Reports estimate up to 40 percent of married couples are impacted by infidelity. And while some experts say it's human nature and blame the internet with giving people more chances to cheat on their spouses, Dr. Kenneth Rosenberg, an addiction psychiatrist and the author of " Infidelity: Why Men and Women Cheat," says science may be able to explain the real reason.
"We’re wired to bond but also wired to stray, it’s part of why we have constraints and programs in our culture to help us with these dual mandates," Rosenberg told Fox News.
In his book, Rosenberg talks of three major factors that play a role in infidelity: our biology, psychology and our culture.
“Our biology plays a big role, [but] we can’t blame it all on biology. You can’t say, 'Testosterone made me do it,' but people who have higher testosterone might cheat more, people who are more captured by their dopamine reward system might cheat more,” Rosenberg said.
In terms of psychology, one of the biggest factors is the feeling that they’re entitled or deserved to cheat. The personality traits associated with this include narcissism, lacking empathy, grandiosity, being impulsive, being a thrill seeker, fearing commitment and being self-destructive.
Demographics can also tell us who might be more inclined to cheat.
"Women who are more educated are more likely to cheat," Rosenberg said. "And men cheat more than women; 20 percent of married men cheat, 15 percent of married women cheat."
The rate of cheating men has stayed stable over the past 20 years, but since 1993, the amount of women who cheat has risen roughly 50 percent, from 10 percent to 15 percent today.
"But if you look at the under-35 populations, younger men and women, there [percentage rate] is kind of 50/50."
Yet, in his clinical experience, the age range between when men and women most likely to cheat is between forty and sixty years old, Rosenberg said.
One of the scariest statistics Rosenberg revealed was that 90 percent of people never find out their spouses are cheating on them.
"You know why the main reason people cheat? Because they can. Often because it’s an opportunity, often because they think they can get away with it, often because they feel compelled to do it."
It’s easy to assume that couples who deal with infidelity don’t have a happy relationship, but Rosenberg says over half of the people who cheat are very happy in their marriages.
"We like novelty, we like things that are new, that are different," Rosenberg said.
In his book, Rosenberg refers to a study on heterosexual women and men who sniffed T-shirts of anonymous gender-opposite people and chose which ones they felt were the sexiest. “Overwhelmingly, the participants selected T-shirts of the people who were genetically different from them in a specific part of the immune system called the major histocompatibility complex. So, by and large, we end up married to people from our tribe, but lust after people from other tribes," he described.
When it comes to forgiving spouses who have been unfaithful, a 2015 YouGov survey found 22 percent of men and 27 percent of women said they have taken back a partner after finding out their spouses cheated.
"You have to be able to forgive and forget," Rosenberg said. "Talking about it can really help, understanding where it comes from. We have a romantic belief that the affair partner is going to save us from boredom or feeling unloved, but if you think of it more internally, these are the problems you need to address.
"'What is it about me that’s making me discard one person?'"