One of Hare’s most important findings involves the distinction between Factor 1 and Factor 2. This research suggests that psychopathy is made up of two relatively distinct personality traits, antisocial attitudes and antisocial behavior. The first trait reflects cold, callous personality features. The second trait reflects impulsive-aggression and poor behavioral control. These traits may have different causes, differ in their underlying neurobiology, and predict to different types of behavior. Although the two factors correlate at 0.5, suggesting about 25 percent overlap, they are really quite distinct.