Stressful upbringings can leave imprints on the genes of children, including African-American boys, according to a study. Such chronic stress during youth leads to physiological weathering similar to aging. "African American children have really not yet been studied through this context," said a co-author. "Previous work has mostly focused on middle-class whites. Our study takes a different approach and really highlights the importance of early intervention to moderate disparities in social and educational opportunities."