The human brain doubled in power, very suddenly, 200,000 years ago. Why?
A long-ridiculed theory about humankind's early leap of consciousness is revived.
- Terence McKenna first proposed psychedelic mushrooms as the trigger for our rapid cognitive evolution.
- McKenna's theory was called the "Stoned Ape Hypothesis."
- The hypothesis is being revisited as a possible answer to a vexxing evolutionary riddle.
There seems to have been a profound difference in cognitive abilities between early Homo sapiens and our immediate predecessor, Homo erectus. Sure, erectus stood upright — a big, um, step forward — but with the emergence of Homo sapiens, we see traces of art, pictography, and tool usage, and we believe humankind made its first forays into language.
In the early 1990s, psychedelic advocate and ethnobotanist Terence McKenna published his book Food of the Gods in which he surmised that homo sapiens' cognitive leap forward was due to their discovery of magic mushrooms. The scientific community never took McKenna's theory very seriously, considering it mostly trippy speculation — these days, his ideas have largely been relegated to the spacier corners of Reddit. Now, however, the idea has acquired a new advocate, psilocybin mycologist Paul Stamets, who's suggesting McKenna was right all along.
The stoned ape
Terence McKenna. Image source: Jon Hanna/Wikimedia
In McKenna's Stoned Ape hypothesis," he posited that as humans began to migrate to new areas, at some point they came upon psychedelic mushrooms growing in cow droppings, as is their wont, and then ate them. After ingesting them, and more specifically the psilocybin they contained, their brains kicked into overdrive, acquiring new information-processing capabilities, and a mind-blowing expansion of our imaginations in the bargain. Many modern users of psychedelics claim the world never looks the same again after such an experience. As McKenna put it, "Homo sapiens ate our way to a higher consciousness," and, "It was at this time that religious ritual, calendar making, and natural magic came into their own."
The return of the stoned ape
Image source: Chris Moody / Shutterstock / Big Think
Regarding this theory, Stamets presented "Psilocybin Mushrooms and the Mycology of Consciousness" at Psychedelic Science 2017. In his talk he sought to rehabilitate McKenna's hypothesis as a totally plausible answer to a longstanding evolutionary riddle. "What is really important for you to understand," he said, "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."
Why not mushrooms? Stamets portrayed a group of early humans making their way through the savannah and happening across "the largest psilocybin mushroom in the world growing bodaciously out of dung of the animals." It needn't have been unusually large to have its effect, of course. In any event, he invited the crowd to suspend their disbelief and admit that McKenna's idea constitutes a "very, very plausible hypothesis for the sudden evolution of Homo sapiens from our primate relatives," even if it's an unprovable one.
The audience's response was reportedly enthusiastic, though it's fair to note that these were people attending a conference on psychedelic science, and thus pre-disposed toward such chemicals' importance.
Image source: Apple2499 / Shutterstock
Certainly, there's general agreement on the mystery Stamets cited, if not so much on timing details. And consciousness, the "hard problem" even in its modern form, is an area rife with unanswered questions. What is consciousness, anyway? Is it a simple enough thing that it could have a single root cause as McKenna and Stamets say? Many experts suspect our brains gained new capabilities as the result of early community ties and the requirements of social interaction, but when?
Anthropologist Ian Tattersall tells Inverse that the where seems obvious enough: Africa, "For it is in this continent that we find the first glimmerings of 'modern behaviors'. . . But the moment of transformation still eludes us and may well do so almost indefinitely."
There are other researchers who've studied early humanity's use of drug plants but who are skeptical of the stoned ape notiion. Elisa Guerra-Doce, an expert in the field, considers the idea too simplistic, potentially a reduction of a complex evolutionary process into a single "aha" — or maybe "oh, wow" — moment. She's also troubled by there being little evidence of such a pivotal moment, or of drug use at all, so early in the archeological record.
Amanda Feilding of the psychedelic think tank Beckley Foundation says, however, that the stoned ape theory is at the very least a valid reminder that humans have always been drawn to and fascinated by mind-altering substances: "The imagery that comes with the psychedelic experience is a theme that runs through ancient art, so I'm sure that psychedelic experience and other techniques, like dancing and music, were used by our early ancestors to enhance consciousness, which then facilitated spirituality, art, and medicine."
