Mankind has dictated what is considered good and evil. When you are born you are a blank slate with basic genetic traits pre-programmed into us to survive. Sure there are some humans born with abnormal brains that are destined to fail, if born into a lawless wild environment.
Depending on the enviornment you are raised in and the individuals you have social interactions with. Will have a great deal to do with how you will turn out. As far as psychopaths go. The outcome will remain the same as long as the enviornment and interactions stays the same. The only difference between a normal and abnormal brain (psychopath) is that the psychopath can be influenced easier, to commit unlawful acts of violence. Because of there lack thereof.
I also believe that if a child is born with a normal brain. He or she can be taught to be evil over time because of their surroundings and their social interactions.