The Psychopathic Personality Inventory: Construct validity of the two-factor structure

Personality and Individual Differences xxx (2007) xxx xxx www.elsevier.com/locate/paid The Psychopathic Personality Inventory: Construct validity of the two-factor structure Katarzyna Uzieblo *, Bruno Verschuere, Geert Crombez Ghent University, Department of Experimental-Clinical and Health Psychology, H. Dunantlaan 2, Ghent 9000, Belgium Received 20 April 2006; received in revised form 8 January 2007 Abstract Evidence suggests that the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996), consists of two factors, Fearless-Dominance (PPI-I) and Antisocial-Impulsivity (PPI-II). The present study investigated the construct validity of the PPI in 165 inmates, and 431 undergraduates. Inmates and students filled in the PPI and the Behavioural Inhibition (BIS) and Behavioural Activation Scales (BAS) (BIS/BAS; Carver & White, 1994). A subgroup of 120 students also filled out the Trait Anxiety Inventory (STAI-T; Spielberger, 1983) and a minor delinquent behaviour questionnaire. Results indicated that PPI-I is related to a low behavioural inhibition (e.g., low distress) and to low trait anxiety, and that PPI-II is related to a strong behavioural activation (e.g., sensation seeking) and to the amount of self reported minor delinquent behaviours. Overall, results support the validity of the two-factor structure of the PPI. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Psychopathy; Psychopathic Personality Inventory; BIS/BAS-Scales; Construct validity; Self-report 1. Introduction Psychopathy is a personality disorder characterized by affective (e.g., lack of remorse), interpersonal (e.g., arrogance), and lifestyle features (e.g., antisocial behaviour). A well validated measure * Corresponding author. Tel.: +32 (0)9 264 91 07; fax: +32 (0)9 264 91 89. E-mail address: Katarzyna.Uzieblo@UGent.be (K. Uzieblo). 0191-8869/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2007.01.008

2 K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx of psychopathy is the Psychopathic Checklist-Revised (PCL-R), which consists of two factors, the affective-interpersonal factor (PCL-R: F1) and the antisocial-lifestyle factor (PCL-R: F2; Hare, 2003). Despite its status as golden standard, the PCL-R has several disadvantages. Completion of the PCL-R is time and labour consuming, with a single assessment readily extending over 2 h. Moreover, the PCL-R is largely based on collateral data, which are not always available. Finally, validation of the PCL-R is primarily based on incarcerated samples, raising the question whether our knowledge of psychopathy is not too much dependent upon data from unsuccessful psychopaths. Acknowledging these limitations, researchers have looked for other instruments. However, many of the self-report instruments do not fully capture the psychopathy concept. Many measures correlate weakly with the total PCL-R score (Kosson, Smith, & Newman, 1990), and often only with the subscale assessing a chronically unstable and antisocial lifestyle (Harpur, Hare, & Hakstian, 1989). A promising instrument is the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996). First, the PPI has a similar factor structure as the PCL-R. Factor analysis in a community sample revealed two factors, i.e. Fearless-Dominance (PPI-I) and Antisocial- Impulsivity (PPI-II), which resemble the content of the two factors of the PCL-R (Benning, Christopher, Hicks, Blonigen, & Krueger, 2003). Second, the PPI significantly correlates with both factors of the PCL-R: The PPI-I-Factor is mainly correlated with PCL-R: F1, and the PPI-II-Factor with PCL-R: F2 (Berardino, Meloy, Sherman, & Jacobs, 2005). Third, the explanatory value of the PPI is similar as that of the PCL-R. Correlations with theoretically relevant constructs such as externalizing behaviours (e.g., antisocial behaviour, alcohol and drug abuse, and aggression) (Benning et al., 2003; Patrick, Edens, Poythress, Lilienfeld, & Benning, 2006), lack of empathy (Sandoval, Hancock, Poythress, Edens, & Lilienfeld, 2000) and fearlessness (Lilienfeld & Andrews, 1996) support this idea. In this study we further investigated the construct validity of the PPI. More specifically, we examined the relationship between the two PPI-Factors and the Behavioural Inhibition