Guang Guo is Professor of Sociology at UNC-CH and CPC fellow. His recent interest concentrates on genes and human behaviors and outcomes, especially the gene by environment interactions. Almost all complex human behaviors or outcomes are a result of both environmental and genetic influences. Genes often provide the potential, which is then moderated by environmental conditions. His aging-related interest is how individuals' early experiences in life affect the genetic expression for such outcomes as healthy survival, mortality, activities of daily living, and extent of suffering before dying.