David Hufford
David J. Hufford is an American folklorist and ethnographer known for his research on paranormal phenomena and sleep paralysis. He is professor emeritus of Humanities and Psychiatry at Penn State University College of Medicine, and the former chair of Medical Humanities. Career. Hufford attributed his interest in sleep paralysis to a personal experience he had with it as a student in 1963. He later went to study at the Memorial University of Newfoundland, where he became fascinated with the local belief in the "Old Hag", which mirrored his earlier sleep paralysis experience. This led him to question whether  the folkloric belief was based solely in cultural beliefs, or whether it was informed by personal experiences. In 1974, he joined the faculty of Penn State University College of Medicine. Hufford is credited with pioneering "an experience-centered approach to supernatural belief" in ethnographic study. He took the position that the dismissal of folkloric traditions as inherently irrational was ethnocentric. He was a proponent of the idea that the distinction between objective knowledge and "beliefs" should be understood as a value judgement. He described his perspective in the formula: "What I know I know, what you know you only believe ." His research in the 1970s reassessed previous positions on sleep paralysis and explored its relation to reported paranormal phenomenon. He theorized that the Old Hag archetype common to folklore around the world was based on experiences of sleep paralysis, which often manifested in similar ways. In 1983, he published "The Terror that Comes in the Night: An Experience-Centered Study of Supernatural Assault Traditions". The book was well received, with praise for Hufford's approach to the ethnography of folklore. At Penn State, Hufford became chair of Medical Humanities, and professor of Neural & Behavioral Science, and Family & Community Medicine. He  left this position in 2007, becoming professor emeritus of Humanities and Psychiatry at Penn State College of Medicine. He is also director of the Doctors Kienle Center for Humanistic Medicine. Hufford is a fellow of the American Folklore Society.