The Relationship Between Psychopathic Personality Features and Malingering Symptoms of Major Mental Illness 1

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1 Law and Human Behavior, Vol. 25, No. 6, December 2001 ( c 2001) The Relationship Between Psychopathic Personality Features and Malingering Symptoms of Major Mental Illness 1 Norman G. Poythress, 2,5 John F. Edens, 3 and M. Monica Watkins 4 This study examined the relationship between psychopathy and malingering in a subsample of male prison inmates (n = 55) participating in a larger study of the clinical utility of various assessment measures in correctional settings. Participants capacity to feign major mental illness successfully was evaluated using standard cutoff scores for the detection of malingering on a variety of instruments, including the Structured Inventory of Malingered Symptomatology (SIMS; G. P. Smith & G. O. Burger, 1997), the Structured Interview of Reported Symptoms (SIRS; R. Rogers, R. M. Bagby, & S. E. Dickens, 1992), and the Personality Assessment Inventory (PAI; L. Morey, 1991). Psychopathic traits were assessed via the Psychopathic Personality Inventory (PPI; S.O. Lilienfeld & B. P. Andrews, 1996). Correlations between the malingering indices and the PPI were low (.14 to.14) and not statistically significant. These findings fail to support the clinical intuition that individuals with higher levels of psychopathy are likely to be more adept at malingering. A controversial issue in the assessment literature concerns the role that psychopathy may play in malingering. There is a clear intuitive basis for assuming that psychopaths are more likely than others to be effective (e.g., go undetected) when they feign mental disorder. Two of the cardinal personality features of this construct, pathological lying and the use of conning and manipulative behavior to deceive others (Hare, 1991a), would suggest that psychopaths may be more adept than most persons at dissimulation. As Hare (1993, pp ) noted, 1 Portions of this research were presented at the Biennial Conference of the American Psychology-Law Society, New Orleans, March Department of Mental Health Law & Policy, University of South Florida, Tampa, Florida. 3 Department of Psychology, Sam Houston State University, Huntsville, Texas. 4 Department of Psychology, University of South Florida, Tampa, Florida. 5 To whom correspondence should be addressed at Department of Mental Health Law & Policy, Louis de la Parte Florida Mental Health Institute, University of South Florida, Bruce B. Downs Boulevard, Tampa, Florida ; poythres@hal.fmhi.usf.edu /01/ /1 C 2001 American Psychology-Law Society/Division 41 of the American Psychology Association

2 568 Poythress, Edens, and Watkins Given their glibness and the facility with which they lie, it is not surprising that psychopaths successfully cheat, bilk, defraud, con, and manipulate people and have not the slightest compunction about doing so... The capacity to con friend and foe alike makes it a simple matter for psychopaths to perpetrate fraud, embezzlement, and impersonation, to promote phony stocks and worthless property, and to carry out swindles of all sorts, large and small. Cleckley (1982) attributed psychopaths success at deceiving others to the observation that Overemphasis, obvious glibness, and other traditional signs of the clever liar do not usually show in [their] words or in [their] manner (p. 207, cited in Kropp, 1994). Aside from clinical descriptions, various theories proposed to explain psychopathy also directly or indirectly have addressed the issue of psychopaths supposed increased capacities for and willingness to engage in deception. Lykken (1995), for example, attributes the insincerity and untruthfulness of the Cleckley psychopath specifically to an attenuated ability to experience fear in the same manner as nonpsychopathic individuals. Drawing on neurobiological models of Gray (1987) and Fowles (1980), Lykken argues for a low fear quotient theory of psychopathy and succinctly asserts, Most people would lie more often (and more skillfully) if they were relatively free of fear (p. 137, emphasis added; for an alternative theory regarding the purported relationship between psychopathy and deception, see Levenson, 1992). Awareness of psychopaths purported skills at deceiving people in the community has given rise to the clinical intuition that psychopathic individuals also may be especially prone to and adept at feigning symptoms of mental disorder in mental health settings. This intuition may be fostered in part by the presence of several of the core features of psychopathy (e.g., pathological lying and conning/manipulative behavior) among the diagnostic criteria for antisocial personality disorder (APD) in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association [APA], 1994) and the DSM-IV s identification of the presence of APD as a primary consideration in the assessment of malingering (p. 683). Thus, conventional clinical wisdom as well as existing diagnostic nomenclature suggest that there is a positive association between psychopathy and malingering, an assumption that forensic practitioners may find irresistible (Rogers & Cruise, 2000, p. 272). Whether true or not, this irresistible assumption may drive clinical decisionmaking, particularly in forensic settings where increased rates of both psychopathy and feigned or exaggerated mental illness may be more prevalent than in other clinical settings. This is especially problematic if patients who are genuinely mentally disordered are presumed disproportionately to be malingering simply because they evince psychopathic personality traits. Several studies have shown that psychopathy and serious mental illness can co-occur (e.g., Heilbrun et al., 1998; Nolan, Volavka, Mohr, & Czobor, 1999; Rice & Harris, 1995; Silver, Mulvey, & Monahan, 1999), which raise concerns that such individuals may be more prone to be denied needed mental health services if evidence of psychopathic traits is used to bolster presumptions of feigning or symptom exaggeration. Despite clinical lore and DSM-IV assertions, empirical findings appear to be somewhat at odds with the intuitive relationship between psychopathy and

