Versatility and exploratory psychometric properties of the Impulsive/Premeditated Aggression Scale (IPAS): A review

Aggression has different conceptualizations and can be behaviorally expressed in diverse ways. Designed to evaluate impulsive and premeditated forms of aggression, the Impulsive/Premeditated Aggression Scale (IPAS; Stanford et al., 2003) is a 30 item self-report questionnaire. The aim of the present study was to explore IPAS versatility in different psychological settings by reviewing and examining the exploratory psychometric properties of the IPAS impulsive and premeditated subscales, across different samples and cultural backgrounds. Fifty-two articles including demographic or psychometric information (internal consistency, factor analysis, validity, reliability) were retrieved. It is suggested that the IPAS is reliable across different cultures, samples and scoring techniques. The two subscales (Impulsive and Premeditated) show acceptable internal consistency. Also, IPAS factors seem to be constant both in clinical and non-clinical samples. The IPAS appears to be a clinically useful instrument for differentiating between subtypes of aggressive behavior, to support risk assessment evaluations, pretrial decisions and better treatment and rehabilitation strategies in offenders and clinical relevant samples.