For years, the common sense description of psychopaths is that they are people who could not empathize with other humans. Lack of empathy was seen as one of the driving forces behind the awful cruelty in which psychopaths often indulged. This description, however, led to a sort of paradox: if psychopaths can’t empathize, why are they seen as so effective at manipulating others? A recent Yale study demonstrates that while psychopaths can in fact understand others’ perspective, they do so opportunistically. Chilling stuff.