The most fulfilling relationships—romantic or platonic—aren’t about finding someone who completes you, but someone who expands you. Psychological research consistently shows that lasting bonds thrive on mutual growth, not static comfort. People fall in love with those who help them discover new sides of themselves, and maintaining that growth is key to keeping the connection alive.
The Roots of Self-Expansion Theory
This isn’t just intuition. The concept, known as self-expansion theory, originated in the 1980s with researchers Arthur and Elaine Aron at Stony Brook University. Their early studies revealed a striking pattern: as couples formed, individuals began to describe themselves with more distinct, diverse terms. Their self-perception literally broadened as they incorporated their partner’s influence and experiences. This wasn’t just anecdotal; formal psychological assessments confirmed that new relationships correlated with increased self-esteem and confidence.
How Growth Deepens Bonds
The impact of self-expansion extends beyond initial attraction. Recent research confirms that feeling personally enriched within a relationship directly translates to stronger passion, commitment, and satisfaction. A decade of studies, including those focused on LGBTQ+ communities, all point to the same conclusion: shared growth fuels deeper connection.
Even relationship longevity is tied to this dynamic. Couples who experience high levels of self-expansion early on are less likely to break up, while those lacking that growth are more prone to infidelity. The science even shows up in brain activity. A 2022 study from Renmin University of China found that couples who expand together exhibit greater neural synchrony—they literally think more alike.
Nurturing Expansion in Relationships
How do you foster this growth? The answer is simple: encourage exploration and meaningful conversation. Couples who introduce each other to new ideas, challenge one another, and support personal aspirations create fertile ground for self-expansion. Over time, partners may even begin to see each other’s strengths as extensions of their own, a phenomenon known as “inclusion of other in the self.” Shared experiences—travel, hobbies, new projects—further accelerate this process.
One powerful technique is deep conversation. The Arons famously developed “36 questions to fall in love,” a series of thought-provoking prompts designed to spark self-disclosure. (Examples include: “What is your most treasured memory?” and “Do you have a secret hunch about how you will die?”) Studies show that even strangers who engage in these conversations report greater intimacy than those stuck in superficial small talk.
Expansion Beyond Romance
The benefits of self-expansion aren’t exclusive to romantic relationships. Research from 2024 demonstrates that it also enriches platonic friendships. Expanding your own horizons—whether with a partner or solo—is inherently rewarding. Challenging yourself, learning new skills, and seeking novel experiences will always be exhilarating, regardless of who shares them with you.
Ultimately, whether you’re celebrating Valentine’s Day with a loved one or embarking on personal growth alone, the key to lasting connection is simple: keep expanding. The more you grow, the deeper your bonds will become.
