Research on jealousy: Impact of sexual vs. emotional infidelity

According to the findings, heterosexual men were more likely than heterosexual women to be most upset by sexual infidelity (54 percent of men vs. 35 percent of women) and less likely than heterosexual women to be most upset by emotional infidelity (46 percent of men vs. 65 percent of women).

Participants imagined what would upset them more: their partners having sex with someone else (but not falling in love with them) or their partners falling in love with someone else (but not having sex with them). Consistent with the evolutionary perspective, heterosexual men were more likely than heterosexual women to be upset by sexual infidelity and less likely than heterosexual women to be upset by emotional infidelity. Bisexual men and women did not differ significantly. Gay men and lesbian women also did not differ.

"Heterosexual men really stand out from all other groups: they were the only ones who were much more likely to be most upset by sexual infidelity rather than emotional infidelity," said David Frederick, Ph.D., and lead author on the study. He went on to note: "The attitudes of gay, lesbian, and bisexual men and women have been historically understudied and under theorized in psychology, particularly in regards to tests of evolutionary perspectives."

Sexual and emotional infidelity can cause harm to both men and women, including leading to broken hearts and relationships coming to an abrupt and painful end; as well as abandonment, partner violence, and loss of resources when these resources are invested into affair partners.

"The responses of men and women to the threat of infidelity range from intense pangs of jealousy to elaborate displays of attention to woo their partner back. Jealousy can also trigger harmful and violent behavior, so it is important to understand what are the most potent triggers of jealousy," said Dr. Frederick.

The evolutionary perspective notes that men face a problem that women never face: paternal uncertainty. They never know if their child is genetically related to them, there is always a chance the child could have been fathered by another man. In contrast, women never face the problem of maternal uncertainty. Thus, while it is expected that both men and women experience sexual jealousy, men may exhibit particularly heightened responses compared with women. Further, while women do not face maternal uncertainty, they risk the potential loss of resources and commitment from partners if they channel their investment to another mate.

Sociocultural perspectives have generally claimed that no difference would be expected between men and women. However, this study notes that men are socialized to be masculine, which includes having great sexual prowess. If a man's partner commits sexual infidelity, this brings into question his sexual prowess and therefore threatens his masculinity, which leads him to react more negatively to his partner committing sexual rather than emotional infidelity.

In contrast, women are taught to think relationally and to be the emotional nurturers in a relationship. If their partner commits emotional infidelity, this may threaten her sense of self more so than if her partner commits sexual infidelity.

"There has been significant disagreement about whether or not men and women tend to differ in their responses to sexual and emotional infidelity. Most research relies on small samples or college samples. We set out to examine a broad and diverse sample of Americans," said Dr. Frederick.

Consistent with evolutionary perspective, one's reaction to sexual verses emotional infidelity is likely shaped by environmental and personal factors. This gender difference emerged across age groups, income levels, history of being cheated on, history of being unfaithful, relationship type, and length. Factors such as age, income and whether people had children were unrelated to upset over sexual versus emotional infidelity. However, younger participants were notably more upset by sexual infidelity than older participants.

A review of ethnographic accounts from 16 societies found that infidelity was the most common cause of marital dissolution. A meta-analysis of 50 studies found that 34 percent of men and 24 percent of women have engaged in extramarital sexual activities. Infidelity in dating relationships is even higher.

A total of 63,894 participants ages 18-65 years completed the survey. On average, participants were in their late 30s.

The paper appears in the journal, Archives of Sexual Behavior.