3 Psychopathy and Malingering 569 malingering. A review by Clark (1997) concluded, most sociopaths 6 are not malingerers. When they do malinger, their feigning is likely to be controlled by exigencies and opportunities rather than simply reflect...character traits. Contrary to expectation, research does not support the belief that sociopathy conveys any advantage to undetected malingering (p. 69). Studies reviewed by Rogers and Cruise (2000) led these authors to the same conclusion:...antisocial persons are generally no more effective than others at feigning mental disorders (p. 272). Despite the purported absence of any connection between these constructs, both Clark (1997) and Rogers and Cruise (2000) acknowledge that there have been relatively few studies to assess directly the psychopathy malingering relationship. Most studies provide only indirect evidence about this relationship because most investigators have not assessed psychopathy per se. Rather, many have used proxy indicators such as APD diagnosis (or, more simply, criminal status) or research/clinical scales (e.g., MMPI Pd Scale) that correlate poorly with more accepted measures of psychopathy, such as the Psychopathy Checklist-Revised (Hare, 1991a). In one of the few studies that used a measure of psychopathic traits, Edens, Buffington, and Tomicic (2000) found that college undergraduates who endorsed higher rates of psychopathic features on the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) were no more adept at avoiding detection when feigning psychotic symptoms than were psychopathic students. Interestingly, the more psychopathic group did report a greater willingness to malinger across various hypothetical situations even though they were no more effective. Given the participants in this study, however, its generalizability to other settings and populations is questionable. The only known study that has directly tested whether an association between psychopathy and malingering exists in a correctional sample is an unpublished dissertation conducted by Kropp (1994; cited in Rogers & Cruise, 2000). Using a simulation design, he found that the presence of psychopathy, measured by PCL-R, did not improve prisoners ability to avoid being detected as malingering on the Structured Interview of Reported Symptoms (SIRS; Rogers, Bagby, & Dickens, 1992). Given the practical implications of this issue (e.g., potential denial of services, stigmatization as both a psychopath and a malingerer ) and the dearth of research to examine it directly, the present study was undertaken to examine directly the relationship between psychopathic personality traits and malingering. Using prison inmates as research participants, we employed a mixed design that included both simulating (i.e., instructed) and known (i.e., judged clinically) malingering individuals. All participants were assessed using a personality inventory designed specifically to assess the core personality features of psychopathy, and multiple measures of malingering were employed to test the null hypothesis of no relationship between psychopathy and efficacy at feigning symptoms of major mental illness. 6 As with DMS-IV defined antisocial personality, the term sociopathy used by Clark is not synonymous with current conceptualizations of psychopathy, although it does share the overlapping features of chronic or habitual lying, conning/manipulating others, and a lifestyle that often involves deceiving others.

4 570 Poythress, Edens, and Watkins METHOD Participants This study is part of a larger research project examining the construct validity and clinical utility of various measures of psychopathy and dissimulation in forensic contexts (see Edens, Poythress, & Watkins, 2001, for further details). Participants were 116 English-speaking, male inmates at a prison in west central Florida. Most were either Caucasian (32.2%) or African American (60.9%), with a mean age of 32.8 years (SD = 9.0). Overall, these individuals reported considerable prior experience with the criminal (and juvenile) justice systems. For example, the mean number of prior misdemeanor and felony arrests were 4.40 (SD = 6.58) and 5.78 (SD = 10.74), respectively. 7 In addition, 58.6% of participants indicate one or more prior prison sentences. Over two-thirds indicated that they had been detained by authorities when they were juveniles and over three-fourths indicated that they had been suspended from school at least once. On average, participants had completed only (SD = 2.05) years of schooling. The total sample consisted of four subgroups of offenders. Two groups of inmates (n = 30 each) were recruited from the general population who had been evaluated by mental health professionals during intake to the Department of Corrections (DOC) and found to be free of major mental disorder. At the time of recruitment into this study, none was taking psychotropic medications or receiving any outpatient mental health services at this prison, which housed a major mental health service facility for DOC. These 60 inmates were randomly assigned to one of two conditions. One of these groups took the clinical and malingering measures (described below) under standard instructions and was labeled GN (General population, Non malingerers); the second of these groups was instructed to malinger on the clinical and malingering measures and was labeled GM (General population, Malingerers). The remaining inmates who participated in this study were recruited from the Crisis Stabilization Unit (CSU), a mental health unit within the prison. Two groups were recruited from this unit, the first of which, Clinical Nonmalingerers (CN) consisted of 30 men admitted to the mental health unit who were judged by the treatment staff to be genuinely mentally ill and not exaggerating or feigning symptoms. The final group (n = 26) consisted of men admitted to the prison s CSU who subsequently were diagnosed by the clinical staff as exaggerating or feigning symptoms of mental illness; this group was labeled CM (Clinical Malingerers). Determinations of feigning were made by the unit s staff psychiatrists, who agreed at the outset of the study to identify to a research assistant those individuals whom they judged to be exaggerating or malingering symptoms of major mental disorder. We provided each psychiatrist a form that listed eight recognized strategies that people may use in order to feign mental illness. This list represented the eight specific strategies that underlie the primary scales of the SIRS (e.g., endorsement of rare symptoms, unusual symptom combinations, inconsistency in observed versus endorsed symptoms, and so forth). For each inmate/patient, the psychiatrist was asked to indicate on the form the malingering strategies detected during the psychiatric assessment. The 7 Three participants who reported greater than 25 prior arrests were excluded from these analyses.

