The aging of the population of the United States is occurring at a time of major economic and social changes. These economic changes include consideration of increases in the age of eligibility for Social Security and Medicare and possible changes in benefit levels. Furthermore, changes in the social context in which older individuals and families function may well affect the nature of key social relationships and institutions that define the environment for older persons.

Sociology offers a knowledge base, a number of useful analytic approaches and tools, and unique theoretical perspectives that can facilitate understanding of these demographic, economic, and social changes, and, to the extent possible, their causes, consequences, and implications. Sociology is an integrative science, concerning itself with how social systems work and how various social institutions are interconnected, with how micro and macro social processes are linked, with how attitudes and values are formed, with how they differ among individuals and groups, and with how realities are socially constructed. In recent years, social demography, social epidemiology, and sociology have been called on to contribute to the study of aging and identify promising new research directions in these subfields.¹ At the request of the National Institute on Aging's (NIA's) Division of Behavioral and Social Research (BSR), the National Research Council's Committee on Population established the Panel on New Directions in Social Demography, Social Epidemiology, and the Sociology of Aging. A major part of the panel's charge in its Statement of Task was to conduct a study and prepare a report that will evaluate the recent contributions of social demography, social epidemiology, and sociology to the study of aging and seek to identify promising new research directions in these subfields. To support the panel's work, nine papers were prepared and presented at a workshop. These papers, included as Part II of this volume, were designed to come from a range of approaches and perspectives—from sociology and demography to social genomics and public health—yet there emerged from the papers a common and a collective highlighting of the broad array of tools and perspectives that can provide the basis for further advancing the understanding of aging processes in ways that can inform policy.

The panel drew on these papers, the discussions at the workshop, and the panel's own interpretation of the state of the literature to identify and recommend to NIA's BSR promising research directions that can reasonably be expected to have high payoff for the study of aging. We arrived at these recommendations by documenting the various approaches to the study of aging and the role of sociology, which is a wide-ranging and diverse field; laying out a proposed three-dimensional conceptual model for studying social processes in aging over the life course; reviewing existing databases and a discussion of data needs and opportunities; and summarizing roadblocks and bridges to the necessary transdisciplinary research that affect future directions in the sociology of aging. This work of the panel is presented in Part I of this volume.

Several themes became evident through the panel's documentation of the various approaches to the study of aging. The first is that aging is a focus of study in virtually all areas of policy and academic research, spanning the basic and applied sciences in fields ranging from anthropology, biology, and gerontology to engineering, architecture, and urban planning. It occurs at many different levels of analysis, from macro structures and systems, to the meso level of social institutions, and to the micro level of individual relationships and behaviors. The study of aging increasingly considers time as an important element embedded in the concept of life course that captures the significance of the passage of time over the lifelong process of aging, because old age itself cannot be understood without an awareness of the accumulated impact of the decades that came before. And the study of aging has fostered collaboration across the traditional disciplines—economics, biology, psychology, sociology—and the emerging fields, such as social genomics, computational sociology, biodemography, and social neuroscience. For example, in social epidemiology researchers originating in the disciplines sociology, epidemiology, physiology, and medicine have collaborated to make significant gains in understanding how factors in the social environment (such as socioeconomic position, income distribution, social networks, social support, social capital, community cohesion, work environment, neighborhood and community) may be related to a broad range of mental, physical, and behavioral health outcomes. This kind of transdisciplinary work can yield great benefits but is difficult to achieve and sustain.

The panel makes a strong case for the development of conceptual models that can encompass the lives, structures, and contexts across the aging process and capture heterogeneity, fluidity, and indeterminacy within the larger patterns. The next phase of aging research must be guided by such models. The panel documents a proposed conceptual model for studying social processes in aging and the life course (see Figure S-1).

FIGURE S-1

Conceptual model for studying social processes in aging over the life course.

The model has three dimensions: (1) levels from macro to subindividual; (2) developmental stages over the life course; and (3) examples of outcomes of interest along social, institutional, and biographical dimensions. The panel's deliberations regarding the further explication of, and connections across, different levels also informed this recommended conceptual model. In reviewing this work, the panel sees needs and opportunities for further developing this model or a set of models to guide research.

