سهم برخی ویژگی های شخصیتی روانی، خودشیفتگی، ماکیاولی و سادیستی برای بزهکاری نوجوانان

Abstract The aim of this study was to assess the relative contributions of psychopathic, narcissistic, Machiavellian, and sadistic traits to delinquent behaviors in adolescents. Participants were 615 high-school students who completed self-report questionnaires. Psychopathic, narcissistic, Machiavellian, and sadistic traits were moderately correlated suggesting they may be overlapping but distinct constructs. Hierarchical multiple regression analyses were conducted to control for other socio-familial or psychopathological risk factors. Psychopathic and sadistic traits were independent predictors of delinquent behaviors in boys only. These findings suggest the importance of studying the role of sadistic traits in juvenile delinquency.

1. Introduction Delinquent behavior among adolescents is associated with a multitude of risk factors (Kazdin, 1992 and Loeber et al., 2000). Among the psychological factors, many dimensions of personality have been associated with juvenile delinquency. The present study focused on the contribution of socially aversive personality traits: psychopathic, narcissistic, Machiavellian and sadistic traits. The role of psychopathic traits has been emphasized in the last decades. The classic clinical description considered psychopathy as a severe personality disorder centered on callousness and unemotionality (Cleckley, 1976). Levenson (1992) suggested conceptualizing psychopathy not as a categorical entity but as a dimension of personality. More recently, the concept of psychopathy has been extended to children and adolescents: antisocial youths with psychopathic traits have been shown to have a greater number, variety and severity of conduct problems in forensic, mental health and community samples (Salekin & Frick, 2005). Narcissistic personality disorder is dominated by a grandiose sense of self-importance, a sense of superiority and lack of empathy. The association between narcissistic and psychopathic personality disorders has been emphasized by Kernberg (1975). Narcissistic personality traits have been found to be linked to conduct problems in children (Barry, Frick, & Killian, 2003). Machiavellianism has been described as a dispositional tendency to manipulate and exploit others (Christie & Geis, 1970). These authors have conceptualized Machiavellianism as a normal dimension of personality and have observed that respondents endorsing Machiavellian traits were more likely to behave in a cold and manipulative way in laboratory and real word studies. Machiavellianism has been recently linked to juvenile delinquency (Hadjar, Baier, Boehnke, & Hagan, 2007). Psychopathy, narcissism and Machiavellianism have been described as the ‘Dark Triad’ of personality (Jakobwitz and Egan, 2006, Lee and Ashton, 2005 and Paulhus and Williams, 2002). In a non clinical sample of college students, Paulhus and Williams found that males scored higher on all three of the ‘Dark Triad’ traits and that measures of these three personality traits were moderately intercorrelated, with Pearson’s r ranging from .25 to .50, suggesting that they were overlapping but distinct constructs. No study to date has explored the association between the ‘Dark Triad’ personality traits and delinquency. Only one study ( Vaughn, Newhill, DeLisi, Beaver, & Howard, 2008) found links between two measures of psychopathy (which had labels alluding to Machiavellianism and narcissism) and three misbehaviors in 94 delinquent girls. Sadistic personality disorder is characterized by a pattern of cruelty, aggression and demeaning behavior. This diagnosis appeared in the DSM-III-R (American Psychiatric Association, 1987) but was removed from the current version of the DSM. Although, research on sadistic personality disorder is on-going to this day, few studies have focused on this disorder in non-offender populations and in adolescents. High rates of sadistic personality disorder or traits have been found in adolescent psychiatric inpatients (Myers, Burket, & Husted, 2006) and in juvenile sexual homicide offenders (Myers & Monaco, 2000). In non-clinical, non-forensic youth populations, the rates of endorsement of sadistic personality disorder traits have been found to be quite high. In a sample of college students, the rate of sadistic personality disorder was 5.7% (Coolidge, Moor, Yamazaki, Stewart, & Segal, 2001). O’Meara, Davies, and Barnes-Holmes (2004) reported that 6.9% of a sample of 407 undergraduates considered themselves sadistic whereas 5.6% claimed to enjoy hurting others. However, so far no studies have explored the association between sadistic traits and delinquency in non-clinical, non-forensic adolescents. Furthermore, there have been no investigations of the relationship between sadistic traits and the ‘Dark Triad’ traits in adolescents. The aim of the present study was to assess the relative contributions of the ‘Dark Triad’ and sadistic personality traits to adolescent delinquent behavior controlling for other major risk factors. A number of psychological and socio-familial risk factors have been identified including impulsiveness and sensation seeking, borderline personality disorder and traits, depression, substance use, social disadvantage, family problems such as poor attachment and parent–child discord, exposure to stressful life events and academic failure (Kazdin, 1992 and Loeber et al., 2000). In this study, we investigated the contribution of the ‘Dark Triad’ and sadistic traits to delinquent behavior in a non-clinical sample of high-school students after controlling for the main other psychological and socio-familial factors.

