Overview of the Triangular Theory of Love
The Triangular Theory of Love, proposed by psychologist Robert Sternberg, is a framework for understanding love as a combination of three fundamental components. Intimacy, Passion, and Commitment form the three vertices of a triangle, and the presence, absence, and intensity of each element define different types of love.
The theory's innovation lies in treating love not as a single emotion or state but as a composite of multiple independent elements. Behind the simple phrase "I love you" lie several qualitatively distinct psychological processes, and their balance determines the nature of the relationship. Even when using the same word "love," the quality of experience differs fundamentally between love based solely on intimacy, love based solely on passion, and love in which all three elements are present.
The Triangular Theory is also useful for understanding how relationships change over time. The three elements shift at different rates as a relationship progresses. Passion rises rapidly in the early stages but tends to diminish over time. Intimacy deepens gradually and is maintained stably. Commitment forms as a conscious decision and strengthens as the relationship matures. Understanding these temporal dynamics helps partners grasp what is happening at each stage of their relationship.
Intimacy - The Foundation of Emotional Connection
Intimacy is the "warmth" element in the Triangular Theory of Love, referring to the sense of emotional closeness, connectedness, and bonding with a partner. Specifically, it includes caring about a partner's well-being, feeling mutually understood, providing and receiving emotional support, sharing personal information, and valuing the partner's presence.
Among the three elements, intimacy tends to develop most stably and be maintained the longest. It grows rapidly in the early stages of a relationship and continues to deepen gradually from the middle stages onward. However, the conscious "feeling" of intimacy can become less noticeable over time. This does not mean intimacy has disappeared; rather, it has receded into the background as "latent intimacy." Like air that is taken for granted, its value is acutely felt only when it is lost.
In terms of Big Five correlations, high agreeableness and extraversion contribute to building and maintaining intimacy. Highly agreeable individuals are sensitive to others' emotions and can naturally provide empathic support. The "warmth" subfacet of extraversion promotes intimacy formation through emotional expressiveness and interpersonal approachability. Conversely, the combination of low agreeableness and low extraversion - associated with avoidant attachment - tends to make building intimacy more difficult.
Passion - The Force of Desire and Arousal
Passion is the "heat" element in the Triangular Theory of Love, encompassing romantic attraction, physical pull, sexual desire, and the intense urge to merge with the other person. Passion is the most instinctive and difficult-to-control element of love, often constituting the core of the experience of "falling in love."
The neurobiological basis of passion involves activation of the dopamine reward system. Passion for a new romantic interest promotes dopamine release in the brain, generating intense pleasure and motivation. However, because this neurochemical response is subject to habituation, passion toward the same person naturally diminishes over time. This is not a "problem" in the relationship but a normal adaptive process of the nervous system.
The decline of passion is a source of anxiety for many couples, but Sternberg emphasizes that passion's decline does not necessarily mean love has disappeared. Even when passion fades, if intimacy and commitment are maintained, the relationship can sustain a high-quality form known as Companionate Love. The real problem arises when the decline of passion is misinterpreted as the failure of the entire relationship, leading to its abandonment.
From a Big Five perspective, extraversion (particularly "excitement-seeking") and openness (particularly the "feelings" subfacet) are associated with the intensity of passion experienced. People high in these traits tend to experience passion more intensely, but they are also more sensitive to its decline and more prone to the anxiety of "maybe I don't love them anymore."
Commitment - The Element of Will and Decision
Commitment is the "cognitive" element in the Triangular Theory of Love, referring in the short term to the decision "I love this person" and in the long term to the will "I will continue to maintain this relationship." While passion is emotional and instinctive, commitment is rational and volitional, providing the relationship with stability that is not swayed by emotional waves.
Commitment functions as an "anchor" when a relationship faces difficulties. When passion temporarily cools, when intimacy wavers, or when external temptations arise, commitment becomes the force that sustains the relationship. The volitional decision to "continue walking together with this person" forms a foundation for the relationship that transcends emotional ups and downs. Related books can also be found at related books (Amazon).
