A new model system for assessing the socio-environmental determinants of the pace of aging: leveraging a long-term study of wild capuchins - PROJECT SUMMARY One of the most enduring questions in public health is why some individuals retain good health into old age while others experience declines in health, physical function, and wellbeing. Growing evidence indicates that socio-environmental factors can contribute to individual differences in the progression of ‘biological aging’, yet we lack a clear understanding of how they influence different body systems. Although these questions have been difficult to address in humans, wild populations of primates offer unique opportunities for progress. This project’s overarching objective is to generate new insights into how social and physical environments influence heterogeneity in rates of aging and health disparities. We will accomplish this by developing a new model system for the study of biological aging, using a combination of field-based behavioral observation and laboratory analyses of noninvasive biological samples from wild white-faced capuchins. Our long-term longitudinal study of this species allows us to leverage almost 40 years of granular data on life-histories, pedigrees, and social behavior, as well as a rich assortment of associated data on the physical environment. The traits that capuchins share with humans, including complex social relationships, omnivory, large brains, and extended longevity, make them well-situated to provide insights into aging and health in our own species. Our first Aim for the Development Phase is to identify, validate, and characterize biomarkers of aging and health in physiological and molecular domains from non-invasive biological samples in a cross-section of adult capuchins of known ages (6-27 years). We have been at the forefront of developing cutting-edge techniques for noninvasive biological sampling, through which we will expand the set of wild animal models in which biological aging can be studied. Second, we will develop new behavioral assessments of physical function that are analogs of common geriatric assessments, and quantify aspects of social adversity parallel to those linked to poor health, reduced survival, or accelerated biological aging in humans. In the Implementation Phase, our Aim is to test the contributions of social and physical environments to trajectories of health and aging across the life course, including sex differences in these relationships. To accomplish this, we will analyze longitudinal variation in the biomarkers and health assessments that we establish during the Development Phase, in combination with our long-term contextual data. By the study’s conclusion, we will have established an innovative wild animal model of health and aging, with newly developed biomarkers to track aging processes in an exceptional breadth of different body systems and extended phenotypes. By integrating these new measures with our outstanding long-term data, we will shed new light on potential mechanisms that explain individual differences in the progression of aging, and in doing so, take an important step toward understanding how to extend the years of active, healthy life in humans.