The Impulsive-Premeditated Aggression Scales (IPAS; Stanford et al., 2003) were developed to yield measures of impulsive aggression (akin to RA) and premeditated aggression (akin to PA). Respondents are asked to indicate level of agreement on a 5 point Likert scale from strongly agree to strongly disagree. Each statement asks subjects to reflect on their emotional, cognitive, or behavioral state before, during, and after aggressive acts committed over their lifetime. A complete listing of items is available in Stanford et al. (2003). In the original study of the IPAS, a community sample of 93 men referred for assessment due to a history of anger/aggression problems were administered the 30-item IPAS (Stanford et al., 2003). A principal components analysis (PCA) yielded a PA factor and a RA factor. Preliminary construct validity was established by comparing the separate factors on a number of external variables. RA scores correlated higher than PA scores on self-report measures of irritability and anger control. PA scores, by comparison, correlated more highly with measures of antisocial/impulsive behavior, extraversion, neuroticism, self-harm, and overall aggression—a profile that is consistent with
