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Smarter Summary

11 min read ⌚ 

Quick Summary: “Smarter” – subtitled “The New Science of Building Brain Power” – explores the obscure nature of human intelligence in view of a 2008 field-defining study which, for the first time in history, demonstrated that even fluid intelligence can be improved. Is it just a hype? Dan Hurley finds out by testing the hypotheses – on himself.

Smarter Summary

Who Should Read “Smarter”? And Why?

Smarter is a book which everyone who believes that IQ cannot be improved should read; if you don’t believe the studies which say otherwise, you’ll have to believe Hurley, because he didn’t stop at merely reading the articles: he tested them out personally.

His findings will certainly interest psychology students and all those people out there who constantly try to hack their brains – and on a daily basis.

Well, time to see what science says about your experiments.

Smarter Summary

Retaking the Mensa Test

Have you ever taken an IQ test with Mensa, “the high IQ society”?

If so, you probably already know two things:

1) You’re in if you score higher than 132;
2) You can’t retake your test.

OK – you understand the first one; but why the second one? Your teachers begged you to take another math or physics test in case you failed the first one! Why is Mensa doing the opposite?

“Mensa does not permit applicants to take its IQ test twice,” says Dan Hurley, “because the organization ascribes to the view that intelligence doesn’t change much, so there’s really no point in retaking it. Either you got it or you don’t.”

Another question:

Doesn’t this imply that your intelligence is kind of inscribed in your genes and there’s nothing you can do to change it?

Well, until as recently as 2008, “the consensus among mainstream intelligence researchers was that human intelligence is just too complex, and too closely linked to innate characteristics of the brain, to be significantly modified by any straightforward training method.”

Because “unlike a test of physical strength, which measures only how you performed today, intelligence tests have always been pitched as an upper limit on what you can ever do: a cognitive glass ceiling, a number tattooed on the soul.”

And then, in May 2008, two Swiss researchers, Susanne Jaeggi and Martin Buschkuehl, published a study in the prominent Proceedings of the National Academy of Sciences reporting on what happened when college students played a peculiar computerized game called the N-back for twenty minutes a day, five days a week, for four weeks.

The title of the study already says a lot:

Improving Fluid Intelligence with Training on Working Memory.”

But to understand its implications, you’ll have to bear with us for 12 minutes.

Intelligence Matters

First of all, something you should never forget – especially not in our just too-PC times: intelligence matters.

Sure, Malcolm Gladwell can say that 10,000 hours of training makes all the difference, and Angela Duckworth can add that the power of passion and perseverance is really what separates the best from the rest, but IQ is (and always will be) a factor of utmost importance.

“Certainly IQ is not everything,” writes Hurley, “perhaps it’s not even the most important thing, but it’s definitely one of them. As we all knew in elementary school and can see in our workplaces and on the front pages of the newspaper every day, intelligence, or smarts, or whatever you want to call it, does matter.”

After all, we are defined by it: the very existence of homo sapiens is a proof that intelligence differentiates species; a fortiori, this means that some humans are most probably different from other humans due to slightly higher intelligence.

Just think of it this way: based on their high scores on standardized tests, both Sergey Brin and Mark Zuckerberg – Lady Gaga as well – were selected to attend the Center for Talented Youth at Johns Hopkins.

And it goes beyond identifying smart people at a very early age!

For example, a recent study of 1,116,442 Swedish men whose IQs were tested at age eighteen found that after twenty-two years (i.e., at the age of 40), those who scored in the bottom 25% were over 5 times more likely to have died of poisoning, 3 times more likely to have drowned, and over twice as likely to have been killed in a traffic accident as those who scored in the top 25 percent!

And a host of other studies confirm this.

The Highly Unamerican Idea of Eugenics

Now, we, as Americans, do not want to be told these kinds of things, right?

After all, this country made its name by adhering strictly to the ultrademocratic motto: everyone can be whatever one chooses to be.

The very idea of your IQ being inscribed in your genes goes so much against this dictum that one would not be blamed for reasoning that it’s preposterous to even think something like “intelligence is heritable” and/or “intelligence cannot be changed” this side of the Atlantic.

And yet, it was in the United States that the pseudoscience of eugenics had its birthplace!

Championed by the likes of Margaret Sanger, J. H. Kellogg, and Alexander Graham Bell, the idea that the unintelligent will forever remain to be that way resulted in over 60,000 forced sterilizations in the US, going all the way into the 1960s!

In fact, for a time, it was even sanctioned by the U.S. Supreme Court and funded by some of the most philanthropic organizations of all times: the Carnegie Institution and the Rockefeller Foundation.

