Development and validation of the Malingering Discriminant Function Index for the MMPI-2.
The predictive capacity of the MMPI-2 (Butcher et al., 2001) "fake-bad" validity scales (F, FB, and FP) is diminished when respondents have knowledge (i.e., coached) about the operating characteristics of these scales. In this investigation, we endeavored to develop a MMPI-2 fake bad validity index that would be less vulnerable to validity-scale knowledge. Applying discriminant function procedures, we derived a set of weighted Clinical and Content scales that reliably distinguished large samples of validity-scale coached undergraduate research participants instructed to feign mental illness (n = 534) from psychiatric patient samples (n = 590). We subsequently validated this Malingering Discriminant Function Index (M-DFI) in independent samples of research participants (n = 230) and patients (n = 300) and showed relatively less attenuation in predictive capacity compared with F, FB, and FP across uncoached and validity scale coached feigning conditions.
Bacchiochi
Jason R
JR
Centre for Addiction and Mental Health, University of Toronto, Canada.
Bagby
R Michael
RM
D000293:Adolescent; D000328:Adult; D008192:Deception; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007721:Knowledge of Results, Psychological; D008950:MMPI / Q000706:statistics & numerical data*; D008297:Male; D008306:Malingering / Q000175:diagnosis* / Q000523:psychology; D001523:Mental Disorders / Q000175:diagnosis* / Q000523:psychology; D008875:Middle Aged; D011594:Psychometrics / Q000706:statistics & numerical data; D015203:Reproducibility of Results