The definition of a romantic relationship – intense love, sexual desire and long-term attachment – is not as uncommon or unattainable in marriages as you may think.

“We are born to love,” writes anthropologist and author of Why We Love, Helen Fisher. “That feeling of elation that we call romantic love is deeply embedded in our brains.”

Our culture can be pretty suspicious about the prospect of romantic love enduring over time and through obstacles, and for good reason. Roughly 50 percent of marriages end in divorce, with 2.4 million U.S. couples splitting in 2012. And among those that stay together, marital dissatisfaction is common. In long-term partnerships that do succeed, romantic love tends to fade into companionship and a love more akin to friendship than to that of a couple in love.

But no matter how cynical we are about the prospect of life-long love, it still seems to be what most Americans are after. Romantic love is increasingly viewed as an essential component of a marriage. One study reports that 91 % of women and 86 % of American men say that they would not marry someone with whom they were not in love. Even if the other person had every other quality they wanted in a partner.

And romantic love is good for both our marriages and our health. Free from the craving and obsession of the early stage of falling in love (I call this the endorphin stage) – research shows it’s correlated with marital satisfaction as well as individual self-esteem and well-being.

Research psychologists who study love, marriage and relationships have pinpointed a number of factors that contribute to long-lasting romantic love.

Here are 6 science-backed secrets of couples that keep intense romantic love alive for decades and entire lifetimes.

1. Life-long romance IS possible.

A 2012 study of couples that had been married for 30 years or more,¨ found that 40 % of women and 35 % of men said they were still very intensely in love.

But don’t be convinced solely by what these couples reported — research in neuroscience has also proven that intense romantic love can last a lifetime.

A 2011 study published looked the brain regions activated in individuals in long-term romantic partnerships, (who had been married an average of 21 years) and compared them with individuals who had recently fallen in love. The results revealed similar brain activity in both groups, with high activity in the reward and motivation centers of the brain, predominantly in the high-dopamine ventral tegmental area (VTA). These findings suggest that couples can not only love each other for long periods of time – they can stay in love with each other.

“The key to understanding how to sustain long-term romantic love is to understand it a bit scientifically,” Dr. Durayappah wrote in Psychology Today. “Our brains view long-term passionate love as goal-directed behavior to attain rewards. Rewards can include the reduction of anxiety and stress, feelings of security, a state of calmness, and union with another.”

2.They maintain a sense of “love blindness.”

When we first fall in love with someone, we tend to see them as the most attractive, smartest and accomplished person in the room. And while we might eventually take our partner off of this pedestal after months or years of being together, maintaining a sense of “love blindness” is actually critical to long-lasting passionate love.

A University of Geneva review of nearly 500 studies on compatibility pinpointed only one personality trait that predicted long-term romantic love –

One’s ability to idealize and maintain positive illusions about their partner.

Couples who see their partner as good-looking, intelligent, funny and caring, or generally as a “catch” – remained happy with each other on nearly all measures over time.

 3. They’re always trying new things together.

Boredom can be a major obstacle to lasting romantic or compassionate love, and successful couples find ways to keep things interesting.

Psychological research has suggested that couples who experience the most intense love are the ones who not only experience a strong physical and emotional attraction to one another, but also who enjoy participating in new or challenging “self-expanding” activities together. (Psychology Today) “Novel and arousing activities are, well, arousing.”

4. They avoid neediness by preserving their independence.

Neediness is the enemy of long-lasting desire (an important component of romantic love), according to psychologist Esther Perel. If couples can maintain a healthy independence and witness each other participating in individual activities at which they’re skilled, they can continue to see their partner in an ever-new light.

“When we see our partner on their own, doing things in which they are absorbed, we momentarily get a shift of perception,” Perel says. “We open to the mysteries that are standing right next to us.”

So if you’re looking to keep that spark going, give your partner the space to do what they’re good at – and make sure to take the opportunity to observe them in their element, when they are “radiant and confident,” Perel says.

5.Their passion for life carries over into their relationship

Psychologists have found that a strong passion for life can help to sustain passion in a life-long romantic relationship. The 2012 Stony Brook University study examining personality qualities that predicted long-term passionate love found that individuals who exhibit excitement for all that life has to offer are more likely to find success in their romantic partnerships. 

6. They see their relationship as a journey together towards self-fulfillment.

More men and women enter into marriage looking for self-actualization and personal fulfillment. Such a marriage can be more satisfying for both partners, but requires each partner to invest more time and energy into the partnership for it to be successful.

Rather than looking to marriage to serve our basic needs for survival and companionship, we’re now seeing marriage as a vehicle for self-fulfillment. This new directive can help to facilitate long-term romantic love, so long as each partner is willing and able to put more of their resources into the relationship.

The potential psychological payoffs have increased,” Dr. Finkel noted, “but achieving those results has become more demanding.”

Excerpts from “Psychology Of Lasting Love”, Huffington Post