2 Ways ‘Dark Personalities’ Justify Cheating, By A Psychologist

Cheating, whether sexual or emotional, can cause deep hurt and emotional distress to the person being cheated on. But what goes through the mind of someone who cheats? Do they feel any guilt, shame or remorse or do they just try to cover their tracks? More importantly, what drives them to cheat?

One 2013 study published in Ethics & Behavior found that people who are thrill-seekers and behave impulsively without thinking about the consequences of their actions are likely to cheat in relationships. They may exhibit underlying traits associated with the Dark Triad, a group of socially aversive personality traits including:

• Machiavellianism. This trait is marked by deception and manipulative behavior with a focus on personal gain.
• Narcissism. This trait is characterized by grandiosity, egocentrism, a constant need for admiration and a strong sense of entitlement.
• Psychopathy. This trait is associated with lack of empathy, impulsivity, shallow emotions and a disregard for social norms and others’ well-being.

In fact, a 2024 study published in the Culture and Evolution found that dark personality traits — especially psychopathy — can shape people’s dating behavior and incidences of infidelity.

Researchers found that higher scores of psychopathy were associated with the willingness to be unfaithful to one’s partner. Such partners, especially men with this trait, were also more suspicious of their own partners being unfaithful to them.

While not all partners who cheat have dark personality traits, those who do often share certain justifications for their behavior.

Here are two insights into why people with dark personality traits cheat.

1. They Stay In Long-Term Relationships But Continue To Seek Excitement

It may seem contradictory, but individuals high in Dark Triad traits often pursue long-term relationships to appear socially acceptable, while still chasing short-term thrills.

Menelaos Apostolou, author of the 2024 study, suggests that from an evolutionary perspective, this is likely also because long-term relationships offer emotional and financial support and are best suited for raising children.

However, evolution may have favored a “mixed strategy,” where someone has a long-term partner but also occasionally seeks out casual relationships on the side. Dark personality traits might actually help pull this off, since such people are more willing to take risks or manipulate others, all while avoiding guilt, which can support this mixed-mating strategy.

However, this behavior comes at a cost. The more partners a person tries to juggle, the more likely they are to get caught. According to Apostolou’s study, individuals high in psychopathy were significantly more likely to be caught cheating.

To make matters worse, people with Dark Triad traits often dominate the relationship, leaving their partner struggling to cope with the betrayal.

“Sexual infidelity is much more problematic when the relationship is unequal, and the partner with the most power is unfaithful, particularly if the inequality means that the other partner would have great difficulty exiting the relationship,” explains Natasha McKeever, PhD, in her 2020 study on the moral justification and severity of sexual infidelity.

2. They Distrust Their Partner Because They Assume Everyone Cheats

Cheating isn’t wrong simply because it hurts one partner, but rather, because the hurt is reasonable. For instance, a man exhibiting jealousy simply because his partner is talking to another man reflects unfair expectations. This dynamic can escalate in extreme ways, as seen in the Sean “Diddy” Combs trial involving Grammy-winning rapper Scott Mescudi, also known as Kid Cudi.

Kid Cudi testified in the trial, alleging that Combs broke into his home and threatened him due to Cudi’s past relationship with Combs’ ex-girlfriend, Cassie Ventura.

Ventura also alleged that Combs told her he would blow up Cudi’s car, and shortly after, his car did explode in his driveway. Though Combs denied the allegation, the incident illustrates how some individuals may attempt to exert control over their current or former partners, even through intimidation or violence, to prevent them from forming new relationships.

This is often the case with cheaters exhibiting Dark Triad traits. People who cheat more often are also more likely to suspect their partners of cheating because they tend to distrust others and assume that others act the same way they do.

In Apostolou’s study, men with high psychopathy scores were especially suspicious of their partner’s fidelity, even when no signs of infidelity were present. This is because such partners cheat more frequently themselves. And if they don’t trust themselves to remain faithful, they likely wouldn’t trust you either.

By committing sexual infidelity while pretending to be monogamous, the manipulative partner gains exclusive emotional and sexual access to the other person, who is under the impression that the relationship is still exclusive. But when the partner at fault gets caught, the illusion quickly falls apart.

This can leave the betrayed partner feeling overwhelmed with feelings of anger, anxiety or even the painful belief that something is wrong with them. If you’ve been cheated on, it might help to understand where such behavior stems from and recognize it before it causes you any further harm.

If you’re the one who has cheated, it helps to reflect on what has driven your behavior and the far-reaching consequences it can have for those around you.

Are you curious if you are inclined to cheating on your partner? Take the evidence-based Propensity Towards Infidelity Scale to gain clarity.