Project Summary/Abstract Using a unique longitudinal data set and linear growth modeling analytic techniques, the proposed research will examine relations between early and life course trajectories of adversity and adult biobehavioral markers of aging. Animal and human studies suggest that early exposure to adversity may negatively impact developing biological systems altering long term structural and functional trajectories, and accelerating aging processes. The proposed research will examine this neurotoxicity hypothesis in relation to brain neurobiology (structure, function, connectivity) and related cognitive and epigenetic markers sensitive to adversity and aging. The research will also examine the role of protective social relationships (especially positive early caregiving) in moderating the adversity-related effects. Based in the Minnesota Longitudinal Study of Risk and Adaptation (Sroufe et al., 2005) and drawing on methodology from the Human Connectome Project in Aging (HCP-A; Bookheimer et al., 2019), the study addresses significant gaps in both neurobiological and behavioral investigations of the origins of adult aging processes and the effects of adversity on development. Unlike concurrent and retrospective studies of risk and protective influences on aging, the proposed study employs a prospective multilevel design with a sample of individuals assessed from birth to middle adulthood. The proposed assessments of neurobiological and cognitive functioning will contribute to an understanding of the impact of exposure to adversity on adult brain health (structure, function, connectivity) and age-related cognition. Specifically, we will examine the timing and chronicity (onset and trajectory) of adversity in relation to adult outcomes. Genetic data will permit analyses of associations between adversity, epigenetic variation (i.e., telomere length, DNA methylation age), and concurrent neural and cognitive functioning. The proposed work will address critical research, policy, and practice questions regarding the effects of adverse experience on the human brain, the cognitive and biological correlates of neurobiological change, and the potential moderating influence of early caregiving experience on these relations, generating testable research hypotheses and contributing to the development of targeted prevention and intervention efforts.