ORANGE, Calif. - In the largest study to date on infidelity, Chapman University has learned men and women are different when it comes to feeling jealous. In a poll of nearly 64,000 Americans this study provides the first large-scale examination of gender and sexual orientation differences in response to potential sexual versus emotional infidelity in U.S. adults. 
 
 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. 
 
 Authorship was: Dr. David Frederick of Chapman University and Melissa Fales, Ph.D. candidate of UCLA. The paper appears in the journal, Archives of Sexual Behavior. 
 
 Consistently ranked among the top universities in the West, Chapman University provides a uniquely personalized and interdisciplinary educational experience to highly qualified students. Our programs encourage innovation, creativity and collaboration, and focus on developing global citizen-leaders who are distinctively prepared to improve their community and their world. 
 
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 Not that I cheated on my college girlfriend when we were both freshmen attending schools 130 miles apart. But if I did, I had an excuse: I was young, I was male and I was an idiot. These are conditions that psychologists like to call “co-morbid.” 
 
 The only good thing I can say about myself in this very hypothetical scenario, is that at least I had the honesty to ‘fess up to my faithlessness the next time I saw her. She was not—you won’t be surprised to learn—pleased with my behavior. But what I was surprised to learn (bearing in mind the young, male and stupid thing again) was that she was less upset by the sexual aspect of my infidelity than the emotional. 
 
 Soon enough, I came to learn that that was the way of things when it comes to women’s reactions to cheating—or at least that’s the stereotype. The equally glib corollary is that men can tolerate the nuzzling and canoodling part of infidelity better than they can the flesh crescendo it leads to. 
 
 Now, research out of Chapman University in Orange, California confirms that when it comes to this one aspect of the great gender divide, the big news is that there is no news to report. The stereotypes, it turns out, are spot on. 
 
 The study, published in the Archives of Sexual Behavior, was an ambitious one, involving a whopping 63,894 male and female respondents of both sexes, aged 18 to 65. In addition to basic biographical information such as income, marital history and sexual orientation, the participants were asked to choose (whether from imagination or painful experience) if they’d be hurt more by the carnal or cuddly part of being cheated on. 
 
 By a margin that would qualify as a landslide in politics, heterosexual men outpaced heterosexual women 54% to 35% on the physical side of the hurt-feelings equation, while heterosexual women beat heterosexual men 65% to 46% on the emotional side. Homosexual and bisexual men and women were troubled more or less equally by both aspects. 
 
 “Heterosexual men really stand out from all other groups,” said psychologist and lead author David Frederick, in a statement. “They were the only ones more likely to be most upset by sexual infidelity.” 
 
 In fairness to the straight guys, there’s more than just the doofus factor at work here—there’s also evolution, according to the authors. Short of a paternity test (which hardly existed when our behavioral coding was first being written millions of year ago), a male can never be absolutely certain that a child his mate bears is his, so physical infidelity poses a much greater risk. 
 
 And while males in the state of nature are hardwired to mate and mate and mate some more because it’s easy, fun and a calorically cheap way to get their genes across to the next generation, females are coded to seek protection and resources since it’s awfully hard to fetch food and defend against predators while giving birth and nursing. Even modern women are thus inclined—at least evolutionarily—to worry more about the outside romance that may cost them a partner than the roll in the hay that could be a one-time thing. 
 
 Societal expectations—outmoded though they may be—exacerbate the difference. Men are still judged more harshly (if only by themselves) in terms of their sexual prowess, while women are brought up to value bonding. Being cheated on thus has a different effect on the sexes because it threatens different aspects of their self-esteem. 
 
 Making the study more impressive was that the researchers corrected for nearly every variable other than gender that could have influenced the results—and repeatedly came up empty. Marital status didn’t play a role, nor did a history of being cheated on, nor did income, length of relationship or whether a respondent had children or not. The only factor that seemed to make some difference was that younger respondents of both genders reported a higher degree of upset at the physical aspects of infidelity. That’s probably because younger people of both sexes are in the stage of their lives when they’re helping themselves to that aspect more, so it makes a bigger difference in their relational well-being. 
 
 None of this alters the larger takeaway, which is that cheating still stinks. And none of it changes the fact that even a few decades on, a hypothetical person who was guilty of such a thing might still feel kind of bad about it. Or that’s what I’ve been told, but I wouldn’t know. Really. 
 
 Read next: Here Are All the Sexist Ways the Media Portrayed Both Men and Women in 2014 
 
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– Ask a heterosexual man and woman about their reactions to their partners cheating, and you'd likely get two very different answers. That's according to a huge study on jealousy among people of different sexes and sexualities. Researchers at Chapman University polled some 64,000 people on how they'd react to hypothetical infidelity, and they found that while gay men and women, as well as bisexual men and women, didn't much differ in their feelings on the matter, heterosexuals did. Straight men, more often than women, found sexual infidelity to be the most disturbing kind, while straight women, more often than men, were most bothered by emotional infidelity—eg, their partners falling in love with another person, a press release reports. "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," says a researcher. And as Time reports, the findings held true regardless of factors like marital and parental status, income, and whether one had been cheated on in the past. (One caveat: Younger people were more bothered by sexual infidelity than older respondents, perhaps because sex plays a larger role in their lives, Time notes.) An evolutionary explanation for the phenomenon would hold that a man can't know for sure whether a child is his own, therefore men are concerned about sexual cheating. A sociocultural explanation would note that men are socialized to take pride in sexual ability, and a partner cheating suggests the man's talents are not so impressive. (We're not the only creatures who experience jealousy.)