A Comparison of Self-Report Measures of Psychopathy Among Nonforensic Samples Using Item Response Theory Analyses

This study investigated how well components of the psychopathy trait are measured among college students with the Levenson Self-Report Psychopathy Scale (LSRP), the Personality Assessment Inventory-Antisocial Features Scale (PAI ANT), the Psychopathic Personality Inventory-Short Form (PPI-SF), and the Self-Report Psychopathy Scale-II (SRP-II). Using Samejima (1969)'s graded response model (GRM), the subscales were found to vary in their ability to measure the corresponding latent traits. The LSRP primary psychopathy factor is more precise in measuring the latent trait than the secondary psychopathy factor. The PAI ANT items show coherent psychometric properties, whereas the PPI-SF factors differ in their precision to measure the corresponding traits. The SRP-II factors are effective in discriminating among individuals with varying levels of the latent traits. Results suggest that multiple self-report measures should be used to tap the multidimensional psychopathy construct. However, there are concerns with respect to using negatively worded items to assess certain aspects of psychopathy. Public Significance Statement This study examines the item properties of 4 self-report measures of psychopathy among college students, with results showing that the factors in the instruments differ in their ability to measure the respective latent traits. Findings suggest that multiple measures should be used to tap the multidimensional concept of psychopathy, and raise concerns regarding the use of negatively worded items to assess certain aspects of psychopathy.