Idiot Brain (18 page)

Similarly, the hippocampus is needed for spatial memory (memory for places and navigation) as well as episodic memory. This makes sense, given that it is responsible for processing memory for complex combinations of perceptions, which is necessary for navigating your environment. Studies by Professor Eleanor Maguire and her colleagues showed that London taxi drivers with the “Knowledge” (the required intricate awareness of London's incredibly vast and complicated road network) had an enlarged posterior hippocampus—the navigation part—when compared to non-taxi drivers.
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These studies were conducted mostly in the days before satnavs and GPS though, so there's no telling how they'd pan out now.

There is even some evidence (although much of it from studies using mice, and how smart can they be?) to suggest that learning new skills and abilities does lead to the white matter involved being enhanced, by increasing the properties of the myelin (the dedicated coating provided by support cells that regulates signal transmission speed and efficiency) around the nerves. So, technically, there are ways to boost your brain power.

That's the good news. Here's the bad.

All of the things mentioned above take much time and effort, and even then the gains can be fairly limited. The brain is complex and responsible for a ridiculous number of functions. As a result, it's easy to increase ability in one region without affecting others. Musicians may have exemplary knowledge of how to read music, listen to cues, dissect sounds and so on, but this doesn't mean they'll be equally
good at math or languages. Enhancing levels of general, fluid intelligence is difficult; it being produced by a range of brain regions and links means it's an especially difficult thing to “increase” with restricted tasks or methods.

While the brain remains relatively plastic throughout life, much of its arrangement and structure is effectively “set.” The long white-matter tracts and pathways will have been laid down earlier in life, when development was still under way. By the time we hit our mid-twenties, our brains are essentially fully developed, and it's fine-tuning from thereon in. This is the current consensus anyway. As such, the general view is that fluid intelligence is “fixed” in adults, and depends largely on genetic and developmental factors during our upbringing (including our parents' attitudes, our social background and education).

This is a pessimistic conclusion for most people, especially those who want a quick fix, an easy answer, a short-cut to enhanced mental abilities. The science of the brain doesn't allow for such things. Sadly but inevitably, there are many people out there who offer them anyway.

Countless companies now sell “brain-training” games and exercises, which claim to be able to boost intelligence. These are invariably puzzles and challenges of varying difficulty, and it's true that if you play them often enough you will get increasingly better at them. But
only
them. There is, at present, no accepted evidence that any of these products cause an increase in general intelligence; they just cause you to become good at a specific game, and the brain is easily complex enough not to have to enhance everything else to allow this to happen.

Some people, particularly students, have started taking pharmaceuticals such as Ritalin and Adderall, intended to
treat conditions like ADHD, when studying for exams, in order to boost concentration and focus. While they might achieve this briefly and in very limited ways, the long-term consequences of taking powerful brain-altering drugs when you don't have the underlying issue they're meant to treat are potentially very worrying. Plus, they can backfire: unnaturally ramping up your focus and concentration with drugs can prove exhausting and depleting to your reserves, meaning you burn out much faster and (for example) sleep through the exam you're studying for.

Drugs meant to improve or enhance mental function are classed as Nootropics, aka “smart drugs.” Most of these are relatively new and affect only specific processes such as memory or attention, so their long-term effects on general intelligence are currently anyone's guess. The more powerful ones are restricted largely to use in neurodegenerative diseases such as Alzheimer's, where the brain is genuinely degrading at an alarming rate.

There is also a wide variety of foods (for instance, fish oils) that are supposed to increase general intelligence, too, but this is also dubious. They may facilitate one aspect of the brain in one minor way, but this isn't enough for a permanent and widespread boost of intelligence.

There are even technological methods being touted these days, particularly with a technique known as transcranial direct-current stimulation (tCDS). A review by Djamila Bennabi and her colleagues in 2014 found that tCDS (where a low-level current is passed through targeted brain regions) does seemingly enhance abilities such as memory and language in both healthy and mentally ill subjects, and seems to have few to no side-effects thus far. Other reviews and studies
have yet to establish a viable effect of the method though. Clearly, there's a lot of work to be done before this sort of thing becomes widely available therapeutically.
¹¹

Despite this, many companies currently sell gadgets that claim to exploit tCDS for improving performance on things like video games. To avoid libeling anyone, I'm not saying these things don't work, but if they do, that means companies are selling items that actively alter brain activity (as powerful drugs do) via means that aren't scientifically established or understood, to people without any specialist training or supervision. This is a bit like selling antidepressants at the supermarket, next to the chocolate bars and packs of batteries.

So, yes, you can increase your intelligence, but it takes a lot of time and effort over prolonged periods, and you can't just do things you're already good at and/or know. If you get really good at something then your brain becomes so efficient at it, it essentially stops realizing it's happening. And if it doesn't know it's happening, it won't adapt or respond to it, so you get a self-limiting effect.

The main problem seems to be that, if you want to be more intelligent, you have to be very determined or very smart in order to outsmart your own brain.

You're pretty smart for a small person

(Why tall people are smarter and the heritability of intelligence)

Tall people are smarter than shorter people. It's true. This is a fact that many find surprising, even offensive (if they're short). Surely, it's
ridiculous to say that someone's height is related to their intelligence? Apparently, it isn't.

Before I get besieged by an enraged but diminutive mob, it's important to point out that this is not an absolute by any means. Basketball players are not automatically more intelligent than jockeys. André the Giant was not smarter than Einstein. Marie Curie would not have been outwitted by Hagrid. The correlation between height and intelligence is usually cited as being about 0.2, meaning height and intelligence seem to be associated in only 1 in 5 people.

