In Defense of the Stoned Ape (As a Question)

“The stoned ape hypothesis has been dismissed as unscientific. What has not been dismissed is the question it asks.”

The stoned ape hypothesis gets the ridicule it receives because McKenna presented it with more confidence than the evidence warranted. No archaeological evidence for regular psilocybin use by early hominids exists. The specific three-stage dose-response mechanism he described is not supported by controlled research.

But stripping away the overconfident packaging reveals a question that is real: what role did psychoactive plants play in human cognitive evolution?

This is not a McKenna question. It is an evolutionary biology question, a cognitive anthropology question, a psychopharmacology question. The available evidence, that every known human culture has plant medicine practices, that the 5-HT2A receptor shows evolutionary divergence from other primates, that psilocybin produces neuroplasticity effects in the prefrontal cortex (Shao et al., Neuron 2021), does not prove the hypothesis. But it doesn't close the question.

The question deserves investigation on its own terms, with better methodology than McKenna applied. The question is: did the long-term human relationship with psychoactive plants have effects on human cognitive development? This is not obviously false, and it is a question that would not have been asked in modern scientific context without McKenna's willingness to ask it loudly and without the evidence to fully support the asking.

Some questions are important enough that having someone ask them badly is better than no one asking them at all.

Sources

• McKenna, Food of the Gods (1992)
• Shao et al., Neuron (2021)