An actor-partner interdependence model of the Dark Triad and aggression in couples: Relationship duration moderates the link between psychopathy and argumentativeness

Prior research has examined links between Dark Triad traits-Machiavellianism, psychopathy, and narcissism-and aggression in individuals, but not couples. Dating heterosexual couples self-reported measures of the Dark Triad and aggression (trait and displaced; Study 1) or negativity (Study 2). Actor-partner interdependence models showed positive links between (a) women's psychopathy and women's trait and displaced aggression (actor effects), and (b) men's psychopathy and women's trait aggression (partner effect). Positive actor effects also linked narcissism to displaced aggression. Using integrative data analysis to combine Studies 1 and 2, relationship duration moderated actor and partner effects linking psychopathy to women's argumentativeness (negativity and verbal aggression); men in longer relationships and women in shorter relationships had psychopathy-argumentativeness slopes that were especially positive.