by Alex Boese
Consider what differentiates animal communication from that of humans. Many animals have simple forms of communication. Dogs bark, and vervet monkeys have been observed making warning calls specific to different predators. But, in these cases, one sound always has one specific meaning. Humans, however, have mastered complex, symbolic forms of language that allow us to communicate highly abstract messages. We mix sounds and concepts together to create an endless variety of meanings. How did our ancestors learn this trick?
Dennis McKenna points out, as his brother did, that the signature effect of psilocybin is synaesthesia. It causes a mixing of the senses. Parts of our brain connect that aren’t normally in tune with each other. This seems like precisely the kind of nudge that might have been needed to help our hominid ancestors make the leap from simple sounds to more complex, symbolic language. It’s tempting to imagine one of them ingesting Psilocybe cubensis and then having a dim awareness form in his head that those sounds emerging from his mouth could have different meanings if combined in new ways. Dennis McKenna has no doubt of the link. He declares it as a fact: ‘[Psilocybin] taught us language. It taught us how to think.’
Along similar lines, author Dorion Sagan, son of Carl Sagan, has drawn attention to the curious similarities between language and psychedelic drugs. Hallucinogens create images in a person’s head, but so does language. We use words to form pictures in each other’s brains. Poetry and song can produce a flood of powerful visual imagery. In this sense, Sagan suggested, language is actually a form of ‘consensual hallucination’. It’s the ultimate hallucinogenic drug.
Perhaps these are just coincidental similarities. We’ll probably never know for sure. It’s hard to imagine a palaeontological finding or psychological experiment that could settle the debate one way or another. But it is intriguing to think that there might be a deep underlying connection between hallucinogens and language.
And there’s one final concept that persuades some the stoned-ape theory might be worth a second look. It’s the idea that the human mind is such an extraordinary thing that to account for it perhaps we need to look beyond standard evolutionary explanations and consider the possibility that a remarkable chance event brought it into being.
Terence McKenna often spoke of mushrooms and early humans forming a symbiotic relationship. It’s easy to dismiss this as one of his poetic flourishes, but it does recall the anthropological concept of efflorescence, a term used to describe how contact between two cultures will often lead to a blossoming of creativity that produces unexpected results. One example is how global trade spread Chinese innovations, such as gunpowder and printing, to Europe, where they were developed in dramatically new ways.
McKenna’s theory asks us to consider that something similar might have occurred in Africa two million years ago. Imagine that two species from different biological kingdoms fortuitously crossed paths. The complex chemical system of a fungus might have encountered a primate that was uniquely ready to benefit from it. The result was an unexpected moment of evolutionary efflorescence. New mental pathways and dormant abilities stirred in the primitive ape brain, and then slowly our ancestors began to hallucinate their way to higher consciousness.
Weird became true: cave art
To step inside the Cave of Altamira, located on the northern coast of Spain, is like walking into a prehistoric cathedral. Its ceiling and walls are covered with stunning depictions of bison, aurochs, deer and horses, all drawn well over 10,000 years ago by artists whose identities have been lost in the mists of time. These magnificent Palaeolithic paintings are today considered to be among the artistic wonders of the world, but, remarkably, they weren’t always held in such high esteem. When the cave was discovered in the late nineteenth century, it was the first time such elaborate prehistoric art had ever been seen, and the leading experts in the young field of prehistory were singularly unimpressed. They promptly declared that it was impossible for cavemen to have created artwork of this kind and dismissed it as a modern-day hoax. It took over twenty years before they finally came around to acknowledging its authenticity and significance.
The paintings were discovered by a wealthy Spanish landowner, Don Marcelino Sanz de Sautuola. In 1878, he had attended the Paris World Exposition, where he saw a collection of prehistoric artefacts found in France. His curiosity stirred as he remembered that, several years before, in 1868, a hunter searching for his dog had found the opening of a cave on his estate. Sautuola wondered if this cave might contain any prehistoric artefacts.
