Psychometric validation of the momentary impulsivity scale among a high-risk sample of emerging adults

Impulsivity assessment has garnered significant attention in the extant literature, as impulsigenic traits relate to a variety of psychopathology; however, traditional trait impulsivity measures neglect intraindividual variability. Laboratory-based assessments of impulsivity have been conceptualized as state-level assessments, but the psychometric soundness of these paradigms is questionable. A self-report measure of momentary impulsivity (the Momentary Impulsivity Scale [MIS]) was recently developed, but its psychometric attributes have yet to be examined outside of its original sample. As a part of a larger daily diary study, 77 high-risk emerging adults were recruited, and participants completed a variety of impulsivity assessments and measures examining risky behavior. The one-factor structure of the MIS fit the data well at within- and between-person levels, but the MIS exhibited more temporal stability and dependency than expected. Content validity analyses suggested the MIS might most reflect emotion-driven impulsivity, and the MIS correlated more strongly with trait self-report measures than laboratory-based impulsivity tasks purported to measure state-level impulsivity. Criterion validity was modestly supported, as the MIS was significantly associated with negative affect and alcohol consumption but was not correlated with other relevant outcomes. Finally, the MIS-alcohol consumption relation was moderated by drinking at a party and drinking at a partner’s residence, such that individuals engaged in elevated drinking regardless of momentary impulsivity levels when drinking outside their home. Despite limitations, findings provide support for the MIS as a self-report state-level measure of impulsivity that can be reliably and validly interpreted. Future research in this area should prioritize revising the MIS to account for the potential multidimensionality of state-level impulsivity, which would mirror trait-level impulsivity conceptualization. Clinical and methodological implications are discussed.