Robert Sternberg's triangular theory of love, published in 1986, proposed that love is composed of three distinct components — intimacy, passion, and commitment — and that different combinations of these three produce qualitatively different types of love. The theory's appeal is its precision: rather than treating love as a monolithic emotion, it distinguishes between what different relationships actually contain, why some feel intense but unstable, why others feel comfortable but flat, and why some rare relationships seem to contain everything. The triangle metaphor is useful but shouldn't be taken too literally; the geometry is a visualisation device, not a structural claim.
The Three Components
Intimacy is the emotional component: the feelings of closeness, connection, bondedness, and genuine knowing of another person. Intimacy develops through self-disclosure, shared experience, and the accumulation of genuine understanding. It's associated with warmth, care, wanting the other person's wellbeing, and the feeling of being truly known rather than merely seen. Intimacy develops relatively slowly and tends to be stable once established — it doesn't spike and crash the way passion does.
Passion is the motivational component: the drives that lead to physical attraction, romance, arousal, and the experience of "being in love." Passion is what produces the urgency, the preoccupation with the other person, and the sometimes overwhelming intensity of early romantic experience. It's also the component that habituates most rapidly — the neuroscience of passion suggests that its intense activation is partly a response to novelty, and novelty is, by definition, temporary. Long-term partnerships rarely sustain the same passion levels as early-stage ones, which Sternberg's theory treats as normal rather than as failure.
Commitment is the cognitive-volitional component: the decision to love a particular person and the decision to maintain that love over time. Commitment is what persists when passion has habituated and when intimacy is tested by difficulty. It includes both the short-term decision ("I love this person") and the long-term intention ("I intend to maintain this relationship"). Commitment without the other components is hollow; commitment plus the other components provides the relational durability that survives inevitable difficult periods.
The Eight Love Types
The three components produce eight possible combinations, each of which describes a recognisable type of love or relationship:
| Type | Intimacy | Passion | Commitment |
|---|---|---|---|
| Non-love | — | — | — |
| Liking/friendship | ✓ | — | — |
| Infatuation | — | ✓ | — |
| Empty love | — | — | ✓ |
| Romantic love | ✓ | ✓ | — |
| Companionate love | ✓ | — | ✓ |
| Fatuous love | — | ✓ | ✓ |
| Consummate love | ✓ | ✓ | ✓ |
Infatuation — passion alone, without intimacy or commitment — is the "love at first sight" experience: intense, preoccupying, and unstable, because it has no relational depth or intention beneath it. It can develop into something more substantial or dissipate rapidly when the object of passion turns out to be an ordinary person with ordinary complexity.
Empty love — commitment alone — is what can remain late in long relationships where intimacy has atrophied and passion has faded but both people have remained through inertia or obligation. In some cultural contexts, it also describes marriages arranged for practical reasons, where commitment exists prior to the development of any emotional connection.
Companionate love — intimacy and commitment without passion — describes many long-term partnerships after passion has naturally habituated. This isn't a failure state; Sternberg describes it as a deeply satisfying form of love for many people. Deep friendship with genuine commitment is a significant relational achievement.
Fatuous love — passion and commitment without intimacy — is commitment that runs ahead of genuine knowing. The couple who become seriously involved or marry very quickly, before developing real knowledge of each other, often occupies this territory. The commitment may be genuine, but it's based on passion rather than on the actual person in full complexity.
Consummate love — all three components — is the complete form Sternberg describes. He's careful to note it's difficult to achieve and harder to maintain: intimacy requires continued investment, passion requires active nurturing in long-term relationships, and commitment requires sustained choice. Achieving consummate love doesn't guarantee it remains.
Love as a Dynamic System, Not a Fixed State
One of the theory's most practically useful insights is that the three components change over time at different rates and for different reasons. Passion typically peaks early and habituates. Intimacy develops gradually and can deepen over years. Commitment may grow steadily or fluctuate through difficulty. A relationship doesn't occupy a fixed type; it moves through different configurations as its components evolve.
This temporal dimension matters for relationship expectations. The intense passion of a relationship's early phase is not a measure of the relationship's depth or potential — it reflects novelty and early-stage neurochemistry more than relational quality. The companionate warmth of a 20-year partnership doesn't represent degradation from some better earlier state — it represents a different and often deeper form of love that took two decades to develop.
Triangles as Compatibility Tools
Sternberg developed the concept of "love triangles" as a compatibility tool: each person in a relationship has both a current triangle (what they currently experience) and an ideal triangle (what they want from the relationship). When these triangles match — when both people experience similar levels of each component and want similar levels — there's a better fit than when they diverge. A person who primarily experiences and wants intimacy and commitment but not much passion will be in structural tension with a partner for whom passion is central.
This framing is clinically useful because it moves relationship problems out of the blame frame and into the mapping frame. The problem isn't that one person is wrong or bad; it's that their love triangles diverge in specific ways. The question becomes whether the divergence can be addressed through communication and deliberate cultivation of the components the other person needs more of, or whether it reflects a fundamental incompatibility in what each person is actually looking for.
To explore what you're actually looking for in relationships across Sternberg's dimensions and related constructs, our free Sternberg love styles assessment maps your profile across intimacy, passion, and commitment.
Frequently Asked Questions
What are the three components of Sternberg's triangular theory of love?
Intimacy (emotional closeness, connection, genuine knowing), passion (physical attraction, arousal, the motivational intensity of romantic feeling), and commitment (the decision to love and the intention to maintain the relationship). Different combinations of these three produce eight qualitatively distinct types of love, ranging from infatuation (passion alone) to consummate love (all three).
What is consummate love?
The form of love containing all three components — intimacy, passion, and commitment simultaneously. Sternberg describes it as the goal many people pursue but notes it's genuinely difficult to achieve and harder to maintain, because all three components require active investment to sustain over time. Achieving consummate love doesn't mean it's permanent; any of the three components can diminish if not tended to.
What is the difference between romantic love and consummate love?
In Sternberg's taxonomy: romantic love contains intimacy and passion but not commitment — the deep feeling and physical attraction without the stable intention to maintain the relationship long-term. Consummate love adds commitment. Romantic love can exist in relationships that haven't made long-term commitment yet, or in relationships where both people resist the commitment dimension while enjoying the connection and attraction.
Is Sternberg's triangular theory scientifically supported?
It has research support for the three-component structure — studies have generally found that love experiences cluster around dimensions corresponding to intimacy, passion, and commitment. Whether exactly three components is the right number, and whether this specific taxonomy is better than alternatives (like attachment theory's secure/anxious/avoidant structure), is debated. It remains one of the most useful descriptive frameworks for relationship research and therapy.
What happens to passion in long-term relationships?
Sternberg's theory predicts — accurately, according to the research — that passion habituates more quickly than intimacy or commitment. The intensity of early romantic passion reflects novelty and early-stage neurochemistry; both naturally diminish as the relationship establishes. This doesn't mean long-term relationships lack passion, but sustaining it requires deliberate cultivation — novelty, maintained attention to physical connection, and continued investment in the relationship's energy. The shift from passionate to companionate love is normal and doesn't indicate failure.