The Association of the Dark Tetrad With the Ability to Feign Schizophrenia

Objective: Since its third edition (American Psychiatric Association, 1980) and in subsequent editions, the Diagnostic and Statistical Manual of Mental Disorders has favored the criminological model in relation to malingering. However, research on the relationship of psychopathy and antisocial personality disorder to the propensity and ability to feign mental illness has yielded mixed results. Importantly, no study has yet examined the relationship between the Dark Tetrad (Machiavellianism, narcissism, psychopathy, and sadism) and the ability to fake mental illness in a credible manner. Our study aimed to fill this research gap by examining whether individuals with higher Dark Tetrad traits report more schizophrenia symptoms and more credibly fake schizophrenia when asked to do so. Method: Eighty-one nonclinical volunteers from Portugal took the Short Dark Tetrad (SD4) and were instructed to respond honestly. They were then instructed to feign schizophrenia on the following tests: the Eppendorf Schizophrenia Inventory (ESI), the Inventory of Problems–29 (IOP-29), and the memory add-on of the IOP-29 (i.e., IOP-M). Results: None of the SD4 scores correlated significantly with the ESI, IOP-29, and IOP-M scores, and all effect sizes were small. Of note, the standard cutoff score of the IOP-29 (i.e., =.50) correctly classified 90.1% of participants as fakers (i.e., sensitivity =.90), and half of the very few false-negative classifications of the IOP-29 were correctly classified as noncredible results by the IOP-M. Conclusions: The ability to plausibly fake schizophrenia is comparable in individuals with higher and lower Dark Tetrad traits. Also, the IOP-29 and the IOP-M showed excellent validity, further supporting their effectiveness in assessing symptom and performance validity.