Abstract

A common assumption among scientists and popularizers is that indigenous peoples around the world have used psychedelics for millennia, often for social and psychological healing. But is this true? In this talk, I will review ethnographic and archaeological evidence to determine where and how psychedelics have been used. Considering classic psychedelics (serotonin 2A agonists), I will argue that, despite the widespread availability of psychedelic substances in nature, reliable evidence of indigenous psychedelic use is restricted to a few locations in Meso- and South America, corresponding roughly to about 1% of documented human societies. Expanding to a broader definition of psychedelics—encompassing, for example, deliriants and dissociatives—leads to a higher estimated prevalence, although reliable evidence of hallucinogenic use remains globally and historically marginal. Finally, I will review ethnographic descriptions of how shamans actually used psychedelics, complicating analogies drawn between traditional shamanic use and modern therapeutic uses. A rigorous evaluation of the scope and history of psychedelic use suggests that modern applications are more novel than many researchers and popularizers admit.