System and Behavioural Activation System (BIS/BAS) scales of Carver and White (1994). The BIS/ BAS-Scales assess differences in personality qualities that reflect the sensitivity of two physiological self-regulatory systems; the behavioural inhibition system and the behavioural approach system (Gray, 1970). According to Gray, the BIS-system is sensitive to signals of punishment, absence of reward, and novelty, and is responsible for the experience of negative affect (e.g., fear, anxiety, and sadness). The BAS-system is sensitive to signals of reward, non-punishment, and escape from punishment. The BAS-system consists of three components, all three assessing how individuals respond to rewarding events: responsiveness to reward, drive toward appetitive goals, and fun seeking (Carver & White, 1994). Recent studies support this four-factor structure (Leone, Perugini, Bagozzi, Pierro, & Mannetti, 2001). Research regarding the interrelationships between psychopathy and the BIS/BAS systems is of theoretical interest. Several authors have hypothesized that psychopathy results from an underactive BIS and/or from an overactive BAS. Gray (1970) suggested that psychopaths seek rewards without fear of punishment, indicating a low activity of the BIS. This view has found support (Arnett, 1997), primarily in research using the PCL-R. Diminished aversive conditioning (Flor, Birbaumer, Hermann, Ziegler, & Patrick, 2002) and reduced fear-potentiated startle in psychopathy (Patrick, 1994), for example are in line with this view. It has also been associated with the lack of anxiety (Cleckley, 1941). Other researchers have suggested a hypersensitivity to reward cues in

K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx 3 psychopaths, which would imply a strong BAS (Gorenstein & Newman, 1980). For example, in comparison to non-psychopaths, psychopaths show greater heart rate responsitivity when they are financially rewarded (Arnett, Smith, & Newman, 1997). Evidence for a weak BIS and a strong BAS in psychopaths has also been found using self report measures. Book and Quinsey (2004) administered the BIS/BAS-Scales in an inmate sample, and found lower BIS-scores and higher BAS-scores in the psychopathic offenders compared to non-psychopathic offenders. In this study we further explore the interrelationships between the PPI-Factors and the BIS/ BAS system. Furthermore, we investigated whether a high PPI-I score was related to a low anxiety. Finally, we expected a positive correlation between the PPI-II and the self-report of petty criminal behaviour. To examine these interrelationships we used both an undergraduate and an inmate sample. 2. Method 2.1. Participants Participants were 442 undergraduates from Ghent University, and 170 inmates from four Belgian prisons. All participants were Dutch speaking. Participants with less than 80% responses on the PPI were excluded (Lilienfeld & Widows, 2005). This resulted in a loss of 11 participants (2.49%) in the undergraduate sample, and a loss of five participants in the inmate sample. The final undergraduate sample consisted of 431 participants (M = 18.81 years, SD = 1.49; range: 17 27 years). The majority of the sample was Caucasian and female (57.6%). However, information about the gender of 37 participants (8.6%) was missing. The final inmate sample consisted of 165 participants (M = 37.65 years, SD = 11.39; range: 20 72 years). Ninety six percent were sentenced, of which 23% were placed in the psychiatric department of the prison. Three percent was awaiting trial. Eighty-four percent was of Belgian nationality, whereas 13% was of a different origin and 2% had a double nationality. 2.2. Procedure All participants provided written informed consent. Undergraduates filled in questionnaires as partial fulfilment of course requirements. The majority filled in the questionnaires in small groups. A small number of participants filled in questionnaires individually as part of an experimental study. The inmate sample filled in the questionnaires as part of a larger experimental study. Inmates were paid the equivalent of 1.5 h prison labour (3 euro) for filling out the questionnaires. This study was approved by the ethical commission. 2.3. Material Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) is a 187-item self-report measure of psychopathic personality features. Items are answered using a 4-point Likert scale (1 = false, 2 = mostly false, 3 = mostly true, and 4 = true). The PPI has eight subscales: Machi-

