Aggressive behavior has traditionally been classified into two distinct subtypes: an affective, impulsive aggressive display or a planned, predatory aggressive act. While a number of investigations have examined the clinical and physiological correlates in impulsive aggressive individuals, very little research has been conducted on those individuals engaging in predominantly premeditated aggressive acts. The present study compared a group of premeditated aggressive psychiatric outpatients with a group of normal, nonaggressive control subjects on personality, neuropsychological and cognitive psychophysiological measures. Consistent with previous work, premeditated aggressors did not differ significantly from controls con most measures of neuropsychological and psychophysiological function. Premeditated aggressors did show significant personality pathology scoring higher on measures of impulsivity, verbal and physical aggression, anger, hostility, psychoticism and neuroticism. Overall, these results suggest a distinctive personality style that is associated with aggressive behavior. With respect to this and previous work, it is suggested that the physiological aspects of behavioral control play a key role in the type of aggressive behavior displayed. (C) 2002 Elsevier Science Ltd. All rights reserved.