It wasn’t until the following year, though, that he got around to following up on this thought and looked more closely at the cave. When he dug near its entrance, he quickly found some flint tools and bones, which excited him. The following day, he brought along his nine-year-old daughter, Maria, so that she could play as he worked. He bent down to resume his digging, and Maria ran into the cave straight away to explore. A few minutes later, Sautuola heard her shout out, ‘Look, Papa, bison!’
He had gone into the cave earlier by himself, but had been so intent on what he might find in the ground that it had never occurred to him to look up at its ceiling. As a result, he had missed the almost life-size multicoloured bison drawn there, until Maria’s call drew his attention to them.
This charming tale of a child’s role in such an important discovery has now become one of the most popular stories in modern archaeology. It’s often told as a reminder not to be too focused on the immediate task at hand. Remember to stop and consider the bigger picture every now and then!
Once he had seen the paintings, Sautuola instantly realized their significance, and he diligently set to work to spread the word of their discovery. He prepared a pamphlet in which he carefully described them, arguing that they had to be prehistoric. He also gained the assistance of Juan Vilanova y Piera, a professor at the University of Madrid, who was similarly impressed by them. Together, the two men travelled to a series of academic conferences in Spain, Germany and France in order to present information about the cave. They had anticipated enormous interest in the find. Instead, they were greeted with open scepticism and contempt.
It didn’t help that Sautuola was an unknown amateur. If an experienced academic with a well-established reputation had made the discovery, perhaps the reception would have been different. Equally, nothing on the scale of this cave art had been seen before. It seemed almost too extraordinary to be true, and, since the discipline of prehistory was at the time only a few decades old, its practitioners were paranoid of being discredited by falling for a hoax.
Most of all, though, the cave art contradicted the prevailing image of our Stone Age ancestors. This image had been shaped by Darwin’s recently published theory of evolution, which argued that humans had descended from apes. Scholars of prehistory took it as a matter of faith, therefore, that our distant, cave-dwelling ancestors must have been closer in behaviour to chimpanzees than to humans. The Altamira cave art, however, was clearly not the work of beings anything like chimps. It had been created by skilled artists, every bit the equal of modern painters.
Two influential French academics, Émile Cartailhac and Gabriel de Mortillet, led the opposition to the discovery. Without having set foot in the cave, and even refusing to do so, Cartailhac declared its paintings to be ‘a vulgar joke by a hack artist’. Both academics denounced the cave art as a hoax deviously conceived as an attack on evolutionary theory. Cartailhac pinned the blame on conservative Spanish clerics, while Mortillet suspected it to be the work of antievolutionist Spanish Jesuits.
An element of nationalistic jealousy may also have influenced Cartailhac and Mortillet. They simply didn’t want to credit ancient Spaniards with having created such magnificent work. If the cave had been located in France, their opinion of it might have been more charitable.
To support their accusation that it was all a fraud, these scholars pointed out unusual features of the cave and the paintings, such as the lack of smoke marks on the ceiling. How, they asked,
could cavemen have painted such works without burning a fire to see? This proved, they declared, that the paintings were of recent origin. The rest of the academic community obediently fell in line behind their lead.
Sautuola found his reputation to be in tatters. He protested that animal fat, when burned, doesn’t produce much smoke, but he was ignored. Instead of being hailed as a great discoverer, he was cast aside as a charlatan. He was even banned from attending further academic conferences.
It was only the discovery of more cave art that eventually vindicated him. In 1895, engravings and paintings similar to those at Altamira – including depictions of bears, mammoths, lions and more bison – were found in caves at Les Combarelles and Font-de-Gaume, in France. This time, no one doubted the artwork was Palaeolithic, and its location in France apparently placated the French scholars. With their nationalistic pride calmed, they reconsidered the authenticity of the Altamira paintings.
