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Gery Karantzas Ph.D.
Gery Karantzas Ph.D.

Why Do People Cheat? It's Not Just About Sex

Only about 20 percent of couples engage in sexual infidelity.

Whether it is the news of an affair involving a high-profile personality, a close family member, or a friend, people are quick to judge and lay blame on those who engage in infidelity. We believe romantic relationships are about meeting our needs for love, comfort, and security.

So when a person is found to be “cheating,” people are often saddened, hurt, and appalled, as the act of infidelity represents a significant violation of relationship norms and betrayal of trust. Infidelity highlights the potential fragility of our closest and most important of relationships.

Many hold the belief that infidelity is the result of immoral and over-sexed individuals wanting their cake and eating it too. But the reality is that infidelity is rarely just about sex. In fact, when it comes to purely sexual infidelity, the average occurrence across studies is around 20 percent of all couples (Baucom et al., 2017). However, this rate increases to around a third of couples when you include emotional infidelity.

Photo by burak kostak from Pexels
Source: Photo by burak kostak from Pexels

An affair is generally a sign that things aren’t right with someone’s relationship. Without the necessary skills to heal the issues, a partner may engage in an affair as an ill-equipped way of attempting to have their needs fulfilled—whether these be needs for intimacy, to feel valued, to experience more sex, and so on. So, the straying partner views an alternative relationship as a better way to meet these needs than their existing relationship.

Who has affairs, and why?

Studies into why people cheat are many and varied. Some find people who lack traits such as agreeableness and conscientiousness are more likely to be sexually promiscuous (Schmitt, 2004), as are those higher in dark triad traits (narcissism, Machiavellianism, psychopathy; Brewer et al., 2015). Other studies find that infidelity is more likely to occur among people who hold less restrictive views about sex, such as that you don’t have to limit yourself to one sexual partner (Mattingly et al., 2011).

Other important factors relate to people’s commitment to their partner and relationship satisfaction (Fincham & May, 2017). Those low on these measures appear more likely to have an affair. Recent work suggests that one of the biggest predictors of having an affair is having strayed before (Fincham & May, 2017).

A survey of 5,000 people in the UK found striking parallels between men and women’s reasons for infidelity, and neither prioritized sex (Majoribanks & Bradley, 2017). The top five reasons for women were related to lack of emotional intimacy (84 percent), lack of communication between partners (75 percent), tiredness (32 percent), a bad history with sex or abuse (26 percent), and a lack of interest in sex with the current partner (23 percent).

For men, the reasons were a lack of communication between partners (68 percent), stress (63 percent), sexual dysfunction with one’s current partner (44 percent), lack of emotional intimacy (38 percent), and fatigue or being chronically tired (31 percent).

So if we have difficulty genuinely communicating with our partner, or they don’t make us feel valued, we may be more likely to stray. People need to invest time and energy into their relationships. Experiencing chronic tiredness over many years means that one’s capacity to put in the necessary work to keep a relationship strong is also compromised.

While some couples report additional reasons, which can include a greater desire for sex, the majority speak to issues that reside either within the couple or outside the relationship. The latter can be stressors that challenge the couple’s ability to make the relationship work.

If you’re experiencing relationship difficulties, getting help from a therapist may well short-circuit the risk factors that can lead to infidelity.

Disclosure and therapy

Some people choose to keep their affair secret, because they may want it to continue, feel too much guilt, or believe they’re protecting their partner’s feelings. But the secret only perpetuates the betrayal. If one is serious about mending their existing relationship, then disclosure is necessary, along with seeking professional guidance to support the couple through the turbulent period towards recovery.

Most relationship therapists suggest that issues around infidelity can be improved through therapy (Majoribanks & Bradley, 2017). But they also report infidelity as one of the most difficult issues to work with when it comes to rebuilding a relationship (Whisman et al., 1997).

There are various evidence-based approaches to dealing with infidelity, but most acknowledge the act can be experienced as a form of trauma by the betrayed person, who has had their fundamental assumptions about their partner violated (Baucom et al., 2017). These include trust and the belief that the partner is there to provide love and security rather than inflict hurt.

But it’s not only the betrayed person who can experience mental health issues. Research has found that when the affair is revealed, both partners can experience mental health issues including anxiety, depression, and thoughts of suicide (Allen et al., 2005). There can also be an increase in emotional and physical violence within the couple.

