Final answer:
Allen and Sara's love experience aligns with obsessive love, which is marked by passion and anxiety, different from romantic love described by Sternberg's theory as having passion and intimacy without commitment.
Step-by-step explanation:
According to Sternberg's triangular theory of love, the type of love illustrated by the combination of passion and intimacy, but lacking commitment, is known as romantic love. Allen and Sara's experience of sleepless nights and painful, anxiety-filled days, as described in the question, is more likely to fit the description of obsessive love, rather than romantic love. Obsessive love can be characterized by heightened feelings of passion accompanied by an unhealthy attachment, leading to anxiety and distress.
Other examples of relationships that might fit different types of love according to Sternberg's theory could include a long marriage with deep affection but dimmed passion (companionate love), or a whirlwind celebrity marriage that is intense and committed in the public eye but lacks deep emotional intimacy (fatuous love). Each type reflects different combinations of the three components of love: intimacy, passion, and commitment.