A century ago people were intrigued by a new invention, the forerunner of the modern kinescope. By inserting a strip of paper containing a series of pictures into a drum, then spinning the drum while peering through a set of slits around the drum's perimeter, one could watch the pictures on the paper slowly coalesce into a repetitive set of coordinated movements. From the drum's disparate pictures, a single, moving picture appeared before one's eyes.

In many respects, our understanding of adolescence at the outset of the 21st century mimics this instrument of entertainment from Victorian parlors. We spin together the related but distinctive features of life for youth around the world and discern a common image of their movement from childhood into adulthood. At a superficial level the pictures coalesce to give the impression that young people worldwide share the same challenges, interests, and concerns. We speak of the emergence of a “global youth culture” (Schlegel 2000), in which young people – at least in the middle class – wear the same clothing and hair styles, listen to some of the same music, and adopt similar slang expressions. We remark on how the world is “shrinking” by virtue of new technologies (e.g., the Internet) that bring people from far-flung corners of the globe into close contact with each other. We emphasize the commonality of experience among youth as opposing ideologies falter and economic systems begin to meld.

This volume is the result of a 3-year enterprise sponsored jointly by the Society for Research on Adolescence and the International Society for the Study of Behavioral Development. The Study Group on Adolescence in the 21st Century brought together an international set of scholars to consider possible life scenarios for adolescents over the next 30 to 50 years. With primary support from the W. T. Grant Foundation, the study group was chaired by Reed W. Larson, with Jeylan T. Mortimer and B. Bradford Brown playing a collaborative role in organizing the study group's activities.

To assist the study group in its work, 2 sets of papers were commissioned. For the set represented in this volume, each scholar was asked to describe current conditions and near-future possibilities for adolescents in a particular nation or region of the world. Mindful of the diversity of experiences among adolescents in their regions, the authors were asked to provide empirically based analyses of the transformation from childhood to adulthood with regard to a standard set of issues and social contexts that affect adolescents' lives. For the other set of commissioned papers, published as a separate volume (Mortimer and Larson 2002), the study group approached a set of experts knowledgeable about external institutions and changes that affect adolescents (e.g., education, health care, the criminal justice system).

One of the hallmarks of American adolescence is the broadening and intensification of peer relationships (Brown, 1990; Hartup, 1993). During this life stage young people typically expand the time spent with peers, rely more on peers for advice and support, and work out their identities and aspirations within the context of peer relationships. The peer system itself expands, most notably with a new form of dyadic association: romantic relationships. To a limited extent, researchers have explored various facets of this new form of relationship: its connection to family structure and processes, its impact on the emotional and sexual lives of young people, its associations with participants' personal characteristics such as sex role orientation or attachment style, and its role in the social mandate of mate selection and marriage. Rarely, however, have researchers given concurrent attention to two other critical components of adolescent romantic relationships: the social context in which they are primarily embedded, that is, the social world of peers and the changes or metamorphosis that they manifest across adolescence. Both of these components are addressed in several other contributions to this volume, but they are the focal interests of this chapter.

For most American adolescents, romantic relationships begin as a remarkable mystery. What's this weird feeling deep in the pit of my stomach? How do I get someone to like me? How do I know if someone I like likes me back? What should we do together? What can we talk about? How can I tell if someone really loves me or is just trying to take advantage of me? If we start having sex, will it change the relationship? Why don't my parents understand that my boyfriend/girlfriend and I need to spend lots of time together? These are mysteries that nearly all American adolescents must confront; they are a part of growing up. For help with such issues, adolescents may turn to friends or family members or even television shows. But at present there is little reason for them to turn to social scientists for insights because research on this topic has been surprisingly sparse.

Investigators have not ignored the topic entirely. Descriptive information on dating has been gathered periodically (e.g., Gordon & Miller, 1984; Hansen, 1977; Roscoe, Cavanaugh, & Kennedy, 1988), and some ethnographers have studied peer group processes and romantic relationships (Dunphy, 1969; Eder, 1985).

Adolescent romantic relationships have received little attention from social scientists, as they have been considered to be ephemeral experiences of little significance. In contrast to this view, the authors in this volume provide a rich and varied set of theoretical ideas concerning the nature of adolescent romantic relationships. What is most striking from reading these chapters is the complexity of these relationships.

This complexity is evidenced in many ways. Witness the diversity of theoretical perspectives taken in this volume, not only across the different chapters but even within a particular one. For example, Gray and Steinberg draw on sociobiological and contextual views of family functioning. Laursen and Jensen-Campbell integrate social exchange and evolutionary theory. Larson, Clore, and Wood incorporate three theories of emotions. Miller and Benson describe the contribution of both biological and cultural processes.

The descriptions of the relationships are equally complex. Connolly and Goldberg discuss emotions, behaviors, motives, and concepts. Downey, Bonica, and Rincon delineate how rejection sensitivity may be played out in terms of relationship processes, partner selection, and the impact of being rejected by a partner. Gray and Steinberg describe multiple mechanisms that may link romantic relationships and the family of origin, and Collins and Sroufe present a series of processes that would lead securely attached individuals to be more able to navigate the new tasks entailed in dating.