Have you ever met somebody with questionable integrity and wondered if they were born that way or if they became that way due to their life experiences?? We all have a basic level of moral expectation. You know, like don't kill, don't steal, don't intentionally inflict pain on any other individuals...you know the elementary things in life...but what causes people to justify the wrong they do? One of the basic questions of life. Could it possibly be that "evil" people are just born that way? When evaluating the reasons behind why we do what we do, there is much to consider.
Of course the natural psyche is based on many scientific things. But in addition to those things I think people are generally of good nature. People want to do the right thing! We all know that hurt people hurt people...and that what we go through in life has a major affect on our mold. For example people who are often labeled as good people are that way because of the examples they've seen in life (normally at a young age)... and I think it's the same way for those who are "morally challenged."
A good example of this theory is in the movie Cruel Intentions. The male leading role in the movie started out with genuinely bad intentons up until the point that he met the female leading role who genuinely had good intentions. After getting to know her, his desire for morality increased as his cruel intentions decreased and he turned his wicked ways around. She taught him a new way of life. Her influence rubbed off on him and through his experience with her he learned that good does exist and that's what he wanted to be.
Another aspect to this question to consider is the intensity of the word evil. There are levels to bad and evil is at the pinnacle. If you're evil you are bad, but if you're bad does that mean you are evil? Evil is not really the opposite of good. Good and bad are polar opposites... where as evil and righteous are more likely to be defined as opposite. What I mean is when speaking in terms of people, I think evil is too strong of a word to use in substitution for bad. We are all flawed so we all have some bad ways but no one is born bad, therefor no one is born evil.There really is no solid answer to this question. It's soley based on opinon...and mine is that just as you have to be taught hatred, I believe you have to be taught "evil" intent or wicked ways. It's one thing that does not just come naturally....it's even possible that the thing that turned one person evil wouldn't have the same effect on another person. Maybe it all just comes down to perspective. Evil is nurtured like how good is....and people aren't just born that way, they become that way.