James Fallon

“People with autism lack theory of mind but not empathy, while people with psychopathy lack empathy but not theory of mind. Without empathy you can still have sympathy, though—the ability to retrieve emotional memories, including those that can predict what painful event is probably about to befall another person, and the will to help that person.”
― James Fallon, The Psychopath Inside: A Neuroscientist's Personal Journey into the Dark Side of the Brain

“Despite the controversy over whether psychopaths exist, psychiatrists generally agree that one of the defining characteristics of those we refer to as psychopaths is the lack of interpersonal empathy, what one might call a flat emotional playing field. Psychopaths may not hate, but they also may not love the way most of us would prefer to love and be loved. Psychopaths are usually manipulative, are champion liars, and can be quite glib and disarmingly charming. They don’t fear consequences the way most people do, and while they may react to the stress of being caught in a lie or violent act like anyone would, some remain cool as cucumbers. Even the most dangerous can appear jovial, carefree, and social at times, but sooner or later they will display a telling distance, a quiet coldheartedness and disregard for others. They are often impulsive, yet lack guilt and remorse, meaning they may invite you to join in on their reckless, even dangerous fun, and then shrug their shoulders if someone gets hurt.”
― James Fallon, The Psychopath Inside: A Neuroscientist's Personal Journey into the Dark Side of the Brain