Distinctiveness of the MMPI-3 Self-Importance and Self-Doubt Scales

The MMPI-3 is an updated version of the MMPI-2-RF that provides enhanced coverage of constructs related to personality and psychopathology. A new Self-Importance (SFI) scale measures individuals' beliefs that they possess special qualities. Low SFI scores indicate that test-takers report lacking such attributes. The Self-Doubt (SFD) scale, which was revised from the MMPI-2-RF, also has a self-orientation and measures a lack of self-esteem. The current study used three college student samples to investigate whether MMPI-3 SFI and SFD measure distinct constructs; in other words, are beliefs about self-importance distinct from self-esteem? SFI and SFD scores were conversely but differentially associated with measures of positive valence, self-esteem, and grandiose and vulnerable narcissism. Dominance and regression analyses indicated that SFI scores generally dominated SFD scores in prediction of positive valence and grandiose narcissism (characterized by grandiosity, dominance, aggressiveness). SFD scores generally dominated SFI scores in prediction of self-esteem and vulnerable narcissism (characterized by negative affect, feelings of incompetence, inadequacy). The current findings indicated that self-importance and self-esteem are two distinct constructs and therefore appropriately measured by separate scales.