The Multidimensional Personality Questionnaire’s Inconsistency Scales Identify Invalid Profiles Through Internal Statistics and External Correlates
Inconsistency scales represent a promising method for separating valid and invalid personality profiles. In a sample of 1,258 participants in the waiting room of the emergency department of an urban university hospital, we examined whether data from participants with profiles flagged as invalid (n = 132) using the Variable Response Inconsistency (VRIN) or True Response Inconsistency (TRIN) scales of the Multidimensional Personality Questionnaire’s brief form (MPQ-BF) differed from those that did not exceed any validity cutoffs (n = 1,026). Invalid profiles’ scores on many scales were less internally consistent and had less variability than those from valid profiles, especially for random and acquiescent response styles. Scores on MPQ-BF primary trait scales from profiles featuring random responses appeared more psychologically maladjusted than those on valid profiles. Compared to primary trait scores on valid profiles, acquiescent profiles generally had higher scores, and counteracquiescent profiles had lower scores. The higher order component structure of invalid profiles was less consistent with published MPQ-BF component structures than that of valid profiles, though negative emotionality was generally reasonably well-preserved. Scores on primary traits associated with negative emotionality generally had larger correlations with demographic criteria for valid profiles than invalid profiles. These results argue that inconsistency scales meaningfully identify invalid profiles in normal-range personality assessment.