It wasn’t until 1902, though, that full scholarly recognition came. In that year, Cartailhac penned a public apology to Sautuola, titled, ‘Mea culpa d’un sceptique’ (‘Mea culpa of a sceptic’). Unfortunately, it was too late for the wronged discoverer to receive it; he had died in 1888. Cartailhac did, however, travel to Spain to apologize in person to Sautuola’s daughter Maria, now an adult. While he was there, he set foot for the first time in the Cave of Altamira and finally gazed upon the amazing paintings, the authenticity of which he had, for so long, refused to acknowledge.
What if humanity is getting dumber?
What would happen if we were able to pluck a caveman out of the Stone Age and drop him down into the twenty-first century? Would we find that he was smarter or dumber than us?
Cavemen don’t get a lot of intellectual respect. The stereotypical image is that they were brutish, stupid, club-wielding oafs. Most people might assume that a time-transported caveman would be out of his intellectual league here in the present. Several scientists, however, have put forward the disturbing suggestion that the caveman would actually mentally outshine modern humans by a wide margin. His mind would be sharp, clear-sighted, able to grasp complex ideas easily, emotionally stable and gifted with a powerful memory. The reason for his mental superiority, according to these researchers, is that the brainpower of Homo sapiens has been heading downhill for the past 12,000 years. The late Stone Age, they say, marked the intellectual high-water mark of our species. This is known as the idiocracy theory, after the 2006 movie of that name about a future world in which humanity has grown morbidly stupid.
The first clue that we may be getting dumber emerged from the field of palaeoanthropology, the branch of archaeology that focuses on the evolutionary history of humans. By the end of the twentieth century, researchers had gathered enough data about the size of the human brain during the course of our evolution to reveal a disturbing fact. Over the three-million-year span of the Stone Age, the average brain size of our ancestors grew substantially, but in the late Stone Age (50,000 to 12,000 years ago) it peaked. Since then, it’s been getting smaller, by quite a bit.
Twenty thousand years ago, for example, the Cro-Magnon people living in Europe boasted an average brain size of 1,500 cubic centimetres. Today, brain size is about 1,350 cubic centimetres, which represents a 10 per cent decline. In visual terms, we’ve lost a chunk of grey matter about the size of a tennis ball. While 20,000 years may sound like a long time, on the timescale of evolution it’s a blink of an eye. Which means that, not only has the human brain been shrinking, but it’s been doing so rapidly.
These gloomy statistics about brain size aren’t being disputed. The real question is, what does the shrinkage mean? Does it indicate that we’re getting dumber? Is it as simple as that?
Maybe not. Anatomists are quick to point out that, while there’s a loose correlation between brain size and intelligence, there’s not a strict one. The brain of a genius, for example, isn’t necessarily going to be larger than the brain of a dullard. Albert Einstein had an average-sized brain.
When comparing brains between species, the most important factor is the ratio of brain volume to body mass. This is known as the encephalization quotient, or EQ. The more brain per ounce of body weight a species has, the smarter it generally is. A small creature with a big brain will, therefore, probably be smarter than a big creature with a big brain. Humans have more brain per ounce than any other species in the animal kingdom, and this seems to be why we’re the Earth’s smartest species. Or, at least, its most dangerous.
So, perhaps the brains of the Cro-Magnons were larger simply because their bodies were also larger. That would be one explanation for our shrinking brains. We could chalk up our small craniums to the general downsizing of our bodies as a whole.
Unfortunately, no dice. Recent studies indicate that Cro-Magnon brains were proportionally larger than ours, even when we consider their larger body size. The human brain has shrunk far more than the human body has. EQ doesn’t get us off the hook.
This finding led David Geary, a cognitive scientist at the University of Missouri, to conclude that we really may be getting stupider. In his 2005 book, The Origin of Mind, he raised the possibility that intellectual abilities may have declined across the human population as a whole. He was the first to jokingly refer to this as the idiocracy theory.
