Idiot Brain (19 page)

Culture plays a massive role in how intelligence manifests. A perfect example of this was provided in the 1980s by Michael Cole.
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He and his team went to the remote Kpelle tribe in Africa, a tribe that was relatively untouched by modern culture and the outside world. They wanted to see if equivalent human intelligence was demonstrated in the Kpelle people, stripped of the cultural factors of Western civilization. At first, it proved frustrating; the Kpelle people could demonstrate only rudimentary intelligence, and couldn't even solve basic puzzles, the kind a developed-world child would surely have no problem with. Even if the researcher “accidentally” gave clues as to the right answers, the Kpelle still didn't grasp it. This suggested that their primitive culture wasn't rich or stimulating enough to produce advanced intelligence, or even that some quirk of Kpelle biology prevented them from achieving intellectual sophistication. However, the story is
that, frustrated, one of the researchers told them to do the test “like a fool would,” and they immediately produced the “correct” answers.

Given the language and cultural barriers, the tests involved sorting items into groups. The researchers decided that sorting items into categories (tools, animals, items made of stone, wood, and so on), something that required abstract thinking and processing, was more intelligent. But the Kpelle always sorted things into function (things I can eat, things I can wear, things I can dig with). This was deemed “less” intelligent, but clearly the Kpelle disagreed. These are people who live off the land, so sorting things into arbitrary categories would be a meaningless and wasteful activity, something a “fool” would do. As well as being an important lesson in not judging people by your own preconceptions (and maybe about doing better groundwork before beginning an experiment), this example shows how the very concept of intelligence is seriously affected by the environment and preconceptions of society.

A less-drastic example of this is known as the Pygmalion effect. In 1965, Robert Rosenthal and Lenore Jacobson did a study where teachers in elementary schools were told that certain pupils were advanced or intellectually gifted, and should be taught and monitored accordingly.
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As you'd expect, these pupils showed tests and academic performance in line with being of higher intelligence. The trouble was, they weren't gifted; they were normal pupils. But being treated as if they were smarter and brighter meant they essentially started performing to meet expectations. Similar studies using college students have shown similar results; when students are told that intelligence is fixed, they tend to perform worse on tests. If told that it's variable, they perform better.

Maybe this is another reason why taller people seem more intelligent overall? If you grow taller at a young age, people may treat you as if you're older, so engage you in more mature conversation, so your still-developing brain conforms to these expectations. But in any case, clearly self-belief is important. So any time I've mentioned that intelligence is “fixed” in this book, I've essentially been hampering your development. Sorry, my bad.

Another interesting/weird thing about intelligence? It's increasing worldwide, and we don't know why. This is called the Flynn effect, and it describes the fact that general scores of intelligence, both fluid and crystallized, are increasing in a wide variety of populations around the world with every generation, in many countries, and despite the varying circumstances that are found in each one. This may be due to improved education worldwide, better healthcare and health awareness, greater access to information and complex technologies, or maybe even the awakening of dormant mutant powers that will slowly turn the human race into a society of geniuses.

There's no evidence to suggest that last one is occurring, but it would make a good film.

There are many possible explanations as to why height and intelligence are linked. They all may be right, or none of them may be right. The truth, as ever, probably lies somewhere between these extremes. It's essentially another example of the classic nature v. nurture argument.

Is it surprising that it would be so uncertain, given what we know about intelligence? It's hard to define, measure and isolate but it's definitely there and we can study it. It is a specific general ability made up of several others. There are
numerous brain regions used to produce intelligence, but it may be the manner in which these are connected that makes all the difference. Intelligence is no guarantee of confidence and lack of it is no guarantee of insecurity, because the manner in which the brain works flips the logical arrangement on its head, unless people are treated as if they are intelligent, in which case it seems to make you smarter, so even the brain isn't sure what it's meant to do with the intelligence it is responsible for. And the level of general intelligence is essentially fixed by genes and upbringing, except if you're willing to work at it, in which case it can be increased, maybe.

Studying intelligence is like trying to knit a sweater with no pattern, using cotton candy instead of wool. Overall, it's actually incredibly impressive that you can even make the attempt.

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Admittedly, there are some genes that are implicated in having a potentially key role in mediating intelligence. For example, the gene apolipoprotein-E, which results in the formation of specific fat-rich molecules with a wide variety of bodily functions, is implicated in Alzheimer's disease and cognition. But the influence of genes on intelligence is breathtakingly complex, even with the limited evidence we currently have, so we won't go into it here.

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Did you see this chapter coming?

The haphazard properties of the brain's observational systems

One of the more intriguing and (apparently) uniquely human abilities granted us by our mighty brains is the ability to look “inwards.” We are self-aware, we can sense our internal state and our own minds, and even assess and study them. As a result, introspection and philosophizing are something prized by many. However, how the brain actually perceives the world beyond the skull is also incredibly important, and much of the brain's mechanisms are dedicated to some aspect of this. We perceive the world via our senses, focus on the important elements of it, and act accordingly.

Many may think what we perceive in our heads is a 100 percent accurate representation of the world as it is, as if the eyes and ears and the rest are essentially passive recording systems, receiving information and passing it on to the brain, which sorts it and organizes it and sends it to the relevant places, like a pilot checking the instruments. But that isn't what's happening, at all. Biology is not technology. The actual information that reaches the brain via our senses is not the rich and detailed stream of sights, sounds and sensations that we so often take for granted; in truth, the raw data our senses provide is more like a muddy trickle, and our brain does some quite incredible work to polish it up to give
us our comprehensive and lavish world view.

