" Nowadays, we have come to understand that brutalizing a child is a surefire way to turn him or her into a sociopath. If a person is hideously maltreated from the earliest years, it is almost guaranteed that he or she will grow up with a malignant view of existence. To such a person, the world is a hateful place where all human relationships are based not on love and respect but on power and domination. Having been tortured by his primary caretakers, he will, in later life, seek to inflict torture on others, partly as a way of taking revenge—of making other people suffer the way he has suffered—and partly because he has been so psychologically warped by his experiences that he can feel pleasure only by inflicting pain. "

― Harold Schechter , Psycho USA: Famous American Killers You Never Heard Of