Results 3.1. Delinquent Behaviors Seventy percent of participants reported at least one delinquent behavior during the past year (77% boys vs. 59% girls). A higher percentage of boys compared to girls had already started a fight (49% boys vs. 27% girls; p < .001), been to school drunk (40% boys vs. 25% girls; p < .001), threatened someone seriously or beaten somebody up (34% boys vs. 22% girls; p < .01), carried a blade, knife, or gun in school (26% boys vs. 14% girls; p < .01), hurt someone badly in a physical fight so that they had to be treated by a doctor or nurse (22% boys vs. 8% girls; p < .01), pick-pocketed somebody (18% boys vs. 10% girls; p < .01), been involved in a gang fight (13% boys vs. 7% girls; p < .05) stolen a motorcycle or a car (11% boys vs. 6% girls; p < .01) and had been to school after smoking marijuana (23% boys vs. 20% girls; p < .01). Boys reported a greater number of delinquent behaviors than girls (6.3 ± 7.3 vs. 3.2 ± 5.1, t = 5.5, p < .0001). 3.2. Comparison between offenders and non-offenders and between genders Two-way ANOVAs were conducted to explore the main effects and interactions between gender and offending for the ‘Dark Triad’ personality traits, sadistic traits, sensation seeking, impulsivity, borderline personality traits, depressive symptoms, cannabis and alcohol users, life events, socio-economic status, attachment to parents, and having repeated a class (Table 1). All main effects were significant save for the main effects of offending on psychopathic traits, parental attachment and family affluence, and the main effects of gender on cannabis use and repeating a class. Only the interaction effect between gender and offending on levels of impulsivity was significant F(1, 598) = 5.72, p < .05. Table 1. Breakdown by gender and offending group of means and standard deviations for study variables. Offenders (n = 430) Non-offenders (n = 185) ANOVA main effects offending M SD M SD YPI Males 33.90 7.05 31.78 6.55 F(1, 598) = 15.05, p < .001∗∗ Females 28.98 6.75 26.32 6.21 ANOVA main effect gender F(1, 598) = 7 .90, p < .001∗∗ NPI Males 5.17 3.23 4.83 3.25 NS Females 4.37 2.76 3.65 2.83 ANOVA main effect gender F(1, 598) = 12.53, p < .001∗∗ MACH IV Males 69.39 10.71 66.15 11.49 F(1,598) = 10.43, p < .001∗∗ Females 66.49 9.35 61.43 11.96 ANOVA main effect gender F(1, 598) = 15.23, p < .001∗∗ MACH-6 Males F(1,598) = Females ANOVA main effect gender F(1, 598) = HS Males 20.60 6.14 17.65 6.25 F(1,598) = 36.65, p < .001∗∗ Females 19.67 6.36 16.10 5.24 ANOVA main effect gender F(1, 598) = 6.31, p < .05∗ Impulsivitya Males 46.55 10.68 45.35 11.39 F(1,598) = 13.25, p < .001∗∗ Females 51.49 9.95 45.71 10.11 ANOVA main effect gender F(1, 598) = 7 .67 p < .01∗∗ BSSS Males 21.78 5.97 19.39 5.87 F(1,598) = 23.15, p < .001∗∗ Females 20.92 5.99 18.05 6.26 ANOVA main effect gender F(1, 598) = 4 .07 p < .05∗ BPD Males 33.06 10.32 30.38 10.97 F(1,598) = 12.45, p < .001∗∗ Females 36.38 11.35 32.15 11.16 ANOVA main effect gender F(1, 598) = 6 .77, p < .01∗∗ CES-D Males 10.05 5.53 8.63 4.80 F(1,598) = 9.93, p < .01∗∗ Females 12.73 5.99 11.04 4.73 ANOVA main effect gender F(1, 598) = 2 6.75, p < .001∗∗ Cannabis Males 1.78 2.68 .22 .99 F(1,598) = 41.17, p < .001∗∗ Females 1.27 2.31 .26 .93 ANOVA main effect gender NS Alcohol Males 2.89 1.82 1.87 1.66 F(1,598) = 35.74, p < .001∗∗ Females 2.24 1.69 1.40 1.47 ANOVA main effect gender F(1, 598) = 12.61, p = 001∗∗ Life events Males 30.88 18.05 21.18 13.95 F(1,598) = 32.53, p < .001∗∗ Females 37.32 16.71 29.32 16.71 ANOVA