The Dark Triad traits (Machiavellianism, psychopathy, and narcissism) are overlapping but distinctive. Although all three traits have been independently linked to relationship infidelity, differences among the traits may exist when examined simultaneously. Moreover, consequences resulting from infidelity have not been explored. A large retrospective survey found that all three traits correlated with reporting an infidelity at some point in a current (or most recent) relationship. Among women, however, only psychopathy and Machiavellianism were unique predictors of infidelity, whereas only psychopathy uniquely predicted infidelity among men. However, infidelity committed by psychopathic individuals led to relationship dissolution, whereas infidelity committed by Machiavellian individuals did not. These findings suggest mindset and long-term goals impact situations to create differences in Dark Triad destructive relationship behaviors.
The Dark Triad consists of three overlapping but empirically and conceptually distinguishable personality traits (psychopathy, Machiavellianism, and narcissism), which are prone to engage in malevolent behavior (Paulhus & Williams, 2002). Note that all three variables are investigated presently in their subclinical form, as found in non-institutionalized samples (LeBreton, Binning, & Adorno, 2005). In such samples, the Dark Triad variables are normally distributed (Williams, Paulhus, & Hare, 2007). Conceptually, the Dark Triad traits share the same location in interpersonal space, which is high agency and low communion (Jones & Paulhus, 2011a). In addition, all Dark Triad traits are callous and manipulative (Jones & Figueredo, in press). Importantly, Jones and Figueredo (in press) also found that once callous-manipulation was extracted from the core of the Dark Triad traits, they were almost completely unrelated.
The common core of the Dark Triad has been linked to short-term sexual relationships (Jonason and Buss, 2012 and Jonason et al., 2009). For example, callous personality traits (e.g., disagreeableness, psychoticism) are associated with high rates of sexual activity and infidelity (Eysenck, 1976 and Schmitt, 2004a). Callousness is related to short-term sexual encounters because individuals are unconcerned with hurting others or forming long-term bonds (Jonason, Lyons, Bethell, & Ross, 2013). In addition, manipulative behaviors and dishonesty also seem to facilitate short-term sexual approaches through mechanisms such as insincere commitment, feigned mate value, and other forms of sexual deception (Jonason and Buss, 2012, Seto et al., 1997 and Tooke and Camire, 1991). Many individuals (particularly women) tend to be attracted to individuals with high levels of dominance and traces of antisocial tendencies (Holtzman and Strube, 2013 and Holtzman and Strube, 2010).
Despite their common manipulation and callousness, the Dark Triad traits are unique (Furnham, Richards, & Paulhus, 2013). For example, Machiavellians are long-term oriented, (Jones & Paulhus, 2009), developmentally sensitive to contextual cues (Vernon, Villani, Vickers, & Harris, 2008), difficult to provoke into aggression (Jones & Paulhus, 2010), have intact executive functioning (Jones, in press) and are instrumental in misbehavior (Kerig & Stellwagen, 2010). Additionally, Machiavellians will only steal when there is little chance of getting caught (Cooper & Peterson, 1980), cheat in strategic ways (Williams, Nathanson, & Paulhus, 2010), and exert effort to resist cheating when short-term goals undermine long-term investments (Jones, in press). These distinguishing features of Machiavellianism should also be evident in how they approach relationships. Machiavellian individuals are prone to infidelity (McHoskey, 2001), but should use caution in how they execute affairs. In sum, Machiavellian individuals will manage partners and interlopers in a way that is maximally advantageous to their selfish goals.
By contrast, those high in psychopathy are highly aggressive (Reidy, Zeichner, & Martinez, 2008), steal even when the payoff is small and risk is large (Hare, 1999), and cheat in impulsive ways (Jones, 2013 and Williams et al., 2010). As a result, psychopathic individuals will be indiscriminately unfaithful, undermining self-interests. Like psychopathy, those high in narcissism are easy to provoke into aggression, but only when the provocation constitutes an ego-threat (Bushman and Baumeister, 1998 and Jones and Paulhus, 2010). Those high in narcissism are also irrational when it comes to their self-image (Morf & Rhodewalt, 2001), often engaging in self-destructive behavior (Vazire & Funder, 2006).
Although all three Dark Triad traits correlated with infidelity, the patterns of correlations differed for men and women. Psychopathy was the primary predictor of infidelity in men, whereas psychopathy and Machiavellianism equally predicted infidelity in women. Among all participants, however, Machiavellianism did not predict dissolution after the infidelity whereas psychopathy did. Thus far, it seems that Machiavellian individuals are likely to maintain a relationship irrespective of infidelity, possibly due to their strategic (cautious and flexible) nature. This strategic nature may help Machiavellian individuals avoid detection, and even when caught, allow them to smooth over conflicts as Machiavellians tend to thrive when tensions are hot and emotions are strong (Christie & Geis, 1970).
