The goal of the proposed research is to investigate the interplay between the social environment and individual genetic characteristics. Specifically, the project team will measure changes in telomere length and DNA methylation between ages 9 and 15 in a birth cohort sample of 4900 children. Under this subcontract Colter Mitchell will collaborate with the project PI to construct biological measures from the assays suitable for analyses with the non-biological survey and observational data. He will oversee data cleaning and coding as part of the integration of the biological data into the larger project. He will be involved in conducting the proposed project analysis described in section D.2 (Analysis Plan) and will carry out the most complex statistical analyses himself. He will also play a lead role in the reporting and presenting of the data, results, and conclusions throughout the project.