Over the next 20 years, the number of young adults in Sub-Saharan Africa will increase to 174 million, rendering the health, fertility behaviors and child investments of this cohort critical factors for the future development of the continent. Many young adults in low-income countries (LICs) have experienced substantial childhood adversity, a likely important impediment to future health. For example, the young adults that we propose to study in Malawi, 82% experienced physical abuse in childhood, 8% reported sexual abuse, 8% were orphaned, and 70% wit- nessed domestic violence. What happens next—in young adulthood—will have ramifications for their own health and that of their children. Our study leverages this young adult cohort to study the impacts of adverse childhood experience (ACEs) on health both across life courses and across generations. We draw on the Malawi Longitu- dinal Study of Families and Health (MLSFH), and specifically on the MLSFH-ACE cohort previously created to study the longitudinal impacts of ACEs during adolescence. This cohort is now entering early adulthood, when new health and parenting challenges emerge. This is a critical lifecycle stage to study pathways driving the intergenerational transmission of adversities. We propose a new round of data collection on the MLSFH-ACE cohort, their partners, and their children. In Aim 1, we will estimate the longitudinal impacts of ACEs on sexual, reproductive, and mental health (SRMH) during emerging adulthood. Key outcomes include HIV incidence, early pregnancy, and depression. In Aim 2, we will estimate the longitudinal impacts of ACEs on the timing and quality of partnerships in emerging adulthood. ACEs may affect the timing and qualities of these partnerships, them- selves a key determinant of emerging adult SRMH. For example, ACEs may influence when individuals marry (e.g., child marriage), whom they select (e.g., age-disparate relationships), and the power dynamics that define the relationship (e.g., partner violence). Thus, we will estimate the impact of ACEs on partnerships and the extent to which this mediates SRMH outcomes. In Aim 3, we will estimate the longitudinal, intergenerational impacts of ACEs on offspring of emerging adults. Our study will examine how the experiences and resulting wellbeing of both mothers and fathers and their interaction influence young children (including their health, language and social-emotional development. We will also document the intergenerational transmission of ACEs during early life (eg, young children's exposure to domestic violence). In Aim 4, we will identify resilience processes that reduce negative consequences of ACEs on emerging adults and their offspring. Despite experiencing ACEs, many people thrive and create healthy families. Studying these processes in Malawi, an LIC where poverty is endemic, will elucidate key sources of resilience that have evolved alongside such extreme adversities. Thus, the study will provide unparal...