Tuesday, 28 May 2013

A Critique of Terence McKenna's 'Stoned Ape Theory'

In his book, Food of the Gods (1992), Terence McKenna describes one of his many controversial ideas. This idea, known as the 'Stoned Ape Theory', is about how our ancestors evolved from an upright walking ape into an upright walking ape who could produce language and create art. The theory basically says that magic mushrooms sped up the evolution of our ancestors and that, ultimately, the psychedelic experience is responsible for the origin of culture.

Between 2 million and 700,000 years ago the brain size of our ancestor, Homo erectus, doubled. The cause of this rapid expansion in brain size is still debated within the scientific community. Humans may have needed a larger brain in order to handle the complex motor skills that are necessary for making and using tools. We may have needed a larger brain for purposes of living in a complex society, for developing a greater capacity in memory, or in order to develop language. It could be a combination of all these factors working together. One hypothesis that is not considered in the scientific community, however, is McKenna's. It has long been said that psychedelics “expand your consciousness”, but McKenna actually thought they literally expanded our ancestors' brains.

Is McKenna's theory ignored for a good reason, namely because it is unscientific and lacks evidence to support it? To answer this question, it will be useful to look at the assumptions that McKenna makes. In support of his theory McKenna refers to a study conducted by R. Fischer and R.M. Hill, claiming that they found that psilocybin in low doses increases something called visual acuity. Visual acuity is clearness of vision or how clearly you can see things. McKenna asserts that if our ancestors ate a low dose of magic mushrooms, then they would have an increase in visual acuity or edge detection ability, and therefore be more successful at hunting.

The problem with this line of argument is that it relies on a series of assumptions which, while possible, are not backed up by convincing evidence. Perhaps magic mushrooms in low doses could increase visual acuity, but McKenna goes on to assume that magic mushrooms grew where our ancestors lived, that our ancestors ate these mushrooms, that they hunted under their effect, that they hunted more successfully, and so on. The argument basically consists of: “If this is possible, then so is this, and this, and this, etc.” McKenna's theory is undoubtedly imaginative, creative and compelling, but each of his assumptions beg the question: how can we know if this is true?

It also appears that McKenna misrepresented the findings of Fischer and Hill. In their study, what they actually discovered was that psilocybin changes perception, not visual acuity or edge detection – the drug changes how things look, not how clearly they are defined. In fact, in a paper by these two scientists they state that the change in perception caused by a low dose of psilocybin “may not be conducive to the survival of the organism." This conclusion is completely at odds with McKenna's interpretation of their findings. It seems he may have skewed their conclusion in order to support his own ideas about human evolution. Furthermore, Fischer and Hill didn't even study psilocybin at low doses, but at medium doses.

McKenna, and others who support his Stoned Ape Theory, might be inclined to believe his argument relating to visual acuity because, under the influence of psilocybin, it may feel like you can see objects more clearly. But there is no evidence to suggest that this actually takes place while under its influence. Some experiment – such as asking a tripping and non-tripping person to do some task or take some visual test – would be required to substantiate this argument.

Another strange thing that McKenna argues is that in higher doses magic mushrooms increase sexual arousal. From this he claims that if our ancestors consumed high doses of the hallucinogen they would be more likely to reproduce, and therefore pass on their genes. For McKenna this shows that the consumption of magic mushrooms would be adaptive and advantageous. Again, however, McKenna cites no evidence to support his claim. There is nothing in the scientific literature which points to the “fact” that magic mushrooms increase sexual arousal.

McKenna also argues that an even higher dose of magic mushrooms would lead to ecstatic, visionary experiences and that these experiences would serve as the foundation of religion. This is an interesting idea, no doubt, but it has not been verified by the facts. The first signs of “religion”, if it can even be called that, would be found in the cave art of Europe, dating back to 40,000 years ago. This is far more recent compared to when our brain size doubled 700,000 years ago. There is just no evidence of religion existing at this time, so it is pure speculation to say that our ancestors were tripping at this time and that this initiated the origin of religion.

In addition, it may seem obvious that an increase in sexual arousal will lead to more sex, but this is not necessarily true. If our male ancestors had to compete for mates, then being a bit more 'horny' than other males is not likely to carry an advantage – other characteristics are more useful in mate competition. On the other hand, if the hominids that McKenna refers to are the Homo erectus species (which would fit his timeline), then an increase in sexual arousal may lead to more sex, since the hunter-gatherer society of Homo erectus could have been quite egalitarian or even orgiastic. Evolutionary scientist Richard Leakey has said that Homo erectus was probably socially very similar to us modern Homo sapiens. However, sexual dimorphism (differences between the male and female) is greater for Homo erectus than for Homo sapiens. The male was 25% larger than the female, which is suggestive of male competition for sexual mates.