4 K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx avellian Egocentricity (30 items; I always look out for my own interests before worrying about those of the other guy. ) assesses narcissistic and ruthless attitudes in interpersonal functioning; Social Potency (24 items; Even when others are upset with me, I can usually win them over with my charm. ) assesses one s perceived ability to influence and manipulate others; Coldheartedness (21 items; I have had crushes on people that were so intense that they were painful. ) assesses a propensity toward callousness, guiltlessness, and unsentimentality; Carefree Nonplanfulness (20 items; I often make the same errors in judgement over and over again. ) assesses the attitude of indifference in planning one s actions, Fearlessness (19 items; Making a parachute jump would really frighten me. ) assesses the absence of anticipatory anxiety concerning harm and a willingness to participate in risky activities; Blame Externalization (18 items; I usually feel that people give me the credit I deserve. ) assesses the tendency to blame others for one s problems and to rationalize one s misbehaviour; Impulsive Non-conformity (17 items; I sometimes question authority figures just for the hell of it. ) assesses a reckless lack of concern regarding social mores; Stress Immunity (11 items; I can remain calm in situations that would make many other people panic. ) assesses the absence of marked reactions to anxiety-provoking events. Adequate internal consistency and test retest reliability have been reported in undergraduates (Lilienfeld & Andrews, 1996), and in inmates (Chapman, Gremore, & Farmer, 2003). Factor analysis of the PPI subscales yields two factors. Fearless-Dominance (PPI-I-score) includes the Stress Immunity, Social Potency, and Fearlessness subscales. Antisocial-Impulsivity factor (PPI-II) consists of Impulsive Non-conformity, Blame Externalization, Machiavellian Egocentricity, and Carefree Nonplanfulness subscales (Benning et al., 2003). In line with Benning et al. (2003), we calculated the factor scores by averaging the mean of the standardized subscale scores. Because the subscales are based on an unequal number of items, we used the z transformation in order to equally weigh the scores. We used the Dutch version of the PPI (Jelicic, Merckelbach, Timmermans, & Candel, 2004). Jelicic et al. (2004) reported high internal consistency coefficients for the total PPI-score (.92), as well as for its subscales ranging from.76 (Impulsive Non-conformity) to.88 (Social Potency). Also the test retest reliability over a retest interval of 4 weeks was high for the PPI-total score (.99), as well as for its subscales, ranging from.82 (Blame Externalisation) to.93 (Social Potency). Behavioural Inhibition and Behavioural Activation Scales (BIS/BAS-Scales; Carver & White, 1994) is a 20-item self-report measure. Items are answered using a 4-point response scale (1 = strongly agree, 2 = mostly agree, 3 = mostly disagree and 4 = strongly disagree). The BIS- Scale (7 items; I worry about making mistakes. ) assesses the tendency to experience negative affect or behavioural inhibition when cues of threat are present. The BAS-Scale assesses the tendency to experience strong positive affect or behavioural approach when cues of incentive are present, and reflects three scales: Fun Seeking (4 items; I crave excitement and new sensations. ) assesses the impulsive pursuit of pleasure; Drive (4 items; I go out of my way to get things I want. ) assesses the motivation to pursue goals; Reward Responsiveness (5 items; It would excite me to win a contest. ) assesses the tendency to respond with positive affect in the context of desired events or cues of potential future reward. Adequate internal consistencies and test retest reliability have been found for the four BIS/BAS-Scales (Carver & White, 1994). In the present study we used the Dutch version of the BIS/BAS-Scales which has satisfactory psychometric properties (Franken, Muris, & Rassin, 2005). Franken et al. (2005) report modest to good internal consistency coefficients ranging from.59 (BAS-Fun-Seeking-Scale) to.79 (BIS-Scale).

