New research suggests that individuals with certain antagonistic personality traits are more likely to bring aggression, dominance, and a preference for unconventional sexual experiences into their romantic relationships. These traits are also associated with a greater likelihood of using manipulative tactics to pressure partners into sexual activity.
The study, published in the Journal of Sex & Marital Therapy, examines what popular culture often refers to as toxic relationships. Rather than relying on vague labels, psychologists focus on measurable personality characteristics that help explain why some individuals repeatedly form controlling or emotionally harmful relationships.
Dark Triad Traits and Attachment
A central focus of the study is the Dark Triad, a cluster of three related personality traits: psychopathy, narcissism, and Machiavellianism. Although each trait has distinct features, all involve some combination of callousness, self-interest, and a willingness to exploit others.
Psychopathy is characterized by impulsivity, low empathy, and antisocial behavior, making the formation of deep emotional bonds more difficult. Narcissism centers on grandiosity and entitlement, accompanied by a strong need for admiration and a tendency toward anger when criticized or rejected.
Machiavellianism, named after the political philosopher Niccolò Machiavelli, reflects a strategic and manipulative approach to social interactions. Individuals high in this trait often hold a cynical view of human nature and see relationships as opportunities to gain power rather than foster mutual connection.
The researchers also drew on adult attachment theory, which proposes that early life experiences shape internal models of intimacy and relationships. Securely attached individuals are generally comfortable with both closeness and independence, whereas insecure attachment may manifest as clinginess, fear of abandonment, or avoidance of emotional intimacy.
Previous research has shown that individuals high in Dark Triad traits often exhibit avoidant attachment styles, maintaining emotional distance as a means of preserving control. The present study extends this work by examining how these traits influence specific expectations and behaviors within romantic relationships.
How the Study Was Conducted
The research team, based at Medical School Hamburg in Germany, recruited 624 adults through an online survey. The sample included 481 women and 143 men, most of whom were in their late twenties, a life stage often associated with long-term relationships and cohabitation.
Participants completed established questionnaires measuring psychopathy, narcissism, and Machiavellianism. They rated their agreement with statements assessing manipulative attitudes, emotional detachment, and self-centered tendencies, generating scores for each Dark Triad trait.
Participants then completed a relationship and attachment inventory focused specifically on their behavior within intimate relationships. The questionnaire assessed physical and verbal aggression, dominance during conflicts, emotional closeness, and preferences for adventurous or risky sexual activities.
A final section examined experiences of sexual aggression in romantic relationships. Participants reported whether they had ever used physical force, verbal pressure, or a partner’s inability to resist in order to obtain sex, as well as whether they had experienced similar behavior from a romantic partner.
Aggression, Dominance, and Risky Sex
The findings revealed a strong association between Dark Triad traits and an aggressive approach to romantic relationships. Individuals with higher scores on these traits were more likely to report relationship styles characterized by physical aggression, provocation, and rudeness toward partners.
Among the three traits, psychopathy emerged as the strongest predictor of combative and dominant behavior. Because psychopathy includes impulsivity and poor behavioral control, the authors argue that it naturally aligns with a greater risk of hostile or violent conflict within intimate relationships.
Dark Triad traits also influenced sexual expectations. Participants with higher scores reported stronger preferences for passionate, adventurous, and, at times, risky or unconventional sexual experiences. Once again, psychopathy emerged as a particularly important predictor.
The researchers suggest that the emotional detachment associated with psychopathy may contribute to a preference for more superficial and purely physical sexual encounters. Rather than valuing tenderness or mutual vulnerability, these individuals may prioritize novelty and sensation-seeking in their sexual experiences.
Manipulation, Dependence, and Coercion
When emotional dependence was examined, the three traits did not function identically. Machiavellianism showed a positive association with anxious attachment and separation distress, indicating a stronger desire to maintain closeness with romantic partners.
At first glance, this may resemble genuine emotional intimacy. However, the authors propose an alternative interpretation. For highly Machiavellian individuals, proximity may serve as a means of monitoring, managing, and controlling a partner whom they fundamentally distrust.
The analysis of sexual coercion produced some of the study’s most concerning findings. Participants with elevated Dark Triad traits were more likely to report having engaged in sexually aggressive behavior toward romantic partners.
Machiavellianism emerged as the most consistent predictor of sexual coercion. The researchers suggest that the strategic and emotionally detached nature of this trait may facilitate subtle forms of manipulation, including guilt induction, deceptive promises, or exploitation of power imbalances to obtain sex.
The study also revealed substantial overlap between perpetrators and self-identified victims. Many respondents who reported coercing partners also reported experiencing coercive tactics themselves, suggesting complex and mutually hostile relationship dynamics.
Gender Patterns and Study Limitations
Consistent with previous psychological research, men scored higher on Dark Triad traits than women. Men were also more likely to endorse adventurous sexual preferences, although both sexes displayed similar associations between dark personality traits and aggression.
The authors caution that the study’s cross-sectional design captures only a single point in time and cannot establish causality. Although Dark Triad traits are strongly associated with certain relationship behaviors, the findings cannot demonstrate that these traits directly cause abuse or coercion.
The recruitment strategy may also have influenced the sample. Because the study advertisement referenced toxic relationships, individuals with difficult relationship experiences may have been more likely to participate, potentially increasing reported rates of victimization.
The reliance on self-report measures introduces additional limitations. Participants may underreport socially undesirable or illegal behaviors, and individuals with manipulative tendencies may be especially likely to minimize or distort their actions.
Implications for Prevention and Support
Despite these limitations, the findings add nuance to public discussions of toxic relationships by grounding them in measurable personality characteristics. The results demonstrate that traits such as psychopathy and Machiavellianism are not merely abstract psychological concepts but can influence concrete behaviors in romantic and sexual relationships.
The authors recommend that future studies assess both partners within a relationship to better understand how dark personality traits interact over time. Longitudinal research may help determine whether these traits predict relationship dissolution, repeated cycles of abuse, or escalating violence.
A deeper understanding of how manipulation, aggression, and coercion emerge within romantic relationships may improve clinical risk assessment and counseling strategies. Tailored interventions could help identify high-risk patterns earlier and provide support for victims and couples before conflicts develop into chronic harm.