My own view is that McKenna's Stoned Ape Theory is entertaining as a narrative or story, but, in the end, it is not supported by reliable evidence. This is not to rule out the possibility that McKenna's theory could one day be vindicated – after all, his theory is still within the realm of possibility and is even plausible.

A positive feature of Terence’s theory is that it does appreciate the behavioural side to the evolutionary process. It has been well documented that adaptive behaviours (those that are conducive to survival and reproduction) are crucial in natural selection. These adaptive behaviours can be heritable, meaning that they are passed on by genes – either through a mutation in the genetic sequence itself or through phenotypes (how genes are expressed), which depend on environmental cues. A heritable adaptive behaviour can also involve genes which give an individual a tendency to respond to environmental cues better than others (say, by eating a certain quantity of magic mushrooms, for example). An adaptive behaviour can also be non-heritable, meaning that the behaviour is not passed on genetically, but is passed on as a taught behaviour.

Some say that eating magic mushrooms could have been part of an epigenetic process. An epigenetic process is when an environmental stimulus changes how genes are expressed, as opposed to changes being made in the gene sequence itself. Despite this counter-argument, it is still difficult to show how tripping on mushrooms would have had an adaptive value. Other proponents of the theory may claim that eating magic mushrooms could be a culturally inherited behaviour. But once again, there is no clear evidence that this behaviour has an adaptive value.

To try and add some more plausibility to Terence's theory, Dennis McKenna (Terence's brother) has proposed that psilocybin could have caused synesthesia in our ancestors. Synesthesia refers to a condition in which one sensory modality is translated into another. An example of a synesthetic experience would be “seeing sounds” or “hearing colours”. Dennis argues that meaning, symbol and metaphor (all central to language) depend on this cross-wiring of different sensory systems. Language is inherently synesthetic because it involves attributing meaning to mouth noises. He maintains that the synesthetic experience of a magic mushroom trip could have made the synesthetic experience of language possible and that, once the benefits of language were experienced, language would be naturally selected for from then on.

It seems like the McKennas were such huge enthusiasts of magic mushrooms that they attributed to them an influence in our evolutionary past which they might not have had. Perhaps they were so blown away by the effect that magic mushrooms had on their consciousness that they thought it could have radically changed our ancestors' consciousness as well. Terence also remarked in an interview that the Stoned Ape Theory proposed in Food of the Gods was “consciously propaganda”, as a way to persuade people that “drugs are natural, ancient and responsible for human nature” and not “…alien, invasive and distorting to human nature.” In other words, it was in a sense fabricated to promote his own agenda (which is not to say that his agenda was bad). 


  1. A sensible, well-informed comment on this 'stoned apes' biz. Welcome and refreshing with the usual gullible gush of "wow, this is really thought-provoking" - except, huh? What 'thought'?

    These 'theories' that apparently don't need evidence, and aren't based in any -insisting they be 'seriously considered' even as they resist (excusing themselves from criticism) - are something else. A recent youtube, interviewer asks Dmack (vid title): Is The Stoned Ape Theory True" (www.youtube.com/watch?v=Wq8-pTN3Hms)

    For reply purpose, question gets dumbed down to, well, maybe. Could be. Like who cares, truth schmuth. Like the interviewer 'missed the point.' - one of the 'customary and usual' retorts. What a great line. It doesn't need to even have a point.

    Bravo, Mr Woolfe - deserves an award for Extraordinary Integrity in Fringe Theory Coverage. Above and beyond the 'customary and usual.'

    1. You think it's nonsense because there's no evidence, yet you don't want anyone to seek evidence because it's nonsense? That's not how science works, you know.

    2. Stoned apes is part TM's deceit, exploiting names of researchers; and part his cluelessness about evolution (biology etc). Despite his (and his defensive admirers') circus show. True, he and his gulls certainly exalt him as some expert . And he sure tossed off ‘science says’ lines in that authoritative-sounding voice he spoke in (like you, Mr 'How Science Works') - talking crap like:

      “Orthodox evolutionary theory tells us small adaptive advantages eventually become genetically scripted into a species” - OMNI interview

      (Earth to weirdo: that’s what Lamarck thought. Like, a couple centuries ago. Long before anyone heard of Darwin, or natural selection. HELLO?)

      Stoned apes isn’t just stupidity acting itself ‘fascinating' - its deceit. Its Modus Operandi is fabricated findings, w names of real researchers pinned on to try and excite whoever, make them think wow, there’s evidence that could support this (“possibly”)? Cool, maaan.

