The past two decades have seen a tremendous increase in research and scholarship devoted to personal relationships. From rather scattered beginnings, a recognizable and recognized field has emerged, whose strength and health is reflected in a wide variety of indicators. At ground level, there is the sheer volume of published journal articles and books. At a second and more organizational level, there is the emergence of two major journals devoted to the field, the International Journal of Personal Relationships and the Journal of Social and Personal Relationships, along with the now firmly established International Society for the Study of Personal Relationships and the long-running series of International Conferences on Personal Relationships. Beyond all this solid evidence there is an interesting form of additional validation in the way many writers, commentators, and editors point out almost as a matter of course how satisfactorily the young field has grown. Indeed, perhaps the most telling sign of all is the fact that dwelling on such an observation is now regarded as hackneyed and trite.
So to use a developmental metaphor, the infant has grown up, the young adult has emerged and is clearly thriving. It is not our intention to go over old ground here. Instead, we wish to pursue the argument a step further by proposing that relationship research has reached a certain stage of maturity that is reflected in the title of this volume. Our contention is that, although the vigor of a field is often shown in the diversity and innovation of its research, it is in the theoretical domain that we find evidence of a real coming of age. The early years of any new scientific endeavor generally require careful empirical work to map out the terrain and its boundaries. Maturity, on the other hand, is