The modern academic idea of shamanism owes more to a single book than to any tradition. Mircea Eliade's study, published in 1951, defined the shaman by ecstatic soul flight, a journey undertaken by the specialist's spirit to other worlds on the community's behalf, and treated possession, in which a spirit enters the specialist instead, as a later degeneration of the pure type.
Anthropologists have objected to almost every part of that. The distinction between journey and possession does not hold in the field, where both frequently occur in the same tradition and often in the same practitioner. The ranking of one as archaic and the other as decayed reflects Eliade's own preferences rather than any evidence about chronology. And the category assembled traditions from Siberia, the Arctic, the Americas, Central Asia and Southeast Asia on the strength of resemblances the author found meaningful.
The word's own history compounds the problem, since it belongs to one Siberian language family and every other tradition it names has its own vocabulary.
A further layer arrived in the 1980s. Core shamanism, taught in workshops to Western students, extracted a set of techniques from their traditions of origin on the theory that a universal method underlies them all. It is a real contemporary practice with real practitioners, and it is not the practice of any of the peoples it draws on, several of whom have said so.
The atlas keeps the term because the literature is written in it, and records the tradition by its own name wherever one exists.
Sources Shamanism: Archaic Techniques of EcstasyMircea Eliade with Shamans: Siberian Spirituality and the Western ImaginationRonald Hutton