Plus, it doesn't make a big difference. Take a random tall person and a random short person and measure their IQs; it's anyone's guess as to who'll be the more intelligent. But you do this often enough, say with 10,000 tall people and 10,000 short people, and the overall pattern will be that the average IQ score of taller people will be slightly higher than that of the shorter people. Might be just 3–4 IQ points' difference, but it's still a pattern, one persistent across numerous studies into the phenomenon.
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What's going on there? Why would being taller make you more intelligent? It's one of the weird and confusing properties of human intelligence.

One of the more likely causes of this height–intelligence association, according to the available science, is genetic. Intelligence is known to be heritable to a certain degree. To clarify, heritability is the extent to which a property or trait of a person varies due to genetics. Something with a heritability of 1.0 means all possible variation of a trait is due to genes, and a heritability of 0.0 would mean none of the variation is genetic.

For example, your species is purely a result of your genes, so “species” would have a heritability of 1.0. If your parents were pigs, you'll be a pig, no matter what happens as you grow
and develop. There are no environmental factors that will turn a pig into a cow. By contrast, if you are currently on fire, this is purely the result of the environment, so has a heritability of 0.0. There are no genes that cause people to burst into flames; your DNA doesn't cause you to burn constantly and produce little burning babies. However, countless properties of the brain are the result of both genes and environment.

Intelligence itself is heritable to a surprisingly high degree; a review of the available evidence by Thomas J. Bouchard
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suggests that in adults it's around 0.85, although interestingly it's only about 0.45 in children. This may seem odd; how can genes influence adult intellect more than children's? But this is an inaccurate interpretation of what heritability means. Heritability is a measurement of the extent to which variation among groups is genetic in nature, not the extent to which genes
cause
something. Genes may be just as influential in determining a child's intelligence as an adult's, but with children it seems there are
more
things that can also influence intelligence. Children's brains are still developing and learning, so there's a lot going on that can contribute to apparent intelligence. Adult brains are more “set”; they've gone through the whole development and maturing process, so external factors aren't so potent any more, so differences between individuals (who in typical societies with compulsory education will have roughly similar learning backgrounds) are more likely to be due to more internal (genetic) differences.

All of this may giving a misleading idea about intelligence and the genes, implying it's a far simpler and more direct arrangement than it is. Some people like to think (or hope) that there is a gene for intelligence, something that could make us smarter if it was activated or strengthened. This
seems unlikely; just as intelligence is the sum of many different processes, so these processes are controlled by many different genes, all of which have a part to play. Wondering which gene is responsible for a trait such as intelligence is like wondering which piano key is responsible for a symphony.
*

Height is also determined by numerous factors, many of them genetic, and some scientists think that there might be a gene (or genes) that influences intelligence that also influences height, thus providing a link between being tall and being intelligent. It's entirely possible for single genes to have multiple functions. This is known as pleiotropy.

Another argument is that there's no gene(s) that mediates both height and intelligence, but rather the association is due to sexual selection, because both height and intelligence are qualities in men that typically attract women. As a result, tall intelligent men would have the most sexual partners and be more able to spread their DNA through the population via their offspring, all of whom would have the genes for height and intelligence in their DNA.

An interesting theory, but not one that is universally accepted. Firstly, it's very biased towards men, suggesting that they only need to have a couple of attractive traits and women will be inexplicably drawn to them, like moths to a gangly, witty flame. Height is far from the only thing people are attracted to. Also, tall men tend to have taller daughters, and a lot of men are put off and intimidated by tall women (or so my tall female friends tell me).

Same goes for intelligent women (or so my intelligent female friends tell me, which for the record is
all
of them). There's no real actual evidence to suggest that women are invariably attracted to intelligent men either, for various reasons; for instance, confidence is often considered sexy and, as we've seen, intelligent people can be
less
confident overall. This isn't to mention the fact that intelligence can be unnerving and off-putting; the terms “nerd” or “geek” may have been largely reclaimed these days, but they were insults for much of their history, and the stereotype is of them being typically dreadful with the opposite sex. These are just a few examples of how the spread of genes for both height and intelligence could be limited.

Another theory is that growing tall requires access to good health and nutrition, and this may also facilitate brain and therefore intelligence development. It could be as simple as that; greater access to good nutrition and a healthier life during development may result in both increased height and intelligence. It can't be
just
that though, because countless people who have the most privileged and healthy life imaginable end up being short. Or an idiot. Or both.

Could it be to do with brain size? Taller people do have typically bigger brains, and there is a minor correlation between brain size and general intelligence.
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This is quite a contentious issue. The efficiency of the brain's processing and connections plays a big part in an individual's intelligence. but then there is also the fact that certain areas, such as the prefrontal cortex and the hippocampus, are bigger and have more gray matter in people of greater intelligence. Bigger brains would logically make this more likely or possible just by presenting the resources to expand and develop. The
general impression seems to be that a bigger brain is maybe yet another contributing factor, but not a definite cause. Big brains perhaps give you more of a chance of becoming intelligent, rather than it being an inevitability? Buying expensive new running shoes doesn't actually make you faster at running, but they might encourage you to become so. The same can be said of specific genes, actually.

Genetics, parenting styles, quality of education, cultural norms, stereotyping, general health, personal interests, disorders; all of these and more can lead to the brain being more or less able or likely to perform intelligent actions. You can no more separate human intelligence from human culture than you could separate a fish's development from the water it lives in. Even if you were to separate a fish from the water, its development would only ever be “brief.”