Psycho~ogicalReporis, 1990, 66, 907-91 1. O Psychological Reports 1990
MMPI SUBTLE-OBVIOUS SCALES A N D MALINGERING: CLINICAL VERSUS SIMULATED SCORES ' PAUL R. LEES-HALEY AND DAVID D. FOX Encino, California Summary.-Subtle-obvious scale discrepancies on the Minnesota Multiphasic Personality Inventory were compared for pathology simulators and clinical groups to test the hypothesis that subtle-obvious scores help differentiate simulators. Total obvious minus subtle T score discrepancy greater than 100 discriminated the student malingerers and produced few false positives among clinical populations such as psychiatric inpatients and outpatients. The hypothesis that these clinical patients score high on these ~ndicesof malingering as a baserate or as a cry for help was rejected. These data suggest that there are differences between simulators and clinical patients, whch are d e ~ e i r ~ b by l e use of subtle-obvious scores, and that this procedure bears further exploration.
Malingering is the simulation of a disorder that does not exist or the exaggeration of one that does (Gorman, 1984). Unlike conversion and other somatoform disorders, malingering is the deliberate simulation or exaggeration of an illness or disability, for example, to avoid an unpleasant situation or to obtain some type of personal gain (Stone, 1988). There are numerous indications that malingering is a real problem which is overlooked or minimized by many clinicians. Attorneys can purchase videotapes and written materials with which to train plaintiffs how to undergo independent examination. This training includes information on what will happen in the evaluation, how to avoid prejudicial questions, and how to testify effectively. This fact should be a signal for the need for caution and skepticism, but most clinicians are not even aware that such training exists. There are numerous documented cases of claimants fooling presumably sophisticated clinicians (Kizorek, 1987; Rosenhan, 1973). According to one judge with considerable experience in trying psychological claims, many psychological evaluators apparently do not consider the possibility that the claimant may not be telling the truth (Lasky, 1988). Clinicians often presume that claimants are telling the truth and support their diagnoses exclusively with claimants' self-reports of unverifiable symptoms (Raifman, 1983). Many other clinicians supplement and cross-validate self-report data by utilizing objective psychological tests w h c h lend objectivity to their assessments. The Minnesota Multiphasic Personality Inventory (MMPI) is the
'Correspondence concerning t h s article should be addressed to Paul R. Lees-Haley, Ph.D., at 16260 Ventura Blvd., Suite LL30, Encino, CA 91436.
P. R. LEES-HALEY & D. D. FOX
most widely used objective personality test in the world. A variety of indicators of malingering are available on the MMPI. These include F, F-K, Gough's Dissimulation Scale and Dissimulation Scale-Revised, and Wiener and Harmon's Subtle-Obvious Scales (Cofer, Chance, & Judson, 1949; Gough, 1947, 1950, 1957; Greene, 1980; Wiener & Harmon, 1946). Lees-Haley (1989) has commented on the need for revision of procedures for the F and F-K indicators when applied to personal injury litigants. This article contributes additional data to the question of the potential utility of the MMPI for discriminating mabngerers of personal injury by reporting data on subtle and obvious discrepancies relevant to issues of concern in personal injury claims. Discrepancies between subtle and obvious scores have been found to be useful by many clinicians and researchers (e.g., R. L. Greene, 1980, personal communication, 1989; Cofer, Chance, & Judson, 1949; J. Ziskin, 1989, personal communication), and others have not found them effective (e.g., Graham, 1989). One possible explanation for the discrepant findings is that these experts reached conclusions on specific data sets and may have overgeneralized, concluding that these scales were, or were not, useful without limiting their conclusions to particular patient samples. Specialists in litigation on personal injury and experts with extensive experience on the application of subtle-obvious items in personal injury settings have reported the subtle-obvious items to be useful in evaluations of personal injury (R.Folse, 1989, personal communication; M . Green, 1989, personal communication; R. L. Greene, 1989, personal communication; LeesHaley, 1989; R. Price, 1988, personal communication, 1989; J. Ziskin, 1989, personal communication; Ziskin & Faust, 1988). Greene (1989, personal communication) says they are "invaluable" in personal injury evaluations. In forensic settings, clinicians often discount or ignore elevations of MMPI indices associated with malingering on the grounds that these elevations arise from genuine emotional distress (the "cry for help" argument) or the theory that such elevations appear in normal medical or psychological clinical populations (the baserate argument). This study was inspired by the concern that these rationales for ignoring the objective data are anecdotal rather than empirical. One measure w h c h has been proposed as raising concerns of malingering is the Total of obvious minus subtle T scores greater than 100. And, in fact, the authors have found this to be a useful procedure in evaluating personal-injury litigants. This criterion was used as a cut-off procedure in this study. METHOD Subjects included several samples potentially relevant to questions about
MMPI SUBTLE-OBVIOUS SCALES
how clinical groups perform on subtle and obvious subscales. The following groups were included: 25 obese women in an outpatient treatment program, average age 44.3 yr., and 25 psychiatric inpatients including 9 men and 16 women with an average age of 34.2 yr. The inpatients' principal diagnoses included 45% nonpsychotic depression, 20% psychotic, 20% bipolar, and 15 % substance abuse. The outpatients with irritable bowel syndrome included 24 women and 1 man; their average age was 41.8 yr. Also included were 64 college students asked to simulate psychopathology as part of a volunteer research project. There were 23 men and 41 women, whose average age was 20.0 yr.
