Hum Nat (2011) 22:225–246 DOI 10.1007/s12110-011-9103-y Darkness’s Descent on the American Anthropological Association A Cautionary Tale Alice Dreger Published online: 16 February 2011 # The Author(s) 2011. This article is published with open access at Springerlink.com Abstract In September 2000, the self-styled “anthropological journalist” Patrick Tierney began to make public his work claiming that the Yanomamö people of South America had been actively—indeed brutally—harmed by the sociobiological anthropologist Napoleon Chagnon and the geneticist-physician James Neel. Following a florid summary of Tierney’s claims by the anthropologists Terence Turner and Leslie Sponsel, the American Anthropological Association (AAA) saw fit to take Tierney’s claims seriously by conducting a major investigation into the matter. This paper focuses on the AAA’s problematic actions in this case but also provides previously unpublished information on Tierney’s falsehoods. The work presented is based on a year of research by a historian of medicine and science. The author intends the work to function as a cautionary tale to scholarly associations, which have the challenging duty of protecting scholarship and scholars from baseless and sensationalistic charges in the era of the Internet and twenty-four-hour news cycles. Keywords American Anthropological Association . Anthropology . Darkness in El Dorado . Napoleon Chagnon . James Neel . Patrick Tierney . Yanomamö I ask readers to keep the following notes on methodology in mind as they consider the findings of this paper: This commentary results from a year of historical research that involved the collection of over a thousand source items, including published works, audio and visual recordings, private correspondence, and approximately 40 original interviews. When I interviewed people orally, I gave interviewees my notes and asked them to take some time to change the notes however they wanted, so that I A. Dreger (*) Medical Humanities and Bioethics Program, Feinberg School of Medicine, Northwestern University, 750 N. Lake Shore Drive, Suite 625, Chicago, IL 60611, USA e-mail: a-dreger@northwestern.edu