In her research, Orbuch has studied one group of couples for the past 16 years. "How you deal with it, that's what matters in a happy marriage," she tells WebMD. "You have to fight fair and stay calm. You cannot be at your problem-solving best when you're angry. Come back to the situation when you're no longer angry, and you can have a whole new perspective."

Also, pick your battles. "You can't have a conflict over everything. That's what we call 'kitchen sinking' -- it means bringing up things that happened five, or even 10 years ago," says Orbuch.

For a happy marriage, here's how to deal with conflict:

*  Bring it up in a nonthreatening way. "Be nice. No name calling," she advises.

*  Bring up specific issues or behaviors, rather than personality qualities. In a happy marriage, there's no attacking the person. "Bring up the specific time, how you felt about it, then people can change the behavior," Orbuch tells WebMD. "Otherwise, they don't know what to do about it, they're boxed in."

*  Use "I" statements. Instead of saying "you're a very messy person' say 'I'm really bothered when you put clothes on the floor." Such statements show how you feel about a specific behavior, and that's important in a happy marriage, she says.

*  Try to stay calm. Studies show that the calmer you are, the more you will be taken seriously, she says. "Take a breath, count to 10, breathe. Try to be nonthreatening."

*  Take a break. "If you're going back and forth and arguing, if you find your blood pressure going up, take minutes or seconds for a break," she says. "Don't take hours however. If you take too long, it festers in the other person. Doing that feels like you're dismissing their feelings and opinions, and even dismissing them."

*  Don't bring it up at night. Choose the right time -- not when people are tired, hungry, when the kids are all around, when you've got a deadline at work. Those are not the best times."

*  Consider your spouse's point of view if you want a truly happy marriage. "I'm a true believer in this," says Orbuch. "Studies show that every single action has a different meaning depending on if you are male, female, your race, your background. That is important to remember in conflict resolution."

Her research "has shown, time and time again, that conflict is not important, but it's how you manage the conflict. It's how you handle it over the long haul which is really important to a happy marriage," Orbuch says. "I'm a big believer in direct, meaningful communication -- but you have to choose the right time."

Also, compromise is necessary in long-term relationships, she adds. "But each partner has to feel that it's reciprocal. One can't feel that they're making all the compromises." When one spouse makes all the compromises, it's uncomfortable for both -- not just the one giving in.

"You have to remember there are ebbs and flows in relationships," Orbuch says. "There will be times when you're making the compromises. But there will be other times when your partner is making them. As long as in the long-term things are reciprocal, that's what is important."