K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx 5 The Trait Anxiety Inventory (STAI-T; Spielberger, 1983) is a 20-item self-report questionnaire of trait anxiety. High internal consistency, with alphas of.90 or higher, has been reported. The test retest reliability with a test retest interval of 104 days was.75 (Spielberger, 1983). We used the Dutch version of the STAI-T, a scale with satisfactory psychometric properties and a good internal consistency with a Cronbach s alpha of.93 (Van der ploeg, Defares, & Spielberger, 1980). Self reported minor delinquent behaviours. An instrument was developed ad hoc to assess the frequency of petty criminal behaviours. The questionnaire consists of nine minor violations (e.g., Have you ever mistreated an animal? ; answer categories: no = 0, yes = 1). The total score was computed by adding up all item-scores. 3. Results 3.1. PPI-Factors and demographic variables Means, standard deviations, and internal consistencies (Cronbach s alphas) of the questionnaire scores are displayed in Table 1. In the undergraduate sample, female undergraduates had lower scores than male undergraduates on the PPI-total, t(391) = 8.48, p <.001, on PPI-I, t(392) = 6.73, p <.001, and on PPI-II, t(391) = 5.95, p <.001. Remarkably, the PPI-scores of the inmates did not differ significantly from the scores of the undergraduates, t < 1. However, in comparison to the inmates, the male undergraduates had higher scores on PPI-total, t(309) = 4.65, p <.001, on PPI-I, t(330) = 3.99, p <.001, and on PPI-II, t(330) = 2.41, p <.05, whereas the female undergraduates obtained lower scores on PPI-total, t(302) = 2.40, p <.05, on PPI-I, t(390) = 2.00, p =.05, and on PPI-II, t(282) = 2.30, p <.05. Because of the gender differences in the undergraduate sample, we also performed separate analyses for males and females. No significant correlations were found between age and PPI-total (r =.13, ns), PPI-I (r =.11, ns), and PPI-II (r =.10, ns) in the male undergraduates. However, in the female undergraduates, age correlated negatively with PPI-total (r =.17, p <.05), and with Table 1 Means, standard deviations, Cronbach s a s of PPI-total score, PPI-I, PPI-II, BIS, BAS, BAS-Reward, BAS-Drive, BAS-Fun, STAI-T, and minor violations from the undergraduate sample, the male undergraduates, the female undergraduates, and the inmate sample Scale Undergraduates Male undergraduates Female undergraduates Inmates n M (SD) a n M (SD) a n M (SD) a n M (SD) a PPI 430 370.21 (41.63).92 167 389.90(38.41).91 226 356.32 (39.08).91 165 367.42 (48.84).93 PPI-I 431 137.02 (21.56).91 167 145.77 (20.27).90 227 131.72 (20.65).90 165 136.18 (23.04).89 PPI-II 430 183.56 (24.02).88 167 191.62 (23.64).88 226 177.56 (22.83).88 165 184.23 (31.69).92 BIS 431 21.08 (3.87).77 167 19.54 (3.88).76 227 22.18 (3.44).73 165 19.54 (3.77).58 BAS 431 43.06 (4.70).76 167 42.81 (4.82).77 227 43.43 (4.53).76 165 41.51 (5.88).78 Reward 431 16.97 (2.20).68 167 16.64 (2.00).59 227 17.29 (2.22).72 165 16.08 (2.53).57 Drive 431 13.21 (2.04).70 167 13.17 (2.10).74 227 13.21 (2.03).67 165 13.43 (2.15).60 Fun 431 12.88 (2.13).63 167 13.01 (2.37).70 227 12.93 (1.92).55 165 12.00 (2.56).60 STAI-T 120 34.56 (7.56).63 82 33.88 (7.27).68 38 36.04 (8.33).46 Violations 120 3.15 (2.37).75 82 3.46 (2.45).76 38 2.47 (2.06).74

6 K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx PPI-II (r =.15, p <.05), but not with PPI-I (r =.10, ns). In the inmate sample, age correlated negatively with PPI-total score (r =.48, p <.01), PPI-I (r =.24, p <.01), and PPI-II (r =.42, p <.01). 3.2. PPI-Factor scores and the BIS/BAS-Scales The zero-order correlations between variables are shown in Table 2. Overall, the pattern of correlations was as expected. The two PPI-Factors intercorrelated in the undergraduate sample, and marginally significantly in the inmate sample (p =.07). In both samples, PPI-I was negatively correlated with the BIS-Scale, and positively with the BAS-Scale, BAS-Drive, and BAS-Fun. In the undergraduate sample, we found a negative correlation between PPI-II and both the BIS-Scale and BAS-Reward, and a positive correlation between PPI-II and BAS-Fun. In the inmate sample, PPI-II correlated positively with the BAS-Scale, BAS-Drive, and BAS-Reward. To further investigate the