The purpose of this study was to identify general levels of performance on subtle-obvious scales for several groups and to judge whether a recognized cut-off procedure in fact discriminated between clinical groups and malingerers from a simulation. These MMPI scores were examined to ascertain whether the mean scores of these samples of clinical patients and malingering adults were similar and to estimate the number of false positives which occurred with use of a cut-off of Total obvious minus subtle T score discrepancy greater than 100. The following Tscores are based on the Minnesota standard norms and were obtained by these groups: for 25 obese patients the mean difference score was 36.2 total (SD = 48.4), for 25 psychiatric inpatients 45.96 (SD = 66.93), for 25 outpatients with irritable bowel syndrome 0.92 (SD = 77.37), and for 64 college students 177 (SD = 65.99). Using the Total obvious minus subtle criterion of 100, 16% of the inpatient psychotics would be incorrectly classified as simulators. Even fewer of the patients in the other normal clinical samples would have been rnisclassified Of the obese sample, 100% would have been correctly classified, and 88% of the sample with irritable bowel syndrome would have been correctly classified. Of the malingering college students, 81% would have been correctly classified as malingerers using the rule of 100. Of these subjects, 97% had a total obvious minus subtle score >50.
Discussion and Conclusion The goal here was to view subtle-obvious scores of patients who were not involved in personal injury litigation and to compare discrepancies between subtle and obvious scores for pathology simulators with the same measures for in viuo clinical patients. These data contradict the baserate argument that any individual with psychological problems is likely to score high on indices associated with malingering. These data also rebut the notion of cry-for-help. Most personal injury litigants, including malingerers, do not present as florid psychotics, so it is quite important that for the most part
P R. LEES-HALEY & D. D.FOX
even inpatient psychotics do not score in the range associated with malingering on the subtle-obvious MMPI scales. Several problems with these data demand cautious conclusions. Use of convenience samples led to comparisons of scores from nonmatched samples. Criterion problems such as the reliability and validity of diagnosis of malingering, the significance of college students' simulations, and the motives of various patients such as those with irritable bowel syndrome and obese patients as they answer the MMPI remain unexplained. However, these concerns apply to all MMPI examinees. In personal injury settings, malingerers are not all malingering the same thing, and they cannot be identified by a single procedure as in research with college students. A traditional comparison for the purposes of identifying malingering has been to compare individual patient results with general trends in mahngering research (Greene, 1980; Graham, 1989; Lachar, 1974; Caldwell, 1988). This type of approach casts too broad a net to capture the more purposeful behavior of actual malingerers. Some claimants malinger mild or moderate pathology with partial or no disability, and some malinger profound suffering and total disability. The dichotomous term "malingerer" is superimposed on a continuum with a very wide range, and traditional measures which seek to only differentiate malingerer from nonmalingerer are simply too gross for the specialized questions we see in practice on personal injury. If a patient is malingering rmld to moderate depression in litigation on personal injury, it is not appropriate to make the common assumption that the patient will display a general tendency to overendorse all forms of pathology assessed by the MMPI. O n the contrary, there is reason to believe that malingering patients avoid those psychopathological admissions which undermine their claims (Lees-Haley, 1989). The present limited data suggest there may be differences between simulators and clinical patients which are detectable by use of subtle-obvious scores and that this procedure bears further exploration. A special need is for data drawn from in vivo malingerers during the process of litigation on personal injury. REFERENCES
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Accepted April 7, 1990.