Idiot Brain (15 page)

For example, if a typical human approaches a gate held shut with large padlocks, they'll quickly think, “Well, that's locked,” and go find another entrance. This may seem trivial, but it's a
clear sign of intelligence; the person observes a situation, deduces what it means, and responds accordingly. There is no physical attempt to open the gate, at which point they'd discover, “Yep, that's locked”; they don't
have
to. Logic, reasoning, comprehension, planning; these have all been utilized to dictate actions. This is intelligence. But that doesn't clarify how we study and measure intelligence. Manipulating information in complex ways inside the brain is all well and good, but it's not something that can be observed directly (even the most advanced brain scanners just show us blurs of differing color at present, which isn't especially useful) so measuring it can be done only indirectly by observing behavior and performance on specially designed tests.

At this point, you might think that something major has been missed here, because we
do
have a way of measuring intelligence: IQ tests. Everyone knows about IQ, meaning Intelligence Quotient; it's a measurement of how smart you are. Your mass is provided by measuring your weight; your height is determined by measuring how tall you are; your intoxication level is calculated by breathing into one of those gadgets the police make you breathe into; and your intelligence is measured by IQ tests. Simple, right?

Not exactly. IQ is a measurement that takes the slippery, unspecified nature of intelligence into account, but most people assume it's far more definitive than it is. Here's the important fact you need to remember: the average IQ of a population is 100.
Without exception
. If someone says, “The average IQ of [country x] is only 85,” then this is wrong. It's basically the same as saying, “ The length of a meter in [country x] is only 85 cm”; this is logically impossible, and the same is true for IQ.

Legitimate IQ tests tell you where you fall within the typical distribution of intellect in your population, according to a proposed “normal” distribution. This normal distribution dictates that the “mean” IQ is 100. An IQ between 90 and 110 is classed as average, between 110 and 119 is “high average,” between 120 and 129 is “superior,” and anything over 130 is “very superior.” Conversely, an IQ between 80 and 89 is “low average,” 70 to 79 is “borderline,” and anything below 69 is considered “extremely low.”

Using this system, over 80 percent of the population will fall in the average zones, with IQs ranging from 80 to 110. The further out you go, the fewer people you'll find with these IQs; less than 5 percent of the population will have a very superior or extremely low IQ. A typical IQ test doesn't directly measure your raw intelligence, but reveals how intelligent you are compared to the rest of the population.

This can have some confusing consequences. Say a potent but bizarrely specific virus wiped out everyone in the world with an IQ of over 100. The people left behind would
still have an average IQ of
100
. Those with IQs of 99 before the plague hit would now suddenly have IQs of 130+ and be classed as the
crème de la crème
of the intellectual elite. Think of it in terms of currency. In the US the value of the dollar fluctuates in accordance with what happens in the economy, but there are always 100 pennies to the dollar, so the dollar has values that are both flexible and fixed. IQ is basically the same: the average IQ is always 100, but what an IQ of 100 is actually worth in terms of intelligence is variable.

This normalization and adhering to population averages means that IQ measurement can be a bit restrictive. People such as Albert Einstein and Stephen Hawking reportedly
have IQs in the region of 160, which is still very superior but doesn't sound so impressive when you consider the population average is 100. So if you meet someone who does claim to have an IQ of 270 or some such, they're probably wrong. They've been using some alternative type of test that isn't considered scientifically valid, or they've seriously misread their results, which does undermine their claim to be a super genius.

This isn't to say that such IQs don't exist at all; some of the most intelligent people on record supposedly had IQs of over 250, according to the
Guinness Book of Records
, although the category of Highest IQ was retired in 1990 due to the uncertainty and ambiguity of the tests at this level.

The IQ tests used by scientists and researchers are meticulously designed; they're used as actual tools, like microscopes and mass spectrometers. They cost a lot of money (so aren't given away online for free). The tests are designed to assess normal, average intelligences in the widest possible range of people. As a result, the further to the extremes you go, the less useful they tend to be. You can demonstrate many concepts of physics in the school classroom with everyday items (for instance, using weights of different sizes to show the constant force of gravity, or a spring to show elasticity) but, if you delve into complex physics, you need particle accelerators or nuclear reactors and frighteningly complex mathematics.

So it is when you have someone of extremely high intelligence; it just becomes much harder to measure. These scientific IQ tests measure things such as spatial awareness with pattern completion tests, comprehension speeds with dedicated questions, verbal fluency by getting the subject to list words from certain categories, and stuff like that; all
reasonable things to look into but not something that is likely to tax a super genius to the extent where it would be possible to spot the very limits of his or her intelligence. It's a bit like using bathroom scales to weigh elephants; they can be useful for a standard range of weights, but at this level they'll give no useful data, just a load of broken plastic and springs.

Another concern is that intelligence tests claim to measure intelligence, and we know what intelligence is because intelligence tests tell us. You can see why some of the more cynical scientist types wouldn't be happy with this situation. In truth, the more common tests have been revised repeatedly and assessed for reliability often, but some still feel that this is just ignoring the underlying problem.

Many like to point out that performance on intelligence tests is actually more indicative of social upbringing, general health, aptitude to testing, education level, and so on. Things that aren't intelligence, in other words. So the tests may be useful, but not for what they're intended.

It's not all doom and gloom. Scientists aren't ignorant of these criticisms and are a resourceful bunch. Today, intelligence tests are more useful—they provide a wide range of assessments (spatial awareness, arithmetic etc.), rather than one general assessment, and this gives us a more robust and thorough demonstration of ability. Studies have shown that performance on intelligence tests also seems to remain fairly stable over a person's lifetime despite all the changes or learning they experience, so they must be detecting some inherent quality rather than just random circumstance.
¹

So, now you know what we know, or what we think we know. One of the generally accepted signs of intelligence is an awareness and acceptance of what you don't know. Good job.

