Project Summary Ethnic/racial minorities (ERMs) are more likely to suffer from short sleep duration and poor sleep quality relative to Whites. Sociodemographic and environmental stressors disproportionately impact ERMs and have been implicated in the development and maintenance of race-related sleep disparities. The transition to college is an especially important time to investigate sleep since young adults encounter a unique configuration of sociodemographic and environmental stressors linked to sleep. No longer tethered to early high school start times, college students report later and more irregular bedtimes. College students also sleep less and more poorly than adults, suggesting a developmental peak in sleep disturbances among young adults. Focusing on two sleep-vulnerable groups ? ERMs and college students - this 5-year longitudinal study investigates race-related sleep disparities in a diverse sample of college students during and after the transition to college; and how race-related sleep disparities forecast downstream health and academic outcomes through students? senior year. The study also investigates the risk and protective effects of ethnic/racial identity as a dynamic and changing moderator during this period. The innovative and novel combination of daily diaries and sleep actigraphy, biannual surveys, and annual assessments of inflammatory biomarkers, telomere length and anthropometric measures offers an unparalleled opportunity to investigate the daily and longer-term mechanisms, pathways, and consequences of race-related sleep disparities in a large sample of ERM and White college students. A key innovation of the study is the intersectional inclusion of ERM, socioeconomic, 1st-generation college, resident and commuter diversity. The three specific aims of the study are informed by strong preliminary data (R21MD011388), scientific premise, and the race-based disparities in stress and sleep in context model. The proposed study: 1. Determines the daily and longer-term impact of sociodemographic and environmental stress on race- related sleep disparities (duration, quality, regularity) during the college transition and the next four years 2. Identifies race-related sleep disparities as an explanatory pathway for sociodemographic and environmental stress to impact health, academic and physiologic biomarker (inflammation and telomere length) outcomes 3. Investigates ethnic/racial identity as a dynamic moderator of the daily and longer-term effects of stress on sleep, and of sleep on outcomes Together, these aims advance developmental and health equity science, investigating how sociodemographic and environmental stress contribute to race-related sleep disparities among diverse college students to forecast daily and longer-term health and academics over time.