Just how early our love affair with hallucinogenic states began may have something to say about the plausibility of McKenna's hypothesis, but, alas, we don't know when that would have been. And, as the saying about the 1960s goes, even if any of these people were still around to ask, anyone who was really there wouldn't be able to remember.
Join Radiolab's Latif Nasser at 1pm ET on Monday as he chats with Malcolm Gladwell live on Big Think.
University of Utah research finds that men are especially well suited for fisticuffs.
- With males having more upper-body mass than women, a study looks to find the reason.
- The study is based on the assumption that men have been fighters for so long that evolution has selected those best-equipped for the task.
- If men fought other men, winners would have survived and reproduced, losers not so much.
Built for mayhem<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzk4NTQ2OX0.my6nML12F3fEQu3H4G0BScdqgaMZkRQHxgyj-Cmjmzk/img.jpg?width=980" id="906fc" class="rm-shortcode" data-rm-shortcode-id="dd77af7a881631355ed8972437846394" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers are, of course, talking averages here, not stating a rule: There are plenty of accomplished female pugilists, as well as lots of males who have no idea how to throw a punch.</p><p>Even so, says co-author <a href="https://www.wofford.edu/academics/majors-and-programs/biology/faculty-and-staff" target="_blank">Jeremy Morris</a> says, "The general approach to understanding why sexual dimorphism evolves is to measure the actual differences in the muscles or the skeletons of males and females of a given species, and then look at the behaviors that might be driving those differences."</p><p>Carrier has been interested in the idea that millennia of male fighting has shaped certain structures in male bodies. Previous research has reinforced his hunch:</p> <ul> <li><a href="https://jeb.biologists.org/content/216/2/236" target="_blank">When a hand is formed into a fist, its structure is self-protective</a>.</li> <li><a href="https://unews.utah.edu/flat-footed-fighters/" target="_blank">Heels planted firmly on the ground augment upper-body power</a>.</li> <li><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909544" target="_blank">A study examined facial bone structure as being especially well-suited for taking a punch</a>.</li> </ul> <p>(That last one is our favorite. Do you know the German word "<a href="https://www.urbandictionary.com/define.php?term=Backpfeifengesicht" target="_blank">backpfeifengesicht</a>?" It's an adjective describing "a face that badly needs a punching.")</p><p>"One of the predictions that comes out of those," asserts Carrier, "is if we are specialized for punching, you might expect males to be particularly strong in the muscles that are associated with throwing a punch."</p>
Testing the theory<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIzMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzMxMTE2MH0.UXJICMy57UPYUWskhK98alctOrPidJL9yxMkz3HDQrM/img.jpg?width=980" id="98718" class="rm-shortcode" data-rm-shortcode-id="b12287684ac3e740b70392e6433a6b8f" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers measured the punching — and spear-throwing — force of 20 men and 19 women. The assumption was that early humans were punchers <em>and</em> spear-throwers.</p><p>Prior to testing, each participant had filled out an activity questionnaire so that "we weren't getting couch potatoes, we were getting people that were very fit and active," says Morris.</p><p>For punching, participants operated a hand crank that required movement similar to throwing a haymaker. The purpose of the hand crank was to spare participants any damage that might be inflicted on their fists by throwing actual punches. Subjects were also measured pulling a line forward over their heads to assess their strength at throwing a spear.</p><p>Even though all of the participants, male and female, were routinely fit, the average power of males was assessed as being 162% greater than females. There were no gender differences in throwing strength recorded. Other untested, though presumably likely, hand-to-hand combat activities come to mind including tackling, clubbing, running, kicking, scratching, and biting.</p><p>Carrier's takeaway: "This is a dramatic example of sexual dimorphism that's consistent with males becoming more specialized for fighting, and males fighting in a particular way, which is throwing punches."</p>
Boys will be boys<p>It, er, strikes us as odd that, even in science fiction — hi-tech weaponry notwithstanding — the hero <em>is</em> going to wind up duking it out with some bad guy, or alien, in the climactic battle. What is it about men punching, anyway? Are they more sexually attractive? The study suggests so:</p><p style="margin-left: 20px;"><em>The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.</em></p><p>It's tough to contribute to the gene pool after being killed in battle.</p><p>Also, while the authors aren't <em>quite</em> saying that males' historical fighting role is mandated by biology and not by social expectations, neither are they quite <em>not</em> saying it.</p><p>As Carrier explain to <a href="https://attheu.utah.edu/facultystaff/carrier-punch/" target="_blank">theU</a>: "Human nature is also characterized by avoiding violence and finding ways to be cooperative and work together, to have empathy, to care for each other, right? There are two sides to who we are as a species. If our goal is to minimize all forms of violence in the future, then understanding our tendencies and what our nature really is, is going to help."</p>
The Labour Economics study suggests two potential reasons for the increase: corruption and increased capacity.
