Another one bites the dust.

Today, Gwyneth Paltrow and Chris Martin announced their official separation (or, in Goop-ese, their “conscious uncoupling.”) “We have been working hard for well over a year, some of it together, some of it separated, to see what might have been possible between us, and we have come to the conclusion that while we love each other very much we will remain separate,” they explained via a special post on Goop.

Say what you will about celebrities and their privilleged lives, but who’s to say they have it any easier than anyone else when it comes to breaking up? In fact—is it harder to maintain a marriage when you’re a celebrity couple?

While the average divorce rate for first marriages hovers around 40%, celebrity divorce lawyer Raoul Felder estimates that the stars’ divorce rate is well over 50 percent and points out that it’s tough to name more than a handful with long-term, happy marriages. What gives?!

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Most of us have some version of “the list”—the celebrities we’d sleep with if we ever got the chance, no matter our relationship status—but the whole point is that we’ll never get that chance (someday, Hugh Jackman, wait for me!). Not so for celebrities. The person topping their list could easily be their next co-star or the host of that night’s house party.

But whether our pretty face is splashed on a billboard or propped up on our mother’s mantle, the science of what keeps us committed or leads us to stray is the same for everyone—celebrity marriages just shine a spotlight on a process we all go through. More than the rest of us, celebrities are constantly surrounded by what psychologists call “attractive alternatives,” meaning people who come into our lives that we might take a chance on if we were single. The more we let them in, the more likely we are to stray.

The Allure of the Attractive Alternative

When we’re in a committed relationship, some level of dependence keeps us coming back. “We are motivated to maintain a relationship when we are dependent on that person to meet our needs,” says Tim Loving, associate professor of psychology at University of Texas at Austin and co-founder of “We stay [in our current relationship] when we think that what we’re getting is better than what we perceive to be available elsewhere. If we think someone else can better meet our needs, then we’re going to leave.” (Think of Allie leaving her fiancé for lifelong love Noah in “The Notebook.”)

For many people, a really great alternative may not come along very often (or ever), but for celebrities, being bombarded with attractive alternatives is just a run-of-the-mill afternoon.

“Celebrities have a high number of attractive people around them,” says Loving. “Then throw into the mix that they’re constantly traveling, doing novel things, working together in arousing situations”—all cornerstones of attraction—“and it becomes really hard not to consider alternatives.” Just that consideration, even if they never act on it, can wear down relationship commitment.

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A twenty-something, married film actress (we’ll call her Aimee Quinn) stars opposite some very recognizable attractive alternatives and says that co-stars often fall for each other. “You’re cast to play a love interest opposite someone you naturally have chemistry with,” she explains. “To be convincing onscreen, you have to let that chemistry happen without letting it cross into your personal life. It’s a fine line to walk.” (Brad Pitt and Angelina Jolie in Mr. and Mrs. Smith and Elizabeth Taylor and Richard Burton in Cleopatra are perhaps the most famous couples that didn’t manage to walk it.)

On top of that, actors are often physically far from their partners. “When you’re filming, you’re with your co-stars 16 hours a day in a remote location so the experience is intensified,” says Quinn. Staying faithful can be a challenge, by no fault of theirs.

“Letting that chemistry happen” on set means convincing yourself—on some level—that you and your co-star could be great together. During a steamy scene, that doesn’t leave much room to be reminding yourself that you actually prefer and are fulfilled by your partner. Instead, the thought patterns that naturally support a committed relationship may take a back burner, leaving a bulls-eye target for temptation. And while actors may be more vulnerable than most, we all have relationships or situations that can break down our defenses too.

Playing Mind Games 

When push comes to shove, commitment is all in your head. When you’re in a committed relationship, your brain lends a hand (or a neuron) to help you stay faithful. “People who are more committed tend to derogate alternatives,” says Loving, meaning that when faced with someone particularly attractive, they will rate them as less attractive or actively distance themselves.In fact, when you’re in a committed relationship, your brain scans literally look different than a single person’s would.