unique value of each PPI-Factor in explaining the BIS/BAS scales, we adopted a similar strategy as Verona, Patrick, and Joiner (2001). These authors calculated relations with each factor while controlling for the influence of the other factor. The resulting partial correlations are presented in Table 3. In both samples, negative correlations between PPI-I and the BIS-Scale, and positive correlations between PPI-I and the BAS-Scale, BAS-Drive, and BAS-Fun were found. In the undergraduate sample, PPI-II was positively related with BAS-Fun, but negatively with BAS-Reward, and BAS-Drive. In the inmate sample, PPI-II was positively related with the BIS-Scale, the BAS-Scale and with BAS-Fun. Using the formula of Cohen and Cohen (1983), we also tested whether the partial correlations differed between the two samples. First, the correlations were converted into z-scores and compared taking the sample sizes into account. With regard to PPI-I, the correlation with BIS (p =.06) differed marginally significantly between the two samples. With regard to the PPI-II, Table 2 Pearson correlations between PPI-total score, PPI-I, PPI-II, BIS, BAS, BAS-Reward, BAS-Drive, BAS-Fun, STAI-T, and minor violations for the undergraduate sample (n = 431; above the diagonal) and the inmate sample (n = 165; under the diagonal) Scale 1 2 3 4 5 6 7 8 9 10 PPI.78 **.83 **.58 **.13 **.17 **.12 *.35 **.14.54 ** PPI-I.62 **.36 **.68 **.29 **.06.26 **.44 **.38 **.34 ** PPI-II.83 **.14.27 **.02.15 **.04.24 **.15.52 ** BIS.24 **.53 **.06.04.26 **.01.18 **.47 **.18 * BAS.38 **.30 **.29 **.11.74 **.76 **.72 **.11.11 Reward.16 *.14.12.21 **.82 **.37 **.26 **.21 *.07 Drive.30 **.30 **.17 *.02.80 **.50 **.33 **.18.01 Fun.46 **.30 **.39 **.03.82 **.47 **.49 **.16.35 ** STAI-T.06 Violations * p <.05. ** p <.01.

K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx 7 Table 3 Zero-order and semi-partial correlations between PPI-Factors and BIS/BAS-Factors for the undergraduate sample (n = 431) and the inmate sample (n = 165) BIS BAS Reward Drive Fun Zero order Zero order Zero order Zero order Zero order Semipartial Semipartial Semipartial Semipartial Semipartial Relations for PPI-I controlling for PPI-II Undergraduates.68 **.65 **.29 **.30 **.06.00.26 **.29 **.44 **.39 ** Inmates.53 **.54 **.30 **.29 **.14.13.30 **.29 **.30 **.28 ** Relations for PPI-II controlling for PPI-I Undergraduates.26 **.04.02.09.15 **.14 **.04.15 **.24 **.10 * Inmates.06.15 *.29 **.26 **.12.09.17 *.15.39 **.37 ** * p <.05. p <.01. the correlations with BIS (p <.05), BAS (p <.01), BAS-Reward (p <.01), BAS-Drive (p <.01), and BAS-Fun (p <.01) differed significantly between the two samples. 3.3. PPI-Factor scores, the STAI-T-scores and the self reported violations Consistent with our hypothesis, partial correlations show a negative relation between PPI-I and STAI-T (r =.50, p <.001) and a positive relation between PPI-II and STAI-T (r =.36, p <.001). Based upon the negative correlation between the PPI-I and BIS, it might be argued that PPI-I is simply measuring the opposite of trait anxiety in undergraduates. In order to address this issue, we conducted an additional analysis to examine whether the PPI-I scale has unique explanatory value beyond the effects of trait anxiety. After controlling for the influence of trait anxiety and PPI-II, the negative correlation between PPI-I and the BIS-Scale remained significant (r =.58, p <.001). A positive zero-order correlation between PPI-I and the amount of violations (r =.34, p <.001), and between PPI-II and the amount of violations was found (r =.52, p <.001) (see Table 2). In line with our hypothesis, partial correlations show that mainly PPI-II was significantly, positively correlated with the amount of violations (r =.45, p <.001). PPI-I was marginally positively correlated with the amount of violations (r =.18, p =.06). 4. Discussion This study investigated the construct validity of the two PPI-Factors, i.e. Fearless-Dominance (PPI-I) and Antisocial-Impulsivity (PPI-II). We examined the differential relationship of the PPI factors with the BIS/BAS-Scales, the STAI-T, and a self reported violations scale. Furthermore, we compared the interrelationships between the different constructs in an undergraduate sample with those found in an inmate sample.