In terms of Big Five correlations, conscientiousness is most strongly associated with commitment. Highly conscientious individuals possess the willpower to follow through on decisions and the ability to sustain effort toward long-term goals. Commitment to a relationship can be understood as a manifestation of this trait. Additionally, high agreeableness supports commitment through the motivation to prioritize harmony with a partner.
On the other hand, a relationship where only commitment is prominent while intimacy and passion are absent is called "Empty Love." A relationship maintained solely by obligation or inertia may formally persist but lacks fulfillment for those involved. Commitment constitutes a rich form of love only when combined with the other two elements.
The Eight Forms of Love
Through the combinations of presence and absence of the three elements, Sternberg defines eight forms of love. The state in which all three elements are absent is "Non-Love," equivalent to a mere acquaintance relationship. "Liking," where only intimacy is present, is the form seen in deep friendships. "Infatuation," with only passion, is typical of love at first sight or unrequited love. "Empty Love," with only commitment, is a formal relationship from which both passion and intimacy have been lost.
Among two-element combinations, there is "Romantic Love," combining intimacy and passion. This is a passionate and intimate relationship without long-term commitment, seen in the early stages of romance or in relationships where the future has not been promised. "Companionate Love," combining intimacy and commitment, is typical of long-term relationships where passion has faded but deep bonds and devotion remain. "Fatuous Love," combining passion and commitment, is a relationship in which commitment was made driven by passion before sufficient intimacy was built, characterized by a fragile foundation.
"Consummate Love," in which all three elements are present, is the form of love Sternberg considers ideal. It is a state integrating deep understanding and bonding through intimacy, attraction and desire through passion, and devotion and will through commitment. However, achieving consummate love is difficult, and maintaining it after achievement requires continuous effort. The balance of the three elements is always in flux; consummate love is not a static destination but a process that must be dynamically sustained.
Triangle Shape and Relationship Quality
Sternberg states that the "size" and "shape" of the love triangle reflect relationship quality. The size of the triangle represents the total amount of love, with a large triangle forming when all three elements are high. The shape of the triangle represents the balance among the three elements, with a shape closer to an equilateral triangle indicating more balanced love.
When analyzing couple compatibility through the Triangular Theory, what matters is the degree of "match" between the two partners' triangles. When both partners' triangles are similar in size and shape, the experience of love is more easily shared and relationship satisfaction is higher. Conversely, when one partner has a large equilateral triangle (all three elements high) and the other has a small skewed triangle (only one element prominent), a large gap in the experience of love emerges, becoming a source of dissatisfaction and misunderstanding.
The gap between the "ideal triangle" and the "actual triangle" is also important. When there is a gap between the form of love one idealizes (for example, emphasizing passion) and the form of love actually experienced in the relationship (for example, companionate love), dissatisfaction with the relationship arises. Whether one makes efforts to bring the ideal closer to reality or revises the ideal itself - this judgment determines long-term relationship satisfaction.
Integrating the Triangular Theory with the Big Five
Each Big Five trait shows characteristic patterns of association with the three love elements. Extraversion positively influences both passion and intimacy, with social energy promoting both romantic attraction and emotional bonding. Agreeableness contributes to intimacy and commitment, providing consideration for others and motivation for relationship maintenance. Conscientiousness is most strongly associated with commitment, supporting the willpower to keep promises and continue investing in the relationship.
Openness is associated with the intensity of passion experienced but has a complex relationship with commitment. People high in openness have a strong desire for new experiences, which can create internal conflict about committing long-term to a single relationship. However, high openness also brings creativity and growth within the relationship, serving as a force that prevents stagnation.
Neuroticism exerts complex influences on all three elements. While it amplifies the experience of passion, anxiety can hinder the building of intimacy, and doubts about relationship stability can shake commitment. However, when neuroticism is appropriately managed within a secure relationship, emotional depth and sensitivity can bring richness to the relationship.
When considering couple compatibility, it is useful to understand which elements of the love triangle each partner's Big Five profile naturally strengthens and which elements it challenges. Combinations where each partner's strengths complement different elements work advantageously in collaboratively building a balanced triangle.