How Intelligence Happens [Paperback]

How Intelligence Happens is a fantastic popular science book about how and where in the brain intelligence occurs and what exactly intelligence is from a psychological perspective. After an entertaining preamble into the basics of learning in the animal kingdom, one classical, profound fact is centred on: that people who do well on one mental task tend to do well on others. This one result, discovered a century ago, Duncan argues, reveals so much about intelligence and cognition in general. Duncan himself was responsible for linking this result with specific brain regions, and much of the rest of the book is concerned with the brain-scanning and monkey single neuron recording studies, primarily in the prefrontal cortex, which reveal the neural signature of intelligence. What exactly is this marker? Duncan argues, partly via results from artificial intelligence, partly from studies in people with low IQ and partly in patients with prefrontal damage, that the key psychological process that makes us intelligent is the ability to chain together a heirarchy of mental programs and sub-programs in order to achieve the complex goals we set ourselves. Therefore, intelligence, as supported by prefrontal (and parietal) regions, is about organising our behaviour in a logical, goal-directed way. Perhaps we learn to generalise these programs to a sufficient degree that they mutate into abstract results, and we gain wisdom and not just intelligence.

Many current popular science books suffer from being written not by scientists embedded in the field but journalists, and thus are filled with inaccuracies or only a superficial understanding of the topic. Others are filled with unsupported hyperbolae. How Intelligence Happens is in some ways the antithesis of those books, since John Duncan is a world leader in the neuroscience of intelligence, and his scholarly knowledge and authority oozes from every page, strongly enhanced by his honesty about the strength - or weakness - of certain results, even from his own lab. You constantly feel that you are hearing from a very bright scientist at the cutting edge of the topic.

The style, especially at the start, is extremely accomplished, rather literary, while for the meat of the book is still always sharp and accurate, to match his thinking. There are regular anecdotes, some very funny, and a fun smattering of references from fiction and television to illustrate his arguments.

This is a marvellously clear, highly focused account of what intelligence is from the point of view of mind and brain - it achieves this goal brilliantly and is one of the best popular science books I've read in a long time.

Intelligence is certainly a very interesting subject, and a very important subject.
Nevertheless, we still have no clear definition of what intelligence exactly is!

However, according to british psychologist Charles Spearman, people who do well on one mental task tend to do well on others. So, Spearman concluded that intelligence is a general cognitive ability that can be measured.
John Duncans book takes off from there, and then goes into these unknown brain lands.

Its a very exciting journey. Where, some parts of the landscape are well described, whereas other parts are new uncharted worlds. Wherever we go, John Duncan is obviously a very knowledgeable and competent guide.
And, in his view, intelligence (organising our behaviour in a logical, goal-directed way), is supported by prefrontal (and parietal) regions of the brain. It follows that the book is very much about giving evidence to support a ''frontal lobe theory of intelligence''.

Sure, it would have been nice with some comments to e.g. Louis L. Thurstones or Howard Gardners theory about intelligence. But, obviously, this is not possible in such a relatively small book.
Instead, the book focus on this ''frontal lobe view'' of intelligence, based on Spearmans work.
And after reading John Duncans book you are certainly convinced that this is a very important aspect of intelligence!

Nevertheless, obviously, as in all good books, in the end there are just as many questions as there are answers.
In the end we are still faced with hard problems, such as the question of qualia. How can we really know about what another person experiences when seeing the color red?

Still, the book is a wonderful read, with many new pieces of information and thoughprovoking ideas.
Brilliant stuff.

-Simon

In this review I will discuss the contents of How Intelligence Happens, give potential readers some expectations before they begin and give some suggestions on how to read it. It is my expectation that this review will help readers decide if this book is appropriate for their research questions and/or personal interests.