5 Psychopathy and Malingering 571 form also provided a place for the psychiatrist to write in any other clinical manifestations of exaggeration/malingering not captured by these eight strategies. Inmates judged to be genuinely ill (for whom no malingering strategies were detected) were assigned to the CN group; when the psychiatrist indicated that one or more exaggeration/malingering strategies had been observed clinically, the inmate was assigned to the CM group. 8 Measures Psychopathy Psychopathy was assessed using the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996), a self-report measure designed to assess specifically the core personality (as opposed to antisocial lifestyle) features of psychopathy. Content validity was established by writing items that represented 24 different focal constructs that were identified, in a comprehensive review of the literature, as being associated with psychopathy (e.g., superficial charm, manipulativeness, lack of emotional depth, failure to delay gratification, inability to form close attachments). All items on the 187 inventory are worded in the first person, singular, and are rated on a 1 4 scale in which respondents indicate the extent to which they agree with the statement. A total score can be derived that provides a global index of the extent to which individuals are evincing psychopathic personality traits. Aside from the total score, factor analyses (using orthogonal rotation) of undergraduates item scores revealed eight discrete subscales assessing various facets of psychopathy. These subscales are Machiavellian Egocentricity, which consists of 30 items (e.g., I always look out for my own interests before worrying about those of the other guy [True]), and assesses narcissistic and ruthless attitudes in interpersonal functioning; Social Potency, which consists of 24 items (e.g., Even when others are upset with me, I can usually win them over with my charm [True]), and assesses one s perceived ability to influence and manipulate others; Coldheartedness, which consists of 21 items (e.g., I have had crushes on people that were so intense that they were painful [False]), and measures a propensity toward callousness, guiltlessness, and an absence of sentimentality; Carefree Nonplanfulness, which consists of 20 items (e.g., I often make the same errors in judgment over and over again [True]), and assesses an attitude of indifference in planning one s actions; Fearlessness, which consists of 19 items (e.g., Making a parachute jump would really frighten me [False]), and assesses the absence of anticipatory anxiety concerning harm and a willingness to participate in risky activities; Blame Externalization, which consists of 18 items (e.g., I usually feel that people give me the credit I deserve [False]), and assesses a tendency to blame others for one s problems and to rationalize one s misbehavior; 8 In order to address whether there were significant group differences on relevant social/criminal history variables, ANOVAs were completed comparing the four inmate groups on the highest grade completed in school, the number of prior misdemeanor charges, and the number of prior felony charges. Results indicated no significant differences on these variables, Fs(3, 112) = ; ps >.15.

