Idiot Brain (17 page)

The phenomenon of less-intelligent people being more confident has an actual scientific name: the Dunning–Kruger effect. It is named for David Dunning and Justin Kruger of Cornell University, the researchers who first looked into the phenomenon, inspired by reports of a criminal who held up banks after covering his face with lemon juice, because lemon juice can be used as invisible ink, so he thought his face wouldn't show up on camera.
⁵

Just let that sink in for a moment.

Dunning and Kruger got subjects to complete a number of tests, but also asked them to estimate how well they thought they had done on the tests. This produced a remarkable pattern: those who performed badly on the tests almost always assumed they'd
done much
much
better, whereas those who did well invariably assumed they'd done worse. Dunning and Kruger argued that those with poor intelligence not only lack the intellectual abilities, they also lack
the ability to recognize that they are bad at something
. The brain's egocentric tendencies kick in again, suppressing things that might lead to a negative opinion of oneself. But also, recognizing your own limitations and the superior abilities of others is something that itself requires intelligence. Hence you get people passionately arguing with others about subjects they have no direct experience of, even if the other person has studied the subject all their life. Our brain has only our own experiences to go from, and our baseline assumptions are that everyone is like us. So if we're an idiot . . .

The argument is that an unintelligent person actually cannot “perceive” what it is to be considerably more intelligent. It's basically like asking a color-blind person to describe a red and green pattern.

It may be that an “intelligent” has a similar take on the world, but expressed in different ways. If an intelligent person thinks something was easy then they may assume everyone else finds it easy too. They assume their level of competence is the norm, so they assume their intelligence is the norm (and intelligent people tend to find themselves in jobs and social situations where they're surrounded by other similar types, so they are likely to have a lot of evidence to support this).

But if intelligent people are generally used to learning new things and acquiring new information, they're more likely to be aware that they
don't
know everything and how much there is to know about any given subject, which would undercut confidence when making claims and statements.

For example, in science, you (ideally) have to be painstakingly thorough with your data and research before making any claims as to how something works. A consequence of surrounding yourself with similarly intelligent people means if you do make a mistake or a grandiose claim, they're more likely to spot it and call you on it. A logical consequence of this would be a keen awareness of the things you don't know or aren't sure about, which is often a handicap in a debate or an argument.

These occurrences are common enough to be familiar and problematic, but obviously aren't absolute; not every intelligent person is racked with doubt, and not every less-intelligent person is a self-aggrandizing buffoon. There are plenty of intellectuals who are so in love with the sound of their own voice that they genuinely charge people thousands to hear it, and there are ample less-intelligent people who freely admit their limited mental powers with grace and humility. It may also have a cultural aspect; the studies behind the Dunning–Kruger effect almost always focus on Western societies, but some East Asian cultures have shown very different patterns of behavior, and one explanation put forward for this is these cultures adopt the (healthier) attitude that a lack of awareness is an opportunity for improvement, so the priorities and behaviors are very different.
⁶

Are there actual brain regions behind this kind of phenomenon? Is there a part of the brain responsible for working out: “Am I any good at this thing that I'm doing?” Amazing as it may seem, there might well be. In 2009, Howard Rosen and his colleagues tested a group of about forty patients with neurodegenerative diseases and concluded that accuracy in self-appraisal correlated with the volume of tissue in the right
ventromedial (lower part, towards the middle) region of the prefrontal cortex.
⁷
The study argues that this area of the prefrontal cortex is needed for the emotional and physiological processing required when evaluating your own tendencies and abilities. This is relatively consistent with the accepted functioning of the prefrontal cortex, which is largely all to do with processing and manipulating complex information and working out the best possible opinion of it and response to it.

It's important to note that this study in and of itself is not conclusive; forty patients isn't really enough to say that the data obtained from them is relevant to everyone ever. But research into this ability to assess your own intellectual performance accurately, known as a “metacognitive ability” (thinking about thinking, if that makes sense), is considered to be quite important, as an inability to perform accurate self-appraisal is a well-known feature of dementia. This is particularly true of frontotemporal dementia, a variation of the disorder that attacks largely the frontal lobe, where the prefrontal cortex is. Patients with this condition often show an inability to assess their performance on a wide variety of tests accurately, which would suggest their ability to assess and evaluate their performance has been seriously compromised. This wide-ranging inability to judge one's performance accurately isn't seen in other types of dementia that damage different brain regions, suggesting an area of the frontal lobe is heavily involved in self-appraisal. So this adds up.

Some propose that this is one reason why dementia patients can turn quite aggressive; they are unable to do things but cannot understand or recognize why, which must be nothing short of enraging.

But even without a neurodegenerative disorder and while
in possession of a fully functioning prefrontal cortex, this means only that you are capable of self-appraisal; there's nothing to say your self-appraisal will be correct. Hence we end up with confident clowns and insecure intellectuals. And it's apparently human nature that we pay more attention to the confident ones.

Crosswords don't actually keep your brain sharp

(Why it's very difficult to boost your brain power)

There are many ways to
appear
more intelligent (using pompous terms such as “
au courant
,” carrying
The
Economist
), but can you
actually become
more intelligent? Is it possible to “boost your brain power”?

In the sense of the body, power usually means the ability to do something or act in a particular way, and “brain power” is invariably linked to abilities that would come under the heading of intelligence. You could feasibly increase the amount of
energy
contained within your brain by using your head to complete a circuit connected to an industrial generator, but that's not going to be something that benefits you, unless you're especially keen to have your mind literally blown (to bits).