8 K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx Overall, our findings support the construct validity of the PPI in both samples. As expected PPI-I was related to a low activation of the BIS in both samples indicating low levels of anxiousness in those scoring high on the PPI-I. This is a robust finding (Benning et al., 2003), and is in line with the low-fear-theory, which states that persons with callous-unemotional traits are characterized by an attenuated experience of fear or anxiety (Lykken, 1995). However, our results also reveal that the relation between PPI-I and BIS cannot simply be explained by a lack of trait anxiety. The negative correlation between PPI-I and BIS remained significant, even after controlling for trait anxiety. It is possible that individuals with psychopathic personality features do not only show a lack of anxiety, but also deficiencies in experiencing sadness, frustration, distress and stress reaction (Benning et al., 2003; Carver & White, 1994; Verona et al., 2001). In our study the emotional-interpersonal traits of psychopathy (PPI-I) were found to be related to thrill and adventure seeking. This is in line with previous support (Benning, Patrick, Blonigen, Hicks, & Iacono, 2005a) and may reflect the impulsive engagement in risky, sensational activities while lacking the behavioural inhibition in threatening situations. Also, PPI-I was correlated with BAS-Drive, indicating that individuals scoring high on PPI-I tend to pursue their goals with no holds barred. This idea is in line with the findings of Pham, Vanderstukken, Philippot, and Vanderlinden (2003), who found that individuals with psychopathic characteristics achieved their goals by breaking rules. There were some marked differences between the undergraduates and the inmates, in particular in the relationships between Antisocial-Impulsivity (PPI-II) and each BIS/BAS-Scale. We found a moderate correlation between the BAS-Scale and antisocial, impulsiveness features in inmates, whereas these constructs did not correlate in undergraduates. Although still speculative, it is possible that the BIS/BAS-balance associated with each psychopathy component is different for successful or non-criminal and the unsuccessful or criminal individuals with psychopathic features. This might explain some discrepancies in the literature: Arnett et al. (1997) found support for the strong-bas-model in unsuccessful psychopaths, whereas studies involving successful psychopaths do not unequivocally support this model (Beauchaine, 2001). An elevated BAS may be considered as a risk factor for impulsive, criminal acts. Nevertheless, our results indicate that non-criminal samples also tend to violate rules and laws. Indeed, we found a correlation between both PPI-Factors, in particular with PPI-II, and self-reported crimes in the undergraduates. It seems that non-criminal psychopathy is a moderate expression of psychopathy. However, the difference may not be entirely quantitative. Hall and Benning (2006) suggested that the difference between criminal and non-criminal psychopaths may be critically dependent upon moderating factors such as socioeconomic status. More differences were found between the two samples with regard to the other BIS/BAS-Scales. First, only in the undergraduate sample PPI-II was negatively related to BAS-Reward-Seeking, and the BAS-Drive. This may imply that individuals scoring high on PPI-II neglect to show positive affect when a future reward is present and do not tend to impulsively pursue their goals. Although these findings contradict the current view of psychopaths as persons who impulsively pursue goals and who are especially sensitive to reward cues (Fowles, 1988), this may again reflect a difference between successful and unsuccessful psychopaths. Second, only in the inmate sample PPI-II was modestly positively correlated to the BIS-Scale (see also Newman, MacCoon, Vaughn, & Sadeh, 2005). PPI-II appears to be related to higher levels of anxiety and neuroticism (Benning et al., 2005a) which could explain an increasing inhibition in response to cues for punishment