6 572 Poythress, Edens, and Watkins Impulsive Nonconformity, which consists of 17 items (e.g., I sometimes question authority figures just for the hell of it [True]), and measures a reckless lack of concern regarding social mores; and, Stress Immunity, which consists of 11 items (e.g., I can remain calm in situations that would make many other people panic [True]), and assesses an absence of marked reactions to anxiety-provoking events. Good evidence for the reliability and validity of the PPI was established in studies with various undergraduate samples. Coefficient alpha for the PPI Total score ranged from.90 to.93 ( for subscales) and test-retest reliability was.95 ( for subscales). The PPI Total score correlated positively with Hare s (Hare, 1985) self-report psychopathy measure (.62,.91), interview-based measures of antisocial personality features (.59), and with interviewer ratings of psychopathic features (.60). Although originally designed to assess psychopathic features in noncriminal populations, subsequent studies also have found evidence of good reliability and construct validity for the PPI with jail and prison samples. Internal consistency (coefficient alpha) for the PPI Total score has remained high (.90.91) in studies with youthful offender prison inmates (Poythress, Edens, & Lilienfeld, 1998) and adult jail inmates (Sandoval, Hancock, Poythress, Edens, & Lilienfeld, 2000); coefficient alpha for the PPI Total score in the present sample was.90. Evidence for the construct validity of the PPI was reported by Sandoval et al. (2000), who found that the PPI Total score correlated in expected ways with self-report measures of empathy (.45), aggression (.64), and borderline personality features (.34.50). Similarly, in the present study, the PPI Total score correlated.62 with the Antisocial Features (ANT) scale of Morey s Personality Assessment Instrument (Morey, 1991). Finally, two studies have shown that psychopathy as measured by the PPI corresponds reasonably to psychopathy as measured using Hare s interview-and-records based approach in prisoner/forensic populations. In a study with 50 youthful offender prison inmates, Poythress et al. (1998) obtained moderately high correlations between the PPI Total score and Factor 1 (.54), Factor 2 (.40), and the PCL-R Total score (.54). More recently, Kruh et al. (2000) administered the PPI and the screening version of the Psychopathy Checklist (PCL:SV, Hart, Cox, & Hare, 1995) to a forensic sample of 50 adult insanity acquittees and obtained positive (and significant) correlations of.45,.65, and.62 with PCL:SV Factors 1, 2, and Total score, respectively. Major Mental Disorder The Personality Assessment Inventory (PAI; Morey, 1991) was used to assess participants presentation of symptoms of major mental disorder. The PAI is a selfreport measure that taps various forms of clinical symptomatology (11 scales), response styles (4 scales), treatment-related characteristics (5 scales), and interpersonal style (2 scales). The 344 items are written in the first person, singular, and are endorsed as being False, Somewhat True, Mostly True, or Very True. Support for the psychometric properties of the PAI is provided in the manual (Morey, 1991) as well as in independent reports (for a summary of relevant research on the use of the PAI in forensic and correctional settings, see Edens, Cruise, & Buffington, 2001).

7 Psychopathy and Malingering 573 Given the instructional set provided to the GM group (see Procedure), clinically significant elevations (T 70) on the Paranoia, Schizophrenia, Depression, and Mania scales were used to define the presentation of symptoms of major mental disorder. Considerable evidence regarding the content, criterion-related, and convergent and discriminant validity of these particular scales has been reported (Morey, 1991). For example, scores on the Schizophrenia scale have been shown to be elevated among several samples of patients with psychotic diagnoses or symptomatology, or both, and to correlate highly both with MMPI scale 8 (r =.55) and Wiggins Psychoticism content scale (r =.76) among clinical samples. Malingering Three instruments were used to assess malingering. The Structured Inventory of Malingered Symptoms (SIMS; Smith & Burger, 1997) consists of 75 True/False items and can be administered in approximately 15 min. Scores >14 on the SIMS Total score suggest feigning mental disorder. Smith and Burger reported that the SIMS identified both honest and simulated profiles with considerable accuracy. High sensitivity rates for the SIMS also have been reported in a study of 53 adolescents undergoing court-ordered treatment (Rogers, Hinds, & Sewell, 1996), and in an analogue study in which college student participants were instructed to feign either psychosis, cognitive impairment, or major depression (Edens, Otto, & Dwyer, 1999). Three malingering indices from the PAI itself were examined. One is the Negative Impression Management (NIM) scale that consists of items that present an exaggerated unfavorable impression or represent extremely bizarre and unlikely symptoms (Morey, 1991, p. 12). NIM scores 92T were considered indicative of malingering. A second is Rogers discriminant function (RDF), an empirically derived value that combines weighted scores for 20 PAI primary and subscales to yield a malingering index (Rogers, Sewell, Morey, & Ustad, 1996). RDF score equivalents 70T were considered indicative of malingering. Third, the PAI Malingering Index (MAL) is a score based on eight configural features of the PAI profile that tend to be observed much more frequently in the profiles of respondents simulating mental disorder (particularly severe mental disorder) than in actual clinical patients (Morey, 1996, p. 120). A MAL score 5 was considered indicative of malingering. Cut scores on all three of these PAI indices of malingering were derived empirically based on the studies noted above (see Edens, Cruise, & Buffington, 2001, for a more comprehensive review). The third malingering measure used was the Structured Interview of Reported Symptoms (SIRS; Rogers et al., 1992). This 156-item interview queries an individual about current symptoms and yields scores on eight primary scales, each of which represents a different strategy that one may employ in feigning mental disorder (e.g., Rare symptoms, Unusual Symptom Combinations, and so forth). Three potential indices for detecting malingering with the SIRS were examined in this study: 1 or more primary scales elevated to the definite malingering range (DEF); 3 or more primary scales elevated to the probable malingering range (PROB); and SIRS Total score 76.

