Differential Item Functioning of the Multidimensional Schizotypy Scale and Multidimensional Scale-Brief Across Ethnicity

Schizotypy refers to traits or symptoms similar to schizophrenia, but in a diminished form, and schizotypy is thought to reflect a liability for the future development of schizophrenia. The Multidimensional Schizotypy Scale (MSS) is a new measure of schizotypy that improves on existing measures. The MSS contains full and brief subscales for positive, negative, and disorganized schizotypy. Although MSS scores have been validated in a variety of populations, the scales have not been thoroughly examined for differential item functioning in East Asian, Southeast Asian, Hispanic, Multiracial, and White participants. The current study included 567 East Asian, 351 Southeast Asian, 360 Hispanic, 230 Multiracial, and 345 White undergraduate participants from the United States. Overall, few of the items in the full or brief versions of the scales displayed differential item functioning across groups. The full and brief versions of the scales also displayed similar and not-significantly different validity coefficients with the Detachment and Psychoticism scales of the Personality Inventory for DSM-5. These findings suggest that the MSS measures the same constructs across ethnic groups, and the scale scores represent the same latent level of schizotypy among groups. Future research may use the MSS in these diverse groups without concern that the psychometric properties differ significantly among groups.