by Dean Burnett
Despite this, many companies currently sell gadgets that claim to exploit tCDS for improving performance on things like video games. To avoid libelling 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 realising 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.12 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. Bouchard13 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 mediate 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 instamce, 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.14 This is quite a contentious issue. The efficiency of the brain’s processing and connections play 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 grey 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 may
be 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 trainers 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’.
Culture plays a massive role in how intelligence manifests. A perfect example of this was provided in the 1980s by Michael Cole.15 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 civilisation. 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.16 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 crystallised, 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 candy floss instead of wool. Overall, it’s actually incredibly impressive that you can even make the attempt.
Notes
1 R. E. Nisbett et al., ‘Intelligence: new findings and theoretical developments’, American Psychologist, 2012, 67(2), pp. 130–59
2 H.-M. Süß et al., ‘Working-memory capacity explains reasoning ability – and a little bit more’, Intelligence, 2002, 30(3), pp. 261–88
3 L. L. Thurstone, Primary Mental Abilities, University of Chicago Press, 1938
4 H. Gardner, Frames of Mind: The Theory of Multiple Intelligences, Basic Books, 2011
5 A. Pant, ‘The Astonishingly Funny Story of Mr McArthur Wheeler’, 2014, http://awesci.com/the-astonishingly-funny-story-of-mr-mcarthur-wheeler/ (accessed September 2015)
6 T. DeAngelis, ‘Why we overestimate our competence’, American Psychological Association, 2003, 34(2)
7 H. J. Rosen et al., ‘Neuroanatomical correlates of cognitive self-appraisal in neurodegenerative disease’, Neuroimage, 2010, 49(4), pp. 3358–64
8 G. E. Larson et al., ‘Evaluation of a “mental effort” hypothesis for correlations between cortical metabolism and intelligence’, Intelligence, 1995, 21(3), pp. 267–78
9 G. Schlaug et al., ‘Increased corpus callosum size in musicians’, Neuropsychologia, 1995, 33(8), pp. 1047–55
10 E. A. Maguire et al., ‘Navigation-related structural change in the hippocampi of taxi drivers’, Proceedings of the National Academy of Sciences, 2000, 97(8), pp. 4398–403
11 D. Bennabi et al., ‘Transcranial direct current stimulation for memory enhancement: From clinical research to animal models’, Frontiers in Systems Neuroscience, 2014, issue 8
12 Y. Taki et al., ‘Correlation among body height, intelligence, and brain gray matter volume in healthy children’, Neuroimage, 2012, 59(2), pp. 1023–7
13 T. Bouchard, ‘IQ similarity in twins reared apart: Findings and responses to critics’, Intelligence, Heredity, and Environment, 1997, pp. 126–60
14 H. Jerison, Evolution of the Brain and Intelligence, Elsevier, 2012
15 L. M. Kaino, ‘Traditional knowledge in curricula designs: Embracing indigenous mathematics in classroom instruction’, Studies of Tribes and Tribals, 2013, 11(1), pp. 83–8
16 R. Rosenthal and L. Jacobson, ‘Pygmalion in the classroom’, Urban Review, 1968, 3(1), pp. 16–20
&n
bsp; * 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
5
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 philosophising 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 per cent 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 organises 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.
