@eerie-resonance if you learned about anthropology, hooman, intrapersonal skill and strategy, as well as psychology, you will exactly know the answer of your topic.
People are unique, somehow they could be same and follow whatever their society expected but suddenly they could be argumentative and against society. Back to the treatment when you are a baby, a kid, till you grow up to be teenagers, your parents, your family beliefs, your friends, your school mates and your teachers also your religion rules (if applicable), they are all combining you to be a person like you are now.
So, if you say that some people are just inherently evil, it is not some people, it is all people. We have angel and satan side, good and bad side, love and hate, like and dislike, etc and many more since it is the rules of this world, the opposite things. It is just a part of the rules of this world :)