I considered myself a sexuality researcher long before I considered myself a relationship researcher, and so when I first started studying the phenomenon of romantic love, it was in the context of studying sexual desire. My particular focus was on same-sex desire, a phenomenon that remains highly stigmatized in our culture and around the globe. My first research project as a new graduate student at Cornell University in the early 1990s involved interviewing young sexual-minority women.

The romantic relationships of emerging adulthood (EA) pose a range of new psychological and emotional challenges that are unique to this stage of life. As youths make the transition from the casual romantic ties of adolescence to more serious and substantive relationships, the “stakes” of day-to-day relational maintenance become progressively higher. Furthermore, the greater depth and complexity of emerging adults' romantic ties place new demands on skills related to conflict resolution, negotiation, responsiveness, accommodation, sacrifice, and compromise. During this stage of life, romance is no longer “just fun” – the work of building and sustaining a long-term pair bond has begun.

Effective self-regulation, more generally, and affect regulation, in particular, are critical to this transition. Self-regulation is broadly defined as the process through which people control and correct their own goal-directed behavior (Aspinwall, 2001; Baumeister, Schmeichel, Vohs, Kruglanski, & Higgins, 2007). Affect regulation refers to the internal and transactional processes through which individuals modulate the experience or expression of positive and negative affect (Gross, 1999; Larsen, 2000). Patterns of affect regulation shape the ways in which individuals perceive, appraise, and react to emotionally relevant relationship experiences (reviewed in Diamond & Hicks, 2004). They are also fundamentally integrated with broader self-regulatory processes, including executive functioning, response inhibition, and the regulation of attention (Koole, 2009; Posner & Rothbart, 2007); hence individual differences in emerging adults' affect-regulatory capacities influence the initial direction and long-term course of their romantic relationship trajectories.

Although the raw number of adolescent romantic and sexual involvements is well documented, the actual experience and meaning of these relationships for adolescents receives little attention. As a result, these relationships are frequently classed together on the basis of surface similarities, despite important structural and functional differences. Attention to these differences, however, reveals how young men and women craft adaptive constellations of peer relationships to meet changing needs for intimacy and social support during the multiple transitions of adolescence. In this chapter we put forth a typology of intimate peer relationships based on the motives prompting adolescents to pursue them, their specific characteristics, and the functions they serve. We specify four varieties of adolescent relationships – sexual relationships, dating relationships, passionate friendships, and romantic relationships – representing prototypical combinations of some of the most salient motives, characteristics, and functions.

Three qualifications are in order. First, our use of this typology is primarily heuristic. We do not suggest that all adolescent intimate relationships can or should be shoehorned into one of these categories or that such a task has any intrinsic value. Rather, we elaborate these relationship categories to demonstrate how an analysis of the motives, characteristics, and functions underlying adolescent intimate relationships elucidates their developmental significance better than an analysis of surface features alone.