Is Infidelity Contagious? University Researchers Think So

By John Jeffay, NoCamels September 13, 2022 5 minutes

Deposit Photos

We’re more likely to cheat if we think everyone else is at it, says study

We’re more likely to cheat on our partners if we think other people are also being unfaithful.

That’s the conclusion of a team of university researchers who set out to discover whether infidelity was “contagious”.

They conducted a series of three experiments on student volunteers, all in long-term heterosexual relationships, who were recruited through fliers, social media posts and word of mouth.

They wanted to test the theory that the more we believe infidelity is the norm, the more likely we are to stray.

“Knowing that others are having affairs may make people feel more comfortable when considering having affairs themselves,” Gurit Birnbaum, professor of psychology at Reichman University, tells NoCamels.

“Of course, environments in which infidelity is prevalent do not necessarily turn people into cheaters. 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.

“Research has indeed shown that social norms, which dictate what behaviors are accepted as normal, affect how people resolve a conflict between short-term temptations and long-term goals in other situations, such as alcohol consumption, gambling, and stealing.

“We wanted to explore whether this social contagion will be observed when it comes to intimate relationships.

“Specifically, we examined whether exposure to norms of infidelity would decrease the commitment to the current partner while increasing desire for alternative mates.”

In the first of three experiments, 145 participants (88 women and 57 men) watched a video about whether humans have evolved to be monogamous.

Researchers at Reichman University believe that infidelity may be ‘contagious’. Deposit Photos

Half watched a version which reported that 86 per cent of adults admitted having cheated on their partner by having sex with someone else.

The other half watched the same video, but with the figure changed to 11 per cent, to see whether their perception of cheating as normal would affect their judgement (Research actually puts the figure at 70 per cent).

They were then asked to write a sexual fantasy, involving someone other than their partner, in graphic detail – with the assurance of anonymity.

The test was designed to determine whether the group who believed infidelity was widespread would be more enthusiastic about expressing their desires than the group who had just been told it was not.

Men expressed more interest than women in having sex with someone else – which didn’t surprise the researchers – but the study didn’t show a significant difference between the “11 per cent group” and the “86 per cent group”.

However the second experiment, conducted with different volunteers, showed clearer results. It was designed to see whether a discussion about cheating in general would arouse thoughts of infidelity, or whether it had to be specifically about sex.

flirt — Flirting by text. Deposit Photos

One group of volunteers read a real-life confession about a woman sharing a passionate kiss with her boss, and a second group read about a student paying someone else to write their essay.

They were then shown 16 pictures of attractive and unattractive people of the opposite sex and asked to make an instant yes/no decision as to whether they rated them as a potential partner.

Sign up for our free weekly newsletter

Those who had been exposed to the infidelity confession were more likely to show an interest in alternative partners. Or as the researchers put it, thinking about infidelity “erodes the motivation to protect the relationship from the allure of alternative mates”.

The team wanted to go a step further and determine how these thoughts about infidelity might actually translate into action. Their third experiment offered the volunteers an opportunity to make contact with an attractive stranger online.

sexchat — Prof. Gurit Birnbaum. Courtesy

One group was exposed to the discussion about adultery mentioned earlier and the other group to the cheating student discussion. Would the adultery discussion prove more provocative?

Both groups were then introduced to a “moderately attractive” real person of the opposite sex on the Instant Messenger service, who was blind to the research aims, but who had been briefed to respond warmly in a manner that conveyed contact readiness.

After a general discussion via text messages about hobbies and interests they were instructed to sign off with a message: “You definitely raised my curiosity! I hope to see you again and this time face-to-face.”

The volunteers’ messages were given a score of one to five for flirtatiousness by trained psychology students.

They were also asked how attractive they found their messaging partner, and how committed they were to their actual partner.

Some clearly deserved a five for their messages, such as: “It was great to get to know you! I’d love to meet you! You sound like a girl I can get along with.”

And “I enjoyed chatting with you! I’d love to see you soon. Would you like that too? Please let me know when we can meet.”

Those who had just been exposed to the infidelity discussion were more likely to pursue a face-to-face meeting than the cheating student group.

The experiment showed that, according to researchers, “greater perceptions of adultery norms were not only associated with greater desire for alternative partners but also with increased efforts to interact with them in the future”.

Monogamy still dominates in Western culture, although alternative lifestyles, such as swinging, open relationships, and polyamory have become increasingly acceptable, they say.

But the high frequency of sexual fantasies with alternative partners is proof that desires for people other than the current partner persist.

“Such environments may make people more vulnerable to, if not outright ‘infect’ them with, infidelity,” says Prof Gurit, who is also director of the Interpersonal Relationships Program at Reichman University.

“People should be more aware of the power of situations and the impact they may have on decision making in the intimate sphere.

“Couples in monogamous relationships who live in an environment in which infidelity is acceptable and are prone to engage in affairs might be offered counselling that encourages refocusing attention on one’s primary partner and has proven useful in intensifying sexual desire and the emotional bond between partners.”