But, says Jane Greer, Ph.D., Redbook Online's resident sex-and-relationships expert, there are certain core values that make some marriages more intimate and resilient than others. You could probably predict the list: trust, mutual respect, commitment and a strong sense of "we" in the relationship. What is surprising, experts point out, is that when you ask loving husbands and wives about the key to their devotion, over and over you'll hear the same things, specific habits that mirror these values. Learning these secrets can make your marriage closer too.
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1. They use terms of endearment
Sure, you may find it cloyingly sweet when you overhear other couples talking like 2-year-olds, but endearments are actually a sign of a healthy rapport.
"Pet names take you back either to the happy childhood you had or the one you wish you had," says Manhattan-based family therapist Carolyn Perla, Ph.D. "They signal a safe, supportive environment." Also, these days, when we're stretched to the limit trying to juggle jobs and kids, "pet names give us the chance to let down our guard, to be vulnerable and childlike. And they make us feel close to one another."
These same feelings of intimacy can also come from using a special tone of voice with each other, sharing silly "inside jokes," or pet-naming your spouse's intimate body parts. The point is to connect with some private message system that's meaningful to you alone, as a couple -- not to the outside world. "This type of playfulness is a statement that you're feeling comfortable with each other and with the relationship," says Dr. Perla.
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2. They do stuff together
When that pheromone-crazy feeling of falling in love passes and happy couples no longer spend all day in bed, they look outward. They start businesses, refinish the attic or take up cooking together.
Of all the variables in a relationship -- from commitment to communication -- the amount of fun couples have together is the strongest factor in determining their overall marital happiness, according to a landmark study by Howard Markman, Ph.D., codirector of the Center for Marital and Family Studies at the University of Denver. Time spent playing together, says Dr. Markman, is an "investment in the relationship"; it provides a relaxed intimacy that strengthens the bond between two people. So even if your life is impossibly frantic, make the time for play. And do all you can to eliminate distractions. Leave the kids with a sitter, ditch the beeper and cell phone. The activity doesn't have to be anything elaborate or costly. Exercising together, browsing in antiques stores, or renting a classic movie can help bring the two of you closer.
3. When the going gets tough, they don't call Mom or Dad
The first task facing all young couples is separating from their families of origin, points out San Francisco-area-based family researcher Judith Wallerstein, Ph.D. This doesn't mean you shouldn't go home for the holidays. But if there's a crisis over whether to have a second child or relocate for a new job, or even if there's good news about a big raise or the results of a medical test, the couple should talk about it together first before dialing Mom. "You wouldn't believe how many people who are getting divorced say to me, 'She was never mine,' or 'His mother always came first,'" Dr. Wallerstein observes.
4. They stay connected to their parents
This doesn't contradict No. 3: You can talk with your mom every day and still be clear about where your attachment to her ends and your love for your mate begins.
"Staying connected to parents, siblings, cousins and the like can be excellent for a marriage because it gives a sense of family continuity," says Dr. Greer. "It generates positive feelings, especially when you incorporate your spouse into that family. You're sharing that part of you with each other."
5. They don't nickel-and-dime about chores
It's no secret that most wives continue to do more in the housekeeping and child-rearing departments than their husbands. Still, when partners become double-entry bookkeepers, adding up every dish washed and every diaper changed, they may be headed for trouble.
"Most couples think they should strive for a relationship that's 50-50," observes Dr. Perla, "but the fact is, they should each give 150 percent. In good relationships, couples give everything they can. They don't nickel-and-dime each other, and they respect that each person gives different things."
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6. They fight constructively
There's fighting and then there's fighting. When couples start yelling and throwing things, when they dredge up every single complaint they've ever had (or "kitchen-sinking," as marital experts typically call it), you can be sure that they won't be celebrating their silver anniversary together. "Studies show that the way couples handle conflict is the most important factor in determining whether or not they stay together," observes Polly Young-Eisendrath, Ph.D., a clinical associate professor of psychiatry at the University of Vermont.
"Happy couples have learned the art of constructive arguing," says Dr. Markman, whose research has demonstrated that it's possible to predict whether or not a couple will divorce after watching them argue for 10 or 15 minutes. In strong marriages, he says, the partners take control of their disagreements by establishing ground rules. They may, for example, call a mutually agreed-upon time-out if the conflict is escalating and unproductive, agreeing to continue the discussion after a cooling-off period. They also truly listen to each other and won't prematurely try to solve the problem before they've heard each other out. Above all, no matter how angry they get, they don't resort to name-calling and insults -- key danger signs, says Dr. Markman.
7. They give each other gifts
Couples who are deeply connected often give each other presents or write little notes, says Thomas Moore, Ph.D., best-selling author of Care of the Soul. What they're doing is preserving the rituals, and the magic, of their courtship.
The gift should carry no strings. Sarah sometimes comes home from work to find that her husband has prepared a candlelight dinner. "But it's not set up to be a prelude to sex," Sarah says laughingly. "John does it because he wants me to feel loved."
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8. They never lose their sense of humor
Humor, as many psychotherapists have observed, is the Krazy Glue that keeps a couple together. When a couple can no longer laugh together, Dr. Moore says, it's a signal that the soul has gone out of their marriage and they are headed for trouble.
But Dr. Moore is quick to point out that lighthearted couples never mock each other. They instinctively know what is -- and isn't -- fair game. "Sam would never dream of making fun of my big butt," notes Catherine.
9. They take "for better or for worse" seriously
Contented couples encounter their share of life's miseries -- whether it's the car breaking down, a nasty cold or a missed promotion -- but they help each other get through. You don't, for example, hear them say, "How could you let that happen?" when a spouse loses a job. "Couples who do well together tend not to do anything that increases their partner's suffering, like become resentful or criticize," notes Dr. Young-Eisendrath. In good marriages, people feel safe from the outside world. Each spouse, stresses Dr. Greer, has the feeling, "I can count on you, our world is all right."