It’s all uphill from Denver to nearby Evergreen in the foothills of the Colorado Rockies. And that’s perhaps as it should be. I’m on my way to interview David Schnarch, the New York-born psychologist who has spent decades upending everything we thought we knew about true love, passion, and hot sex. Especially hot sex.

Once considered a heretic, Schnarch is today a distinguished presence in psychology, a pioneer set on redefining intimacy and reinvesting marriage with the passion that usually fades. “It’s easy to have hot sex with a stranger,” Schnarch insists. “But passionate marriage requires that you become an adult.”

And this, Schnarch admits, is a challenge. Becoming an authentic adult means going against the whole drift of the culture. It specifically means, among other things, soothing your own bad feelings without the help of another, pursuing your own goals, and standing on your own two feet. Most people associate such skills with singlehood. But Schnarch finds that marriage can’t succeed unless we claim our sense of self in the presence of another. The resulting growth turns right around and fuels the marriage, enabling passionate sex. And it pays wide-ranging dividends in domains from friendship to creativity to work.

To understand just how subversive such thinking is, it helps to know that Schnarch has been articulating his ideas about the emotional and erotic power of independence within relationships just as mainstream psychology has almost unanimously endorsed attachment as the heart of adult relationships. In fact, Schnarch finds that our preoccupation with attachment, with its ideal of feeling and acting as one, keeps partners infantile and overly emotionally dependent—enmeshed, in the language of psychology; fused is the way Schnarch puts it.

Applied to infants, attachment theory has value. The consistent attention of a caregiver allows a helpless baby to develop emotional security, the hallmark of which—in fact, the condition under which it is tested—is his growing ability to explore the world on his own. Extended to marriage, attachment implies that if couples can simulate that early bond, they’ll bask in emotional security for life.

Schnarch contends that marital attachment doesn’t leave enough space for partners to speak their own mind, think their own thoughts, or attain their ambitions and dreams. Attachment not only reduces adults to infants, it also reduces marriage to a quest for safety, security, and compensation for childhood disappointments. “We’ve eliminated from marriage those things that fuel our essential drives for autonomy and freedom,” says Schnarch. “It becomes a trap that actually prevents us from growing up. Instead of infantilizing us, marriage can—and must—become the cradle of adult development.”

The path to this goal is differentiation—the dynamic process through which you can live in close proximity to a partner and still maintain a separate sense of self. “By differentiation, I mean not caving in to pressure to conform from a partner who has tremendous emotional significance in your life.” The best marital brew is neither dependence nor independence, but a balanced state of interdependence, Schnarch contends.

Interdependence allows partners who are each capable of handling their own emotional lives to focus on meeting their own and each other’s ever-evolving goals and agendas in response to shifting circumstances, rather than on keeping one another from falling apart. It is marked by flexibility and focuses on strengths. Dependent partners, by contrast, spend their lives compensating for each other’s limitations and needs.

It’s not that hard to be independent when you’re alone, Schnarch observes. But pursuing your own goals and standing up for your own beliefs, your personal likes and dislikes, in the midst of a relationship is a far tougher feat. Once achieved in the context of a relationship, differentiation becomes possible outside of it as well. If you can stand your ground with your partner, who means so much to you, you can defend your turf at the office and maintain your principles when pressured.

Claiming adulthood is an evolutionary mandate, Schnarch insists; “1.2 million years ago the human cranium evolved to maintain a sense of selfhood. There is lust, there is romantic love, there is attachment. But the strongest desire comes from the self’s ability to choose another self.” Only the differentiated can truly be known and loved for themselves.

An Eye-Opening Shift

The path to differentiation runs straight through sex. But not just standard Saturday night sex.

Schnarch came of professional age as a sex therapist in the 1970s, at the height of the Masters and Johnson era. For William Masters and Virginia Johnson, intimacy was largely a matter of mechanics. The big sex killer was anxiety—the cause of rapid ejaculation, erectile dysfunction, and general failure to perform. To rid a couple of anxiety, partners were first to avoid all sexual contact for months. Then they were instructed to focus on the physical sensations of touching each other in turns, giving feedback as to how to make the touching better. Eventually they progressed to intercourse.