      Besides making up that “psilocybin, in low doses, enhances visual acuity” (and therefore … etc) bs - and pinning it on names real researchers - the extent of how shameless is unreal. The sheer number of lies (different shapes and sizes) he told to weave a whole web of deception.

      And nobody ever questioned, just went ‘wow, wow.' Bought it hook line and sinker. Like some weird mass hypno-lobotomy. Or just afraid what they’d find if they did - their hero, a fraud and liar. And thus, voila, TM's legacy - some glorious golden missionary cause, a pledge drive for more converts.

      Stoned apes is about "go forth and spread the word" - recruits needed, to help ensnare and delude more fishers of men to help cast the lines. Of all the lies about Fischer's study TM told – here, a couple faves:

      1) No ‘enhancement of visual acuity’ from psilocybin has ever been reported in scientific lit, at any dose, by anyone. That goes double for research TM pinned that claim on.

      2) The whole “low dose” piece of talk is empty allusion - pure ‘smoke and mirror.' Um, what ‘low dose’? How many µg/kg? Funny, he never said. And nobody going ‘wow, wow …’ ever asked. What a weird universe, imagine that … my mind is blown.

      3) And how interesting: Fischer, in his research with psilocybin - pure compound (not mushrooms with whatever percent, variable) - DIDN'T EVEN STUDY LOW DOSE EFFECTS.

      For psilocybin, here's dosage range - based in research, not fairy tales (Wackermann J, et al., 2008. Effects of varied doses of psilocybin … Neuroscience Newsletters 345: 51-55):

      12 µg/kg = Very Low Dose
      115 µg/kg = Medium Dose
      250 µg/kg = High Dose

      Now, the envelope: Dosage Fischer et al used to study effects was … (drumroll) 160 µg/kg

      Its pretty intriguing - how those parroting Terence's claims in his name (amen) - never quote Fischer’s pubs. Just robotically repeat what Terence said. Fans can't quote the research, they've never even read it. Not one. Prove me wrong, link - a single exception anywhere throughout internet.

      No wonder the circus. Here's Terence 'fessin' up about his little Operation Stoned Apes:

      “I felt if I could … convince people drugs were responsible for large brain size … get drugs insinuated into a scenario of human origins, I would cast doubt on the whole paradigm of Western Civilization. So, it was CONSCIOUSLY PROPAGANDA …” (http://deoxy.org/t_mondo2.htm).

      Well well, that explains a few things. Another good one from that con, candid camera style:

      “Since I feel pretty much around friends and fringies here, it doesn’t trouble me to confess ... FOOD OF THE GODS, I conceived of as an intellectual Trojan horse. Written as though it were a scientific study, citations to impossible-to-find books and so forth … simply to ‘assuage’ academic anthropologists. THE IDEA IS – to leave this thing on their doorstep; rather like an abandoned baby, or Trojan horse” (http://www.youtube.com/watch?v=kuhrhT8Z5QA).

      Well, whaddya know? Turns out, behind the phoney idea, there actually is a real idea there after all - an ulterior one.

    3. The commentary writing style of mr. Anonymous here above does ring a bell. I have seen it commenting on other articles/vidoes. There is a strong sense of anger in his writing. But... Everyone is entitled to his or her opinion.

      Otherwise, nice article!

    4. Yup, it's Jan Irvin for sure. Don't read anything that guy has to say lol.

    5. Ignorance is obviously bliss for you. However, Terence McKenna, was certainly NOT ignorant; Terence was EXPERIENCED.

      Q. Are YOU experienced?

      A. Phuck no‼

    6. Ignorance is obviously bliss for you. However, Terence McKenna, was certainly NOT ignorant; Terence was EXPERIENCED.

      Q. Are YOU experienced?

      A. Phuck no‼

    7. In the Fischer study it was noticed that when graduate students were given psilocybin, they were able to more quickly ascertain when two parallel lines became skewed. One plausible way to explain this phenomenon would be increased edge detection. The most base term for visual acuity is sharpness of vision. Could one not say that increased edge detection is increased visual acuity (the increased acuity of the edges)? Interestingly in 2006, it was noted by Sharif, Kelly, and McLaughlin that 5-HT2a agonists, of which psilocybin is one, reduce intraocular pressure meaning...

      Also, Fischer and McKenna were very close, McKenna even quoting Fischer as saying, "So here you have the proof that a drug can show you a truer picture of reality!" Another important note to consider is that being a research scientist in the 70's and saying positive things about hallucinogenic substances was in extremely poor taste. Even today - https://en.wikipedia.org/wiki/David_Nutt#Dismissal.