8 574 Poythress, Edens, and Watkins Procedure Classification Division personnel at the prison identified potential general population participants. A clinic coordinator identified CSU inmates assessed by clinical staff as exaggerating or feigning symptoms of major mental disorder. Interviews were conducted by a research assistant either in the Classification Division Conference Room or in a private interview room on the mental health unit at the prison. After informed consent was obtained using procedures approved by a university Institution Review Board, participants completed a brief personal history/ demographics questionnaire and then took the PPI under standard (answer honestly) instructions. 9 The remaining measures (SIRS, PAI, SIMS) were then administered in random order. The GN, CN, and CM participants were given standard instructions for completing these measures; however, the CM group was advised that results from two of the measures (i.e., SIRS and PAI) would be shared with the CSU staff. This instruction was an effort to reinstate the motivation to malinger in CM inmates who, having now gained admission to the CSU, might have been less motivated to feign illness. The GM group was instructed to answer the questions in such a way as to make a trained psychologist think that you are truly experiencing symptoms of a major mental illness while preventing that psychologist from detecting that you are faking. In all groups, each person was paid $5 for participating in the study. As an incentive to try to malinger without being detected, participants in the GM group were advised that a bonus of $50 would be paid to the person who was most successful at presenting himself as mentally ill without being detected as faking. RESULTS Manipulation Checks Preliminary analysis revealed that for one person in the GM group, none of his scores on the PAI Paranoia, Schizophrenia, Depression, or Mania scales were 70T. Thus, this individual was dropped from the analyses as having failed to meet the experimental definition of presenting symptoms of major mental illness. Table 1 provides the mean T-scores for each group on the Depression, Mania, Paranoia, and Schizophrenia scales of the PAI. Results of a one-way MANOVA to determine whether there was a difference between participants in the GN, GM, CN, and CM groups with respect to their scores on these scales indicated a significant multivariate effect, Wilks λ =.421; F(3, 111) = 9.23, p <.001. Subsequent univariate analyses revealed significant differences among the groups on each of the four clinical scales: depression, F(3, 111) = 26.82, p <.001; mania, F(3, 111) = 4.40, p <.006; paranoia, F(3, 111) = 18.84, p <.001, and schizophrenia, F(3, 111) = 26.14, p <.001. Planned contrasts revealed that the GN group, as expected, obtained significantly lower mean scores on each of these psychopathology scales than the GM, CN, 9 Because of concerns about reading level with this population, items from the PPI and other self-report measures were read aloud by the research assistant.

9 Psychopathy and Malingering 575 Table 1. T-Score Means (Standard Deviations) on Selected PAI Scales for All Groups Group PAI Scale GN GM CM CN Depression (6.43) (15.59) (15.31) (13.18) Mania (11.42) (12.78) (14.63) (14.90) Paranoia (7.58) (15.16) (13.58) (11.68) Schizophrenia (6.84) (22.39) (18.58) (15.35) Note: GN general population inmates, instructed to answer honestly (nonmalingerers); GM general population inmates, instructed to feign mental disorder (malingerers); CM mental health unit inmates judged clinically to be exaggerating or feigning (malingerers); and CN mental health unit inmates judged clinically not to be exaggerating or feigning (nonmalingerers). and CM groups combined (all ps <.001). Further, the mean scores of the GM group were not significantly different from those of the combined CM and CN groups for the depression and mania scales (ps =.13 and.18, respectively), and their mean scores were significantly higher than those of the combined clinical groups for the paranoia, F(1, 84) = 10.26, p <.001, and schizophrenia scales, F(1, 84) = 13.60, p <.001. Thus, with the possible exception of the one excluded participant noted above, members of the GM group did respond to the experimental instruction to endorse symptoms of major mental illness. Psychopathy and Malingering The mean PPI Total score for the sample was (SD = 47.15); the mean of the combined malingering groups (GM, CM) was (SD = 43.67) and did not differ substantially from that of the combined nonmalingering groups (GN, CN), (SD = 51.09). The analyses examining the relationship between psychopathy and malingering involved the 55 participants who were instructed either to fake bad (GM, n = 29) or clinically assessed as feigning (CM, n = 26) and are presented in Table 2. Point-biserial correlations between the continuous PPI score and dichotomous malingering outcome for each index are shown separately for each group and for the two groups combined. These results provide no basis for rejecting the null hypothesis in favor of the contention that psychopathy conveys an advantage in feigning mental illness. Only 2 of 21 correlations are statistically significant and one of those is in the opposite direction from what the alternative hypothesis would predict. The remaining correlations are low and, in many instances, also in the reverse direction from what the alternative hypothesis would predict. As noted earlier, the personality features that give rise to intuitions about successful feigning by psychopaths include pathological lying and conning/manipulative behavior. Thus, although the PPI Total score bore no significant relationship to malingering success, it is possible that effective feigning might be associated with particular facets of psychopathy. We therefore examined the correlations between the eight PPI subscale scores 10 and outcomes on the seven malingering indices. Again, we found 10 Among PPI subscales, the Machiavellian Egocentricity and Social Potency subscales contain most of the items that relate to deceiving and manipulating others (Lilienfeld, 1999, personal communication).

