ABSTRACT This proposal seeks funds for a series of five summer workshops that will train a diverse group of early-career scholars on the use of the Fragile Families and Child Wellbeing Study (FFS), a population-based, longitudinal, NIH-funded birth cohort survey developed to further understanding of the social and behavioral factors affecting the development of urban children. Compared with children born to married, college-educated parents, children born to unmarried parents, who lack a college education, often referred to as “fragile families,” are much more likely to grow up in poor, high crime and violent neighborhoods and to attend schools with other poor children. Biomedical and population scientists have raised a multitude of questions about the extent to which such environmental factors affect child and adolescent wellbeing, the extent to which they may moderate the genetic predispositions of children and adolescents toward health or behavioral challenges, and the mechanisms that govern any causal effects. The FFS has played an important role in addressing these questions; however, much remains to be learned, and the collection of new contextual and genetic FFS data stands to further advance the research literature. As such, the proposed workshops will each focus on a thematic area relevant to the above-mentioned concerns and will discuss different aspects of the FFS data not covered in prior training workshops, including adolescent sleep, health behavior relationships; cognitive development; DNA methylation ; brain development; criminal justice involvement; and outcomes for children when they are 22 years old. The proposed series of workshops will train a new generation of researchers from a variety of disciplines in the social and biomedical sciences on the capabilities of the FFS data and will result in the dissemination of the Fragile Families data, an improved understanding of the issues facing adolescents and young adults in fragile families, and opportunities for mentorship and collaboration for a new generation of social, behavioral, and biomedical scientists.