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 prop- erties 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 eva- luations, pretrial decisions and better treatment and rehabilitation strategies in offenders and clinical relevant samples.
This work was supported by The Foundation for Science and Technology (Grant number SFRH/BD/76062/2011), and the Portuguese Ministry of Science, Technology and Higher Education
through national funds and co-financed by FEDER and COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER007653) - Psychology Research Centre (UID/PSI/01662), awarded to the first author. The study was also supported by Grant SFRH/BPD/108602/2015 from the Portuguese Foundation for Science and Technology awarded to Andreia de Castro-Rodrigues.