Ordinary people, extraordinary evil:
James Waller, a professor of psychology at Whitworth College in Spokane, Wash., suggests that perpetrators of genocide -- those who commit what Waller calls "extraordinary human evil" -- aren't just ideologically committed sociopaths or else passive weaklings who've been forced to pull the trigger...Instead, according to Waller, complex forces in human nature make all of us capable of committing acts of genocide.
Something to bear in mind.