How Healthy Relationships Grow Over Time: Understanding the Triangular Theory of Love
Relationships don’t stay the same. That’s not a sign something is wrong
A common source of anxiety in relationships is the belief that love should be “easy” or that it should feel exactly the same over time. When intensity changes, routines settle in, or connection feels different than it once did, people often assume something has been lost or broken.
In reality, healthy relationships aren’t defined by consistency of feeling, they’re defined by adaptation.
A helpful way to understand this is through the Triangular Theory of Love, by psychologist Robert Sternberg. This framework suggests that love is made up of three core components: intimacy, commitment, and passion. Different relationships (and different stages of the same relationship) emphasize these components in different ways.
The three components of love
Intimacy refers to emotional closeness. It’s the sense of being known, understood, and emotionally connected. Intimacy grows through openness, shared meaning, and feeling emotionally safe enough to be honest.
Commitment is the choice to remain engaged in a relationship over time. It shows up as consistency, reliability, and a willingness to stay present even when things feel imperfect or inconvenient.
Passion includes desire, energy, and engagement. Yes, this often associated with romantic or sexual attraction, but passion also refers more broadly to vitality: feeling interested, alive, and emotionally invested in the relationship.
All three matter. But they don’t always show up equally. And they don’t need to!
Why problems often come from mismatched expectations
Different types of relationships naturally emphasize different parts of the triangle.
Romantic relationships often begin with high passion, with intimacy and commitment developing more gradually.
Long-term partnerships tend to rely heavily on intimacy and commitment, even while passion fluctuates.
Friendships are usually built on intimacy and consistency, with little emphasis on passion.
Family relationships often center on commitment, with varying degrees of intimacy and emotional closeness.
Difficulty arises when expectations don’t match the reality of what a relationship can offer in its current form. For example, expecting constant passion in a long-term partnership, or deep emotional intimacy in a relationship that’s primarily structured around obligation.
Understanding this framework helps shift the question from “What’s wrong with this relationship?” to “Which parts of the triangle are being nurtured, and which might need more attention?”
Nurturing intimacy across different relationships
Intimacy grows through emotional presence, not intensity.
In romantic relationships, this might mean making space for honest conversations that go beyond logistics.
In friendships, intimacy can be nurtured by sharing experiences, checking in emotionally, and staying curious about each other’s lives.
In family relationships, intimacy may involve acknowledging history while also allowing space for change.
In your relationship with yourself, intimacy looks like self-awareness: noticing your feelings without immediately judging or dismissing them.
Intimacy deepens when people feel safe enough to be real.
Strengthening commitment without rigidity
Commitment isn’t about obligation or endurance, it’s about choice.
In partnerships, commitment shows up as follow-through, reliability, and repair after conflict.
In friendships, it might mean maintaining consistency over time, even as life gets busy.
In families, commitment can involve staying engaged while also setting boundaries that protect your well-being.
With yourself, commitment looks like keeping promises you make to your own values, even when motivation fluctuates.
Healthy commitment allows for flexibility. It makes room for growth rather than demanding exact sameness.
Rekindling passion and engagement
Passion often gets misunderstood as something that should happen automatically. In reality, it’s responsive to attention, novelty, and presence.
In romantic relationships, passion may be nurtured through shared experiences, playfulness, or intentional time together.
In friendships, it can show up as shared interests, humor, or mutual enthusiasm.
In family relationships, passion might look like rediscovering ways to connect that aren’t tied to roles or responsibilities.
In your relationship with yourself, passion involves staying engaged with what brings curiosity, meaning, and a sense of aliveness.
Passion doesn’t require constant intensity, it requires room to breathe.
Growth happens when the triangle is allowed to shift
Healthy relationships aren’t balanced all the time. They evolve. One area may need more attention during certain seasons, while another carries more weight elsewhere.
What sustains relationships over time isn’t perfection, but responsiveness: the ability to notice what’s changing and respond with care rather than fear.
The Triangular Theory of Love reminds us that love isn’t a single feeling to be maintained. It’s a dynamic relationship that grows through attention, honesty, and ongoing adjustment.
This applies to every relationship (including the one with yourself)
Your relationship with yourself also involves intimacy (self-understanding), commitment (staying aligned with your values), and passion (engagement with your life).
When one of these areas gets neglected, things can start to feel flat or disconnected… not because something is broken, but because something needs tending.
Healthy relationships, of all kinds, grow when there’s space to notice what’s needed now, and permission to evolve over time.
If you’re noticing shifts in your relationships and want support understanding what needs tending, therapy can offer clarity and perspective. Learn more about working with a therapist at Havn.