Sternberg's Triangular Theory of Love
Robert Sternberg's Triangular Theory of Love conceptualizes love as comprising three fundamental components: intimacy (emotional closeness and bonding), passion (romantic attraction and physical desire), and commitment (the decision to maintain the relationship). These three elements combine in different configurations to produce eight distinct types of love, from non-love (absence of all three) to consummate love (presence of all three in balance).
Each component follows a different temporal trajectory: passion rises rapidly but tends to decline over time due to habituation, intimacy develops gradually and maintains stability, and commitment forms through conscious decision and strengthens with relationship maturity. Understanding these dynamics helps couples recognize that passion's natural decline does not signal love's end but rather a transition toward different love forms.
Big Five personality traits relate distinctly to each component: extraversion fuels both passion and intimacy, agreeableness supports intimacy and commitment, conscientiousness anchors commitment, and openness intensifies passion while potentially complicating long-term commitment. Couple compatibility can be assessed by comparing the size and shape of each partner's love triangle, with greater similarity predicting higher satisfaction.