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A 2011 study published in Cognition & Emotion showed what happens in the brain when we see attractive alternatives. Fourteen people in exclusive, heterosexual relationships rated 80 color photos of the opposite sex. The pictures with the highest attractiveness ratings activated a region of the brain called the ventral striatum, a reward center that plays a role in attraction. But for those who felt committed to their relationships, another region kicked in as well: a region responsible for emotion regulation.“

The more a subject activated the emotion regulation region, the weaker the activation in the ventral striatum,” says Meghan Meyer, lead author and doctoral student at University of California, Los Angeles. In layman’s terms, this suggests that the emotion regulation region sends a signal that decreases attraction, making a former hottie just so-so.The right ventral lateral pre-frontal cortex (say that three times fast!) is the main region that engages to lower your attraction to others. If you’re trying to act brave when you’re scared or confident when you’re shy, this cortex is in high gear. Mind over matter starts here.

Not everyone has a strong pre-frontal cortex. “Just like you need a bicep to throw a ball, you need your pre-frontal cortex to regulate your emotions, and there are individual differences in its strength,” says Meyer. In fact, the study found that there was a direct relationship between commitment and pre-frontal cortex activation. More committed subjects showed more activation, suggesting that mentally committing to your partner strengthens your natural defenses against attractive alternatives.

The effect isn’t sheer willpower—in fact, it’s automatic. “When you ask people in relationships if they downplayed the person’s attractiveness, they say, ‘no way,’” says Meyer. “They think they rated them accurately, without bias.”Of course, your mind can also play tricks on you, making you think an alternative is more attractive than he or she really is.Spend enough time in any relationship and eventually, the warts start to show and bad habits come out of the woodwork. “Long-term partners naturally have the disadvantage of showing their negative sides,” says Loving. “Someone we just met has none of that negative stuff, so it’s tough for other people not to seem attractive. This is why relationships take work.”In fact, sometimes that new person—still devoid of personal flaws—can seem like the solution to all of life’s problems. Rebecca Roy, MFT, a Beverly Hills-based psychotherapist who specializes in treating entertainment industry professionals, works with many people (including celebrities) who’ve given in to temptation. She finds, “They often have this fantasy that this new person is a pure, innocent love that’s going to absolve them of any shame or guilt they might be carrying. They think, ‘If I attract this wonderful person, then by osmosis, I am also wonderful.’”The appeal of that fantasy can be powerful, but eventually, the curtain has to fall. Roy’s experience has led her to one conclusion: “Prince charming is probably just a frog. Usually, it’s just a few months before that croaking starts.”

Resisting the Siren Call 

If you do find yourself falling for an alternative, Roy recommends taking a step back and thinking, “What do I want from this person? What is missing in my primary relationship?” When you see the gaps in your current relationship—the needs that aren’t being fulfilled—bring them up with your partner. You might say, “I’ve been feeling lonely or distant and I’d like to work on this together.” That might sound tough, but it’s a whole lot easier than having the “I-slept-with-someone-else” conversation.

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In the face of an attractive alternative, some studies suggest that women have more natural defenses than men do. A 2008 study, published in the Journal of Personality and Social Psychology, found that after being exposed to an attractive alternative, men in committed relationships were less likely to forgive a partner’s transgressions, while women were more likely to forgive in an effort to defend the relationship.But as the study went on to show, commitment can be taught. Researchers primed the men with the following sentence: “When I am approached by the attractive girl, I will then [insert action here] to defend my relationship.” The men completed the sentence on their own. Afterward, men were just as likely as women to defend their relationship, possibly because they were less likely to seek out attractive alternatives.

Quinn—who was filming on location when we spoke—believes in reinforcing her relationship if it’s threatened. “If I felt myself developing feelings for someone else, I’d contact my husband a lot more to keep that connection,” she says. For Quinn, that means sharing the intimate, sometimes insignificant details of her day with him, like a funny moment or a picture of the restaurant where she ate lunch—the small moments they might share over dinner. “My big thing is just to feel like we’ve been a part of each other’s day. Communication is the key to not going astray.”

Still, at the end of the day, she’s realistic that our feelings aren’t always entirely under our control. “Innocent crushes are fine as long as that’s all it is,” says Quinn. But she stresses that boundaries matter. “Getting coffee is one thing, but getting a hotel room is quite another.”