10 576 Poythress, Edens, and Watkins Table 2. Point Biserial Correlations Between PPI Psychopathy and Success at Malingering Group Malingering index GM (n = 29) CM (n = 26) Combined (n = 55) SIMS Total SIRS DEF SIRS PROB SIRS Total Score PAI NIM.41* PAI RDF.12.58*.06 PAI MAL Note: GM general population inmates instructed to malinger; CM mental health unit inmates judged clinically to be malingering; SIMS Total total score on the Structured Inventory of Malingered Symptoms; SIRS Structured Interview of Reported Symptoms; DEF 1 or more scores elevated in the definite malingering range on the SIRS; PROB 3 or more scores elevated in the probable malingering range on the SIRS; Total total score on the SIRS; PAI Personality Assessment Inventory; NIM Negative Impression Management; RDF Roger s Discriminant Function index; and MAL Malingering index. *p <.05. little evidence that higher scores on any facet of psychopathy, as measured by the PPI, conveys an advantage for feigning major mental disorder. Only three of the 56 correlations were statistically significant, the highest being.30 ( p <.05); 16 of the correlations were negative, and an additional 14 were less than.10. DISCUSSION In this study using prison inmates as research participants, psychopathy, as measured by the Psychopathic Personality Inventory, was unrelated to success at defeating a variety of psychometric indices for detecting malingering. The results do not support the proposition that individuals with substantial psychopathic features are likely to be more effective at feigning symptoms of serious mental illness than those who do not evince these personality traits. These results, in conjunction with the findings of other research noted earlier, clearly question the rationale of including APD as a risk factor for malingering in DSM-IV and support the contention of Clark (1997) and Rogers and Cruise (2000) that the association between these constructs primarily appears to be a spurious one. The clinical implications of this illusory correlation potentially are quite significant, in that determinations of malingering may have profound consequences for examinees undergoing forensic evaluations. For example, in one recent federal case, a defendant received an enhancement to his sentence for obstruction of justice because of his purported feigning of mental disorder (Frederick & Conroy, 1999). One hypothesis as to why people with higher levels of psychopathy may not have been effective at dissimulating in this research context is that little clinical judgment was involved in classifying participants as malingering versus not. The measures used to detect malingering (SIMS, SIRS, PAI) all employ indices with recommended

11 Psychopathy and Malingering 577 decision-making cutoffs established in prior studies (see Edens, Cruise et al., 2001; Morey, 1991; Rogers et al., 1992; Smith & Burger, 1997, for an overview of this research). Although in clinical practice these cutoff scores are not dispositive of the judgment concerning malingering, they function in this context like purely actuarial measures. To the degree that success at deceiving others (e.g. clinicians) depends in part on interpersonal interactions during which various manipulations or strategies may be attempted to convey certain impressions or to generate particular reactions, the research design employed here precluded such activities. However, Cogburn (1993) found that psychopathic prison inmates (defined by the PCL-R) were rated as less believable in interviews, which would militate against this alternative hypothesis. To our knowledge, such research has not been conducted on nonincarcerated (i.e. successful ) psychopaths, however, which would be an informative line of future research. Another consideration in terms of understanding our results is the degree to which special knowledge or expertise may be needed to deceive successfully in mental health evaluations. Rationally constructed measures, such as the SIRS, capitalize on special knowledge concerning the nature and patterns of symptoms, trajectories of mental illnesses, and so forth. The presence of enhanced features of psychopathy offers no assurance that the special knowledge needed to cope with sophisticated detection strategies will be at hand. Indeed, the PCL-R scoring instructions for rating the presence of glibness/superficial charm note that psychopathic individuals may casually use technical terms and jargon effectively enough to impress most people. Careful questioning will usually reveal that his knowledge is only superficial (Hare, 1991b, p. 19). The use of both simulators and known malingerers potentially is a strength of the present study although questions regarding the diagnostic criteria for defining the known malingering group is always a concern. In this study we accepted treating psychiatrists judgments that certain inmates were exaggerating or feigning symptoms of mental disorder and made categorical classifications as to whether feigning was present or absent. However, this approach is not entirely satisfying, and the development over the past 15 years of structured and standardized approaches to the assessment of malingering has been spurred in part precisely by concerns about the validity of such clinical judgments. Others (e.g., Gacono, Meloy, Sheppard, Speth, & Roske, 1995) have identified known malingerers on the basis of those individuals own admission to having previously feigned mental illness. However, such self-nominators are not always available and, as Rogers and Cruise (2000) have noted, questions can be raised about the validity of such groups some such individuals may have motivations to confess falsely to prior malingering. Moreover, nothing is learned from such studies regarding malingerers who do not admit to such exaggeration or dissimulation. Some support for the validity of our CM group is found in Table 1, which indicates that these inmates scores on key PAI scales were comparable to those of the inmates who were instructed to malinger. We also compared the CM group with the CN group in terms of the proportion of participants classified as feigning by each of the seven malingering indicators. Under the assumption that the psychiatrists malingering judgments were (at least somewhat) valid, we would expect that