Cool hand rebuke<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTIyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjY1NTYyOH0.0MCPKN3If94mYCNf3mMNrnTvJXjXN_bKLhgk9203EXk/img.jpg?width=917&coordinates=0%2C0%2C0%2C0&height=453" id="1627b" class="rm-shortcode" data-rm-shortcode-id="6d76421ba1ea0de4b09956b97e80c384" data-rm-shortcode-name="rebelmouse-image" />
A chart showing prison population rates (per 100,000 people) in 2018. The United States has the highest rate of incarceration in the world.
Who profits with for-profit prisons?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="97ac37e6c7f6f22ec130ea2d56871701"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/dB78NV2WpWc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>The Labour Economics study suggests that privately-run prisons do convicts a few favors at the moment of sentencing. However, proponents of private prisons often point to other benefits when making their case. Specifically, they argue that private prisons reduce operating costs, stimulate innovation in the correctional system, and reduce recidivism—the rate at which released prisoners are rearrested and return to prison.</p><p>In regard to recidivism, the research is mixed. <a href="https://journals.sagepub.com/doi/abs/10.1177/0011128799045001002" target="_blank">One study</a> compared roughly 400 former prisoners from Florida, 200 released from private prisons and 200 from state-run facilities. It found the private-prison cohort maintained lower rates of recidivism. However, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-9133.2005.00006.x" target="_blank" rel="noopener noreferrer">another Florida study</a> found no significant rate differences. And two other studies—one from <a href="https://journals.sagepub.com/doi/abs/10.1177/0011128799045001002" target="_blank" rel="noopener noreferrer">Oklahoma</a> and another out of <a href="https://journals.sagepub.com/doi/abs/10.1177/0734016813478823" target="_blank" rel="noopener noreferrer">Minnesota</a>, both comparing much larger cohorts than the first Florida study— found that prisoners leaving private prisons had a greater risk of recidivism.</p><p>The research is also inconclusive regarding cost savings. <a href="https://www.hamiltonproject.org/assets/files/economics_of_private_prisons.pdf" target="_blank" rel="noopener noreferrer">A Hamilton Project analysis</a> noted that such comparisons are difficult because private prisons, like all private companies, are not required to release operational details. In comparing what studies were available, the authors estimate the costs to be comparable and that "in practice the primary mechanism for cost saving in private prisons is lower salaries for correctional officers"—about $7,000 less than their public peers. They add that competition-driven innovation is lacking as the three largest firms control nearly the entire market.</p><p>"We aren't saying private prisons are bad," Galinato said. "But states need to be careful with them. If your state has previous and regular issues with corruption, I wouldn't be surprised to see laws being more skewed to give longer sentences, for example. If the goal is to reduce the number of incarcerated individuals, increasing the number of private prisons may not be the way to go."</p>
What exactly does "questions are the new answers" mean?
- Traditionally, intelligence has been viewed as having all the answers. When it comes to being innovative and forward-thinking, it turns out that being able to ask the right questions is an equally valuable skill.
- The difference between the right and wrong questions is not simply in the level of difficulty. In this video, geobiologist Hope Jahren, journalist Warren Berger, experimental philosopher Jonathon Keats, and investor Tim Ferriss discuss the power of creativity and the merit in asking naive and even "dumb" questions.
- "Very often the dumb question that is sitting right there that no one seems to be asking is the smartest question you can ask," Ferriss says, adding that "not only is it the smartest, most incisive, but if you want to ask it and you're reasonably smart, I guarantee you there are other people who want to ask it but are just embarrassed to do so."