Where are your trousers, professor?

(How intelligent people end up doing stupid things)

The stereotype of an academic is a white-haired white-coated chap (it's almost always a man) in late middle age, talking quickly and often about his field of study while being utterly clueless about the world around him, effortlessly describing the fruit fly genome while absent-mindedly buttering his tie. Social norms and day-to-day tasks are completely alien and baffling to him; he knows everything there is to know about his subject, but little to nothing beyond that.

Being intelligent isn't like being strong; a strong person is strong in every context. However, someone brilliant in one context can seem like a shuddering dunce in another.

This is because intelligence, unlike physical strength, is a product of the never uncomplicated brain. So what are the brain processes that underpin intelligence, and why is it so variable? Firstly, there is ongoing debate in psychology about whether or not humans use a single intelligence, or several different types. Current data suggests it is probably a combination of things.

A dominant view is that there is a single property that underpins our intelligence, which can be expressed in varying ways. This is often known as “Spearman's g,” or just
g
. Named after Charles Spearman, a scientist who did a great service for intelligence research and science in general in the 1920s by developing factor analysis. The previous section revealed how IQ tests are commonly used despite certain reservations; factor analysis is something that makes them (and other tests) useful.

Factor analysis is a mathematically dense process but what you need to know is that it is a form of statistical decomposition. This is where you take large volumes of data (for example, those produced by IQ tests) and mathematically break them down in various ways and look for factors connecting or influencing the results. These factors aren't known beforehand, but factor analysis can flush them out. If students at a school got mediocre grades overall on their tests, the principal might want to see exactly how the grades were achieved in more detail. Factor analysis could be used to assess the information from all the test scores and take a closer look. It could reveal that math questions were generally answered well, but history questions were answered poorly. The principal can then feel justified about yelling at the history teachers for wasting time and money (although he probably isn't justified, given the many possible explanations for poor results).

Spearman used a process similar to this to assess IQ tests and discovered that there was seemingly one underlying factor that underpinned test performance. This was labeled the single general factor,
g
, and if there's anything in science that represents what your everyday person would think of as intelligence, it's
g
.

It would be wrong to say that
g
= all possible intelligence, as intelligence can manifest in so many ways. It's more a general “core” of intellectual ability. It's viewed as something like the foundations and frame of a house. You can add extensions and furniture, but if the underlying structure isn't strong enough it'll be futile. Similarly, you can learn all the big words and memory tricks you like, but if your
g
isn't up to scratch you won't be able to do much with them.

Research suggests there might be a part of the brain that is responsible for
g
.
Chapter 2
discussed short-term memory in detail and alluded to the term “working memory.” This refers to the actual processing and manipulation, the “using” of the information in short-term memory. In the early 2000s, Professor Klaus Oberauer and his colleagues ran a series of tests and found that a subject's performance on working-memory tests corresponded strongly with tests to determine his or her
g
, indicating that a person's working-memory capacity is a major factor in overall intelligence.
²
Ultimately, if you score high on a working-memory task, you're very likely to score high on a range of IQ tests. It makes logical sense; intelligence involves obtaining, retaining and using information as efficiently as possible, and IQ tests are designed to measure this. But such processes are basically what the working memory is for.

Scanning studies and investigations of people with brain injuries provide compelling evidence for a pivotal role of the prefrontal cortex in processing both
g
and working memory, with those afflicted with frontal-lobe injury demonstrating a wide range of unusual memory problems, typically traced back to a deficit in working memory, thus further implying a large overlap between the two things. This prefrontal cortex is right behind the forehead, the beginning of the frontal lobe that is regularly implicated in higher “executive” functions such as thinking, attention and consciousness.

But working memory and
g
are not the whole story. Working-memory processes mostly work with verbal information, supported by words and terms we could speak aloud, like an internal monologue. Intelligence, on the other hand, is applicable to all types of information (visual, spatial, numerical . . .),
prompting researchers to look beyond
g
when trying to define and explain intelligence.

Raymond Cattell (a former student of Charles Spearman) and his student John Horn devised newer methods of factor analysis and identified two types of intelligence in studies spanning the 1940s to 1960s; fluid intelligence and crystallized intelligence.

Fluid intelligence is the ability to
use
information, work with it, apply it, and so on. Solving a Rubik's cube requires fluid intelligence, as does working out why your partner isn't talking to you when you have no memory of doing anything wrong. In each case, the information you have is new and you have to work out what to do with it in order to arrive at an outcome that benefits you.

Crystallized intelligence is the information you have stored in memory and can utilize to help you get the better of situations. Knowing the lead actor in an obscure 1950s film for a trivia game requires crystallized intelligence. Knowing all the capital cities of the northern hemisphere is crystallized intelligence. Learning a second (or third or fourth) language utilizes crystallized intelligence. Crystallized intelligence is the knowledge you have accumulated, where fluid intelligence is how well you can use it or deal with unfamiliar things that need working out.

It's fair to say that fluid intelligence is another variation of
g
and working memory; the manipulation and processing of information. But crystallized intelligence is increasingly viewed as a separate system, and the workings of the brain back this up. One quite telling fact is that fluid intelligence declines as we age; someone aged eighty will perform worse on a fluid intelligence test than he or she did aged thirty, or
fifty. Neuroanatomical studies (and numerous autopsies) revealed the prefrontal cortex, believed responsible for fluid intelligence, atrophies more with age than most other brain regions.