Development and validation of an MMPI-3 Antagonism scale.

Antagonism is a personality domain located in most major trait models and is central to multiple personality disorders. This construct has been linked to many societally harmful externalizing behaviors (e.g., criminal conduct). Consequently, accurate assessment of this trait is important in both research and clinical settings. The Minnesota Multiphasic Personality Inventory-3 (MMPI-3) is among the most widely used personality assessment instruments, and both researchers and clinicians using it can benefit from proper assessment of antagonism. Although the Personality Psychopathology Five measures aggressiveness (AGGR), a conceptual cognate to antagonism, its content is restricted. Thus, the current studies aimed to develop and validate a new MMPI-3 Antagonism (ANT) scale using six different samples drawn from university, community, and mental health settings (s = 289-1,660). Scale development (Study 1) was approached using criterion validity and latent modeling methods with a series of conceptually indicated candidate items. The resulting scale had improved content coverage of antagonism when compared to the AGGR scale. Subsequent validation analyses (Study 2) examined the ANT scale in terms of convergent and incremental validity against antagonism criteria, as well as its discriminant validity against disinhibition criteria. The results largely supported superior construct validity of ANT scale scores over those of AGGR, indicating that the ANT scale has promise as meaningful addition to the MMPI-3 in the assessment of this construct. (PsycInfo Database Record (c) 2025 APA, all rights reserved).