Michael Harner (1929-) is an American anthropologist, best known for his interest in shamanism, for which he established the Foundation for Shamanic Research. His initial field research, which included participation in shamanic ritual and the associated psychotropic substances, was with the Jivaro people of the Amazon River basin.
From the standpoint of some social scientists, Harner was controversial as a "participant observer" rather than an uninvolved anthropologist. The participant-observer role, however, is accepted and sometimes preferred in those following a model of transpersonal psychology. He described certain shamanistic widely diverse cultures that are unlikely to have had contact. These include the belief in a ordinary state of consciousness (OSC) that corresponds to physical reality, and a shamanic state of consciousness (SSC) that is an alternate reality. The different cultures share a common idea of a shamanic journey between the OSC and SSC. 
His first work as a shaman took place, according to Stanislav Grof, "in his 1960-61 stay with the Conibo people of the Peruvian Amazon. He subsequently returned to the Shuar for additional practical training in shamanism. He became recognized as a shaman by the indigenous shamans with whom he worked, including ones belonging to the following peoples: the Conibo and Shuar (formerly Jívaro) in South America; the Coast Salish, Pomo, and Northern Paiute in western North America; the Inland Inuit and the Sami ( formerly Lapps) in the Arctic; and the Tuvans of central Asia. "
The Jivaro used a datura-based preparation. "Nonordinary reality" (i.e., the SSC) has been monitored and does show altered brain activity, which is different from other trance and seizure states. The nature of this brain function may indicate there is a genetic ability to enter the SSC, with or without drugs, which would be consistent with indigenous beliefs that not all individuals are capable of the shamanic journey. 
He also wrote of the cause of violence in human is the theory that humans are violent due to the nature of their psyche, explaining that the human memory stores feeling of resentment and pain caused by insults, losses and injuries. He attributes this ability to the high levels of violence in the Amazon, claiming that the indigenous tribes of the basin fight for revenge. As documented by several ethnographic case studies, this is true. Harner asserts that this is a valid theory to explain the high levels of violence in the Basin, however he fails to distinguish between the internal and external violence of the Jivaro people, applying his theory to violence in general. His theory well explains that internal feuds are driven by revenge, but external violence, such as raids and war, are understood to be driven by other and even stronger motivations.Cite error: Invalid
<ref> tag; invalid names, e.g. too many While this does serve as an explanation for some of the high levels of violence in the Amazon Basin, it is generally agreed upon that his theory lacks explanation as to why there are in fact there are higher levels of violence among some cultures rather than others.
- Rick Doblin (1991), "Pahnke's "Good Friday Experiment": A Long-Term Follow-Up and Methodological Critique", Journal of Transpersonal Psychology 23 (1)
- Michael Harner, The Way of the Shaman
- Dr. Michael Harner, Foundation for Shamanic Education
- Wright PA. (1989 Jan-Mar), "The nature of the shamanic state of consciousness: a review.", J Psychoactive Drugs 21 (1): 25-33