Tripping our way into consciousness
By Clara Bils, Behavioral Neuroscience, 2023
At some point between 2,000 and 2 million years ago, Homo sapiens diverged from their closest relatives as our neocortex nearly doubled in size. Recent research has discovered that the ARHGAP11B gene may have played a role in this expansion; the gene was detected in our hominid cousins, the Neanderthals and Denisovans, but not in ape genomes. When the gene was placed in embryonic mouse brains, folding in the brain, or gyrification, occurred, which correlates to an expansion of the neocortex.
The study concludes that the gene possibly contributed to our grand evolution long ago, leaving room for other explanations. One of these explanations comes from renowned mycologist and psychonaut Terence McKenna, who coined the “Stoned Ape Theory” in 1992. McKenna claims that “the synergy of the psilocybin in the hominid diet brought us out of the animal mind and into the world of articulated speech and imagination.” Psilocybin is the psychoactive compound in magic mushrooms. That’s right, McKenna claims that we tripped our way into conscious, higher-level thinking.
“Stoned Ape Theory” claims that “the synergy of the psilocybin in the hominid diet brought us out of the animal mind and into the world of articulated speech and imagination.”
In a nutshell, the theory presents that Homo erectus was forced into grasslands as the African climate got drier. There they stumbled upon scat-fostered mushrooms containing psilocybin and had multiple community-wide psychedelic tripsーultimately resulting in the expansion of the neocortex. Specifically, McKenna claimed that shrooms increased sexual drives, heightened clarity while hunting, and induced the genesis of speech. Some psychedelic users experience glossolalia (also known as “speaking in tongues”), which is the production of sounds that resembles a language unknown to the user. McKenna claims this phenomenon may explain how Homo sapiens began using language as a means of communication.
Stamets suggests that psychedelics also reduce fear and increase empathy, explaining how the species became better hunters and communicators.
In 2017, Paul Stamets, a modern-day mycologist who produces medical applications derived from various mushrooms, expounded the hypothesis further. Stamets specified that the likely source of the psilocybin was the fungus psilocybe cubensis, whose psychedelic properties incite a process known as “epigenetic neurogenesis.” In this case, epigenetic neurogenesis is the process in which psilocybin replaces serotonin as a neurotransmitter, initiating neurogenesis and creating new pathways in the brain. Stamets suggests that psychedelics also reduce fear and increase empathy, explaining how the species became better hunters and communicators. A study conducted in 2013 found that small doses of psilocybin increased neurogenesis within a mouse population and heavily reduced classically conditioned fear responses.
As more evidence arises, we hone in on the neurological and mental adaptations of those who walked before us. Yet indisputably, there is not enough evidence to support the Stoned Ape Theory or to conclude that one gene alone is responsible for our species’ ascent into consciousness.
DOI: 10.1016/j.cub.2017.01.020
DOI: 10.1007/s00221–013–3579–0