An expanded self‐report, vignette‐based, questionnaire was developed to assess five components in a social emotional information processing model (SEIP: attribution, emotional response, response valuation, outcome expectancy, response efficacy, and response enactment), first in a population‐based sample (n = 250) and, second in healthy control participants (n = 50) and in those with DSM‐5 Intermittent Explosive Disorder (IED: n = 50). SEIP‐Q vignettes depict, separately, both overtly aggressive and relationally aggressive as well as socially ambivalent scenarios. This expanded SEIP‐Q assessment demonstrated good internal reliability, as well as convergent and discriminant validity, for all five SEIP components. IED participants differed from healthy controls in all SEIP‐Q components. This expanded SEIP‐Q assessment is thus proposed as a reliable and valid method for studying the various stages of SEIP in adult human subjects. Aggr. Behav. 43:47–59, 2017. © 2016 Wiley Periodicals, Inc.