Experimenter Analyzes Human Morality

I like to think that I am a good person. But when I honestly think about it, there is no reason for me to believe that this is due to anything but sheer luck. I have lived a privileged life, and I have no idea what I would be capable of if circumstances ever pushed me to the edge. It is easy to assume that the horrors of this world are the handiwork of deranged, unstable people, but the evidence of history, full of genocide, mass murder and ethnic cleansing shows this to be a dangerous misconception. How is this possible?