The psychology of good and evil

Just yesterday I was discussing with a friend, what is it that makes people Good or Bad. Good or Evil. Selfish or Selfless. The main criteria we were debating on was whether it is upbringing, circumstances and experiences or life decisions the individual makes. And hey presto! Here come the answers today. I just happened to chance upon this article with current interest for all things Episode III... Lucas Talks About Anakin's Good Side - Yahoo! News