Are evil people born or created?

I feel we are all born with the opportunity to be good or bad. Nobody is evil nor good in the begining. It's what life throws at us, your upbringing, trama, hardships that sculpt a person into who they are. How someone is, is there temperments, reactions, and how they handle the scenarios.
And truely, nobody us completely evil or completely good. Even "evil" people have a heart.