Want to hear the worst part?

The eugenics movement in the US “was credited by Nazi leaders, including Adolf Hitler himself, as inspiring their ‘war on the weak.’”

If you think that’s a thing of the past, think again: your President, just like this Harvard alumnus, base their worldviews upon this kind of reasoning, still believing, for example, that illegal Hispanic immigrants to America have lower IQs than non-Hispanic whites.

Fluid and Crystallized Intelligence

Now, back to our May 2008 study.

You got the gist of that title: intelligence can be improved.

However, you may have had some problems understanding the meaning of that word “fluid” before the word “intelligence.”

Unsurprisingly, that’s the keyword.

You see, back in 1971, the British-American psychologist Raymond Cattell first theorized the existence of two different types of general intelligence: fluid and crystallized intelligence.

Crystallized intelligence is your “treasure trove of stored-up information and how-to knowledge, which just keeps growing as you age – the sort of thing tested on Jeopardy! or put to use when you ride a bicycle.”

Fluid intelligence, on the other hand, is “the underlying ability to learn, the capacity to solve novel problems, see underlying patterns, and figure out things that were never explicitly taught.”

And unlike crystallized intelligence, fluid intelligence peaks in early adulthood and then gradually declines.

This is the reason why most mathematicians, physicists, musicians and chess players are best in their 20s and 30s; afterward, they are unable to solve novel problems, so the quality of their work declines.

Another problem with fluid intelligence: based on everything we knew for half a century (and even the whole century before that), it was “impervious to the effects of training.”

We now know better.

Measuring Fluid Intelligence

No matter what most people say nowadays, standard IQ tests are not a bad indicator of someone’s intelligence; after all, we do know that if you score below a certain number on those tests, then you’ll probably receive Social Security income.

However, we do know – at least now – that standard IQ tests are not perfect; and that no matter how good they are, they can’t be, by definition, objective.

However, though intuitively quite graspable, intelligence – just like some other important things (love, truth, time) – is scientifically wholly inscrutable.

Where is it located? How does it work? How is it related to memory?

The bad news: we’re still far from finding the exact answers to these questions; the good news: we’re getting there.


By scanning the brain, of course.

Even though numerous studies had discovered that the size of the brain does matter when it came to intelligence even before the last decade, none of them had shown the actual extent.

That is, until recently.

Now, fMRI scans have discovered an almost exact number: about 6.7% of a person’s fluid intelligence can be explained by the overall volume of neurons in his/her “gray matter.” In other words, the bigger your brain, the smarter you are.

And it goes beyond the gray matter: an addition 5% of the fluid intelligence can be explained by the size of a particular region of the brain – the left lateral prefrontal cortex.

In case you don’t know what that is, it is a section located behind the upper-left edge of your hairline.

Well, fMRI scans have shown that this part of your brain becomes highly active during tests of working memory.

Now, if your working memory is connected to a part of your brain which is connected, in turn, to your fluid intelligence – that’s right!

The N-Back Game

Let us remind you of the title of that field-defining study we mentioned in our first section: “Improving Fluid Intelligence with Training on Working Memory.”

Now it doesn’t seem that incomprehensible, does it?

Well, time to explain how Susanne Jaeggi and Martin Buschkuehl proved this.

As we mentioned above, they did so, using a peculiar game called N-back. After four weeks of tests, students who played the game for 20 minutes a day 5 days a week increased their intelligence by almost 40%!

If you don’t believe the hype, ask the author of this book himself: for the purposes of his book, he went through the same kind of training (coupled with some things explained below), and, by the end of it, his intelligence scores climbed 16.4 percent.

In other words, his fluid intelligence measurably improved.

What’s this game we’re talking about, you ask?

Well, nothing particularly fancy.

The N-back game consists of guessing how far back a particular letter appeared in a sequence. In other words, if you’re playing the 1-back game, you’re asked to press a keyboard key when you notice that a letter has just appeared.

For example, in the sequence “A B C B B A,” the only time you’ll have to press a keyboard key after the fourth (here bolded) letter.

In the 2-back game, the same rules apply, only in this case, you’ll have to remember up to two places back, i.e., in the sequence above, you’ll have to press the keyboard key after the third letter (“A B C B B A”).

There’s also a dual N-back game (where you follow both audio and visual signals), and you can play it here for free.

Do play it – because it makes you certifiably smarter.

Other Ways to Increase Your Intelligence

Playing computer games (at Lumosity you can find a few even more) is not the only way to increase your fluid intelligence.

