In recent decades, researchers have developed an array of tested-effective and promising universal, school- and family-based preventive interventions, such as Raising Healthy Children (RHC), that reduce substance use and other problem behaviors and promote positive youth development. The Seattle Social Development Project (SSDP) is a quasi-experimental test of RHC, a school-based, universal preventive intervention delivered in elementary school (Grades 1 – 6). SSDP has followed participants (n = 808) from elementary school through age 39 (1985 – 2014; 15 data collections; 88% retention). Follow-up data show that the RHC intervention demonstrated long-term benefits for participants' health and well-being into adulthood, including lowered rates of mental health problems, heavy alcohol use, antisocial behavior, and early pregnancy, as well as higher educational attainment. Many youth who experienced the RHC preventive intervention as part of the SSDP later became parents. Known associations exist between parental mental health, substance use, antisocial behavior, and academic attainment and their children's functioning. The fact that RHC showed long-term benefits in these areas raises the exciting possibility that benefits experienced by intervention participants may echo into the next generation. This three year R01 project will analyze existing prospective data linking 2 generations from SSDP and SSDP-The Intergenerational Project (SSDP-TIP), which followed up SSDP participants and their children. SSDP-TIP began in 2002 when SSDP participants were about 27 years old, and included those SSDP participants who had become parents, the oldest biological child with whom they had regular contact, and a second caregiver who shared responsibility for raising the child, when present. New families were enrolled in the study as SSDP participants became parents for the first time. SSDP-TIP data were collected repeatedly between 2002 and 2018 (10 data collections, n = 426 families). Offspring ranged between ages 4 and 29 years (M = 17.2, SD = 6.1) in 2018. Of the SSDP parents participating in TIP, 79 received the RHC intervention in grades 1-6 (full intervention), 141 received the intervention in grades 5-6 only (late intervention), and 121 were in the control group. Prior analyses published in JAMA: Pediatrics demonstrated cross-generational intervention effects. The offspring of RHC intervention participants in the full intervention group were less likely to exhibit a range of developmental delays at ages 1- 5, had lower levels of teacher-rated behavior problems and higher levels of teacher-rated academic skills and performance (ages 6-18), and were less likely to report substance use by age 18. The proposed project will expand on these groundbreaking findings by (Aim 1) testing long-term effects of the RHC intervention on parenting practices and mate selection, (Aim 2) testing cross-generational effects of the intervention among young adult offspring (ages 1...