People have been enthralled with the roots of behavioral modernity and what exactly makes us human for hundreds of years. Numerous hypotheses have been proposed to explain why this behavior may have originated and which ancient human ancestor was the first to exhibit characteristics that distinguished them from other apes.

How humans developed from our Homo erectus ancestors, doubling our brain capacity within a space of around 200,000 years - which in evolutionary terms is the blink of an eye - is one mystery that people have sought to find an answer for.

Terence McKenna, a well-known mystic and psychonaut, defied convention when he explained how humans had grown rapidly in such a short period. The so-called "stoned ape" idea approaches the problem from an unconventional angle. But is it truly as absurd as some think, or is it conceivable that McKenna had a point?

"Stoned Ape Theory," Says Magic Mushrooms Might Have Caused Human Cognitive Evolution

Ancient Origins, citing McKenna's "Stoned Ape Theory," said Psilocybe cubensis was a surprise addition to the human diet during the evolutionary transition between Homo erectus and Homo sapiens (magic mushrooms).

How eating mushrooms could have such a significant effect that Homo erectus doubled its brain size sounds absurd. McKenna's idea was founded on studies done in the 1960s by Roland Fischer, a scientist who studied the effects of psychedelic substances extensively.

He thought that when the environment in Africa changed, Homo erectus was compelled to seek out new food sources, such as magic mushrooms. The impacts of the mushrooms caused Homo erectus's thinking processes to rearrange quickly.

Despite the lack of concrete evidence for this highly speculative concept relating to mushroom links, a recent study in the journal Frontiers in Psychology makes a case for it.

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Mushroom's Role

The same animals, excrement, and herbs are used in a more extreme interpretation of these occurrences, along with psychedelic medications. Terence McKenna, an ethnobotanist and supporter of psychedelics, suggested in his 1992 book Food of the Gods that Homo erectus's interaction with magic mushrooms and the psychedelic component psilocybin throughout that evolutionary voyage was what allowed it to develop into Homo sapiens.

Inverse, citing McKenna, said psilocybin allowed the early brain's information-processing capacities to rearrange quickly, sped up cognition's development, and gave rise to the early art, language, and technology documented in Homo sapiens' ancient past. He said that, as primitive people, we "ate our way to higher consciousness" by ingesting these mushrooms, which, according to his theory, developed from animal excrement. He said psilocybin lets "us escape from the world of articulated speech and imagination and enter the world of the animal mind."

According to McKenna, human cultural progress resulted in the domestication of wild cattle, which increased human exposure to cow excrement. Additionally, because psilocybin mushrooms frequently grow in cow manure, "the interspecies dependence between humans and mushrooms was developed and strengthened. During this period, natural magic, calendar-making, and religious ritual developed to their full potential.

McKenna, who passed away in 2000, had a strong conviction in his theory, but the scientific community never gave it any thought while he was alive. McKenna's notion was disregarded as being very speculative and now only sporadically appears in internet discussion forums and Reddit pages devoted to psychedelics.

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