Schnarch thought it an adolescent approach, preoccupied with technique and anathema to the deeper emotional connection that heightens responsiveness in adults. As an assistant professor at Louisiana State University in New Orleans, Schnarch was listening to his own patients.  Indeed, great sex is not about technique but about feeling close.

From his clients, Schnarch found that married couples often wished they felt in the bedroom what they felt just making eye contact with strangers walking down the street. Call it sizzle.

Now that is truly intimate—looking someone in the eye while making love, really seeing them.

“To feel comfortable looking each other in the eye,” says Schnarch, “you have to confront conflicts you’ve swept under the carpet. You aren’t likely to let your partner look deep inside you until you’ve done that yourself.”

Eyes-open sex drills right to the heart of differentiation and drives the process of growing up. Closed-eye partners can get close enough to copulate, but not so close that they have to confront the differences between them or delve into who they are. The discomfort of eyes-open sex, on the other hand, heightens connectivity. Physical sensation and emotional connection become integrated rather than remaining separate dimensions that can interfere with each other. At the same time, the sense of individual selves is enhanced.

The Path to Interdependence

Eyes-open sex helped bring couples closer, but because it is also confrontational, it seemed at direct odds with the entire field of marriage therapy, which prescribed compromise and calm as the way to work things through. Then Schnarch discovered the work of Murray Bowen, a pioneering psychiatrist at Georgetown University who was in the process of revamping family therapy. He, too, saw the limitations of attachment theory in relationships.

Indeed, Schnarch now saw, in one clinical session after another, the most troubled couples were often far too enmeshed in the very relationships they complained were not close enough. And they typically felt obligated to seek approval from a partner instead of feeling confident about their own thoughts and actions, the imprimatur of the adult.

Forget empathy. Schnarch sees a better approach in self-validated intimacy. “You say what you have to say, and your partner either gives a supportive response or says, ‘That is the stupidest thing I ever heard.'” Either way, you pat yourself on the back, respect your own thoughts and feelings, and maintain your sense of self-worth. Instead of asking someone for a stamp of approval, you do what any grown-up does—approve of yourself. The irony is that when you say what you think without fear of rejection, your partner loves and respects you more, because they knows who you really are.

And when you become your own person within a relationship, you leave room for someone else to do the same. Instead of depending on a partner to help you manage your own feelings and maintain your equilibrium, you are free to choose to be with your partner. “You can offer your partner a hand instead of just your needs,” says Schnarch. The ideal dynamic for marriage is what Schnarch calls “interdependence,” somewhat like the cells of an organism. Each cell functions individually, but they thrive best by relating to other cells in the context of the whole.

Marriage, the System

The more Schnarch observed marriage, the more he realized it was a system unto itself. And that system has unique, built-in hurdles to happiness. Their purpose is to provide the pressure for people to grow up.

Dating is one thing. As Schnarch describes it, “We date and you see only what I want you to see. I tell you some pseudo deep, dark secret and we feel close and we have sex.” But with marriage, “You may start out talking about all that deep and important stuff, but eventually it gets used up. Then we make deals: I want to spend time with the boys. You want time with your friends. We agree. But now we have used up all the things we agree about, and we are left only with the things we disagree about.” Couples become gridlocked. It provokes anxiety. But to Schnarch, therein lies the best chance most people ever get for growing up, a trial-by-fire crucible.

Schnarch compares marital gridlock to an intricate Chinese puzzle, with each partner’s movement blocked by the other’s position. At a standstill in their relationship, Brandon and Sue began impeding each other’s dreams. One wanted a city apartment, the other a house in the suburbs. One wanted children to follow strict routines, the other wanted freewheeling fun. They would not adapt to each other, nor would they confront their own roles in the standoff.

