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Cross-cultural validation and standardization of the Impostor-Profile 30
The impostor phenomenon describes a maladaptive personality style marked by persistent self-doubt and fear of being exposed as a fraud despite evident success. Despite its global relevance, the construct’s cross-cultural measurement invariance has not yet been empirically established. This study assessed the measurement invariance of the Impostor-Profile 30 across six European countries (N= 2472; 60.0% female; M age= 31.34, SD= 13.36), and standardized the instrument by deriving normative values. Multi-group confirmatory factor analyses supported partial scalar invariance across five countries (excluding Italy; CFI= 0.897, RMSEA= 0.060, SRMR= 0.090), strict invariance across genders (CFI= 0.932, RMSEA= 0.051, SRMR= 0.057), and metric invariance across age groups (CFI= 0.915, RMSEA= 0.055, SRMR= 0.070). Age-specific percentile ranks were derived to enable norm-based interpretation. These results confirm the cross-cultural equivalence of the IPP across five European countries, supporting its standardized use in psychological research and practice.