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 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.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 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