Comparing Job Applicants to Non-applicants Using an Item-level Bifactor Model on the HEXACO Personality Inventory

The present study evaluated the ability of item-level bifactor models (a) to provide an alternative explanation to current theories of higher order factors of personality and (b) to explain socially desirable responding in both job applicant and non-applicant contexts. Participants (46% male; mean age = 42 years, SD = 11) completed the 200-item HEXACO Personality Inventory-Revised either as part of a job application (n = 1613) or as part of low-stakes research (n = 1613). A comprehensive set of invariance tests were performed. Applicants scored higher than non-applicants on honesty-humility (d = 0.86), extraversion (d = 0.73), agreeableness (d = 1.06), and conscientiousness (d = 0.77). The bifactor model provided improved model fit relative to a standard correlated factor model, and loadings on the evaluative factor of the bifactor model were highly correlated with other indicators of item social desirability. The bifactor model explained approximately two-thirds of the differences between applicants and non-applicants. Results suggest that rather than being a higher order construct, the general factor of personality may be caused by an item-level evaluative process. Results highlight the importance of modelling data at the item-level. Implications for conceptualizing social desirability, higher order structures in personality, test development, and job applicant faking are discussed.