From: Investigating Intelligence

What if you could take a pill that would make you more intelligent?

Science fiction? Well, maybe not. Researchers have been studying intelligence for some time now and have begun to make significant progress. But it all starts, of course, with understanding what, exactly, we mean by intelligence in the first place.

In his popular book, How Intelligence Happens, University of Cambridge cognitive scientist John Duncan sets the stage by re-introducing us to the work of the influential English scientist Charles Spearman.

Back in 1904, Spearman discovered that a clear correlation existed between people’s abilities to perform various tasks. Those who were good at one sort of thing tended, in a mathematically quantifiable way, to be good at others. The wider the sample of tasks, the clearer this correlation became. This led Spearman to develop his theory of a so-called “g factor” or “general factor”, reflecting a certain aptitude that some people had which enabled them to be successful across a wide range of activities.

Intriguingly, some tasks proved to be fairly reliable indicators of this factor almost all by themselves: Spearman applied his statistical approach to the work of Alfred Binet and others, and the modern “IQ test” was born.

But what does it all mean?

Well, it’s hardly straightforward: the road to a more rigorous understanding of human intelligence is fraught with difficulties.

The first is sociological. Many are concerned that such investigations are driven by a dangerous sense of elitist eugenics that seeks to extend itself far beyond any strictly defined sense of cognitive ability.

A common criticism levelled against IQ tests, for example, is that they are motivated by an insidious desire to reduce all human experiences, and all humans, to a single number.

Howard Burton in conversation with John Duncan, University of Cambridge

John unhesitatingly dismisses this idea straight away:

“Right from the very beginning of the scientific study of cognitive abilities it’s been perfectly clear that you cannot assess somebody’s abilities, and certainly not their worth, through a single number. In fact, there are an infinite number of things that are important to people and we value them for so many different characteristics: their honesty, their good humour, their ability at math, their ability to play football and so on — an infinite number of different things. That is the truth; and if you think you can explain everything important about somebody with one test, it’s obviously doomed. As far as I know, nobody has ever thought that, although many people are criticized for thinking it.

“However, what started with the work of the British psychologist Charles Spearman in the early part of the 20th century was the study of something much more specific than that. That was an empirical discovery drawn from experiments on measuring people’s ability to do things; and putting forward a theory to explain it.”

The problem is, of course, that the scientific study of intelligence has a nasty habit of running smack into our pre-conceived egalitarian principles.

“It’s very common to hear that everybody has their strengths, and that’s a great thing. But then, meanwhile, you go into the job interview next door and people say, “I really like that candidate, that’s the smart one.” Well, what do they think they mean by that? They don’t believe this person will do well at the job because of being good at this or that particular thing, but rather because they just somehow felt that they got more out of them intellectually.

“I think people always have an intuition — which to some extent, at least, is true — that the same people tend to be able to flexibly address themselves to different sorts of problems. But what’s important about a scientific program is that for a given question, such as predicting how well a person will do in a new job when you’re interviewing her, this is something that you can actually measure.”

But it’s one thing to measure something and another to truly understand it. If this g factor is a real thing that somehow enables some of us to more flexibly address different sorts of problems, what is it, exactly? And where can it be found in the brain?

Through years of rigorous testing and close examination of brain-imaging technology, Duncan believes he’s narrowing in on the answer.The key to g, he believes, lies in a very particular brain network that lies in the frontal and parietal lobes.

“Very interestingly, if you gave many different sorts of tasks — tests of memory or language, or even identifying faces or holding something in short term memory — this same network tends to be a part of the brain’s response.

“So whatever g is, it’s something that’s important in organizing many different sorts of activity, which is just what you should think if it’s going to explain the g factor. And much of what we’re doing now is trying to understand what’s going on inside these regions of the brain as problems are solved.”

The key word here is “organizing”. John is convinced that the primary role this network plays is to allow us to focus sufficiently on a task at hand in order to select the key thing that enables us to find the solution. That is, in a nutshell, what separates those with high g from those without it, and effectively what we mean when we call someone “intelligent”.

“Focus is really the same thing as selection, if you go into it. It means that you take part of the problem and not the rest. Interestingly, I think this is also very closely related to what many people think of as the heart of what’s special about the human mind: the power of abstraction, being able to think abstractly.

“Often we tend to think of abstraction in, if you like, rather abstract terms: we think that abstract thinkers are philosophers or those who can tackle complex and recondite problems. I think there’s probably a simpler way to think about abstraction as the ability to see the common important thread between a great many instances that are different from one another. This is what we mean by abstraction.

“An instance of justice occurs, for example, no matter whether it happened in the court or on the playground. You can see we’re now very close to the idea of attention or focus: we’re picking up just one critical aspect of a situation and throwing away all the other things that differ between them.

“I think that this brain network we associate with g is very much related to this heart of human thinking: the ability to abstract out just which aspect of a situation is critical for the current moment.”

Now that we have a clearer sense of what we mean by intelligence, together with where the networks associated with it can be found in the brain, might we finally find a way to increase it? Can we improve our own g factor?

“I’m certain that it’s possible and I’m equally certain that we have very little idea at present how to do it.

“To me the most interesting thing is that no matter what experiment you look at, there’s always a strong environmental component to it. That means that somewhere in a person’s life, stuff did happen that really affected their scores on tests like this.

Since the scores are so predictive of how well you solve problems in your everyday life, that implies that some kinds of experience do enable a person to learn better to solve the problems that they care about.

“And that is very big news, if we could only find a way to do it.

Far from steering us towards eugenics, then, John’s research is pointing us firmly in the direction of better educational techniques.

That smart pill, in other words, might just be a better teacher.

This is the introduction written by Howard Burton of the book, Investigating Intelligence, which is based on an in-depth, filmed conversation between Howard and John Duncan, Professor of Cognitive Neuroscience and programme Leader, Executive processes group of the MRC Cognition and Brain Sciences Unit at the University of Cambridge.

The book is broken into chapters and includes questions for discussion at the end of each chapter. The book is also available as part of the 5-part Ideas Roadshow Collection called Conversations About Neuroscience.

Visit the dedicated page for our conversation with John Duncan on Ideas On Film: https://ideas-on-film.com/john-duncan/. On our Ideas On Film YouTube channel you can watch a clip from the filmed conversation: https://youtu.be/-9jG2gSdc94.

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