Recommendation 1. The National Institute on Aging should engage researchers in the development of a conceptual model, or a number of conceptual models, for social processes in aging over the life course in multiple dimensions.

The resulting model, which may be a version of the one used by the panel or may be actually several models, can play a much more specific role than simply serving as a guide for framing the aging research program. A model can make a contribution to standardizing the approach that science takes in assessing issues associated with an aging population. It can lay the intellectual basis for the development of cross-disciplinary metrics.

Recommendation 2. The conceptual model, or models, should be used by the National Institute on Aging to serve as the basis for developing a standard set of key measures, across disciplines, for use in surveys and other types of data collections and analyses that focus on aging issues.

Indeed, new requirements for data and new opportunities for data gathering have been generated by the ongoing changes in the social contexts of aging and refinements in the conceptualization of aging, particularly the appreciation of dynamic and reciprocal relationships between individuals and social contexts. The panel identifies several key areas in need of further development to enhance measurement and improve data quality, including the important task of wedding the timing and frequency of measurements to the conceptual models motivating their collection. The panel also emphasizes the promise of the growing study of biomarkers, which in turn generates a growing need for new measures to investigate the mediation of the social environment over the life course and identifies opportunities to gather data to take advantage of ongoing studies, linkages to existing databases, and new social media and technologies. We point out the importance of data-gathering efforts that harmonize across different disciplines, given the increasing prominence and promise of transdisciplinary research and make several recommendations to implement these findings.

Recommendation 3. The National Institute on Aging should manage its research program in a manner that promotes implementation of models and metrics in the areas of:

• Encouraging conceptualization of family relationships and exchanges, including behavior, expectations, plans and attitudes, and to develop measures of key family concepts, because the family is a fundamentally important social context for aging.
• Encouraging conceptualization of characteristics of contexts and local areas through development of new measures, expanded links to existing data, and ongoing incorporation of new technologies, such as global positioning systems, smartphones, and area mapping.
• Building on recent advances in the use of biomeasures and linking them to social and behavioral processes through conceptualization of the potential links, attention to measurement tools and analysis techniques, identification of “best practices” in developing the linkages, and the development of protocols for cross-training of researchers in sociology with other relevant disciplines, such as genetics, economics, medicine, and biology.
• Illuminating the mechanisms that mediate between social contexts and health, both across the life course and over generations.

This new focus should be data-based. There are a myriad of opportunities for generating the data that are needed to encourage and illuminate these new approaches. They range from augmenting existing studies to add scope and depth, to subsampling for populations of interest in ongoing surveys, to adopting new sample design strategies, to exploitation of the resources of the Internet.

Recommendation 4. The National Institute on Aging should seek opportunities to:

• Supplement ongoing surveys by addition of respondents related to members of current samples.
• Identify subpopulations of interest and ensure their representation in its sponsored surveys.
• Explore the use of the Internet and other electronic media to gather information on patterns of human interaction, consumption, and behavior.

This report repeatedly underscores the importance of the transdisciplinary approach to the study of aging. This approach is a process as well as a challenge. It demands the transformation of individual researchers into an effective team with a shared vision and a common vocabulary; however, there are both roadblocks and bridges to implementing this approach. The panel documents institutional and administrative impediments, disciplinary boundaries set by professions, disciplinary preferences exhibited by funding agencies, and, finally, the disciplinary silos within which the research community has been accustomed to operate and which have served as barriers to developing new and promising ways of studying important issues in aging. Nevertheless, there are growing examples of transdisciplinary bridges through institutional and administrative changes and the conscious efforts of journals, societies, and funding agencies to break down the walls between the disciplines. In view of the importance of the transdisciplinary approach to the study of aging, these fledgling efforts would benefit from promotion and extension.

Recommendation 5. The National Institute on Aging should encourage universities and research organizations to intentionally promote transdisciplinary research by:

• Reducing institutional barriers to transdisciplinary research and interdisciplinary research teams.
• Developing structures to encourage input and participation from outside ongoing projects in such a way as to bring together, in a transdisciplinary research environment, researchers from several institutions, and representing multiple approaches.