In order to improve analysis for disease association studies, matching for transplant, and data collection for population studies, our group has been investigating and assessing alternative approaches to measuring self-identified race and ethnicity, by direct comparison of ancestry survey responses with genetic ancestry defined by HLA variation in a very large (N>100,000) cohort. Despite its clear importance, contention over racial and ethnic definitions and the role of genetics in social science research has resulted in limited interdisciplinary work examining how individuals self-identify. This ongoing collaborative research represents the first interdisciplinary investigation of this subject, synergizing contemporary knowledge in human genetic variation with modern methods of survey research and demography.