You've probably seen ads for things that claim to offer substances, tools or techniques for boosting your brain power, usually for a price. It's highly unlikely that any of these things will actually work in any significant way, because if they did they'd be far more popular, with everyone getting smarter and bigger-brained until we're all crushed under the weight
of our own skulls. But how does one genuinely increase brain power, boosting intelligence?

For this, it would be useful to know what differentiates the unintelligent brain from the intelligent one, and how do we turn the former into the latter? One potential factor is something that seems completely wrong: intelligent brains apparently use
less
power.

This counterintuitive argument is something that arose from scanning studies directly observing and recording brain activity, such as functional magnetic resonance imaging (fMRI). This is a clever technique where people are placed in MRI scanners and their metabolic activity (where the tissues and cells in the body are “doing stuff ”) is observed. Metabolic activity requires oxygen, supplied by the blood. An fMRI scanner can tell the difference between oxygenated blood and deoxygenated blood and when one becomes the other, which occurs at high levels in areas of the body that are metabolically active, like brain regions working hard at a task. Basically, fMRI can monitor brain activity and spot when one part of the brain is especially active. For example, if a subject is doing a memory task, the areas of the brain required for memory processing will be more active than usual, and this shows up on the scanner. Areas showing increased activity would be identifiable as memory-processing areas.

It isn't as simple as that because the brain is constantly active in many different ways, so finding the “more” active bits requires much filtering and analysis. However, the bulk of modern research about identifying brain regions that have specific functions have utilized fMRI.

So far, so good; you'd expect that a region responsible for a specific action would be more active when having to do that
action, like a weightlifter's bicep is using more energy when picking up a dumbbell. But no. Bizarre findings from several studies, such as those from Larson and others in 1995,
⁸
showed that in tasks designed to test fluid intelligence, activity was seen in the prefrontal cortex . . . except when the subject was
very good
at the task.

To clarify, the region supposedly responsible for fluid intelligence apparently wasn't used in people who had high levels of fluid intelligence. This didn't make a lot of sense—like weighing people and finding that only lighter people show up on the scales. Further analysis found that more intelligent subjects
did
show activity in the prefrontal cortex, but only when their tasks were challenging, as in difficult enough for them to have to put some effort into it. This led to some interesting findings.

Intelligence isn't the work of one dedicated brain region but several, all interlinked. In intelligent people, it seems these links and connections are more efficient and organized, requiring
less
activity overall. Think of it in terms of cars: if you've got a car with an engine roaring like a pack of lions impersonating a hurricane, and a car making no noise whatsoever, the first one isn't automatically going to be the better model. In this case, the noise and activity is because it's trying to do something the more efficient model can do with minimal effort. There's a growing consensus that it's the extent and efficiency of the connections between the regions involved (prefrontal cortex, parietal lobe and so on) that has a big influence on someone's intelligence; the better he or she can communicate and interact, the quicker the processing and the less effort is required to make decisions and calculations.

This is backed up by studies showing that the integrity
and density of white matter in a person's brain is a reliable indicator of intelligence. White matter is the other, often overlooked, kind of tissue in the brain. Gray matter gets all the attention, but 50 percent of the brain is white matter and it's also very important. It probably gets less publicity because it doesn't “do” as much. Gray matter is where all the important activity is generated, white matter is made up of bundles and bands of the parts that send the activity to other locations (the axons, the long bit of a typical neuron). If gray matter were the factories, white matter would be the roads needed for delivery and resupply.

The better the white-matter connections between two brain regions, the less energy and effort is required to coordinate them and the tasks they're responsible for, and they're harder to find with a scanner. It's like looking for a needle in a haystack, only instead of a haystack it's a massive pile of slightly bigger needles, and the whole thing is in a washing machine.

Further scanning studies suggest that the thickness of the corpus callosum is also associated with levels of general intelligence. The corpus callosum is the “bridge” between the left and right hemispheres. It's a big tract of white matter, and the thicker it is the more connections there are between the two hemispheres, enhancing communication. If there's a memory stored on one side that needs to be utilized by the prefrontal cortex on the other, a thicker corpus callosum makes this easier and faster. The efficiency and effectiveness of how these regions are connected seems to have a big impact on how well someone can apply their intellect to tasks and problems. As a result of this, brains that are structurally quite different (the size of certain areas, how they're arranged in the cortex, and so on)
can display similar levels of intelligence, like two game consoles made by different companies that are similarly powerful.

Now we know efficiency is more important than power. How does that help us go about making ourselves more intelligent? Education and learning is an obvious answer. Actively exposing yourself to more facts, information and concepts means every one you remember will actively increase your crystallized intelligence, and regularly applying your fluid intelligence to as many scenarios as possible will improve matters there. This isn't a cop-out; learning new things and practicing new skills can bring about structural changes in the brain. The brain is a plastic organ; it can and will physically adapt to the demands made of it. We met this in
Chapter 2
: neurons form new synapses when they have to encode a new memory, and this sort of process is found throughout the brain.

For example, the motor cortex, in the parietal lobe, is responsible for planning and control of voluntary movements. Different parts of the motor cortex control different parts of the body, and how much of the motor cortex is dedicated to a body part depends on how much control it needs. Not much of the motor cortex is dedicated to the torso, because you can't do much with it. It's important for breathing and giving your arms somewhere to connect to, but movement-wise we can turn it or bend it slightly, and that's about it. But much of the motor cortex is dedicated to the face and hands, which require a lot of fine control. And that's just for a typical person; studies have revealed that classically trained musicians such as violinists or pianists often have relatively huge areas of the motor cortex dedicated to fine control of the hands and fingers.
⁹
These people spend all their lives performing
increasingly complex and intricate movements with their hands (usually at high speeds), so the brain has adapted to support this behavior.