SALT LAKE CITY — When it comes to cheating or staying true in a romantic partnership, generations behave differently, new research finds. Generation X and millennials tiptoe closer to the line — or cross over — into unfaithful behaviors, especially online. And virtual dalliance can jeopardize real-world relationships.

The two generations' "porous boundaries" online — including flirting with an old flame or sparking an emotional connection in cyberspace — could harm their real flesh-and-blood relationships, according to the 2019 edition of the annual "State of Our Unions," produced collaboratively by the National Marriage Project at the University of Virginia and and the Wheatley Institution and School of Family Life at BYU. The report tracks what it calls "iFidelity" — staying true to one's partner in an age of social media and technology — with an online study conducted by YouGov involving 2,000 adults, their numbers matched to be nationally representative in terms of married, cohabiting or single.

Overall, the study found, most people eschew behaviors that could be viewed as infidelity. But online behavior can be murky.

"We do still get strong support for fidelity in multiple areas of life, both in terms of real-life behavior and also online behavior," said study co-author Jeff Dew, an associate professor at Brigham Young University. But he said Gen X and millennials "were more likely to engage in online infidelity or online dalliances" compared to older generations.

That "greater permissiveness" among younger Americans means they may not recognize that "the tendency to push boundaries puts a relationship at risk — making them less likely to invest with a real relationship in the here and now," said study co-author W. Bradford Wilcox, associate professor of sociology at the University of Virginia and director of the National Marriage Project.

The study provides a snapshot, rather than proving causation, but Dew said it's "unsurprising" to find an association between big problems and "what people might think of as smaller things. There is a relationship between online and full-blown sexual affairs."

Social media can complicate relationships, said Galena K. Rhoades, a research associate professor of psychology at the University of Denver, who was not involved with the report.

"It adds so much more for couples to sort out in their relationships. What I see in my practice is people don't know that they're essentially breaking expectations around infidelity until after it happens. Then they learn it went against the expectation their partner had and that can cause a lot of problems," she said.

When iFidelity becomes iInfidelity

The study identified three behaviors that a majority of people across generations do not see as cheating at all, even by someone in a committed relationship: real-life flirting with someone besides the partner, following a former boyfriend or girlfriend online or viewing pornography.

"Still, when you look at those three behaviors, they tend to be problematic for relationships," Dew said.

On the other hand, at least 70% of Americans rate other behaviors as cheating: having sex, sexting, cybersex, a real-life secret emotional relationship, sexual talk online (so-called hotchatting) and a secret emotional relationship online.

A clear majority of all generations say they support sexual fidelity and say they practice it in real life. But behavioral differences based on generations are clear. For example, the report said 18% of millennials engaged in sexual conversations online with a nonpartner, compared to 3% of those in the greatest/silent generations and 3% of baby boomers. Generation X was close behind millennials, at 16%.

The report defines fidelity as "that sense of being off the market once we enter marriage or a committed cohabiting relationship — purposefully avoiding emotional and physical intimacy with former partners, work colleagues and friends."

Just 18% of millennials agree that "all of the electronic behaviors that blur romantic and sexual lines with others are inappropriate, compared to 26% of baby boomers," according to the report.

Dew said part of the reason for the generation gap is that younger adults "grew up" online and are likely more comfortable there than older adults, using it for many aspects of their life — including potentially problematic behaviors.

A 2017 survey for the Deseret News conducted by Y2 Analytics and YouGov also found that the internet and social media can muddy boundaries in relationships.

"New technologies muddle old assumptions about adultery, creating a gray area that couples can struggle to navigate together," Katherine Hertlein, a therapist and professor at the University of Nevada, Las Vegas, who studies how technology affects family life, told the Deseret News at the time.

"I'm very surprised when I ask a couple about their definition of infidelity during premarital counseling and they respond, 'What are you talking about? It means physically touching someone else,'" she said. "I tell them they need to wake up."

The Deseret News poll also "found a deep gender divide on what constitutes adultery, with women more likely than men to define 11 behaviors on the survey as cheating. The gap was especially large on activities enabled by the internet, such as maintaining an online dating profile, which 70% of women but only 55% of men say is always cheating," the article said.

The new study from UVA and BYU also documents a link between fidelity and happiness. "Relationship outcomes are markedly worse when iFidelity becomes iInfidelity," the report says. "For example, married and cohabiting Americans who break three or more romantic or sexual boundaries online are 26 percentage points less likely to be very happy in their real-life relationship, compared to those who push none of those boundaries." It also says cohabiters are more likely than married individuals to exhibit problematic behaviors.

The report tracks long-term trends in marriage, cohabiting and divorce. It finds more people cohabiting before marriage and more social acceptance of the practice. And teenagers especially think it's a good idea to cohabit before committing to someone by marrying.

Greener pastures?

Rhoades believes that keeping track of people who might be available to you in the future — old loves, those with whom you flirt or form emotional attachment, among others — can hamper commitment to the partner, relationship and family you have.

Not everyone who flirts or tracks a former love online has "one foot out the door, but the door's still open. That can be stressful for relationships," Rhoades said. For one thing, it indicates partners aren't prioritizing their relationship the same way. And it can lead to distrust.

"It makes a lot of sense that social media, dating apps, etc., encourage people to think about the volume of alternatives they have. By doing so, it may make it harder to commit to a new, ongoing relationship," said Rhoades. "I also imagine it's a common step for people considering leaving a relationship to get on social media and look for alternatives. Not necessarily to pursue them, but to give a sense, 'If I leave this relationship, there will be an alternative one.'"

She added, "If you're the one keeping track of other options, it can take away your sense of commitment and desire to work on the relationship. ... You may not focus on and work on the relationship, especially in times when things are not great — and we all have those times."

Trust can also erode if someone who is pushing boundaries online assumes their partner is doing the same.

Children are an important reason to think about online behavior and curb any that's problematic, because divorce and infidelity travel together. "It fundamentally changes a relationship. Children who grow up with parents in a stable relationship together have the best outcome," said Rhoades.

Another negative ramification involving kids is they could learn their parents are doing something inappropriate, lowering some of their faith in and respect for their parents, Wilcox said.

The three experts all suggest that people pay attention to behavior online that could endanger their real relationships. And Wilcox adds that "for the sake of the kids, parents would be well served to be more physically and emotionally present to their spouse and children. This is one more way in which an online temptation distracts us from being with the people who are the most important in our world."