Robert Sternberg's Triangular Theory of Love proposes that romantic love can be understood as combinations of three basic components: intimacy, passion, and commitment. The Triangular Love Scale is the psychometric instrument he developed to measure these three dimensions in actual relationships. Unlike most popular frameworks for categorising love, Sternberg's model is grounded in empirical research and produces a profile that can be compared between partners — revealing where a relationship is strong, where it's lacking, and whether two people's love profiles are well matched.
The Three Components of the Triangular Theory
Sternberg originally proposed the three-component model in 1986, and the Triangular Love Scale emerged from subsequent attempts to operationalise it as a measurable construct. The three components are conceptually distinct:
Intimacy refers to feelings of closeness, connectedness, and emotional bonding. It includes the desire to promote the other person's wellbeing, the experience of emotional support from them, mutual understanding, sharing of self, and the warmth and care that characterise deep friendship. Intimacy in Sternberg's model is the "heart" component — it grows gradually, requires vulnerability, and tends to be relatively stable once established.
Passion refers to the drives that lead to romance, physical attraction, and sexual consummation in romantic relationships. It's the component that creates the intense pull toward another person early in a relationship. Passion is the most volatile of the three components — it activates quickly and, in long-term relationships, tends to habituate. The neurochemistry of early passion (elevated dopamine, norepinephrine) is genuinely different from the neurochemistry of long-term attachment.
Commitment refers to the decision to love someone in the short term and to maintain that relationship in the long term. It's the cognitive and volitional component — the decision-making element of love that persists through periods when intimacy and passion may be reduced. In established relationships, commitment is often what holds things together during the inevitable dips in the other two components.
The Eight Love Types
Sternberg identified eight types of love based on which combination of the three components is present:
| Type | Intimacy | Passion | Commitment | Description |
|---|---|---|---|---|
| Consummate love | High | High | High | The "complete" love most people aspire to; difficult to achieve and maintain |
| Romantic love | High | High | Low | Intimacy + passion without long-term plans; summer romances and early-relationship intensity |
| Companionate love | High | Low | High | Intimacy + commitment without passion; many long-term marriages shift toward this |
| Fatuous love | Low | High | High | Passion + commitment without intimacy; the "whirlwind marriage" pattern — high risk |
| Liking | High | Low | Low | Intimacy alone; deep friendship without romantic elements |
| Infatuation | Low | High | Low | Passion alone; "love at first sight" without yet knowing the person |
| Empty love | Low | Low | High | Commitment alone; staying in a relationship from obligation when other elements have dissipated |
| Non-love | Low | Low | Low | Absence of all three; acquaintanceship without significant emotional content |
Most real relationships don't sit purely in one category — they move between types as circumstances and time change. The model's value is in identifying which components are currently active and which are absent or declining.
How the Triangular Love Scale Works
The Triangular Love Scale consists of three subscales, each measuring one component. The original version used 45 items (15 per component); later versions varied in length. Typical items look like:
- Intimacy: "I am able to count on [partner name] in times of need" / "I feel that I can really trust [partner name]"
- Passion: "I find [partner name] very physically attractive" / "I cannot imagine another person making me as happy as [partner name] does"
- Commitment: "I expect my love for [partner name] to last for the rest of my life" / "I will always feel a strong responsibility for [partner name]"
Crucially, Sternberg found that comparing the love triangle profiles of both partners in a relationship was more informative than assessing either person alone. When both partners' triangles are large and similarly shaped — both have high intimacy, both have similar passion levels, both are comparably committed — satisfaction tends to be higher than when the shapes diverge.
What Research Has Found About the Scale
Validation studies of the Triangular Love Scale have produced a few consistent findings:
- The three-factor structure replicates reliably — intimacy, passion, and commitment do appear to be distinct dimensions rather than a single general "love" factor
- All three components correlate positively with relationship satisfaction, but intimacy and commitment tend to show higher correlations with long-term satisfaction than passion alone
- Passion tends to decline faster than intimacy and commitment in long-term relationships — couples who report high passion after 10+ years are genuinely exceptional rather than typical
- The discrepancy between partners' triangles is itself predictive: the larger the mismatch in any component, the lower the reported satisfaction
How Love Types Change Over Time
Sternberg and subsequent researchers documented predictable shifts in love component profiles across relationship stages. Early romantic love is typically high passion with growing intimacy and relatively little commitment. With time, passion habituates while intimacy deepens and commitment strengthens. Many long-term partnerships settle into companionate love — high intimacy and commitment, lower passion — which is often described as disappointing but is actually a form of love associated with high stability and genuine mutual care.
The challenge for couples is that the culturally idealised form of love (consummate) requires maintaining passion alongside deep familiarity — which runs against psychological habituation. Research on couples who sustain high passion over decades suggests that novelty, shared challenge, and deliberate attention to attraction all play roles. These behaviours can sustain passion, but they require conscious effort rather than natural persistence.
Our free love style test measures your current relationship across all three Sternberg dimensions and shows how your profile compares to population norms for different relationship stages.
Frequently Asked Questions
What does a high intimacy, low passion relationship mean?
This is Sternberg's "companionate love" — which describes many long-term relationships accurately. It's characterised by deep mutual care, trust, and commitment, with lower levels of romantic or physical intensity. It's not a failed relationship; it's a different form of love. Whether it's satisfying depends heavily on what each partner values and what they expected the relationship to become over time.
Can passion be rebuilt in a long-term relationship?
Research on sexual desire and long-term couples suggests that passion can be partially sustained or renewed — but it requires the conditions that originally generated it: novelty, focused attention, physical investment, and some separation or anticipation. Esther Perel's work on long-term desire in couples is probably the most accessible treatment of this question. The short answer: yes, but it requires active cultivation, not passive hope.
Is commitment enough to sustain a good relationship?
Commitment without intimacy and passion is what Sternberg calls "empty love" — staying from obligation or habit rather than genuine connection. It can provide stability, particularly in contexts where leaving is very difficult, but it doesn't constitute a satisfying relationship. Commitment matters most as the ingredient that holds a relationship together while intimacy and passion fluctuate, rather than as a substitute for them.
How does the Triangular Love Scale compare to attachment theory?
They're complementary rather than competing frameworks. Attachment theory addresses the emotional regulation system underlying all close relationships — secure, anxious, avoidant patterns. Sternberg's model describes the structural components of romantic love itself. Attachment style influences how each component of the triangle develops — anxiously attached people may show high passion (hyperactivation) but struggle to build stable commitment; avoidantly attached people may develop limited intimacy even in long-term relationships.
What happens when partners have very different love triangle profiles?
Sternberg found that profile mismatch — particularly when one partner has much higher passion or commitment than the other — predicts lower satisfaction and higher conflict. The mechanism is partly about unmet expectations and partly about the interpretive errors that arise when one person's lower score on a dimension is read as evidence of diminished love rather than a different baseline. Making the profiles explicit can convert confusing relational dynamics into a concrete conversation about what each person needs.