A Concise Measure of the Impostor Phenomenon: The Brief Impostor Phenomenon Scale (BIPS).

The aim of the study was to introduce a concise measure for assessing the impostor phenomenon. We reduced the Perceived Fraudulence Scale (PFS) in a sample of 1,001 Polish-speaking adults through the use of exploratory (n = 500) and confirmatory (n = 501) factor analysis to 12 items, composed of three subscales: self-deprecation, external ability attribution, and inauthenticity. This brief scale showed scalar measurement invariance between men and women, and between students and working professionals. Item Response Theory (IRT) analyses further supported individual items' properties. The measure also demonstrated good internal consistency and validity. Impostor phenomenon correlated negatively with self-esteem, emotional stability (i.e., low neuroticism), extraversion, conscientiousness, and intellect (i.e., openness to experience). In addition, women scored higher than men on overall impostor phenomenon which was driven only by the self-deprecation aspect. Students scored higher than working professionals on both the general score and all three subscales. The initial psychometric properties suggest that the Brief Impostor Phenomenon Scale (BIPS) is a valid and reliable short measure, supporting its further use in research. These results also add to the currently underdeveloped body of research on the impostor phenomenon in a non-English speaking cultural setting.