By Published: April 4, 2018

Research from CU Boulder graduate student strives to gain better understanding of infidelity

Americans who admit to having extramarital sex most likely cheat with a close friend, according to research from the University of Colorado Boulder’s Department of Psychology and Neuroscience.

Just over half (53.5 percent) of those reporting extramarital sex said they were unfaithful with someone they knew well, such as a close friend. About a third of affairs are with someone who’s somewhat well-known, such as a neighbor, co-worker or long-term acquaintance (about 29.4 percent). The rest of affairs occur with casual acquaintances.

And on the question of who reports cheating more, the researchers—Lindsay Labrecque, a PhD psychology student, and Mark Whisman, a psychology professor at CU Boulder—say it is consistently reported more frequently by men, despite reports from the media and some clinicians that men and women engage in infidelity at similar rates.

The researchers culled data from nine years of the General Social Survey, analyzing responses from 13,030 people nationwide.


Lindsay Labrecque

The two researchers found that about 21 percent of men and 13 percent of women reported infidelity at some point in their lifetime and that this gender difference has been consistent from 2000 to 2016.

Labrecque adds that men are more likely than women to hold more favorable attitudes about extramarital sex.

Another gender difference: Among those who reported having extramarital sex in the past year, men were much more likely than women to have paid for—or to have received payment for—sex, at about 12 percent compared to just 1 percent.

Labrecque and Whisman say they wanted to shed more light on extramarital sex, especially about the identity of extramarital partners along with gender differences and attitudes.

“I’ve always been very interested in understanding how sex contributes to relationship satisfaction and mental health,” says Labrecque, who plans to work after graduation with couples on sexual and relationship adjustment.

“We know infidelity impacts relationship satisfaction … it’s the most common reason given for divorce or separation and it’s a difficult issue to treat in therapy. A better understanding of all the issues related to extramarital sex may help improve treatment.”

The researchers say they also found that attitudes about extramarital sex are growing slightly more relaxed.

“We found that while most Americans still disapprove of extramarital sex, there has been a small change that may reflect more tolerance and flexibility in attitudes,” Labrecque says.

In 2000, about 79 percent of Americans viewed extramarital sex as “always wrong” and about 7 percent of Americans reported extramarital sex as “wrong only sometimes” compared to 76 percent and 9 percent in 2016, respectively.

And again, there were gender differences in these attitudes. Men were less likely to report that extramarital sex was always wrong.

The research also showed that the number of married people who reported ever having sex with someone other than their spouse decreased between 2000 and 2016, albeit by a small percentage. Specifically, lifetime prevalence of extramarital sex decreased from 17.8 percent in 2000 to 16.3 percent in 2016.

We know infidelity impacts relationship satisfaction … it’s the most common reason given for divorce or separation and it’s a difficult issue to treat in therapy. A better understanding of all the issues related to extramarital sex may help improve treatment."

“Overall, rates of extramarital sex have remained fairly constant over the 17-year period and may be lower than popularly held beliefs about extramarital sex reported in the media,” Labrecque says.

As for why people cheat, Whisman says prior experiences of extramarital sex, more permissive attitudes towards extramarital sex, and a greater acceptance of casual sex are all related to a greater likelihood of engaging in extramarital sex.

“With respect to relationship factors, the association between lower relationship satisfaction and extramarital sex is a well-established finding,” Whisman says.

“Finally, there are several contextual variables that have been linked with extramarital sex, including lack of religious attendance, work-related opportunities, and a social group in which extramarital sex is relatively more prevalent and accepted.”

Up next for Labrecque is more work on the topic—studying how, if at all, extramarital sex with different types of partners affects the duration of marriage. For example, would a couple be more likely to divorce if the husband cheated with a close friend versus someone he didn’t know as well?

“I wonder whether married individuals who have extramarital sex with partners such as a close friend or co-worker are choosing such partners as a commitment to form a new relationship and by proxy, to leave their marriage,” Labrecque says.

“These partners possess or provide inherent qualities including emotional intimacy, closeness, friendship, support etc., and choosing to have extramarital sex with a partner with these qualities may reflect a preference for a committed and/or intimate extramarital relationship more so than a partner paid for sex or a casual date.”