In a 1973 study, scientists at the University of Chicago fitted cocaine-dependent rhesus monkeys with stainless steel catheter harnesses, allowing them to self-administer PCP to until they were “highly intoxicated.”

This type of research isn’t exactly unusual — for decades, humans have been pumping primates full of psychedelics like LSD and DMT to study the effects of hallucinogenic drugs.

But in a recent first, researchers at the Federal University of Rio Grande do Norte in Brazil gav