K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx 9 (Gray, 1987). Nevertheless, replication of our results in larger inmate samples and inclusion of female inmates is warranted to further corroborate the implications of these differences. Several issues of this study require consideration. First, in the present study the two PPI-Factors were intercorrelated, whereas previous research has found no significant correlation (Patrick et al., 2006; but see Benning, Patrick, Salekin, & Leistico, 2005b). Second, unexpected results were found with regard to the PPI-scores. The PPI-scores of the whole undergraduate sample did not differ significantly from those of the inmates. Moreover, the PPI-scores of the male undergraduates were even higher than those of the inmates. Previous studies also failed to find higher PPIscores in inmates compared to control samples (Chapman et al., 2003; Lilienfeld & Widows, 2005). This finding should be explored in future research. Third, because of the absence of female inmates, we cannot generalize our findings to female inmates. Fourth, the present study is restricted to self-report measures. There is a danger of self-presentation strategies. Although the BIS/BAS-Scales is a widely used and psychometrically sound instrument, the interrelationships between behavioural, physiological and self-report measures of the BIS- and the BAS-system remain unclear (Brenner, Beauchaine, & Sylvers, 2005). Finally, in both samples the combination of a weak BIS and a strong BAS was only related to the scores on the Fearless-Dominance factor. Researchers have theorized that the BIS/BAS-balance differs depending on the type of psychopathy. An underactive BIS, and possibly an overactive BAS, may underlie primary psychopathy that is characterized by features encompassed in the fearless-dominance component (Fowles, 1980; Lykken, 1995), whereas an overactive BAS may underlie secondary psychopathy that is characterized by features encompassed in the antisocial-impulsivity component (Lykken, 1995). However, this study does not allow us to investigate this difference. Acknowledgement This research was supported by a doctoral fellowship awarded to the first author by the Fund for Scientific Research, Flanders. References Arnett, P. A. (1997). Autonomic responsitivity in psychopaths: a critical review and theoretical proposal. Clinical Psychology Review, 17, 903 936. Arnett, P. A., Smith, S. S., & Newman, J. P. (1997). Approach and avoidance motivation in psychopathic criminal offenders during passive avoidance. Journal of Personality and Social Psychology, 72, 1413 1428. Beauchaine, T. (2001). Vagal tone, development, and Gray s motivational theory: toward an integrated model of autonomic nervous system functioning in psychopathology. Development and Psychopathology, 13, 183 214. Benning, S. D., Christopher, J. P., Hicks, B. M., Blonigen, D. M., & Krueger, R. F. (2003). Factor structure of the Psychopathic Personality Inventory: validity and implications for clinical assessment. Psychological Assessment, 15, 340 350. Benning, S. D., Patrick, C. J., Blonigen, D. M., Hicks, B. M., & Iacono, W. G. (2005a). Estimating facets of psychopathy from normal personality traits a step toward community epidemiological investigations. Assessment, 12, 3 18. Benning, S. D., Patrick, C. J., Salekin, R. T., & Leistico, A. M. R. (2005b). Convergent and discriminant validity of psychopathy factors assessed via self-report. A comparison of three instruments. Assessment, 12, 270 289.

10 K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx Berardino, S. D., Meloy, R. J., Sherman, M., & Jacobs, D. (2005). Validation of the Psychopathic Personality Inventory on a female inmate sample. Behavioral Sciences and the Law, 23, 819 836. Book, A. S., & Quinsey, V. L. (2004). Psychopaths: cheaters or warrior-hawks? Personality and Individual Differences, 36, 33 45. Brenner, S. L., Beauchaine, T. P., & Sylvers, P. D. (2005). A comparison of psychophysiological and self-report measures of BAS and BIS activation. Psychophysiology, 42, 108 115. Carver, C. S., & White, T. L. (1994). Behavioural inhibition, behavioural activation, and affective responses to impending reward and punishment: The BIS/BAS scales. Journal of Personality and Social Psychology, 67, 319 333. Chapman, A. L., Gremore, T. M., & Farmer, R. F. (2003). Psychometric analysis of the Psychopathic Personality Inventory (PPI) with female inmates. Journal of Personality Assessment, 80, 165 173. Cleckley, H. (1941). The mask of sanity. St. Louis, MO: Mosby. Cohen, J., & Cohen, P. (1983). Applied multiple