If humans have been using psychoactive plants habitually — and sometimes to the point of significant physical harm — since the Ice Age, then the starting assumption for any serious policy discussion cannot be that drug use is something that needs to be explained as a deviation from a normal, drug-free baseline.

The drug-free baseline, if it ever existed, existed only before Homo sapiens arrived.

The Sulawesi forager who sucked betel nuts 25,000 years ago was not suffering from social alienation, not responding to modernity’s discontents, not self-medicating the stresses of urban life.

They were doing what humans apparently do, in the conditions available to them.

Understanding that is, at minimum, relevant to thinking about what we do about it.

What Brumm’s Team Has Established