Even Mass Killers Act on the Margin

Most people are not tempted to commit mass killings but, obviously, some are. Casual observation suggests that mass killers are nearly always losers – in the Merriam-Webster sense of "a person who is incompetent or unable to succeed." Of course, not all losers have the preferences of mass killers, but for some of them, mass killing is not out of the realm of utility.

Source