Effectiveness of MMPI-2 validity scales in the detection of dishonest responding in an outpatient community sample
While research on the effectiveness of the MMPI-2 validity scales has been extensive, past studies have mostly relied on one research design: the "simulation" study. In this design, participants are instructed to feign psychopathology by overreporting symptoms or feign defensiveness by presenting oneself in a positive light. Their response set is compared to profiles from participants given standard instructions. This research design accounted for 22 of the 23 studies published since 1991, as reviewed by Baer in his 2002 meta-analysis; and all 68 of the studies reviewed by Rogers in his 2003 meta-analysis. Using this design, researchers have placed their confidence in the overall usefulness of the MMPI-2 validity scales. Despite the popularity of this method, researchers do not know the extent to which experimental feigners resemble genuine feigners. This puts the generalizability of any findings into question. Another design administers the MMPI-2 to a large group of individuals and selects out a subset of participants who are later discovered to have misrepresented themselves. These feigned profiles are compared to honest profiles. This "known-groups" design is believed to be more generalizable because these feigners are genuine feigners. The present study used the "known-groups" design with the Q-sort (a measure known for its high reliability) as the independent measure of feigning. 104 outpatients from a community mental health clinic completed the Minnesota Multiphasic Personality Inventory 2nd edition. An expert interpreted the MMPI-2 profiles and, blind to the validity scales, created a Q-sort profile. The therapists of the participants provided behavioral correlates by describing the participants using another Q-sort. Therefore, this study gave us two types of data: (1) description of a person by interpretation of an MMPI-2, and (2) description of a person by someone who knew that person on an intimate level. The two Q-sorts were correlated providing an index of how accurately the MMPI-2 matched a therapist's experience of that individual. There were four hypotheses in the study. Hypothesis 1. This examined the degree to which a score on a validity scale could detect genuine dishonest responding. It was predicted that MMPI-2 profiles with low Q-correlations would have high validity scales scores. This was indeed the case for the scales measuring underreporting which appeared to be functioning intact as predicted by previous research. However, the F scales performed very poorly, contrary to the literature. This suggested that established cutoffs scores for the F scales, which were firmly established using a simulated design, may not work when applied to a genuine population. Hypothesis 2. This examined the degree to which a score on a validity scale could predict the type and level of faking. Last among the Q-sort items was the critical item \#100 "Overall, this individual is psychologically healthy and well-adjusted." rated on a Likert scale of 1 to 7. The difference between the expert-interpreted score on this item and the therapist-rated score indexed the degree to which the participant faked. Correlations showed that L + K, K and S were best at predicting a faked profile. Scales L, Fb, and Fp performed worst. The results also suggested that low scores on the underreporting scales could be used to detect overreporting. Hypothesis 3. This examined whether fakers from past simulation studies resembled genuine fakers. The MMPI-2 profiles of those deemed to be genuine fakers were compared to previously published MMPI-2 profiles of participants who were instructed to fake. MMPI-2 profiles from past simulation studies produced more exaggerated response styles when compared to genuine fakers. In other words, simulation studies may not be the optimal method to study MMPI-2 validity scales. Hypothesis 4. This examined whether the validity scales, when used holistically, were useful in determining whether a profile was answe (PsycINFO Database Record (c) 2007 APA, all rights reserved)
https://www.upress.umn.edu/test-division/bibliography/2000-2009/2007/chung_effectiveness_2007
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Junmo J Chung
(2007)
Effectiveness of MMPI-2 validity scales in the detection of dishonest responding in an outpatient community sample
PhD thesis.