"Psychopaths are a paradox. So many of them, like Bundy, are intellectually high functioning, and they clearly know right from wrong. They are not delusional, but they are socially inept. They seem to lack normal self-control, and they persistently violate social, legal and moral rules. They don’t—as Bundy’s words suggest—comprehend the human social contract. But why? What’s the glitch in the mental machinery? ...Two psychological scientists at the University of New Mexico—Elsa Ermer and Kent Kiehl—suspected that such specific reasoning deficits might underlie the disorder, which would explain why psychopaths’ general reasoning ability seems to stay intact."