Gridlock in marriage is guaranteed. After all the late night confessionals and wild sex, after all those walks in the park and vacations with friends, after the children have gone to bed and the bills have been paid, only gridlock remains. And there’s just one road out of gridlock if you want to keep your marriage intact. You can’t communicate your way out of it. You can’t empathize your way out of it. You have to learn to soothe your own discomfort, regulate your own emotions, and pursue your own goals. To stop being a drain on your partner and to handle problems on your own. That way, says Schnarch, we “open enough space” to get closer and provide room for passionate love to return.

Gridlock creates anxiety, anger, feelings of rejection, and emotional pressure, Schnarch observes. When the negative feelings become unbearable, the relationship must either change or break apart. Those who stay together must look within themselves for insight, confronting their role in maintaining the conflict. “The only solution is for one person to differentiate, moving forward and making room for the partner to grow as well.”

Sure, differentiation is a complex feat, but Schnarch is creating an operational road map. Starting with a list of component skills first developed by Bowen—including withstanding peer pressure, collaborating with others, controlling one’s own anxiety, persevering in the face of difficulty, and changing direction when further struggle is futile or foolhardy—he has field-tested them on more than 4,000 people. The elements of maturity, he has found, cluster into four distinct if interrelated groups he calls the Four Points of Balance.

One involves operating according to deeply held personal values and goals even when pressured to abandon them. A second revolves around handling one’s own inner emotional life and dealing with anxiety and emotional bruises without needing to turn to a partner for help. A third focuses on not overreacting to—but still facing—difficult people and situations. The fourth involves forbearance and perseverance in the face of failure and disappointment to accomplish one’s goals. The four groups emphasize resilience, because they also involve the ability to adapt and change direction when need be without losing track of one’s overall goals, agendas, or sense of self.

Ending Mind Games

No matter how differentiated, how self sufficient, how resilient you become, a relationship can still veer off track. Differentiation is necessary to salvage a marriage, but it isn’t quite enough because, Schnarch has found, people play mind games with each other that keep the relationship going but destroy intimacy. It is essential to confront one’s partner and oneself over the games and drop the pretense that neither one knows what’s going on. Schnarch saw the collusion operating most clearly in one client couple.

“Couples are always complaining that they don’t communicate,” Schnarch says, “but that’s not true.” Often, they grasp the dynamic quite well. “We take it as an article of faith that bad behavior in troubled relationships stems primarily from good intentions gone wrong.” Schnarch calls this “the big lie.” People usually know the harm they’re doing and do it intentionally.

Not only are most people aware of the mind games they perpetrate, they’re aware that their partner is aware that they’re aware, a dynamic Schnarch calls “mind-mapping,” after the brain’s ability to make a mental map of how another mind works. A man sees an overweight woman on the street and comments disparagingly on her girth to his wife, then insists he couldn’t know his wife, at virtually the same weight, would feel wounded. The next day the woman goes on at length about the success of her old friend the investment banker despite the fact that her husband has just lost his job. At some level they both know she is returning the pain. The insidious nature of such exchanges could be one of the best-kept secrets in marriage. Partners are perpetually in collusion, clearing a path of mutual sadism.

Whether partners can come to the anxiety-provoking—and disappointing—realization that their partner has been mapping their mind, not just noting but relishing their pain, depends on their level of differentiation. Those overwhelmed by that recognition are likely to retreat right back into collusion. The road back for couples is clear: It’s essential to stop playing mind games and confess their hurtful intent.

In one young couple, the woman complained that the husband was so uninterested in sex that every time she broached the subject, he retreated to the basement, evading conflict.

Yet when the partners were asked to gaze into each other’s eyes, it was the woman who panicked. She had chosen a mate whom she knew could not engage emotionally. Her own father had been cruel, and her family never looked one another in the eye. The wife attacked her husband as emotionally disconnected to protect herself. The couple did engage emotionally—through squabbling—but at a deep level he knew she was no more capable of intimacy than he was. By confronting each other, the couple was able to end the collusion and set on a path to improve the marriage.