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Who Is Likely to Be Unfaithful, and Why?

An inside look at what causes infidelity.

Key points

  • Attachment style may predict which romantic partners remain faithful to each other.
  • Anxiously attached, married people are potentially at risk for infidelity, either on their part or on the part of their spouses.
  • Attachment-based couples therapy can help address insecurity within a relationship.

The perspectives on relationships provided by attachment theory provide important insights in the factors that influence the course of a couple’s dynamics over time.

According to attachment theory, the earliest relationships we had in childhood provide us with mental models that we carry into our adult lives. These models take the form of “attachment styles,” or approaches to the people with whom we become close in our romantic lives.

Most people have the “secure” attachment style, in which they feel that they can rely on their intimate partners to care for them and place high priority on their well-being. People with insecure attachment styles either fear abandonment (“anxious” attachment) or prefer to retain their independence from others (“avoidant” attachment).

People can overcome the challenges presented by having developed an insecure attachment style. However, their chances of having positive, lasting romantic relationships are much lower unless these attachment issues are addressed somehow.

Even from this brief description, you can see how attachment style may play a role in predicting which romantic partners remain faithful to each other.

Attachment styles and romantic relationships

People who are securely attached have confidence in the stability of their relationship and neither fear the other person’s infidelity nor are likely to stray from their partner. By contrast, people who are anxiously attached need constant reassurance from a partner in order to feel that they can carry on from day to day. If their partner fails to provide this reassurance, then they may look elsewhere for comfort. The anxiously attached may seek sexual encounters, even if they’re already in a relationship, because they equate sex with love. Those who have an avoidant attachment style, on the other hand, have difficulty making commitments and therefore are likely to stray because they don’t feel that connected to their partner.

Challenges with previous studies on attachment and infidelity

As sensible as this reasoning is, Florida State University psychologist V. Michelle Russell and her colleagues (2013) found that previous studies on attachment style and infidelity were inconclusive. In large part, this was because most of the previous studies were conducted with undergraduate students who were in dating, but not marital, relationships. People in dating relationships may very well behave differently than those in relationships between spouses because they haven’t made the kind of long-term commitment involved in marriage.

The Russell team also believed that it was in addition to looking at married partners, they needed to control for such factors as personality, satisfaction in the relationship, and frequency of sexual activities. Importantly, the previous studies hadn’t controlled for the partner’s attachment style either. Because an intimate relationship is, by definition, one involving two people, both contribute to the likelihood that things will go either well or poorly over the course of the couple’s time together.

With this background in mind, let’s turn to the study itself.

The Russell study on infidelity

With a sample of over 200 newlywed couples, Russell and her coauthors investigated personality, attachment style, marital satisfaction, sexual activity, and infidelity (of self or partner) over the course of from 3-1/2 to 4-1/2 years. The couples completed the questionnaires 6 times during this period.

Who, then, was most likely to be unfaithful? As I pointed out earlier, previous studies on dating couples had showed that the anxiously attached were least likely to be unfaithful and the avoidantly attached the most. Among these married couples, however, the anxiously attached were the most likely to cheat on their partners. In fact, if either partner was anxiously attached, the couple had higher odds of one of them being unfaithful. Those with a partner who had an avoidant attachment style actually had the lowest rates of infidelity.

Russell and her collaborators believe that attachment anxiety increases the risks of infidelity by providing “enough of a threat to intimacy to motivate spouses to seek out alternative partners.” In other words, if either partner communicates extreme neediness and worry about the relationship’s stability, this seems to be enough to set the stage for one or both of them looking elsewhere for emotional closeness. The fact that they were already in a committed relationship, unlike partners who are not yet married, seemed to throw their anxiety about closeness into a more prominent role. Perhaps the marriage commitment led one or both of the partners to feel that they needed to live up to a higher level of intimacy, and this drove them to feeling they weren’t close enough as a married couple ought to be.

Those whose partners were avoidantly attached, by contrast, seemed more concerned about protecting their spouses and therefore became less likely to stray. Unlike people who are dating, once again, the marriage commitment seemed to lead partners of the avoidant style to want their spouses to feel secure and loved.

The takeaway

The take-home message from this study is that married people who are anxiously attached are potentially at risk for infidelity, either on their part or on the part of their spouses. As a preventive measure or to help married partners who are experiencing infidelity, attachment-based couples therapy can help address their insecurity about the relationship.

Before the relationship reaches crisis point, however, couples can also benefit from recognizing the signs of attachment insecurity in themselves and each other. Reaching out to your partner, either because you are high in attachment anxiety or your partner is, can help provide the reassurances that can prevent a search for comfort outside the home. Asking attachment insecurity questions, such as whether one of you fears losing the other’s love or feels that you can’t get close enough, can provide cues to understanding your needs and those of your partner.

Finally, there is another point worth mentioning of a more methodological nature. Be wary of advice about relationships that stems from research on dating couples, particularly when those couples are college undergraduates. As the study conducted by Russell and her team shows, couples who are dating may have radically different perspectives, not only because they’re younger, but because they haven’t made a long-term commitment to each other.

The good news from this study is that it suggests ways that people may be able to avoid unhappy endings to their long-term intimate relationships. Attachment style, though it may originate in early childhood, continues to evolve over adulthood. Through connections with an understanding partner, counseling, or self-growth, you may be able to shift your views of yourself and your needs and ultimately achieve greater fulfillment in your long-term relationships.

Copyright Susan Krauss Whitbourne, Ph.D. 2013

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Russell, V. M., Baker, L. R., & McNulty, J. K. (2013). Attachment insecurity and infidelity in marriage: Do studies of dating relationships really inform us about marriage? Journal of Family Psychology, 27, 242-251. doi: 10.1037/a0032118

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