12 578 Poythress, Edens, and Watkins proportionately fewer CN participants than CM participants would be classified by the various measures as malingering. This was in fact what we found. Depending on the particular malingering index examined, 8 20% fewer CN than CM participants met the cutoff score for malingering. Recognizing that neither the psychiatrists judgments nor the instruments yield perfectly valid decisions, these findings offer some support for the CM group as defined in this study. One common concern in this type of research is our use of a dimensional (as opposed to categorical) measurement of the psychopathy construct. The PPI was designed to assess the core personality features of psychopathy dimensionally and there is no accepted cut score for dichotomous classifications. 11 The PCL-R also assesses psychopathy dimensionally although Hare (1991a) recommends that a PCL-R score 30 may warrant a diagnosis that an individual is a psychopath. Those who advocate the view that psychopathy is a taxon might consider it a limitation in this research that the PPI does not identity dichotomously true psychopaths whose skill as malingerers can then be assessed. 12 Whether psychopaths represent a discrete class, however, is controversial. We have found only one published study (Harris, Rice, & Quinsey, 1994) providing limited support for the notion that psychopathy is a taxon, and Lilienfeld (1998) has noted several limitations of this research and concluded that the results...should be viewed with caution for several reasons. First, they found evidence of taxonicity only for Factor II and only for childhood antisocial behaviors. No evidence of taxonicity was found for Factor I traits, which ostensibly represent the core personality features of psychopathy. Consequently, their conclusion that Results supported the existence of a taxon underlying psychopathy (p. 387) appears to be unwarranted (pp ). Hare, too, considers that more research is needed (1996, p. 36) on this issue and that whether psychopathy is a taxon remains an open question (Hare, 2000, personal communication). Thus, we take the view that psychopathy assessed dimensionally, as with the PPI, is a viable approach given the current evidence on this issue. A related concern about our choice of the PPI as our index of psychopathy relates to its self-report format. Researchers and clinicians have expressed concerns regarding the efficacy of assessing psychopathic features with a self-report inventory, which may be viewed as a limitation of the present study. Hare (1985, 1991a, 1996), for example, has repeatedly cautioned against the use of self-report scales to assess psychopathy, and with good reason. Scales from general personality inventories such as Pd and Ma from the MMPI/MMPI-2 and So from the California Psychological Inventory have been found to correlate weakly with the PCL-R, the most widely accepted clinical and research measure of psychopathy. Although these scales occasionally correlate moderately with the PCL-R Total score or with Factor 2, which 11 An empirically derived PPI cut score in the study by Poythress et al. (1998) accurately classified 86% of the prison inmates according to PCL-R diagnosis. However, that cut score has not been cross-validated and thus was not employed in the analyses here. 12 Although we have reservations about the utility of group-level analyses on the PPI, we reran our primary analyses after dividing participants into high psychopathy (upper 20% of our sample) and low psychopathy (lower 80%) groups. Results were basically identical to the dimensional analyses, in that members of the high psychopathy group were no more able to avoid detection than those of the low psychopathy group.

