The Dark Triad (psychopathy, Machiavellianism and narcissism) in adults: Only psychopathy and Machiavellianism were related to adult offending

How well do the Dark Triad characteristics explain individual differences in offending in a representative non-clinical adult sample? Wim Hardyns et al. Current Research in Behavioral Sciences, October 5 2022, 100084. https://doi.org/10.1016/j.crbeha.2022.100084

Highlights
•    Psychopathy, Machiavellianism and narcissism make up the Dark Triad of personality
•    These Dark Triad traits were proven to be related to numerous antisocial behaviors
•    Such research on the Dark Triad has mainly focused on adolescent (online) samples
•    We tested the effect of these traits on offending in a representative adult sample
•    Of the three, only psychopathy and Machiavellianism were related to adult offending

Abstract: The present study investigates to what extent the three key concepts from the Dark Triad Theory can explain individual differences in adult offending. Data were collected through a cross-sectional survey amongst a representative sample of 1587 adults, living in Ghent, Belgium (Mage = 48.06, 51.4% female). Negative binomial regression analyses are run and show that Machiavellianism and psychopathy have strong independent effects on adult offending, independent of age, sex and immigrant background.

4. Discussion

The main objective of this study was to examine to what extent the key dimensions of the Dark Triad Theory are able to explain individual differences in self-reported adult offending. This study adds to existing and still scarce literature by examining this association in a representative non-clinical sample of adults, whereas previous research on the Dark Triad personality traits has primarily focused on adolescent (online) samples.

Psychopathy and Machiavellianism had substantial net effects on adult offending, which is consistent with our hypothesis and previous research with adolescent samples (e.g., Flexon et al., 2016; Lyons & Jonason, 2015; Wright et al., 2016). However, in contrast to our hypothesis and previous research (e.g., Blinkhorn et al., 2018), narcissism was not significantly related to self-reported adult offending. This lack of association could possibly be explained by Bushman and Baumeister's (1998) threatened egotism hypothesis, which posits that individuals who are high on narcissism are prone to react in a violent or aggressive manner as a defense mechanism when faced with challenges to their self-esteem. Several studies have found evidence for this hypothesis (e.g., Baumeister, Bushman, & Campbell, 2000; Lambe et al., 2016; Twenge & Campbell, 2003). Our data did not allow to distinguish proactive offending from reactive offending (such as an ego threat), thus we cannot fully explain this lack of association. Future research could examine this further by including measures of both proactive and reactive offending behaviors.

Next to discussing the net effects of the Dark Triad traits, it is also worth mentioning that the effects of age and immigrant background on offending behavior were in line with previous research (e.g., Junger-Tas et al., 2009; Rocque et al., 2015). However, our third control variable sex did not have the expected effect on offending. Research has repeatedly shown that males are more prone to offending than females (e.g., DeLisi & Vaughn, 2016), but in our study this effect of sex is not substantial. One possible explanation for this is that the effect of sociodemographic variables such as sex may weaken when other variables, such as personal attitudes, values or personality traits, are taken into account when analyzing offending behavior (Ivert et al., 2018). In our study, the effects of the Dark Triad personality traits could have weakened the effect of sex on adult offending, but further research is required to support this claim.

5. Limitations and future directions

Several limitations must be taken into account. First, the cross-sectional nature of the study makes it impossible to draw causal conclusions and therefore limits the ability to discuss clear causal relationships of our findings. From a developmental point of view, a panel study should be implemented to assess the temporal order of the concepts in our model and to examine whether changes in the presence of the Dark Triad personality traits are indeed associated with changes in offending behavior.

A second limitation concerns the self-report nature of the measures of each construct. This raises problems with memory recall in regard to the questions on offending, the willingness to report about sensitive topics like offending, and social desirability bias, especially considering the Dark Triad traits are characterized by tendencies towards self-promotion (Paulhus & Williams, 2002). However, previous research has demonstrated that self-report measurements of the Dark Triad can be quite accurate (Jonason & Webster, 2010), and a recent study by Kowalski et al. (2018) found that only narcissism is associated with social desirability, which can be an explanation for the non-effect of narcissism in this study. We tried to limit the confounding effects of the social desirability bias by shielding the questions relating to offending behavior and Dark Triad personality traits from the interviewers. Future research could also assess the validity of self-reporting occurrences of offending behavior through the use of factorial designs (randomized vignette studies).

Third, in our operationalization of the Dark Triad personality traits, we used a concise measure (Dirty Dozen; Jonason & Webster, 2010). While there is considerable support for the adequacy of the psychometric properties of this scale such as internal consistency, factor structure and test-retest validity (e.g., Chiorri, Garofalo, & Velotti, 2019; Jonason et al., 2013; Jonason & Luévano, 2013; Jonason & McCain, 2012; Jonason & Webster, 2010; Jones & Paulhus, 2014), there are some concerns regarding the brevity of the instrument in relation to full-length measures of the Dark Triad traits³. Some scholars have proposed that this short measure may fail to capture some aspects of psychopathy and narcissism (e.g., Maples, Lamkin, & Miller, 2014). However, the structure of the Dirty Dozen questionnaire appears to be stable across different cultural contexts and populations and seems to provide a reasonable tradeoff between efficiency and accuracy (Jonason & Luévano, 2013; Rogoza et al., 2020).

Lastly, the adults offending scale is based on four items referring to four types of offending behaviors. Our choice was guided by (1) general applicability towards a community sample and (2) high prevalence offences.⁴ Future research on the association between the Dark Triad traits and offending behavior could incorporate measures of more specific types of offending behaviors.

Despite these limitations, our findings show that the Dark Triad Theory can be applied to explain individual differences in adult offending and as such, the theory could be integrated in contemporary theories of antisocial behavior. Future research could examine which mechanisms lie underneath this relationship between the Dark Triad traits and self-reported offending, by integrating the findings of this study with for example theory on the role of self-control (Flexon et al., 2016; Gottfredson & Hirschi, 2019; Vazsonyi et al., 2017; Wright et al., 2017) and strains (Agnew et al., 2002; Lee & Kim, 2022) in criminal behavior, or the theory of cumulated disadvantage (Sampson & Laub, 1997). Furthermore, given the moderate to large heritability of the Dark Triad traits (Kavish & Boutwell, 2022; Vernon et al., 2008), future research could explore the role of genetic confounding in the association between these three dark personality traits and offending behavior. This strategy of theoretical elaboration could lead to a more thorough understanding of the individual factors that play a role in offending behaviors.