Barnes received her BA in American Studies from Smith College, her Master of Theological Studies from Harvard Divinity School, and her M.A. and Ph.D. from Harvard University in Comparative Religion and the allied field of Medical Anthropology.
Since 1999, Barnes has been a member of the faculty of Boston University School of Medicine (BUSM), where she founded and directed an urban ethnographic program-the Boston Healing Landscape Project (BHLP), a program for the study of religions, medicines, and healing funded by the Ford Foundation from 2001-2007.