13 Psychopathy and Malingering 579 measures primarily social deviance and antisocial lifestyle, low and (often) nonsignificant correlations have been found routinely with Factor 1, which measures core personality features of psychopathy (see, e.g., Brandt, Kennedy, Patrick, & Curtin, 1997; Haapasalo & Pulkkinen, 1992; Harpur, Hare, & Hakstian, 1989). A similar pattern of results was obtained recently with the Antisocial (ANT) scale of Morey s (1991) PAI (Edens, Hart, Johnson, Johnson, & Olver, 2000; Edens, Buffington, Colwell, Johnson, & Johnson, in press). It is more difficult, however, to levy this criticism against the PPI. The development of both the PCL-R and the PPI was influenced significantly by attention to Cleckley s clinical characterization of the psychopathic personality although neither captures all of (nor exclusively) the cardinal features described by him. For example, the PCL-R includes criminal history variables not included in the original description of the syndrome, and it does not assess directly for the absence of nervousness/trait anxiety (Schmitt & Newman, 1999). The grounding of the PPI in the same conceptual framework as the PCL-R perhaps contributes to the research, noted above, finding moderately high correlations between the PPI Total score and all three PCL indices in studies with both prison inmates and forensic psychiatric patients. Thus, the available evidence provides ample support for the research use of the PPI to assess the core personality features of psychopathy. One limitation of this study is the small number of research participants. With n = 55 for our correlational analysis, the study does not have sufficient power to detect a small association (e.g., r =.10.20) between psychopathy and malingering (Cohen, 1988, Table 3.3.2). Further research using larger samples will be needed to further explore this issue. Another potential limitation relates to the generalizability of this research because of our use of a corrections sample. It can be argued that people with psychopathic traits who are incarcerated represent a particularly unsuccessful subgroup who may not be as effective at manipulation as others with comparable psychopathic features who have avoided major criminal sanctions. Both Cleckley (1982) and Hare (1996) have suggested that psychopathic features are well-represented in the general population, and it may be that psychopathic individuals capable of surviving (and thriving!) in the community may have superior skills at manipulating and deceiving others, which would enable them also to effectively feign mental disorder. The limited research to date with college student samples, however, does not support this hypothesis. Edens, Buffington, et al. (2000) found that students with higher levels of PPI psychopathy perceive that they are able to con and manipulate others effectively; however, these individuals displayed no particular skill at feigning mental disorder. Finally, we note that various malingering indices employed in this study differed considerably in their hit rates for detecting malingerers. For group GM, the proportion avoiding detection ranged from a low of 10.3% (SIMS Total and SIRS Total) to a high of 48.3% (SIRS DEF and PAI MAL) whereas for the CM group, this proportion ranged from a low of 15.4% (SIMS Total) to a high of 76.9% (SIRS DEF). These variations in sensitivity raise questions about construct validity of these measures and their comparability for the clinical assessment of malingering. Some of this variation may be explained by differences in the way the various tests were constructed. The SIRS, for example, was developed from a comprehensive analysis and set of items written specifically to reflect various deception strategies that

14 580 Poythress, Edens, and Watkins had been identified in the anecdotal clinical literature; the PAI RDF index, on the other hand, was derived from a more purely empirical investigation of PAI scales, not all of which were written specifically to assess some aspect of malingering. Further, the cutoff scores selected by the developers of these measures may have been set on the basis of different values or judgments about the costs of different types of errors. For example, cutoff scores for screening instruments (such as the SIMS) are often designed for maximum sensitivity and with (relatively) less concern for false positive errors; other indices (e.g., SIRS PROB) explicitly place a premium on avoiding false positive classifications, but at the cost of lower sensitivity. Although it was beyond the scope of the present investigation, it may be of interest for future researchers to establish experimental cutoffs on these various indices on the basis of a common rational or metric, thus enabling them to examine the comparability of performance in detecting malingering in various populations of interest. In summary, our results, as well as the findings of other investigators, offer essentially no support to the position that psychopathy predicts an increased ability to feign successfully the symptoms of mental disorder. Clinicians and diagnosticians should be wary of drawing unwarranted conclusions about the extent to which knowledge of examinees level of psychopathic traits informs their understanding of these individuals abilities to malinger, particularly in forensic or correctional contexts. ACKNOWLEDGMENTS This research was supported by a grant to the first author from the Division of Sponsored Research at the University of South Florida. The authors express their thanks to Scott O. Lilienfeld for comments on an earlier draft of this paper. REFERENCES American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: American Psychiatric Press. Brandt, J. R., Kennedy, W. A., Patrick, C. J., & Curtin, J. J. (1997). Assessment of psychopathy in a population of incarcerated adolescent offenders. Psychological Assessment, 9, Cleckley, H. (1982). The mask of sanity (5th ed.). St. Louis: Mosby. Clark, C. R. (1997). Sociopathy, malingering, and defensiveness. In R. Rogers (Ed.), Clinical assessment of malingering and deception (2nd ed.) (pp ). New York: Guilford. Cogburn, R. A. K. (1993). A study of psychopathy and its relation to success in interpersonal deception. Unpublished doctoral dissertation, University of Oregon, Eugene. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Erlbaum. Edens, J. F., Buffington, J. K., Colwell, K., Johnson, D. W., & Johnson, J. (in press). Psychopathy and institutional misbehavior among incarcerated sex offenders: A comparison of the Psychopathy Checklist- Revised and the Personality Assessment Inventory. Journal of Forensic Mental Health. Edens, J. F., Buffington, J. K., & Tomicic, T. L. (2000). An investigation of the relationship between psychopathic traits and malingering on the Psychopathic Personality Inventory. Assessment, 7, Edens, J. F., Cruise, K. R., & Buffington, J. K. (2001). Forensic and correctional applications of the Personality Assessment Inventory. Behavioral Sciences and the Law, 19, Edens, J. F., Hart, S. D., Johnson, D. W., Johnson, J., & Olver, M. E. (2000). Use of the Personality Assessment Inventory to assess psychopathy in offender populations. Psychological Assessment, 12,

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