The potential is there for each and every one of us. Some more susceptible than others.I do believe people can be born evil- I obviously don't believe that babies are evil, just that the potential will have always been there. There are many reasons how traumas and experiences alter us. It's not a one fits all scenario. I know people in my line of work who have suffered horrendous trauma who you'd excuse for bad behaviours, but they are really really good decent people. Also have came across people with wonderful childhoods and adult experiences who are what I would deem as bad. Satan did masquerade himself as an angel of light.
Satan?