Imagine a police sketch artist, constructing an image of a person from secondhand descriptions. Now imagine it's not one other person who's providing the descriptions, but hundreds. All at once. And it's not a sketch of a person they have to create but a full-color 3D rendering of the town in which the crime occurred, and everyone in it. And they have to update it every minute. The brain is a bit like that, only probably not quite as harassed as this sketch artist would be.

It is undeniably impressive that the brain can create such a detailed representation of our environment from limited information but errors and mistakes are going to sneak in. The manner in which the brain perceives the world around us, and which parts it deems important enough to warrant attention, is something that illustrates both the awesome power of the human brain, and also its many imperfections.

A rose by any other name . . .

(Why smell is more powerful than taste)

As everyone knows, the brain has access to five senses. Although, actually, neuroscientists believe there are more than that.

Several “extra” senses have been mentioned already, including proprioception (sense of the physical arrangement of body and limbs), balance (the inner-ear-mediated sense that can detect gravity and our movement in space), even appetite, because detecting the nutrient levels in our blood and body is another sort of sense. Most of these are concerned with our internal
state, and the five “proper” ones are responsible for monitoring and perceiving the world around us, our environment. These are, of course, vision, hearing, taste, smell and touch. Or, to be extra scientific, ophthalmoception, audioception, gustao-ception, olfacoception and tactioception, respectively (although most scientists don't really use these terms, to save time). Each of these senses is based on sophisticated neurological mechanisms and the brain gets even more sophisticated when using the information they provide. All the senses essentially boil down to detecting things in our environment and translating them into the electrochemical signals used by neurons which are connected to the brain. Coordinating all this is a big job, and the brain spends a lot of time on it.

Volumes could be and have been written about the individual senses, so let's start here with perhaps the weirdest sense, smell. Smell is often overlooked. Literally, what with the nose being right below the eyes. This is unfortunate, as the brain's olfactory system, the bit that smells (as in “processes odor perception”), is odd and fascinating. Smell is believed to be the first sense to have evolved. It develops very early; it is the first sense to develop in the womb, and it has been shown that a developing baby can actually smell what the mother is smelling. Particles inhaled by the mother end up in the amniotic fluid where the fetus can detect them. It was previously believed that humans could detect up to 10,000 separate odors. Sounds like a lot, but this total was based on a study from the 1920s, which obtained the figure largely from theoretical considerations and assumptions that were never really scrutinized.

Flash forward to 2014, when Caroline Bushdid and her team actually tested this claim, getting subjects to discriminate
between chemical cocktails of very similar odors, something that should be practically impossible if our olfactory system is limited to 10,000 smells. Surprisingly, the subjects could do it quite easily. In the end, it was estimated that humans can actually smell in the region of 1
trillion
odors. This sort of number is usually applied to astronomical distances, not something as humdrum as a human sense. It's like finding out the cupboard where you store the vacuum cleaner actually leads to a subterranean city with a civilization of mole people.
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So how does smell work? We know smell is conveyed to the brain through the olfactory nerve. There are twelve facial nerves that link the functions of the head to the brain, and the olfactory nerve is number 1 (the optic nerve is number 2). The olfactory neurons that make up the olfactory nerve are unique in many ways, the most pronounced of which is they're one of the few types of human neurons that can regenerate, meaning the olfactory nerve is the Wolverine (of
X-Men
fame) of the nervous system. The regenerative capabilities of these nose neurons means they are extensively studied, with the aim of exploiting their regenerating abilities to apply them to damaged neurons elsewhere—for instance, in the spine of paraplegics.

Olfactory neurons regenerate because they are one of the few types of sensory neurons that are directly exposed to the “outside” environment, which tends to degrade fragile nerve cells. Olfactory neurons are in the lining of the upper parts of your nose, where the dedicated receptors embedded in them can detect particles. When they come into contact with a
specific molecule, they send a signal to the olfactory bulb, the region of the brain responsible for collating and organizing information about odor. There are a lot of different smell receptors; a Nobel Prize–winning study by Richard Axel and Linda Buck in 1991 discovered that 3 percent of the human genome codes for olfactory receptor types.
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This also supports the idea that human smell is more complex than we'd previously thought.

When the olfactory neurons detect a specific substance (a molecule of cheese, a ketone from something sweet, something emanating from the mouth of someone with questionable dental hygiene) they send electrical signals to the olfactory bulb, which relays this information to areas such as the olfactory nucleus and piriform cortex, meaning you experience a smell.

Smell is very often associated with memory. The olfactory system is located right next to the hippocampus and other primary components of the memory system, so close in fact that early anatomical studies thought that's what the memory system was for. But they're not just two separate areas that happen to be side by side, like an enthusiastic vegan living next to a butcher. The olfactory bulb is part of the limbic system, just like the memory-processing regions, and has active links to the hippocampus and the amygdala. As a result, certain smells are particularly strongly associated with vivid and emotional memories, like how a smell of roast dinner can suddenly remind you of Sundays at your grandparents' house.

You've probably experienced this yourself on many occasions, how a certain smell or odor can trigger powerful memories of childhood and/or bring about emotional moods associated with smells. If you spent a lot of happy time as a
child at your grandfather's house and he smoked a pipe, you will likely have a sort of melancholy fondness for the smell of pipe smoke. Smell being part of the limbic system means it has a more direct route to triggering emotions than other senses, which would explain why smell can often elicit a more powerful response than most other senses. Seeing a fresh loaf of bread is a fairly innocuous experience,
smelling
one can be very pleasurable and oddly reassuring, as it's stimulating and coupled with the enjoyable memories of things associated with the smell of baking, which invariably ends up with something pleasant to eat. Smell can have the opposite effect too, of course; seeing rotten meat isn't very nice, but smelling it is what'll make you throw up.