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How Attachment Styles Impact Attitudes Toward Infidelity

Avoidant people tend not to feel seriously threatened by emotional infidelity, used with permission
Source:, used with permission

Many studies over the years have shown that men tend to be more jealous when their partner engages in sex with another man than if she is getting emotionally involved with the guy without having sex with him. Women, on the other hand, are more jealous if their man is "merely" getting emotionally involved with another woman than if he has sex with her without any emotional involvement.

Evolutionary psychologists originally offered the following explanation. Sexual infidelity would be a lot worse than emotional infidelity for our male ancestors compared to our female ancestors because it would make it less certain that these males were the father of any children their female companions had. Sexual infidelity could potentially leave them in a situation where they would waste valuable resources providing for another man’s children. This would limit the chance that the man’s own genes were passed on, as he would have fewer resources to keep his own children alive.

By contrast, it would be a great risk for ancient women if their man became emotionally attached to another woman, because that would increase the risk that her provider would leave her and her children, making it less likely that her children would survive and hence making it less likely that her genes would be passed on. Jealousy was a way of ensuring just that these disadvantageous situations didn’t arise as often as they otherwise would have.

The theory faces several challenges. First, in many societies women were their own providers or contributed equally to the family as providers. Women in Ancient Egypt, for example, normally worked good jobs alongside the men they married. Going further back, the gatherers in hunter-gather societies contributed equally to the household. Many of these ladies could provide for themselves and did not depend on the baby daddy for food or security, which raises the question of why the genes of those women weren't not selected for. Second, while studies appear to show that more men are concerned with sexual infidelity than women, there is still a large fraction of men who feel worse about emotional infidelity than sexual straying.

Pennsylvania State University psychological scientists Kenneth Levy and Kristen Kelly recently provided a different explanation of why people respond differently to sexual versus emotional infidelity. They hypothesize that which kind of infidelity is most upsetting for a person depends on that person’s attachment style.

A person with an anxious attachment style (co-dependency) constantly fears that the relationship will end and hence is more concerned about emotional infidelity than sexual straying.

People with an avoidant attachment style, on the other hand, seek great levels of personal autonomy and tend to shun committed relationships. If they are in a relationship, it will tend to be one based on sexual intimacy rather than emotional closeness.

Because avoidant people seek to avoid emotionally investing themselves in committed relationships, they typically do not feel seriously threatened by a partner's emotional involvement with another person. If a sexual partner engages in sexual infidelity, on the other hand, this provides a threat to the only way in which they can be intimate with their sex partner. Because of this particular way of viewing relationships, avoidant people are more concerned when their partner strays sexually than if he or she engages in emotional infidelity.

Source: Levy et al. Sex Differences in Jealousy: A Contribution From Attachment Theory. Psychological Science, 2009; DOI: 10.1177/0956797609357708

Berit "Brit" Brogaard is the author of On Romantic Love