Psychopathy is thought to be composed of a combination of three distinct things: disinhibition, boldness, and meanness. At the moment, those things can really only loosely be associated with the big five personality traits established in the aforementioned state-by-state research used in the study, but a forthcoming paper -- which was also considered in this research -- does in fact connect them. Specifically, that paper speculates that “boldness corresponds to low neuroticism and high extraversion, meanness corresponds to low agreeableness, and disinhibition corresponds to low conscientiousness."
So where are all the psychopaths living these days? The study awards Connecticut as the most psychopathic state, followed by California then New Jersey in the number two and three spots, respectively. Conversely, of all 48 contiguous states, West Virginia has the fewest psychopaths within its borders, followed by Vermont, then Tennessee. Here's how the full rankings panned out.