Gian C. Gonzaga et al. (2006)
"Two schools of thought converge on the notion that romantic love and sexual desire are independent relational processes. Relationship researchers have long grappled with the question of how romantic love and sexual desire emerge and evolve over the course of intimate relationships (Aron & Aron, 1998; Hatfield, 1988; Hatfield & Rapson, 1993; Hatfield & Walster, 1978; S. S. Hendrick & Hendrick, 1992; R. J. Sternberg, 1986). Within this tradition, researchers differentiate between companionate love (or romantic love, in our terminology), which involves deep feelings of commitment, intimacy, and connection, and passionate love (or sexual desire, in our terminology), which involves powerful feelings of attraction, desire, passion, and infatuation (Diamond, 2003; Hatfield, 1988; Hatfield & Rapson, 1993; Reis & Shaver, 1988). Within this framework, romantic love fulfills a commitment role, sustaining long-term bonds by promoting intimacy, connection, and the formation of mutual long-term plans (e.g., Aron & Aron, 1998; Diamond, 2003; Dion & Dion, 1973; Ellis & Malamuth, 2000; Hatfield & Rapson, 1993; S. S. Hendrick & Hendrick, 1992; R. J. Sternberg, 1986). In line with this thesis, romantic love relates to an interest in being close to a partner (Aron & Aron, 1998; Hatfield, 1988; Hatfield & Walster, 1978) and encourages self-disclosure (Aron, Norman, Aron, McKenna, & Heyman, 2000; S. S. Hendrick, Hendrick, & Adler, 1988; Wieselquist, Rusbult, Foster, & Agnew, 1999). Moreover, the feeling of falling in love involves a rapid expansion of the self to include the partner (Aron & Aron, 1997), and perceptions of increasing love across the duration of a relationship predict later relationship continuation (Sprecher, 1999).
In contrast, sexual desire—and related feelings of passion and infatuation—fulfill an initiation role, motivating sexual interest, proximity seeking, and initial contact. By motivating proximity seeking, sexual desire promotes contact and allows commitment to grow (e.g., Hazan & Zeifman, 1994, 1999; Zeifman & Hazan, 1997). In line with this thesis, passion— or sexual desire—tends to peak early in a relationship (Aron & Aron, 1991; Berscheid, 1985; Regan, 1998; R. J. Sternberg, 1986), and behaviors motivated by sexual desire, such as sexual contact or certain kinds of touch, are less frequent in more established relationships (Sprecher & Regan, 1998).
Evolutionary and attachment-related accounts of relationships have similar claims about romantic love and sexual desire (e.g., Diamond, 2003; Fisher, 1998; Hazan & Shaver, 1987). Romantic love is thought to be part of a pair-bonding system, which keeps partners together in long-term relationships that are oriented toward raising vulnerable, dependent offspring to the age of viability (Buss, 1988, 1994; Buss & Schmitt, 1993; Fisher, 1998; Kenrick & Trost, 1997; Simpson, 1994). As a part of the mating system and with the primary goal of reproduction, sexual desire responds to cues of reproductive readiness, such as physical markers of fertility or status (Buss, 1994).
This evolutionary, attachment-related approach is best encapsulated in Diamond’s (2003, 2004) biobehavioral model of romantic love and sexual desire. Diamond argued that romantic love and sexual desire serve different functions, namely to promote pair bonding and sexual behavior, respectively. In support of these claims, Diamond reviewed evidence showing that the subjective experiences of romantic love and sexual desire are functionally independent: Individuals can feel romantic love but not sexual desire, or sexual desire but not romantic love, toward another person. Romantic love and sexual desire, Diamond claimed, also appear to be mediated by different physiological processes: oxytocin (OT) and endogenous opioids in the case of romantic love, and gonadal estrogens and androgens in the case of sexual desire. ..."