Geary suspects that our cranial downsizing was related to the adoption of agriculture in the late Neolithic period, around 12,000 years ago. He charted human brain size over time and discovered that it was at this exact historical moment, as population densities increased, that the human brain began noticeably shrinking. This trend repeated throughout the world, wherever complex societies emerged.
Geary reasons that, cavemen stereotypes aside, it took high intelligence to survive in the Stone Age, when our ancestors lived as hunter-gatherers. There was a broad array of skills that had to be mastered, such as how to find and identify edible food consistently, how to avoid predators and how to hunt well. You couldn’t be a dummy and stay alive. If you made a mistake, you didn’t get a slap on the wrist. You died. This placed enormous selective pressure on intelligence.
When our species adopted agriculture, this provided a more reliable supply of food, and populations began to swell. Towns formed around the fields, and then cities took their place. Civilizations were born. Often, even the most positive developments, however, can have unintended consequences. In this case, agriculture eased the pressure on our species to be smart. It created a kind of safety net, so the less quick-witted remained alive and passed on their genes. Over the span of millennia, this absence of selective pressure steadily lowered the average brain size of our species. The end result has been that we’re getting dumber.
As if having a shrinking brain wasn’t bad enough, another argument for the idiocracy theory has emerged from the discipline of genetics. In a two-part article that appeared in the January 2013 issue of Trends in Genetics, Stanford professor Gerald Crabtree argued that a straightforward genetic analysis also suggests we’ve been getting dumber since the Stone Age. He called it the ‘fragile intellect’ phenomenon.
The problem, as he described it, is that our intelligence requires many genes to be functioning just right. He estimated that between 2,000 and 5,000 genes are involved in maintaining our intellectual abilities, representing 10 per cent of our entire genome. According to Crabtree, the sheer number of genes associated with intelligence presents a problem, because it allows a greater chance for harmful mutations to accumulate. This makes it a fragile trait, prone to fading away over the span of generations.
To understand this argument, think of the game of Telephone (or Chinese Whispers, as it’s sometimes called), in which a message is transmitted along a line of people, each individual whispering the message into the ear of their neighbour. If the message is simple – one word, perhaps – there’s a good chance it will arrive at the end of the line unchanged. The longer the message, however, the higher the chance for alteration. The analogy isn’t exact, but
the same basic concept holds with genes. The more genes that are involved with a trait, the greater the chance for mutations to accumulate as the genetic information is transferred from one generation to the next, and if nothing is done to weed out these mutations, their numbers will multiply, eventually causing a negative impact on the trait – in this case, intelligence.
If this is true, how did intelligence ever evolve in the first place? The answer, explained Crabtree, was because of the force of selective pressure during the hundreds of thousands of years that our ancestors lived as hunter-gatherers. As Geary had previously noted, there was extreme selective pressure on intelligence, because only those with the wits to survive in a harsh, unforgiving environment lived to pass their genes on. In these circumstances, humans grew very smart, but they paid a terrible price with their lives.
Crabtree, like Geary, sees the adoption of agriculture as a pivotal moment in our evolutionary history. It shielded our species from the intense selective pressure required to maintain the genes for intelligence intact. We flourished, but the cost of this success has been a slow inevitable decline in our intellect. To put it bluntly, dumb people are no longer being culled from the human herd. Crabtree estimated that, compared to a late-Stone Age hunter-gatherer, each of us has between two and six deleterious mutations in our intelligence-related genes, which doesn’t sound like a lot, but it may be enough to make us generally more slow-witted than our ancestors. These mutations will just keep accumulating in future generations, so our descendants can look forward to being even more intellectually dull than we are.
So, both palaeoanthropology and genetics suggest we may be getting dumber. ‘But wait a second!’ you may be tempted to say. How is it possible for anyone to seriously argue that we’re getting dumber? Just look at all the amazing things our species has done in the past hundred years. We sent men to the moon, cracked the genetic code and created computers. If anything, humans seem to be getting more intelligent, not less.