The Psychometric Properties and Validity of the 5-Item German-Language Clance Impostor Phenomenon Scale in the SOEP-IS (SOEP-GCIPS)

The impostor phenomenon (IP) refers to individual differences in difficulties in internalizing positive feedback and success, and fear of being exposed as an intellectual fraud. The 2015 wave of the SOEP-IS study included five of the 20 items of the German-language Clance Impostor Phenomenon Scale. This study analyzed the psychometric properties and validity of the IP measure used in the SOEP-IS data ( N = 2,643). Confirmatory factor analysis supported a unidimensional model and invariance across sex. The internal consistency was good for a very brief measure (α and ω = .78). Correlations with self-esteem, the Big Five traits, sadness and worrying met expectations and were stable across a 2-year interval ( r change ≤ .05). The findings support the reliability and validity of the abbreviated IP measure. Its use for analyzing panel data such as the SOEP-IS is recommended considering its limitations (e.g., limited reliability and coverage of the IP).