Project Summary/Abstract Reductions in telomere length (TL), a biomarker of cellular stress, are linked with later atypical human development, including elevated risk for psychopathology, chronic disease, and mortality. Understanding factors that either positively or negatively impact children’s TL is needed to enhance children’s long-term health and well-being. Currently, stress-inducing adverse experiences (risk exposures), such as household economic strain, exposure to violence, and neighborhood disadvantage, have both an independent and a dose- dependent effect on TL, with the occurrence of each additional adverse experience accelerating TL shortening. Prior work in this area is limited, however, in that it has conceptualized risk exposures as static rather than dynamic and has failed to investigate protective factors that mitigate the effect of cumulative risk exposures on children’s outcomes. The proposed project aims to (1) examine how fluctuations in cumulative risk exposure are prospectively associated with children’s telomere length and (2) examine how parents’ supportiveness towards each other serves as a moderator between cumulative risk exposure and children’s telomere length. To achieve these aims, the research team will conduct a dyadic, longitudinal analysis of data from the Fragile Families and Child Wellbeing Study (FFCWB). Findings from this project will contribute to a broader understanding of factors that positively or negatively impact children’s TL and elucidate sensitive periods in which cumulative exposure to adverse experiences may be most harmful for children.