Dr. Neiderhiser is interested in understanding the interplay between genes and environment throughout the lifespan. The environmental influences that she has examined most closely are interpersonal relationships – including parent-child, spouse, sibling and peer relationships. Examining how individuals influence their environments, in part because of their genetically-influenced characteristics (genotype-environment correlation), has long been a focus of her work. The studies that have been used to examine these research questions include the following three sets of studies: The Nonshared Environment in Adolescent Development (NEAD) project; the Young Adult Sibling Study (YASS) and the Twin/Offspring Study in Sweden (TOSS). Finally, the Early Growth and Development Study is a prospective, longitudinal study of 559 sets of adopted children, their adoptive families and birth parents. All of these studies include extensive assessment of the environment within the household, interpersonal relationships, adult and child adjustment, temperament and personality and other related measures. DNA has also been collected or will be collected for these samples.