Abstract Maladaptive family environments marked by high chaos and violence, food insecurity, parent aggression and lack of warmth, and parent mental health and substance use problems harm children’s development, costing over $4.2 trillion in adverse child and family outcomes each year worldwide and lowering global GDP by 2-5%. Maladaptive family environments are also passed across generations. One (mostly untested) hope of preventive interventions in childhood is to disrupt cross-generational continuity in maladaptive family environments. We hypothesize that intervention delivered to parents in one generation (G1) will lead to better parenting by their children (G2) when they grow up to become parents, and intervention delivered to G2 children will lead to better adjustment in their offspring (G3). This project tests intergenerational impacts of two different interventions in which the original child participants have been followed into adulthood and are now parenting their own children. First, the Great Smoky Mountains Study (GSMS) is a longitudinal study of three representative cohorts of children (aged 9, 11, and 13) living in 11 counties in North Carolina (n=1420), with oversampling of American Indian children (n=349), followed into their 30s. Three years after the start of the study, an income supplement was given to every member of the Eastern Band of Cherokees following a casino opening, creating a natural experiment. The GSMS has documented positive effects of this income shock on G1 parenting and G2 children’s adjustment as participants grew into young adults. Second, the Fast Track (FT) randomized controlled trial (n=891) tested the impact of a targeted intervention aimed at preventing violence in high-risk five-year-olds through comprehensive training of G1 parents and social-cognitive skill-building delivered to G2 children. Random assignment to FT had positive impact on G1 parents’ interactions with their children and G2 children’s criminal behavior and mental health through age 25. Over the next five years, we will measure G2 parenting and G3 behavior at the same ages that intervention effects had been documented in the prior generation. We will test GSMS and FT intervention impacts on G2 parenting and G3 adjustment, examine intergenerational continuity and discontinuity in parenting and child adjustment, and evaluate characteristics that might moderate intervention impacts and intergenerational continuity in parenting and child adjustment. This research will have high impact on public health by (1) estimating the extent to which two forms of childhood interventions (cash transfers and intensive social-cognitive skill building) can affect family environments and child outcomes across generations, (2) identifying risk and protective factors that disrupt intergenerational continuity in maladaptive parenting and child adjustment problems as potential future intervention targets, and (3) evaluating lifespan developmental processes to in...