I don't know if, for me personally, I would say half the people I encounter are evil in some way but I wouldn't be surprised if it were close. I have been looking into the effects that a person who has malignant narcissism has on the people around them. A lot of times the children who are not taken away from the parent end up becoming like the sick parent.
I would guess that because we live in a society that does nothing to really punish those who physically, sexually, and/or emotionally abuse children/young adults that a portion of them will grow up to be like their abuser. The more the sick people abuse, the more abusers/mentally unstable people they create.