Serial infidelity has been correlated with personality disorders. To be specific, three personality disorders; Narcissism, Borderline Personality Disorder, and Psychopathy.

It’s important to point out that not every unfaithful spouse has a personality disorder, nor does every spouse with some degree of personality disorder engage in infidelity.

At the top of the list is narcissism. Research tells us that a narcissist personality is one of the strongest predictors that a spouse will be unfaithful.

Narcissists tend to be self-centered, overly confident, and vain. They enjoy bragging about their accomplishments and displaying themselves to others. They talk about themselves regularly and disparage others that they perceive as inferior for whatever reason.

Borderline Personality Disorder is characterized by unstable emotions. They are partners who are fundamentally emotionally unstable and inherently unreliable. They are also poorly organized, careless, and self-indulgent. They find it very difficult to resist temptation, maintain personal boundaries, and resist attractive others.

I have often seen cases where a husband gets involved with a BPD co-worker. Once the affair is ended the borderline affair partner can be consumed with rage.

They may stalk and attack their affair partner’s wife on social media. Some will call the wife and explain that they are “ugly” , inadequate, and don’t deserve their husband.

I’ve even seen police involvement in these cases more than once.

The essential problem with BPD is poor impulse control, compromised adult reasoning, and an inability to self-soothe and express empathy. In all intimate relationships, including illicit ones, a person with Borderline Personality Disorder will often display irrational jealousy, emotional volatility, and may become both physically and emotionally abusive.

For such people “love” is subordinated to intense feelings of painful yearning and powerful desire. Thus, people with BPD are often compelled to chase partners who are emotionally unavailable. Their yearning is fueled by the chaos and drama of pursuing an unattainable partner.

On the other hand, Psychopathic personalities have no compelling sense of yearning. They simply have no sense of personal responsibility. They are entirely careless and irresponsible. They live in the moment, spontaneous and manipulative in their pursuit of pleasure and self-gratification.

Research on Serial Infidelity and Personality Disorders

Buss and Shackileford (1997) studied 107 married couples. They examined three possible predictors of infidelity:

  • Personality factors such as narcissism and conscientiousness.

  • The social contexts that intimate relationships inhabit (including what Gottman calls “perpetual problems”).

The relative “mate value” of each partner.

The researchers used self-reports and spouse-report data on the relative susceptibility to infidelity.  They also used self-reports, spousal reports, as well as interviewer reports on personality, relationship context, and relative mate value.

Personality factors most strongly linked to susceptibility to infidelity were low conscientiousness, high narcissism, and high psychoticism.

Relationship contexts most strongly linked to vulnerability to infidelity include ongoing sexual dissatisfaction and particular perpetual problems such as a partner complaining about feeling jealous.

Serial infidelity and personality disorders have now been highly correlated. But how do these unfaithful partners explain their behavior?

Serial Infidelity and Personality Disorders…How Infidelity is Rationalized

It’s no surprise that partners who were dissatisfied with their relationship were more likely to be unfaithful.

But the research also discovered that partners with a long laundry list of complaints about their partners were also more likely to have an affair.

This research found that there were specific complaints that predicted infidelity; problem drinking, including substance abuse, condescending behavior, jealousy, and controlling behaviors were specifically mentioned in this study.

Although narcissism was the personality disorder most strongly linked to infidelity, the researchers commented on two other personality traits tied for second place:

“…two equally strong predictors of mild and serious infidelity are low Conscientiousness and high Psychoticism. These variables are correlated and share the common component of impulsivity and an inability to delay gratification."

And like Narcissism, Conscientiousness and Psychoticism are stronger predictors of women’s anticipated infidelities than men. These findings suggest that perhaps women with personality disorders suffer from poorer impulse control than men with personality disorders. However, I’m sure more research is needed before we can be sure of that.

The study authors put it this way:

“One of the strongest predictors is Narcissism. Women high on Narcissism predict that they will flirt with, kiss, and date other men, as well as have one-night stands, brief affairs, and serious affairs with other men.”

In other words, if your spouse has a personality marked by impulsivity, low dependability, and low reliability, the likelihood of infidelity is markedly increased.

Infidelity typically has a highly corrosive impact on intimate relationships:

“Infidelity may be the most destructive source of conflict inflicted on a marriage. Despite its destructive impact, infidelity is estimated conservatively to occur in about half of all marriages.”

Final Thoughts about Serial Infidelity and Personality Disorders

This Research makes sense when you think about a narcissist’s ability to create a story in their head that they are not being treated fairly, that they deserve better, etc. 

One thing we’ve learned from Dr. Gottman’s research about trust and commitment is that negative comparisons are the bedrock of betrayal.

Some partners with a more fragile sense of self might tend to make unfavorable comparisons, thinking such thoughts as ‘I can do better’ or ‘I deserve better’ etc. and then negatively comparing your spouse to other people, both real or imagined. 

This is the kind of thinking that softens the ground for an affair. It is easy to see how a narcissist could repeat this pattern in a serial fashion.

Although clearly even people who do not have narcissistic traits take part in affairs on a regular basis, it’s easy to see how narcissistic traits could present an enduring vulnerability, resulting in an increased likelihood of affairs.

One thing I find interesting about this research is the increased likelihood of affairs when there is alcohol abuse, psychopathy, and low conscientiousness. This reminds me of Eli Finkel’s writings on Relationship Aptitude.

This means when you are searching for a long-term partner, it’s more important to look past what you have in common, or how you complement each other. Instead, look for a partner who has emotional intelligence, what Dr. Finkel calls a “Relationship Aptitude.”

What is Relationship Aptitude?

A potential partner with Relationship Aptitude has low levels of neuroticism, has no addictions, and possesses high levels of being able to be securely attached and agreeable.

The correlation between these traits of Personality Disorders and traits related to increased likelihood of affairs is very interesting, as there does seem to a significant degree of overlap.

It also makes sense that a partner with these negative traits would struggle in a relationship and then feel more willing to seek comfort or excitement from someone else when their own primary relationship is on the rocks.

Serial Infidelity and Personality Disorders…Learning Relationship Aptitude

So just as there are personality traits that create vulnerability to infidelity, there is also a concept developed by Dr. Finkel’s research team called Relationship Aptitude which is protective of relationships. The good news is that Relationship Aptitude is, more or less, by definition, a teachable skill set.

Couples therapists are preoccupied with helping their clients improve their relationship aptitude, and be able to express empathy while being able to see their part in the problems in a relationship and be willing to change and grow in a positive direction. 

All this while helping them learn to engage in positive comparisons which helps build commitment.

How you think about your relationship matters. Just as negative comparisons can fuel discontent, positive comparisons (or, pro-relationship thoughts) would involve thinking thoughts such as “I’m so lucky this is my partner, they are so good to me.”

We know that people who have a firm sense of commitment are vigilant, and have firm boundaries against betrayals and affairs. We can help with that.

Learn Relationship Aptitude. Science-Based Couples Therapy Can Help!


The study was published in the Journal of Research in Personality (Buss & Shackleford, 1997).

Originally published September 23, 2018.

Ready for a change in your relationship?

It starts with a no-obligation 15 minute phone call with our client services team.

Daniel Dashnaw

Daniel is a Marriage and Family Therapist and the blog editor. He currently works with couples online and in person. He uses EFT, Gottman Method, Solution-focused and Developmental Models in his approaches. Daniel specializes in working with neurodiverse couples, couples that are recovering from an affair, and couples struggling with conflict avoidant and passive aggressive behavior patterns.

Leave a Reply

Your email address will not be published.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}