regression/correlation analysis for the behavioural sciences. Hillsdale, NJ: Erlbaum. Flor, H., Birbaumer, N., Hermann, C., Ziegler, S., & Patrick, C. J. (2002). Aversive Pavlovian conditioning in psychopaths: peripheral and central correlates. Psychophysiology, 39, 505 518. Fowles, D. C. (1980). The three arousal model: implications of Gray s two-factor learning theory for heart rate, electrodermal activity and psychopathy. Psychophysiology, 17, 87 104. Fowles, D. C. (1988). Psychophysiology and psychopathology a motivational approach. Psychophysiology, 25, 373 391. Franken, I. H. A., Muris, P., & Rassin, E. (2005). Psychometric properties of the Dutch BIS/BAS-Scales. Journal of Psychopathology and Behavioral Assessment, 27, 25 30. Gorenstein, E., & Newman, J. P. (1980). Disinhibitory psychopathology: a new perspective and a model for research. Psychological Review, 87, 301 315. Gray, J. A. (1970). The psychophysiological basis of introversion extraversion. Behaviour Research and Therapy, 8, 249 266. Gray, J. A. (1987). Perspectives on anxiety and impulsivity a commentary. Journal of Research in Personality, 21, 493 509. Hall, J. R., & Benning, S. D. (2006). The Succesful psychopath adaptive and subclinical manifestations of psychopathy in the general population. In C. J. Patrick (Ed.), Handbook of psychopathy (pp. 459 478). New York: Guilford Press. Hare, R. D. (2003). The hare psychopathy checklist-revised. Toronto: Multi-Health Systems. Harpur, T. J., Hare, R. D., & Hakstian, A. R. (1989). Two-factor conceptualization of psychopathy: construct validity and assessment implications. Psychological Assessment, 1, 6 17. Jelicic, M., Merckelbach, H., Timmermans, M., & Candel, I. (2004). De Nederlandstalige versie van de Psychopathic Personality Inventory: Enkele Psychometrische Bevindingen [The Dutch Version of the Psychopathy Personality Inventory: some psychometric results]. De Psycholoog, 61, 89 93. Kosson, D. S., Smith, S. S., & Newman, J. P. (1990). Evaluating the construct validity of psychopathy in black and white male inmates: three preliminary studies. Journal of Abnormal Psychology, 99, 250 259. Leone, L., Perugini, M., Bagozzi, R. P., Pierro, A., & Mannetti, L. (2001). Construct validity and generalizability of the carver-white behavioural inhibition system/behavioural activation system scales. European Journal of Personality, 15, 373 390. Lilienfeld, S. O., & Andrews, B. P. (1996). Development and preliminary validation of a self-report measure of psychopathic personality traits in noncriminal populations. Journal of Personality Assessment, 66, 488 524. Lilienfeld, S. O., & Widows, M. R. (2005). Psychopathic Personality Inventory revised: Professional manual. Florida: Psychological Assessment Resources, Inc. Lykken, D. T. (1995). The antisocial personalities. Mahwah, NJ: Erlbaum. Newman, J. P., MacCoon, D. G., Vaughn, L. J., & Sadeh, N. (2005). Validating a distinction between primary and secondary psychopathy with measures of Gray s BIS and BAS constructs. Journal of Abnormal Psychology, 114, 319 323. Patrick, C. J. (1994). Emotion and psychopathy: startling new insights. Psychophysiology, 31, 319 333.

K. Uzieblo et al. / Personality and Individual Differences xxx (2007) xxx xxx 11 Patrick, C. J., Edens, J. F., Poythress, N. G., Lilienfeld, S. O., & Benning, S. D. (2006). Construct validity of the Psychopathic Personality Inventory two-factor model with offenders. Psychological Assessment, 18, 204 208. Pham, T. H., Vanderstukken, O., Philippot, P., & Vanderlinden, M. (2003). Selective attention and executive functions deficits among criminal psychopaths. Aggressive Behavior, 29, 393 405. Sandoval, A. R., Hancock, D., Poythress, N., Edens, J. F., & Lilienfeld, S. (2000). Construct validity of the Psychopathic Personality Inventory in a correctional sample. Journal of Personality Assessment, 74, 262 281. Spielberger, C. D. (1983). Manual for the State-Trait Anxiety Inventory. Palo Alto, CA: Consulting Psychologists Press. Van der ploeg, H. M., Defares, P. B., & Spielberger, C. D. (1980). Handleiding bij de Zelfbeoordelingsvragenlijst: een Nederlandse bewerking van de Spielberger State Trait Anxiety Inventory. Lisse, The Netherlands: Swets & Zeitlinger. Verona, E., Patrick, C. J., & Joiner, T. E. (2001). Psychopathy, antisocial personality and suicide risk. Journal of Abnormal Psychology, 110, 462 470.