularly primordial about such arrangements; certainly, there is no reason to believe they are in any sense hardwired into the human psyche. On the contrary, it’s almost invariably necessary to employ some combination of ritual, drugs and psychological techniques to convince people, even adolescent males, to kill and injure each other in such systematic yet indiscriminate ways. It would seem that for most of human history, no one saw much reason to do such things; or if they did, it was rare.
