Afterglow: Vilca Beer, Pro-Social Feelings, and Wari Geopolitics in the Ancient Andes

Although archaeologists increasingly consider the roles of psychedelics in past societies, there is little attention paid to their longer-term psychological impacts. One of these impacts is a neuroplasticity that may elicit enduring pro-social feelings. A beer laced with the psychedelic Anadenanthera colubrina (also known as vilca) was regularly consumed at feasts during the Wari Empire of Middle Horizon Peru (600-1000 CE). We suggest that vilca’s “afterglow” could have helped rebuild communities after the disruptions of imperial expansion, thus playing an integral role in Wari governance. The longer-term impacts of psychedelics may have also significantly shaped the history of other regions.