And we know this at least since the 1960s when one study demonstrated that older people who regularly play tennis are consistently better at cognitive tests than those who didn’t.

With this in mind, Teresa Liu-Ambrose – “a spritely forty-year-old jogger, dog lover, and mother of three who holds an impressive list of academic credentials” – randomly divided 86 women into three groups.

Each of these was supposed to train something for six months: one group toning, the other aerobic and the last one resistance.

At the end of the study, this last group showed significant improvements in traditional cognitive tests; even better: fMRI scans discovered increased activity in the areas connected to fluid intelligence.

Resistance training, it is then!

Add to that something more enjoyable: music lessons.

Glenn Schellenberg, a psychologist who doesn’t really believe in the Mozart effect, has shown that whether it is voice lessons, keyboard lessons or acting lessons – they all improve fluid intelligence.

Voice lessons in particular; keyboard lessons follow; and even acting lessons are better than no lessons at all.

In other words, your brain is an organ and is worse off when not used; if used correctly, it can improve your chances at success in life.

Demonstrated by many studies of the last decade.

Tested by Dan Hurley.

And – get this! – approved by the US military which, in 2006, founded the Intelligence Advanced Research Projects Activity (IARPA) whose mission is explicitly stated thus: “to envision and lead high-risk, high-payoff research that delivers innovative technology for future overwhelming intelligence advantage.”

Still skeptical?

Key Lessons from “Smarter”

1.      There Are Two Types of Intelligence – and Only One of Them Gets Better with Age
2.      There’s a Good Chance That Some Computer Games Might Make You Smarter
3.      Never Mind the Scores: Intelligence Is Tested by Life

There Are Two Types of Intelligence – and Only One of Them Gets Better with Age

The reason why Mensa doesn’t allow people to retake their tests is simple: they believe that intelligence doesn’t change much throughout life.

The truth is – a part of it most certainly does.

It is called crystallized intelligence, and it is the “treasure trove of stored-up information and how-to knowledge” in your brain. As expected, on average, older people know more than young ones – and this is due to their crystallized intelligence.

However, young people are far more creative and capable of solving novel problems. This is due to another part of the general intelligence, called fluid intelligence.

Now, unfortunately, fluid intelligence declines with age; and this is that part of your intelligence that Mensa believes is unchangeable.

New studies, however, show that it is.

There’s a Good Chance That Some Computer Games Make You Smarter

According to a field-defining 2008 study by two Swiss scientists, the so-called N-back game (which you can play for free online) improves one’s fluid intelligence.

And this is true even if merely played for 20 minutes, 5 days a week, over a 4-week period.

What are you waiting for?

Here’s one game you can convince your parents that is definitely for your sake.

Never Mind the Scores: Intelligence Is Tested by Life

Computer games are not the only thing proven to improve intelligence; resistance training and music lessons have pretty much the same effect as well.

Using a combination of science-backed exercises for intelligence improvement, the author of Smarter, Dan Hurley, did indeed become smarter by 16.4%.

“And so what?” – he writes in the last chapter of his book. “Those are just numbers on a test. In the end, for all of us, the best test of cognitive abilities is one for which there is no answer key. It’s called life.”

And he offers a great example of what he means by this:

“From 1986 to 1989, Marilyn Vos Savant was listed in the Guinness Book of World Records as having the highest recorded IQ in the world for women, at 190. Since then, what has she done? She has been writing Parade magazine’s ‘Ask Marilyn’ advice column. I mean – really?”

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Smarter Quotes

After weaning, the only food proved to enhance cognition is coffee. Click To Tweet As more attention is given to distinguishing between pinpoint differences in touch, sound, or sight, the area of the brain devoted to that distinction expands and, in the process, gets better at it. Click To Tweet Animals need a reward to motivate them, but humans usually find motivation in just trying to succeed at a task. That’s a big difference between rats and humans. Click To Tweet A multitude of studies suggest that the ancient practice of mindfulness meditation actually holds promise as a way to improve cognitive abilities, to increase attention, expand working memory, and raise fluid intelligence. Click To Tweet Video-game training can improve eyesight, as measured by an individual’s ability to perceive subtle differences in shades of gray, something that had previously been demonstrated only with surgery or glasses. Click To Tweet

Final Notes

First published in 2013, Smarter has become even more relevant with each passing year; after all, if the US military is investing millions of dollars into intelligence-improving programs, then there has to be something in them, right?

Dubbed “an essential read,” Smarter is “a riveting look at the birth of a new science as well as a user’s manual for anyone who wants to be better at solving problems, learning new things, and coming up with creative ideas.”Daniel Pink says that.

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