The influence of genetic factors on health and behavior is conditioned by social, cultural, institutional, and physical environments in which individuals live, work, and play. We encourage studies supporting multilevel integrative approaches to understanding these contributions to health, and describe the Add Health study as an exemplar. Add Health is a large sample of US adolescents in grades 7 to 12 in 1994-1995 followed into adulthood with 4 in-home interviews and biomarker collections, including DNA. In addition to sampling multiple environments and measuring diverse social and health behavior, Add Health features a fully articulated behavioral genetic sample (3000 pairs) and ongoing genotyping of 12,000 archived samples. We illustrate approaches to understanding health through investigation of the interplay among biological, psychosocial, and physical, contextual, or cultural experiences.