Transforming Knowledges: Ayahuasca, Expertise, and the Human Sciences in Peru, 1962–72

This paper examines the rising scientific scrutiny of ayahuasca in the mid-twentieth century. Ayahuasca is a divinatory, hallucinogenic, and therapeutic concoction composed of several vines and leaves harvested from Amazonia. While its exact use and composition varies according to local practices, historical epochs, and particular geographies, it has, for centuries, been imbibed by both healers and the unwell in many Indigenous tribes across the Amazon.

Between 1962 and 1972, psychologists, psychiatrists, and anthropologists affiliated with the Universidad Nacional Mayor de San Marcos in Lima attempted the ambitious task of transforming ayahuasca into a biomedical therapeutic. Such an endeavor required these human scientists to rely on those with an intimate knowledge of ayahuasca: health practitioners who knew how to transform the vines and leaves into an efficacious concoction; patients who had experienced its corporeal and spiritual effects; merchants who knew how to identify and transport the plant matter. I refer to these individuals as “plant matter experts,” both because of their intimate yet varied ayahuasca knowledge and the key role their authority played in ayahuasca research. With the aid of these experts, human scientists began to transform ayahuasca into a biomedical object. They gathered ethnographic data by witnessing ayahuasca healing ceremonies and interviewing the clients of shamans, while merchants transported the plant matter to their laboratories in Lima. Once ayahuasca had reached the laboratory, it underwent a transformation from vines and leaves to chemical distillations whose effects could be quantified and recorded according to biomedical standards. Yet, I argue that these plant matter experts contributed more than “raw” data and plant materials. Through these exchanges and interactions, plant matter experts shaped how human scientists understood their own biomedical practices and knowledge. More broadly, I show how these investigations led human scientists to increasingly draw racialized boundaries between knowledge, science, and tradition.