Most violent crime involves impulsive aggression. It is no surprise, then, to find that, on average, violent criminals have many of the characteristics associated with impulsive aggression. They are largely male, young, have problems regulating their aggression, and tend to have lower IQs, less education, and lower SES than the general population. They are also more likely to have childhood histories of physical abuse and neglect. Cognitively, they have difficulty anticipating the consequences of their actions, and tend toward a narrow, rigid, and essentially paranoid interpretation of others’ intentions. Ambiguous gestures are interpreted as threatening and hostile, setting off a hair-trigger aggressive reaction. Non-impulsive violent criminals are more likely to have psychopathic traits; that is, they have the callous, exploitive, and unemotional traits of a psychopath.