main effect gender F(1, 598) = 21.61, p = .001∗∗ IPPA Males 32.84 5.85 33.33 5.70 NS Females 31.55 6.99 31.94 6.56 ANOVA main effect gender F(1, 598) = 5.56, p = .05∗ FAS Males 9.11 1.52 9.24 1.50 NS Females 8.75 1.60 8.66 1.48 ANOVA main effect gender F(1, 598) = 11.36, p = .01∗∗ Repeating a class Males .69 .72 .37 .57 F(1,598) = 12.90, p < .001∗∗ Females .60 .62 .48 .70 ANOVA main effect gender NS Note: YPI = Youth Psychopathic Inventory; NPI = Narcissistic Personality Inventory; Mach 6 = 6 items of the Machiavellianism Inventory; HS = urting Scale; BSSS = Brief Sensation Seeking Scale; BPD = Borderline Personality Disorder; CES-D = Center for Epidemiological Studies-Depression scale; IPPA = Inventory of Parent and Peer Attachment; FAS = Family Affluence Scale. a Statistically significant interaction between gender and offending group, p < .05. Table options 3.3. Intercorrelations between psychopathic, narcissistic, Machiavellian, and sadistic traits Psychopathic, narcissistic, Machiavellian and sadistic traits were moderately correlated, with Pearson’s r ranging from .27 to .37 (Fig. 1). To evaluate if the different measures of these four traits loaded on a more general second-order factor, we conducted a hierarchical analysis of oblique factors which showed there was not a general deviant personality factor that was likely to reflect all types of traits. There appeared to be four primary unique factors corresponding to psychopathic, narcissistic, Machiavellian and sadistic traits. The four constructs thus obtained, appeared to display a greater degree of independence than the original four, with Pearson’s r ranging from .01 to .26 ( Fig. 1). Correlations amongst all the study variables are presented in Table 2 and Table 3. Correlations between the measures of the Youth Psychopathic traits Inventory, ... Fig. 1. Correlations between the measures of the Youth Psychopathic traits Inventory, Narcissistic Personality Inventory, Machiavellianism inventory and the Sadistic Attitudes and Behavior Scale and correlations between the Factor Scores (in brackets). Figure options Table 2. Correlation between all variables among boys (n = 380). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1. Age − .18⁎⁎ −.09 −.12⁎ .61⁎⁎⁎ .05 .10⁎ .08 .19⁎⁎ .23⁎⁎ −.06 .10⁎ .04 −.01 .06 .25⁎⁎ 2. Life events − −.25⁎⁎ −.04 .23⁎⁎ .12⁎ .40⁎⁎⁎ .38⁎⁎⁎ .26⁎⁎⁎ .16⁎⁎ .07 .03 .03 .06 .18⁎⁎ .27⁎⁎⁎ 3. Attachment to parents − .23⁎⁎ −.10⁎ −.06 −.31⁎⁎⁎ −.36⁎⁎⁎ −.16⁎⁎ −.12⁎ −.19⁎⁎ −.04 −.10⁎ −.17⁎⁎ −.24⁎⁎ −.18⁎⁎ 4. Socioeconomic status − −.13⁎ .03 −.15⁎ −.12⁎ −.13⁎ .01 −.04 −.06 .02 −.04 −.05 −.10⁎ 5. Repeating a class − .03 .08 .02 .15⁎ .11⁎ −.02 .04 −.01 −.02 .06 .28⁎⁎ 6. Sensation Seeking − .20⁎⁎ .05 .26⁎⁎⁎ .22⁎⁎ .27⁎⁎⁎ .18⁎⁎ .13⁎ .18⁎⁎ .24⁎⁎ .24⁎⁎ 7. Borderline traits − .49⁎⁎⁎ .22⁎⁎ .23⁎⁎ .25⁎⁎ .02 .07 .18⁎⁎ .30⁎⁎⁎ .24⁎⁎ 8. Depressive symptoms − .10⁎ .11⁎ .14⁎ −.06 −.04 .06 .20⁎⁎ .15⁎ 9. Cannabis use − .32⁎⁎⁎ .16⁎⁎ .11⁎ .19⁎⁎ .10⁎ .21⁎⁎ .54⁎⁎⁎ 10. Alcohol use − .17⁎⁎ .08 .15⁎ .18⁎⁎ .26⁎⁎ .32⁎⁎⁎ 11. Impulsivity − .17⁎⁎ .14⁎ .18⁎⁎ .11⁎ .19⁎⁎ 12. Psychopathic traits − .32⁎⁎⁎ .32⁎⁎⁎ .38⁎⁎⁎ .35⁎⁎⁎ 13. Narcissistic traits − .39⁎⁎⁎ .40⁎⁎⁎ .24⁎⁎ 14. Machiavellian traits − .48⁎⁎⁎ .25⁎⁎ 15. Sadistic traits − .40⁎⁎⁎ 16. Delinquent behaviors − ⁎ p < .05. ⁎⁎ p < .01. ⁎⁎⁎ p < .001. Table options Table 3. Correlation between all Variables among Girls (n = 230). