When couples first fall in love, desire often feels effortless. It only takes something as simple as a text message to trigger excitement. Hours disappear in conversation. Even mundane activities seem infused with novelty. Then, gradually, life and habitual routines start getting in the way, and many couples are left wondering where that initial spark went.
One of the most influential explanations for why desire thrives (or declines) over time comes from self-expansion theory, developed by psychologists Arthur and Elaine Aron, which argues that humans are motivated to grow, learn and broaden their sense of self throughout life. Romantic relationships are particularly powerful vehicles for this growth because they expose us to new experiences and ways of seeing the world.
In the early stages of a relationship, self-expansion is largely automatic, as new partners are most inclined at this point to learn about each other’s unfamiliar interests, social circles, habits and ideas. And although their eventual familiarity with one another creates a foundation of stability and trust, it can also reduce opportunities for growth if curiosity disappears completely.
What self-expansion theory suggests is that maintaining desire may depend less on trying to recreate the excitement of the honeymoon phase and more on continuing to expand through the relationship. Here are three evidence-based ways couples can put it into practice, according to psychological research.
Habit 1: Regularly Engage In Novel, Shared Activities
One of the simplest ways to create self-expansion is to do something together that neither of you normally does. That could mean taking a dance class, learning a language, trying indoor rock climbing, exploring a new neighborhood, signing up for a cooking workshop, tackling a challenging hiking trail — or anything, really, that’s outside of your norm. The specific activity matters less than the fact that it feels fresh and engaging.
In a 2018 study published in the Journal of Social and Personal Relationships, researchers examined whether the benefits most commonly associated with novel and exciting shared activities stem primarily from physiological arousal or from self-expansion itself.
The authors discovered that self-expansion consistently predicted positive outcomes for romantic relationships, as well as individual outcomes, regardless of whether arousal was statistically controlled for. In other words, the growth and expansion generated by an experience seem to matter above and beyond simply getting an adrenaline rush.
Psychologists have known for decades that exciting experiences can heighten attraction between romantic partners. What these findings suggest, however, is that the deeper ingredient in this phenomenon might be the feeling that an experience is helping you grow as a person and as a couple.
There’s intuitive appeal to this finding. Sexual attraction booms when a relationship feels dynamic rather than fully predictable. Novel shared experiences create opportunities for partners to see new or forgotten sides of each other. The partner who folds laundry every Tuesday suddenly becomes the person fearlessly navigating a kayak through white water or sexily mastering a dance sequence.
Habit 2: Have Identity-Broadening Conversations As Often As Possible
When people think about keeping a relationship exciting, the first thing they tend to focus on is activities: dates, outings, vacations, adventures and so on. These are undeniably important for self-expansion — but realistically, it’s not feasible to do these activities as regularly as you’d want.
Thankfully, some of the most powerful forms of self-expansion can also happen through conversation. The trouble is that long-term couples often reach a point where they stop asking each other the kinds of questions they asked when they first met. They know each other’s favorite foods, childhood stories and career histories — what more is there to know?
In turn, everyday conversations tend to become more pragmatic than curious, dominated by mostly by logistics. But human beings are constantly evolving, even when we don’t realize it. Our ambitions emerge. Our opinions change. We develop new fears. We find new interests. This means couples who forget to ask deeper questions are actually much less familiar with one another than they’d rate themselves.
As such, it’s important to make time for identity-broadening conversations in between your logistical ones. The trick is to ask questions, and lots of them, such as:
- What’s something you’ve changed your mind about recently?
- What goal feels most important to you right now?
- What’s a part of yourself you’d like to explore more in the next few years?
- What are you most scared of right now?
- What’s new in your life recently that I haven’t noticed or asked you about yet?
According to 2022 research published in the Journal of Social and Personal Relationships, feeling close to a partner and seeing them in a new light were associated with greater sexual desire. The researchers highlighted the importance of both closeness and what they referred to as “otherness”: the ability to perceive a partner as a distinct, evolving individual rather than someone who is entirely known.
This idea helps explain a paradox many couples encounter. Closeness is vital for intimacy, but total predictability can sometimes dampen desire. This means that desire needs a degree of mystery, individuality and psychological distance. It thrives when partners feel connected while still maintaining their sense of autonomy; they need to see one another as separate people with inner worlds worth exploring.
Identity-broadening conversations are an accessible and creative way for couples to maintain this balance. They remind us that the person sitting across from us is still changing, still growing and still capable of surprising us.
Habit 3: Deliberately Break Out Of Your Routine
Routine is not inherently bad for relationships. In fact, many “boring” routines are real expressions of commitment — like your morning coffees, a weekly grocery shopping trip or nightly bedtime conversations. These recurring patterns create security and predictability, which are indeed instrumental in instilling a sense of stability. The actual problem with routine arises when it becomes so dominant that couples have virtually no opportunity or time for expansion.
A 2022 review published in the Journal of Social and Personal Relationships examined the growing body of research on self-expansion motivation as it relates to including others in one’s sense of self.
Among its key conclusions was that boredom and declining novelty can reduce a partner’s perceived reward value — that is, the extent to which interacting with them feels stimulating, engaging, and psychologically rewarding. So as reward value decreases, sexual desire often follows suit.
This isn’t to say that people stop loving their partners as soon as they develop a routine. Rather, it’s that when routines become too rigid, the relationship may stop providing the sense of growth and discovery that originally made it so exciting.
Imagine, for instance, a couple who spends every weekend together exactly the same way: the same restaurant, the same television shows, the same schedule. While there’s nothing inherently wrong with these routines on paper, in practice, too much repetition can detract from what originally made the weekend feel special.
Deliberately disrupting that familiarity can help counteract the process. That might mean taking a spontaneous day trip instead of staying home, signing up for an activity neither of you has tried before, swapping responsibilities for a week or simply choosing to explore a different part of your city. Aim not for excitement for excitement’s sake, but rather to intentionally create opportunities for discovery.
The secret to this habit’s success is that they allow partners to experience each other outside of your norms and comfort zone. You see your partner navigating an unfamiliar situation, expressing a side of themselves you don’t encounter every day, or responding to a new challenge. And in doing so, they become psychologically interesting again.
When novelty disappears entirely, the relationship can begin to feel less rewarding, even if it’s still loving and secure. By periodically breaking out of routine, you find new reasons as to what made your partner so enthralling when you first fell in love.
Curious whether these habits are paying off in your relationship? Take my science-backed Relationship Satisfaction Scale to measure your current level of satisfaction, and find out how you compare to others.
