People with certain hostile personality traits often approach romantic partnerships with heightened aggression, dominance, and a preference for unconventional sexual experiences. These same characteristics are associated with a higher likelihood of using manipulative tactics to coerce intimate partners into sexual acts. The study mapping these behavioral patterns was published in the Journal of Sex & Marital Therapy.
In popular culture, the phrase toxic relationship is used to describe a partnership that is defined by a controlling, manipulative, or emotionally abusive power relationship. Psychologists prefer to use concrete, measurable concepts to understand why certain people routinely develop highly contradictory or even harmful romantic bonds. One of the main areas of focus is a set of personality profiles known as the Dark Triad.
The Dark Triad consists of three distinct but related personality traits: psychopathy, narcissism, and Machiavellianism. Psychopathy includes high impulsivity, a marked lack of empathy, and a tendency to act antisocially. People with high levels of psychopathy have a hard time forming true emotional bonds. Narcissism is characterized by an exaggerated sense of self-importance. Narcissistic people constantly demand praise and often react with hostility when they feel rejected or insulted.
Machiavellianism is named after the Renaissance political philosopher Niccolo Machiavelli. This trait focuses on manipulating others to gain or maintain power. People with this trait have a cynical view of human nature. They rely on deception and strategic planning to achieve their goals, and treat interpersonal relationships as games that must be won.
Psychologists also understand troubled relationships through the lens of adult attachment theory. This theory suggests that humans develop internal mental models of relationships during early childhood. This model persists into adulthood. People with a secure attachment style feel comfortable with emotional intimacy and independence. People with an insecure attachment style may cling anxiously to their partner or avoid emotional intimacy altogether. Previous research suggests that people who score high on Dark Triad measures often display an avoidant attachment style, where people distance themselves to maintain control or prevent vulnerability.
Based on this, researchers have observed a phenomenon known as relational personality. This concept posits that individuals exhibit a relatively stable set of behaviors that are unique to their intimate partners, unlike how they interact with friends and colleagues. People tend to look for partners who cater to the nature of their particular relationship. This habit often leads people to choose the same type of romantic partner over and over again, despite past negative experiences.
Researchers Judith Antonia Ifland, Lara Katharina Albrecht, and Ursula Martiniuk from the Medical University of Hamburg in Germany wanted to understand how Dark Triad traits are reflected in expectations for specific relationships. They aim to bring scientific rigor to common toxicity concepts. They designed a study to systematically assess whether psychopathy, narcissism, and Machiavellianism predict aggressive, controlling, and sexually coercive behavior in intimate relationships.
The research team recruited 624 adult participants for an online survey. The participant group included 481 women and 143 men, with an average age in their late 20s.
Participants completed standard psychological questionnaires designed to assess levels of psychopathy, narcissism, and Machiavellianism. The survey asked participants to rate their agreement with statements that reflected manipulative or emotionally callous attitudes.
Next, the researchers assessed the participants using the Relationship and Attachment Personality Inventory. This tool measures certain attitudes and behaviors that people exhibit toward their romantic partners. The inventory included questions about tendencies toward dominance and aggression, such as whether to respond to provocation with physical aggression. We also measured their need for emotional intimacy and their preference for adventurous, risky, or deviant sexual activities.
The final part of the survey asked participants about their experiences with sexual aggression. Participants were asked whether they had ever used physical force, verbal pressure, or a partner’s lack of resistance to coerce a romantic partner into sexual activity. They were similarly asked whether they had ever experienced such coercive tactics from their partners.
The data revealed a strong association between Dark Triad traits and a highly proactive approach to love. Those who scored high on these traits were significantly more likely to report a relationship style defined by physical aggression, rudeness, and a tendency to cause fights.
Of the three traits, psychopathy was found to be the strongest predictor of this combative and controlling relationship style. Because psychopathology includes elements of impulsivity and decreased behavioral control, the researchers noted, it makes sense that psychopathology maps closely onto aggressive relationship dynamics.
Personality traits were also associated with clear sexual expectations. Participants with higher Dark Triad scores expressed a stronger preference for passionate, adventurous, and sometimes risky sexual activities. Psychopathy again emerged as a strong predictor in this category. The researchers suggested that the emotional isolation associated with psychopathy may lead to a preference for superficial or purely physical sexual gratification over tender romantic love.
When looking at emotional dependence, its characteristics were diverse. Machiavellianism was positively correlated with anxious desire for intimacy. People with heightened Machiavellian traits reported higher separation distress and a stronger desire to merge with their partner. Researchers theorize that this desire for closeness may actually be a strategy to monitor and control one’s partner, reflecting an underlying sense of mistrust rather than true love.
The researchers then analyzed data on sexual coercion in intimate partnerships. They found that people harboring these dark traits were more likely to act as perpetrators of sexual aggression. Specifically, Machiavellianism was the trait most reliably associated with perpetration of sexual coercion.
The lack of strategic thinking and empathy common to Machiavellianism can lead people to use subtle manipulation to initiate sex. Such coercive strategies may include making false promises, creating guilt trips, and using positions of power. Researchers noted that these people often try to maintain their dominance in social interactions, which unfortunately extends to the bedroom.
Survey data also highlighted the overlap between perpetrators and targets of sexual violence. The majority of respondents who admitted to using coercive sexual strategies also claimed that they had also been the target of sexual attacks by their partners. The researchers hypothesized that people high in manipulative traits may be quicker to perceive a situation as coercive or feel themselves to be psychologically manipulated due to a weaker desire for control.
Men in the sample scored higher than women on the Dark Triad scale, reflecting a pattern found in the broader psychology literature. Men also reported higher levels of adventurous sexual desire. Statistical models showed that the underlying associations between personality traits and aggressive relationship behaviors were similar for both men and women.
The authors noted several limitations regarding the study design. This study relied on cross-sectional survey data. This means the researchers took one snapshot in time. They cannot prove that these personality traits are definitive causes of abusive behavior, only that they are strongly correlated.
The language used to recruit participants may also have introduced certain biases. Advertisements for this study featured the term toxic relationships, which may have attracted a disproportionate number of people with problematic relationships. A very high proportion of female respondents reported experiencing sexual victimization by a partner. The researchers acknowledge that these rates do not reflect the general population, but rather indicate self-selection bias among those surveyed.
Furthermore, the reliance on self-reporting means that some of the data may be affected by social desirability bias. People are generally reluctant to acknowledge socially unacceptable or illegal behavior. Because people high in Dark Triad traits are more prone to deception, they may have downplayed the true extent of their coercive or manipulative behavior.
The researchers recommend assessing both members of a couple simultaneously for future sociological studies. Studying partners together helps scientists understand how these difficult personality traits interact with those of the spouse to influence relationship stability and conflict over time. A better understanding of how manipulation and coercion operate in these relationships may ultimately improve risk assessment tools and counseling strategies to prevent interpersonal violence.
The study, “The Dark Triad and Relationship Expectations: Attempting an Empirical Approach to Study Toxic Relationships,” was authored by Judith Antonia Iffland, Lara Katharina Albrecht, and Urszula Martyniuk.

