Psychological Assessment Copyright 1997 by the American Psychological Association, Inc. 1997, Vol. 9, No. 4, 406-413 1040-3590/97/$3.00 Effectiveness of the MMPI-2 Validity Defensive Responding in Clinical R. Michael Bagby Clarke Institute of Psychiatry University of Toronto Indicators in the Detection of and Nonclinical Samples Richard Rogers University of North Texas Robert A. Nicholson University of Tulsa Tom Buis York University Mary V. Seeman and Neil A. Rector Clarke Institute of Psychiatry University of Toronto In this study, patients diagnosed with schizophrenia (n = 38) who had previously completed the Minnesota Multiphasic Personality Inventory--2 (MMPI-2) by responding honestly were asked to complete it again with instructions to conceal their symptoms.A student group (n = 49) followed similar instructions. Under instructions to fake good, both students and patients were able to produce clinical profiles that were significantlyless pathological. The Other-Deceptionand SuperlativeScales were best at distinguishingfake-good and honest profiles in the student sample. The Edwards Social Desirability Scale and the L scale were best at distinguishingfake-good and honest profiles in the patient sample. The Wiggins Social Desirability scale was best at distinguishinghonestly responding students from patients faking good. In many situations individuals undergoing psychological as- sessment have much to gain by concealing or otherwise min- imizing psychopathology. Are the parties to a custody dispute as well-adjusted as they claim or merely adept at masking psy- chological dysfunction? Does the repeat offender appear ready to be reintegrated into society because he or she has been reha- bilitated or because he or she has learned to simulate psychologi- cal health (Pope, Butcher, & Seelen, 1993, p. 97)? Is the person with schizophrenia desiring discharge from the hospital really free of symptoms likely to compromise adjustment to the com- munity and precipitate readmission? The Minnesota Multiphasic Personality Inventory--2 (MMPI-2; Butcher, Dahlstrom, Gra- ham, Tellegen, & Kaemmer, 1989) contains a number of indica- tors and scales specifically designed to detect overt denial and R. Michael Bagby, Section on Personality and Psychopathology, Clarke Institute of Psychiatry, and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Richard Rogers, Department of Psychology, University of North Texas;RobertA. Nicholson,Department of Psychology,University of Tulsa;Tom Buis, Departmentof Psychology, York University,Toronto, Ontario, Canada; Mary V. S eeman and Neil A. Rector, Schizophrenia Program, Clarke Institute of Psychiatry,Univer- sity of Toronto, Toronto, Ontario, Canada. This study was supported by an operating grant from the Social Sciences and Humanities Research Council of Canada. Correspondence concerning this article should be addressed to R. Michael, t3agby, Section on Personality and Psychopathology, Clarke Institute of Psychiatry, 250 College Street, Toronto, Ontario, Canada M5T 1R8. Electronic mail may be sent via Internet to bagbym@ cs.clarke-inst.on.ca. minimization of psychological symptoms, and it may be espe- cially useful for assessing this response style. Detection of a fake-good response style poses a significant challenge to clinical assessors and appears to be a more difficult task than the detection of fake-bad responding. In a meta-analy- sis of 25 studies that examined the ability of the various MMPI (Hathaway & McKinley, 1940) scales and indicators designed to detect fake-good responding, Baer, Wetter, and Berry (1992) reported an overall mean effect size (Cohen's d) of 1.05. This effect size is only one half of the size of the mean effect (d = 2.07) found in an earlier meta-analysis of 28 studies examining the ability of various MMPI validity scales and other indicators designed to detect fake-bad responding (Berry, Baer, & Harris, 1991). In the first published study to evaluate the effectiveness of the MMPI-2 validity scales to detect fake-good responding, Graham, Watts, and Timbrook (1991) compared the clinical and standard validity scales of the MMPI-2, using a sample of 56 college students who had been asked to complete the MMPI- 2 under honest and fake-good instructions. Scores on the validity scales L (Lie) and K (Correction) were significantly higher for participants in the fake-good group compared with those for participants in the honestly responding group. For the clinical scales, men in the fake-good condition scored significantly lower on 5 of the 10 clinical scales than did the men in the honestly responding condition, whereas women in the fake-good condi- tion scored significantly lower on 8 of the 10 clinical scales than did the women in the honestly responding condition. Simi- lar results for the validity scales L and K were reported by 406