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A new study in the Archives of Sexual Behavior suggests that how people react to sexual versus emotional infidelity is shaped by more than just biological sex. While heterosexual men were more distressed by sexual betrayal and women by emotional betrayal, the findings indicate that traits like masculinity, femininity, and sexual attraction also influence these responses in flexible ways.
For several decades, psychologists have observed that men and women tend to react differently to infidelity. Men are more likely to be disturbed by sexual infidelity, while women are more upset by emotional cheating. Evolutionary psychologists have suggested that this might reflect reproductive pressures. For men, the risk of raising another man’s child might have favored the development of stronger reactions to sexual betrayal. For women, the loss of a partner’s emotional commitment could mean fewer resources and support for offspring, making emotional infidelity more threatening.
But this difference is not universal. Studies have shown that it becomes much less pronounced among sexual minorities. Gay men and lesbian women often report similar levels of distress over emotional and sexual infidelity, rather than showing a clear difference based on biological sex. This has raised the question of whether the difference between men and women is really just about being male or female—or whether other psychological traits might be involved.
The researchers behind the current study wanted to examine this question in more detail. They were interested in whether traits often associated with masculinity or femininity might influence how people respond to infidelity. They also wanted to test whether sexual orientation, measured not just as a label but as a continuum of attraction to men and women, could account for some of the variation in jealousy responses.
“We have for many years found robust sex difference in jealousy, but we have also been interested in any factors that could influence this pattern. Other researchers discovered that sexual orientation might influence that pattern. We also were influence by David Schmitt’s ideas on sexual dials vs. switches — how masculinization/feminization might be much better described as dimensional than categorical, including sexual orientation and jealousy triggers,” said study author Leif Edward Ottesen Kennair, a professor at the Norwegian University of Science and Technology.
For their study, the researchers collected data from 4,465 adults in Norway, ranging in age from 16 to 80. The sample included people who identified as heterosexual, gay, lesbian, bisexual, and pansexual. Participants were recruited through social media advertisements and LGBTQ+ websites. Each person completed a survey about their responses to hypothetical infidelity scenarios, along with questions about their childhood behavior, personality traits, sexual attraction, and self-perceived masculinity or femininity.
To measure jealousy, the participants were asked to imagine different types of infidelity. In one example, they were asked whether it would be more upsetting if their partner had sex with someone else, or if their partner developed a deep emotional connection with another person. Their answers were used to calculate a jealousy score that reflected how much more distressing they found sexual versus emotional betrayal.
The results supported some long-standing findings. Heterosexual men were much more likely than heterosexual women to be disturbed by sexual infidelity. In fact, nearly 59 percent of heterosexual men said sexual betrayal was more upsetting, compared to only 31 percent of heterosexual women. This pattern was consistent with past research.
But among sexual minorities, the sex difference mostly disappeared. Gay men and lesbian women responded in ways that were more alike, with both groups tending to be more upset by emotional infidelity. Bisexual men and women also reported similar responses. This suggests that sexual orientation plays a key role in how people experience jealousy.
The researchers then examined sexual attraction as a continuous variable. Rather than looking only at how people labeled themselves, they measured how strongly participants were attracted to men and to women. Among men, those who were exclusively attracted to women showed the highest levels of sexual jealousy. Men who had even a small degree of attraction to other men reported less distress about sexual infidelity.
The researchers also measured four different psychological traits related to masculinity and femininity. These included whether participants preferred system-oriented thinking or empathizing, whether they had gender-typical interests as children, whether they preferred male- or female-dominated occupations, and how masculine or feminine they saw themselves. These traits were used to create a broader measure of psychological gender.
In men, higher levels of psychological masculinity were linked to both a stronger attraction to women and a greater tendency to be disturbed by sexual infidelity. But the connection between masculinity and jealousy seemed to depend on whether the man was attracted to women. Masculinity influenced jealousy only when it was also linked to strong gynephilic attraction—that is, attraction to women.
Among women, masculinity was related to sexual orientation, but not to jealousy responses. This suggests that masculinity and femininity may play different roles in shaping sexual psychology for men and women.
Kennair told PsyPost that these findings suggest “that sexual orientation might be best measured dimensionally (as involving both gynephilia and androphilia), that sexual orientation influences sex differences (in this case, jealousy triggers), and that gendering and sex differences are not primarily categorical processes but dimensional processes that are largely influenced by biological sex, but absolutely not categorically determined in an either/or switch pattern. Rather, they function more like interconnected dimensional dials.”
A surprising finding came from a smaller group: bisexual men who were partnered with women. “In the current study, we found that bisexual men with a female partner were still more triggered by emotional than sexual infidelity,” Kennair explained. “Bisexual men should also be concerned about who the father of their partner’s children really is, from an evolutionary perspective, but it seems that only the highly gynephilic men are primarily triggered by sexual infidelity. This needs further investigation and theorizing.”
But the study, like all research, has some caveats. The participants were recruited online, which means the sample might not fully represent the broader population. In addition, the jealousy scenarios were hypothetical, and people’s real-life reactions might differ from what they imagine.
The study raises some new and unresolved questions. One puzzle is why sexual jealousy in men seems to drop off so steeply with even a small degree of androphilic attraction. From an evolutionary standpoint, any man who invested in raising a child would have faced reproductive costs if his partner had been unfaithful, regardless of his own sexual orientation. Yet the findings suggest that the mechanism for sexual jealousy may be tightly linked to sexual attraction to women, rather than simply being male or being partnered with a woman.
It also remains unclear why women’s jealousy responses are less influenced by sexual orientation or masculinity. The results suggest that emotional jealousy is a more stable pattern among women, while sexual jealousy in men appears more sensitive to individual differences in orientation and psychological traits.
“I think this is a first empirical establishment of the dials approach,” Kennair said. “I think it might be helpful to investigate this approach with other phenomena. Also, the research cannot address the developmental and biological processes underlying the psychological level we addressed in the paper. The causal pathways therefore need further investigation. And theorizing.”
He hopes that “maybe in the current polarized discussion of identity and sex/gender, people will find the dimensional and empirical approach of this paper a tool to communicate better than the categorical approaches let us do.”
The study, “Male Sex, Masculinization, Sexual Orientation, and Gynephilia Synergistically Predict Increased Sexual Jealousy,” was authored by Leif Edward Ottesen Kennair, Mons Bendixen, and David P. Schmitt.