So a couple should seek professional help to deal with the aftermaths of an affair, not only to possibly heal their relationship but also for their own psychological well-being.

There are many approaches to counseling couples after an affair, but generally, it’s about addressing the issues that precipitated and perpetuated the infidelity. One of the most well-researched methods of helping a couple mend these issues involves addressing the initial impact of the affair, developing a shared understanding of the context of the affair, forgiveness, and moving on (Baucom et al., 2017).

Choosing to stay or go

Overall, therapy seems to work for about two-thirds of couples who have experienced infidelity. If a couple decides to stay together, they must identify areas of improvement and commit to working on them (Baucom et al., 2017).

It’s also vital to re-establish trust. The therapist can help the couple acknowledge the areas of the relationship in which trust has already been rebuilt. Then the betrayed partner can be progressively exposed to situations that provide further reassurance they can trust their partner without having to constantly check on them.

But if therapy works for two-thirds of couples, it leaves another one third who experience no improvement. What then? If the relationship is characterized by many unresolved conflicts, hostility, and a lack of concern for one another, it may be best to end it. Ultimately, relationships serve the function of meeting our attachment needs of love, comfort, and security.

Being in a relationship that doesn’t meet these needs is considered problematic and dysfunctional by anyone’s definition.

But ending a relationship is never easy due to the attachment we develop with our romantic partner (Gillath et al., 2016). Even though in some relationships, our attachment needs are less likely to be fulfilled, it doesn’t stop us wanting to believe our partner will (one day) meet our needs.

The impending end of a relationship fills us with what is termed “separation distress.” Not only do we grieve the loss of the relationship (no matter how good or bad), but we also grieve over whether we will find another who will fulfill our needs.

The period of separation distress varies from person to person. Some may believe it’s worth celebrating the end of a toxic relationship, but they will still experience distress in one form or another. If the couple decides to end the relationship and are still in therapy, the therapist can help them work through their decision in a way that minimizes feelings of hurt.

So infidelity is less about sex and more about matters of the heart and a misguided quest to have one’s relationship needs met. The problem is that some people choose to seek their relationship needs in the arms of another rather than working on their existing relationship.

A version of this article was originally published by Gery Karantzas (Deakin University) on The Conversation. Read the original article.

Facebook image: Mivolchan19/Shutterstock


Allen, E. S., Atkins, D. C., Baucom, D. H., Snyder, D. K., Gordon, K. C., & Glass, S. P. (2005). Intrapersonal, interpersonal, and contextual factors in engaging in and responding to extramarital involvement. Clinical Psychology: Science and Practice, 12, 101-130.

Baucom, D. H., Pentel, K. Z., Gordon, K. C., & Snyder, D. K. (2017). An integrative approach to treating infidelity in couples. In J. Fitzgerald (Ed.) Foundations for Couples' Therapy: Research for the Real World (pp. 206-215). NY: Routledge.

Brewer, G., Hunt, D., James, G., & Abell, L. (2015). Dark Triad traits, infidelity and romantic revenge. Personality and Individual Differences, 83, 122-127.

Fincham, F. D., & May, R. W. (2017). Infidelity in romantic relationships. Current Opinion in Psychology, 13, 70-74.

Gillath, O., Karantzas, G. C., & Fraley, R. C. (2016). Adult attachment: A concise introduction to theory and research. Oxford: Academic Press.

Marjoribanks, D., & Bradley, A. D. (2017). Let’s talk about sex: The state of our sexual relationships in the UK today. UK: Relate.

Mattingly, B. A., Clark, E. M., Weidler, D. J., Bullock, M., Hackathorn, J., & Blankmeyer, K. (2011). Sociosexual orientation, commitment, and infidelity: A mediation analysis. The Journal of Social Psychology, 151, 222-226.

Schmitt, D. P. (2004). The Big Five related to risky sexual behaviour across 10 world regions: Differential personality associations of sexual promiscuity and relationship infidelity. European Journal of Personality, 18, 301-319.

Whisman, M. A., Dixon, A. E., & Johnson, B. (1997). Therapists' Perspectives of Couple Problems and Treatment Issues in Couple Therapy. Journal of Family Psychology, 11, 361-366.

About the Author
Gery Karantzas Ph.D.

Gery Karantzas, Ph.D., is an associate professor and the director of the Science of Adult Relationships (SoAR) Laboratory in the School of Psychology at Deakin University.

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