When you look back into history you have to wonder occasionally "how on earth could people do that?". Take public executions, for example : what kind of person could sit and watch the slow torture and death of another human being? Can you ever get into the mindset of the kind of person who can take pleasure at the suffering and misery of others?
Yes you can : just watch the House of Commons Treasury Committee interview the chairmen of the big UK banks. Enjoy their humiliation, take pleasure at their discomfort, rejoice in their anguish. As Hooker said to Gondorff at the end of "The Sting", "You were right, Henry, It's not enough ... but it's close"