Replicable Factor Structure and Correlates of an Alternate Version of the Narcissistic Personality Inventory

The Narcissistic Personality Inventory (NPI) traditionally has been administered using 40 pairs of items with a forced-choice response format. However, recent NPI research indicates that it may be advantageous to administer only the item from each pair that is in the narcissistic, keyed direction (i.e., using a "single-stimulus" format) in conjunction with a Likert style response rating scale (Ackerman et al. 2016). This same research and other prior studies also suggest that the NPI items assess distinct grandiose narcissistic traits (e.g., manipulativeness, leadership), such that focusing solely on total scores for analyses may be problematic. We extend this previous work by examining the NPI's factor structure and correlates in both clinically-oriented community (N = 700) and undergraduate (N = 527) samples when this measure is administered using a single-stimulus format and a Likert style rating scale. Our results indicated that five replicable NPI factors (i.e., Manipulativeness, Grandiose Fantasies, Vanity, Leadership/Authority, Superiority) could be identified across samples. Subscales modeling these factors showed distinctive patterns of personality and psychopathology relations. For example, some subscales (e.g., Leadership/Authority, Superiority) showed strong positive relations with agentic aspects of extraversion and robust negative relations with neuroticism, but other subscales (e.g., Manipulativeness, Grandiose Fantasies) showed comparatively weaker associations with these personality traits. These results highlight a potentially more useful administration format for the NPI, and also underscore need to consider the distinctive nature of NPI subscales in future research using this measure.