There are many mysteries about human evolution, and many questions about how we became the thinking species that we are today. One of the most interesting potential explanations for the development of our mental capacities is the “Stoned Ape Theory,” which suggests that our ancient primate ancestors stumbled upon psychedelic mushrooms and integrated them into their diet, creating a massive jump in the evolution of the brain.
Scientists and anthropologists tend to agree that the brain size of our hominid ancestors rapidly doubled sometime in our distant past, but they disagree about exactly when this could have happened. Other researchers suggest that there were multiple periods of rapid brain growth in the history of our species.
Some anthropologists believe that somewhere between 2 million and 700,000 years ago, the brain of the average Homo erectus doubled in size, while others point to a possible tripling of brain volume in the Homo sapiens between 500,000 and 100,000 years ago.
The theory was first proposed by Terrence McKenna and his brother Dennis, who were pioneers of the counter-culture, and the once-anonymous authors of the first manual for at-home mushroom cultivation. The McKenna brothers suggested that psychedelic mushrooms would have been an obvious source of food for our primate ancestors. If this was the case, the theory asserts that the psychedelic mushrooms could have rewired their brains in a way that allowed for the development of language and more complex thinking. As to be expected, the mainstream scientific community has been largely dismissive of this theory.
However, the idea has recently gotten a new push from mycologist Paul Stamets, who says that the Stoned Ape Theory is a “very, very plausible hypothesis for the sudden evolution of Homo sapiens from our primate relatives.”
“What is really important for you to understand, is that there was a sudden doubling of the human brain 200,000 years ago. From an evolutionary point of view, that’s an extraordinary expansion. And there is no explanation for this sudden increase in the human brain,” Stamets says.
This hypothesis remains unproven, but scientific findings in recent years do seem to support the fundamentals of the theory, or at the very least have shown us that it is possible for psychedelics to “rewire” the brain and accelerate brain growth.
In a study last year from the University of California, researchers showed that psychedelic compounds can rewire a person’s brain, and even increase in neuron branches, dendritic spines, and synapses.