    8. So you copied/pasted yourself here - http://mysteriousuniverse.org/2014/01/stoned-ape-theory-might-be-more-than-just-stoner-logic/

      'Might just be more than stoner logic'? Well - I wouldn't bet on it. But since you like c/p - here, from a reply you just got to your John Smithing - at that "Might Just Be" (linked). Not to spoil it all for you - just a sampler:

      In reality, not only did Fischer never claim "acuity enhanced" - Terence couldn't even truthfully state what his experiment was, and did. You wouldn't know, and like all Bardlings couldn't care less. Even the least, most micro-minimal facts are falsified under the Terence spell.

      As you'd know only by doing - the Unthinkable - reading Fischer yourself to actually see what it says, for minimal competence (no Bard fan has ever done that) - the screen display he used had a SINGLE line - ONE - not "two" (parallel or skewed):

      "The subject views a horizontal 15 x 0.7 cm black line, at 40 cm distance ... The just-noticeable bending of the black line marked a subject's 'Spatial Distortion Threshold' (SDT) ..." (p 122, R.M. Hill & Roland Fischer, 1971).

      When people who don't know what they're talking about act like World's Experts - to anyone who'll listen - but in reality don't even know what research they claim even says - one observes quite an 'Emperor's New Clothes' spectacle - of brain washing, and driven flight from reality.

      I can only tell the truth by talk - to show I'm right takes others, to model the walk And you've demonstrated by volunteer example - the exact form, precisely as I've discovered it. I wouldn't be able to show (not just tell) the truth - except for the unwitting assistance of you and other 'Terence's Heroes' - who come riding to his rescue - right on cue.

      All I need do is note, factually and truthfully - what Fischer et alia's work really says - in plain view right there on the page (as opposed to Terence's 'Version of Events'). And WHAM - that's the Pavlovian bell, reaction cue for the McKennae.

      You're hardly the only one. On self-appointed 'emergency response' you and 'the Others' - go right into '911 rescue' operations - posting empty claims, sticking to the script. Its like a Keystone Cops fire alarm. To one with a certain sense of warped humor, it might be amusing - almost.

      Alas. Good luck to parrots far and wide. Better keep (aWK!) repeating the scripture, reciting the lines faithfully - over and over and over. How many repetitions of a lie does it take, until it 'becomes true' (as Hitler wrote in MEIN KAMPF). That's how many readings of the Bardic script it might take for you and Others - to magically transform what Fischer et alia's research says - to match the woven web about it, in 'Clever Terence's' name-dropping 'Science Sez' exploitation. Best get busy, it'll be the 12th of Never.

      Read all about it - unless you're afraid (and why wouldn't you be, with all your eggs in a delusional 'stoned apes' basket of lies). Fischer and Hill's publications and findings - are right there in black and white, on printed page. Just like FOOD OF THE GODS - where it'll be hard to 'transform' what Terence wrote, to match what Fischer's work really says. Best content yourself with the Terrential fairy tales about Fischer's work, in service to 'stoned apes' - in Terence's name (amen) - as endlessly broadcast throughout the McKennasphere, by its spellbound bots. There is no helping such a condition. There is no effective medication for it, and its no more responsive to any form of therapy - than any form of fanaticism is. You might as well try curing jihadists, or Heaven's Gators.

  2. Thanks for the youtube link it was interesting and i didnt roll my eyes once (seriously)! My favorite comment from Dennis McKenna was simply, "Its a plausible idea, there's no proof for it but it's a reasonable thing to suppose."

    I would be shocked if stoned ape theory was correct on all examples, for instance i KNOW i wouldnt go hunting on shrooms, no way im shooting an arrow at a.....bison or whatever while im high. However, most of the Stoned Ape theory makes sense when explaining our speedy evolution. If mushrooms containing psilocybin were bountiful when plants were not available (I think they survive droughts and severe weather better than plants), eating them would HAVE to have a long term effect on my personality. A mushroom trip is the first time all of my senses acted differently, and the only way to really measure what someone is going through is to compare it to a religious experience, at least according to computers hooked up to peoples brains during some studies from a dude with a doctorate, i'll just go ahead and take his word for it until another doctor says not to.

    Personally, ive done mushrooms four times knowing full well what i was getting into, well at least for three of those times. Simply said, the first time was easily one of the top five most brain-altering and intense experiences of my life.

    Now, if i was hungry one day and ate a mushroom while chasing a large animal because my family was desperate for protein, i very well may come back with some strange ideas about planning ahead for food that wouldnt spoil.....like beer.....i guess.

