This F31 project seeks to advance the evidence on the violence prevention potential of early childhood education programs and examine the interactive effects of such programs with multi-level social, economic, and environmental factors on violence across the life course. In 2020, there were 4.6 million nonfatal violent victimizations and almost 25,000 homicides in the United States (US).1,2 That year 15.2 million people aged 12 and older reported serious thoughts of suicide, and over 45,000 people died by suicide.1,3 While firearm access is a significant determinant of violent death,4 risk is also profoundly determined by social and structural conditions across the life course and inter-generationally, including poverty, early life adversity, and economic opportunity.5 Despite evidence that sources of risk and resilience begin early in life and accumulate over the life course and across generations, and that early childhood education can address shared developmental etiologies of multiple forms of violence, there are critical gaps in our understanding of the long-term effects of large-scale early childhood education programs on violence.6 This F31 project examines the long-term effects of Head Start—one of the oldest and largest preschool programs for vulnerable children in the US—on inter- personal violence perpetration and suicidal ideation, and the social and structural factors that modify those effects. In Aim 1, we will examine inter-generational effects of Head Start on the second generation’s suicidal ideation and inter-personal violence perpetration in adolescence and adulthood using a quasi-random variation in Head Start roll-out over time and place and inter-generationally linked nationally-representative data from the National Longitudinal Survey of Youth 1979 and Child & Young Adult cohorts. In Aim 2, we will examine whether Aim 1 effects are modified by offspring sex and race/ethnicity, community disadvantage, and state policies related to economic opportunity and structural racism. In Aim 3, we will examine the intra-generational effects of Head Start on handgun carrying and inter-personal violence perpetration in adolescence and adulthood using data from the National Longitudinal Survey of Youth 1997. In Aim 4 will examine whether Aim 3 effects are modified by participant sex and race/ethnicity, community disadvantage, and state policies related to economic opportunity and structural racism. All Aims will use targeted maximum likelihood estimation, a doubly-robust estimator for causal inference with observational data. This project provides the opportunity to evaluate the effects of a widely implemented program to reduce the toll of violence in the nation. It will contribute to scholarship on both early childhood education and violence prevention at a time when policy conversations about violence and its social determinants are increasing in prominence and urgency. This project will provide the F31 candidate rigorous training in 1)...