On the Incremental Validity of MMPI–2 Psychopathology–5 Scales over the Revised Neo Personality Inventory Scales for Predicting Personality Disorders

The hypothesis that the MMPI–2 Psychopathology–5 scales are better predictors of personality disorders than the Revised NEO Personality Inventory scales was tested using Personality Adjective Checklist personality disorder scales with a 9-point response format. The three inventories were completed by 258 introductory psychology students (113 men and 145 women) for partial course credit. Hierarchical multiple regression analysis was performed for predicting each Personality Adjective Checklist scale by entering the Revised NEO Personality Inventory scales as a set in the first step and the Psychopathology–5 scales as a set in the second step. Incremental validity of the Psychopathology–5 scales over the Revised NEO Personality Inventory scales for predicting each Personality Adjective Checklist scale was measured by the R² change at the end of the second step in the hierarchical multiple regression analysis. Incremental validity values ranged from .01 to .09, with a median of .03, and were significant for only five Personality Adjective Checklist scales. Such results provided very little support for the hypothesis of relative superiority of the Psychopathology–5 scales over the Revised NEO Personality Inventory domain scales for predicting personality disorders.