What Makes Infidelity Contagious? A Researcher Explains

Psychological research shows one way to control our extra-relational urges.

By Mark Travers, Ph.D. | September 20, 2022

A new study published in the Archives of Sexual Behavior underscores the power of situational forces in making someone susceptible to the possibility of considering romantic alternatives.

"A peer environment that gives the impression that infidelity is acceptable may make people gravitate toward attractive alternatives and knowing that others are having affairs may make people feel more comfortable when considering having affairs themselves," says psychologist Gurit Birnbaum, a faculty member of the Baruch Ivcher School of Psychology in Israel and the lead author of the paper.

"Of course, environments in which infidelity is prevalent do not necessarily turn people into cheaters," says Birnbaum. "Even so, if someone is already vulnerable to cheating or if opportunities for infidelity arise, these environments can give the extra push needed to resolve the conflict between following moral values and succumbing to temptations in a way that promotes infidelity."

To better understand the phenomenon of infidelity, the authors explored whether exposure to stories and instances of infidelity would decrease the commitment to one's current partner while increasing the desire for alternative mates.

In three studies, the researchers exposed romantically involved participants to others' cheating behavior. This was followed by recording participants' reactions while they were thinking of or interacting with attractive others.

The researchers found that participants experienced less commitment to their current relationship and expressed a greater desire for alternative partners if they were exposed to others' dishonest acts and cheating behavior.

"Environments that foster a greater prevalence of infidelity may make people more vulnerable to, if not outright 'infect' them with, infidelity," says Birnbaum.

Perceptions of high norms of dishonesty, therefore, enable people to justify misbehaviors as less immoral which in turn helps them dismiss the moral confusion between long-term goals that support moral values and short-term temptations.

There are, however, differences in people's susceptibility to perceiving such norms and behaving in accordance with them. Past research has shown that several personality characteristics, such as neuroticism, narcissism, and attachment insecurities, make people more prone to engaging in affairs outside of their committed relationship. Other research suggests that infidelity is predicted by higher levels of neuroticism and lower levels of religiosity.

Some research suggests that approximately half of married U.S. adults (53% of women and 44% of men, to be exact) have engaged in extra-marital sex.

Though there was no gender difference in the extent to which men and women experienced interest in alternative partners following exposure to norms of infidelity, the authors found that men were less committed to their current relationship.

The authors offer the following words of wisdom for people who struggle with the temptation to cheat:

  1. Couples in monogamous relationships who live in an environment in which infidelity is acceptable might seek counseling that encourages refocusing attention on one's primary partner. Counseling and couple's therapy have proven useful in intensifying sexual desire and the emotional bond between partners (motivating efforts to make the partner feel special, for example).

  2. It is important that people become aware of the power of situations and the impact they may have on decision-making in the intimate sphere

  3. Some individuals find success in using relationship-protective strategies such as ignoring suitors or perceiving them as less attractive than they are

  4. Be mindful of your social influences. Associating with people in your community who are committed to their partners can help reinforce your own level of commitment.

A full interview with the researchers on the link between social norms and infidelity can be found here: A psychologist explains why infidelity is contagious