    So anyway, that's how beer was invented.....i think.

    Anyway, great article!

    1. If you had only snacked on one mushroom you found in the woods you might be good to go hunting, although maybe not with modern firearms.

  3. An aspect of Terence's theory that was not mentioned is that while under the influence of the mushroom one has thoughts and ideas that one would never have otherwise. If our ancestors ingested the mushroom, they would be using their brain in new ways, thinking new thoughts. These thoughts are not forgotten. A hallmark of the thinking style of those on mushrooms is the fluid connecting of ideas and concepts, events and feelings, seeing relationships that were invisible before.

    These new ideas are utilized. Advances are made. Changes happen epigenetically and by teaching each successive generation the new ways. Eventually the brain changes to facilitate the new behaviors. I find nothing wrong with this idea. Other points Terence makes may be far less convincing. I am confident in this idea, however.

    If someone were to be good friends with a chimp who spoke sign language with them, and they both tripped and hung out, and observations were made then and for the following months, we might learn something. The chimp could tell us what tripping was like. If there were changes to behavior or what the chimps says that indicate a change in conception of themselves or the world, it would help to validate my this part of the theory.

    I think what I have stated is the core of Terence's theory, the rest of the pontifications are non-fundamnetal aspects.

  4. "it is not supported by reliable evidence." True. Although that's but a scratch in the surface. The problem with this stoned apes shit is plenty worse: it can't be supported by any evidence. Because it defies everything known about evolution top to bottom. Lamarck would roll over in his grave, listening to Terence & Philip butcher his wrong ideas - as a foundation to 'build on.'

    Evolutionary processes are well enough understood to decisively rule out the sort of 'theorizing' (ahem). Lying one's ass away as TM did for his little purposes - is no theorizing; neither in effect nor by intent. Closest thing to an idea in there boils down to ulterior motive - plus means, and opportunity ("Modus Operandi" in police talk). I guess folks are more sympathetic to con artists and charlatans than I am - pathological liars can be so 'entertaining' or - something? And whoever painted a counterfeit Van Gogh, why hey - that took some impressive artistic talent in itself. Who cares about forgeries and fraud? Is that the ethic 'we' (as in Us/Them, the cultic relations protocol) represent and stand for? Mkay, just asking.

    "This is not to rule out the possibility McKenna's theory could one day be vindicated" -

    Not sure that can keep you safe from being denounced or ostracized by the McKult. That stoned apes is even a 'theory' - is substantively erroneous, not even true. The 'theory' can't be vindicated, there's no evidence that could prove it any more than Adam and Eve might be 'scientifically vindicated.'

    Ideas that smugly defy the very premises of scientific understanding, disqualify themselves from ever having any validity. Discovering errors - and correcting them is how science advances. That's the opposite of holding mistakes above correction, in order to perpetuate them - in service to some glorious inspiration: T-R-I-P-P-I-N-G and T-E-R-E-N-C-E.

    Contrary to its press releases and the breathless excited FYI about stoned apes - its not a theory, nor can it be. Nor is it a hypothesis - by definition that's based in preliminary data that raise questions. Real ones not fabricated from lies. Made-up or concocted stories about 'researchers discovered visual acuity ...' blah blah - that ain't no data.

    Same with TMac's story-telling (then the Logos told me "Terence, look in the I Ching" etc). The very lynchpin of stoned apes defiant doctrine is "ITS POSSIBLE!" ("And You Can't Disprove It!") - the act is 'we're not fanatics, we're not saying its definitely proven true (voila, that proves we're not cultic moths drawn to some charismatic creep's flame).

    Well no its not possible, despite its party line. Directly questioned (under oath) it explodes in adamant indignation, 'how dare you' incorrigibility and aggression. We all witness the effects this kind of 'oh boy' brainwash has on flies caught in its silky web.

    The Terence Effect (90% loss of rational better purpose, and reality-interest orientiation) - parades in the 'lively discussion' about stoned apes - right in plain view for all to see. Its like some naked emperor, "thinking" (if it can be called that) he's nawt naked! He's beautifully attired (although the fabric can't be seen by 'bad people'). And its "proven" by acclaim, all the "oohs" and "ahhs" of those subject to the naked emperor's rule, under his authority.

    One witnesses a sick cultic spectacle of narrative acting itself all this and that - proliferating below 'conventional' society's radar (blissfully unaware, paying no attention) - in the 'lively discussion' surrounding stoned apes, attending to it ... like an incompetently protective bodyguard of noisy lies.