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1. Age − .04 .03 −.21⁎⁎ .55⁎⁎⁎ −.07 −.06 −.01 .06 .04 −.10⁎ .16⁎⁎ .01 −.08 .09 .01 2. Life events − −.09 −.06 .04 .07 .44⁎⁎⁎ .46⁎⁎⁎ .17⁎⁎ .12⁎ .15⁎ −.01 .20⁎⁎ .07 .36⁎⁎⁎ .22⁎⁎ 3. Attachment to parents − .17⁎⁎ .05 −.06 −.19⁎⁎ −.21⁎⁎ −.16⁎⁎ −.04 −.01 −.10⁎ −.03 −.04 −.11⁎ −.12⁎ 4. Socio-economic status − −.13⁎ .10⁎ −.01 .01 −.06 −.02 .00 −.03 .11⁎ −.06 −.16⁎⁎ .02 5. Repeating a class − −.07 .04 −.01 .08 .03 −.07 .01 −.05 −.04 .10⁎ .10⁎ 6. Sensation seeking − .15⁎ −.04 .17⁎⁎ .27⁎⁎⁎ .21⁎⁎ .03 .22⁎⁎ .11⁎ .15⁎ .17⁎⁎ 7. Borderline traits − .53⁎⁎⁎ .12⁎ .21⁎⁎ .24⁎⁎ .06 .13⁎ .23⁎⁎ .23⁎⁎ .14⁎ 8. Depressive symptoms − .06 .14⁎ .17⁎⁎ .07 .03 .17⁎⁎ .19⁎⁎ .22⁎⁎ 9. Cannabis use − .50⁎⁎⁎ .06 .08 .15⁎ .09 .21⁎⁎ .52⁎⁎⁎ 10. Alcohol use − .18⁎⁎ .19⁎⁎ .16⁎⁎ .14⁎ .18⁎⁎ .39⁎⁎⁎ 11. Impulsivity − −.04 .11⁎ .27⁎⁎⁎ .19⁎⁎ .13⁎ 12. Psychopathic traits − .22⁎⁎ .23⁎⁎ .23⁎⁎ .33⁎⁎⁎ 13. Narcissistic traits − .28⁎⁎⁎ .29⁎⁎⁎ .16⁎⁎ 14. Machiavellian traits .31⁎⁎⁎ .26⁎⁎⁎ 15. Sadistic traits − .30⁎⁎⁎ 16. Delinquent behavior − ⁎ p < .05. ⁎⁎ p < .01. ⁎⁎⁎ p < .001. Table options 3.4. Hierarchical regression analysis predicting delinquent behaviors among boys and girls We performed a regression analysis including sex as a covariate and, as it was significant, the analysis was repeated for males and females separately. As the measure of delinquent behavior was positively skewed, a square root transformation was used which reduced skewness. All predictor variables had tolerance values >.4 excluding multicollinearity. Age was entered into the first step of this analysis and appeared to be a significant predictor among boys (β = .17, p < .0001) but not among girls. In the second step of the analysis, we entered relevant socio-familial and psychological factors (socio-economic status, life events, having repeated a class, attachment to parents, sensation seeking, impulsivity, borderline traits, depressive symptoms, frequencies of cannabis and alcohol use). They accounted for an increase of 27% in the explained variance among boys and 23% among girls. Life events appeared to be a significant predictor among both genders (β = .15, p = .003 for boys; β = .15, p = .02 for girls). Having repeated a class was a significant predictor for both genders (β = .13, p = .02; β = .14, p = .04). Cannabis use appeared to be a significant predictor for both genders (β = .40, p < .0001 for boys; β = .23, p < .0001 for girls). Alcohol use was a significant predictor for girls only (β = .19, p = .007). Among the psychopathological variables, depressive symptoms was a significant predictor for girls only (β = .20, p = .008). In the last step, the ‘Dark Triad’ and sadistic traits were added to the analysis. We used the factor scores resulting from the hierarchical factor analysis to better identify the unique contribution of each component. They accounted for an increase of 8% in explained variance among boys and 3% among girls. Among boys, the incremental F ratio (F(4, 368) = 11.9) exceeded critical F for the .05 level of significance, indicating that these four variables significantly increased the explained variance. Among girls, the incremental F ratio (F(4, 219) = 2.2) was not significant. The psychopathic and sadistic factors appeared to be significant positive predictors among boys (β = .19, p < .0001 and β = .20, p < .0001, respectively). Among girls, the Machiavellian factor was negatively related to the outcome variable suggesting that it was a protective factor against delinquent behavior (β = −.14, p = .02). All together, the variables accounted for 38% of the variance in predicting delinquent behaviors among boys and 26% of the variance among girls.