Many childrearing experts believe that at-risk children are better off as wards of the state than in their own “dysfunctional” homes. New evidence proves those experts mistaken. Kids fare better at home than in foster care — even if their home is under investigation for domestic trouble. So says Joseph Doyle, an MIT professor who studies social policy, in a recent report in USA Today. Doyle’s foster-care research, which was funded by the National Science Foundation and tracked at least 15,000 kids from 1990 to 2002, is the largest study ever conducted on the efficacy of foster care. The key finding: Kids who stayed with their families were less likely than foster-care kids to become juvenile delinquents or teen mothers, and more likely to hold jobs as young adults.