Overall, I thought this was a wonderful book. It is well written and contains useful, relevant examples that are interspersed in the text. It made is easy to read and kept it from sounding like a textbook, as there is a fair share of factual information included. Duncan's writing style follows a general pattern. He often begins a chapter offering up his opinions or conclusions regarding the chapter's topic studies, providing a "big picture" look at the topic. He then goes into the specifics, often providing examples or revisiting examples and tying them together. Duncan generally uses a basic vocabulary when possible, making this book very easy to read without having to do any dictionary searches.

There are eight chapters, which are preceded by the prologue describing Duncan's central ideas and his motivation for writing the book. Each of the chapters has a general theme surrounding some aspect of intelligence, neuroscience and the combination of the two.

"Intelligence, the Brain and Free Will"

Duncan begins by describing the lure of this kind of study. As can be expected, searching for information regarding the nature of intelligence can be extremely interesting, controversial, and mysterious. Duncan begins with a discussion of intelligence, the "types" of intelligenc, and the history of intelligence testing. Duncan explains that there are obvious signs of what we consider intelligence, such as academic ability or memory. He also explains that while recent studies are strongly suggesting that all behavior is entirely biological, bringing up the age-old question of free will. However, Duncan firmly states that responsibility still lies with the individual. In regards to a proposed book explaining how people's brains make them do things that they shouldn't, he argues that he would prefer the title to read "Yes, It's Your Brain - But It's Still Your Fault." This is both an interesting and important way to start, in my opinion. Discussing the nature of intelligence can be highly controversial as the general public general assumes race is a determining factor. However, Duncan tends to be a little philosophical throughout the books and I felt this was one of those points. My purpose of reading this book was to learn more about the neurophysiology of intelligence so Duncan's ideas on free will and responsibility were of lesser interest to me.

"Types of Intelligent People"

Duncan delves into the types of intelligence found in people and how this explains their behavior. Strong correlations behind IQ, success in academia as well as success in the work force can be made, revealing a lot about an individuals potential. In addition to IQ tests, there are several exams that can be used to evaluate a person's intellect, such as Raven Matrices, which analyze logic skills, or multiple-battery assessments, which generate an average score based off an individual's scores from a variety of different tests. I found this section extremely interesting, as Duncan explained that Raven Matrices, which are eloquently basic puzzles, could provide the same information regarding intelligence as elaborate testing methods. I appreciated that Duncan provided a thorough background of previous works, the changes in how science views intelligence and how older studies had been built upon. Because this is a particular interest of mine, I did not mind all the details that Duncan included, however, most readers may find this part over extensive.

"Understanding the Brain"

Next, Duncan explains the important physiological structures of the brain, providing the necessary background information for discussing how the brain controls behavior, personality and what we consider intelligence. He then continues by connecting structures and types of intellect; specifically, the multiple-demand system. The multiple-demand system is a key component of higher thought and a constant topic throughout the book. While examining the multiple-demand system, Duncan suggest how the components of the brain could all possibly work together when it comes to producing cognitive thought and processing. He compares human cognition to artificial intelligence. While computers are capable of highly logical processing and analysis, well beyond the limits of human computing, humans are capable of stringing those ideas together, seeing the "bigger picture." Duncan also discusses the frontal lobe studies done on monkeys that let to the identification of cells and neurons responsible for decisions, delving into the neurophysiology of intelligent thought.

For those who haven't studied the brains anatomy, this will be an extremely useful section. It may be beneficial to do some background searching or to follow along with an online resource, as having visual aids will help. I enjoyed the level of detail that Duncan provided, as it was sufficient to understand his point without being overly scientific. The examples that Duncan uses in this section are also very interesting, as he discusses many very fascinating cases of psychological disorders and their relationship to changes in the brain.

One of my favorite parts of this book involved Duncan's discussion of cognitive dissonance. The short and long of it is that we are extremely biased to the point that our brains will alter the way we perceive information to better support ourselves. One of Duncan's examples was "The fox wants the grapes until it is clear that they will not be obtained...he reasons that those grapes were not so wonderful after all..." Looking into my own life and decisions, I can think of clear examples of when I have gone through this sort of thinking myself.

"The Future of Intelligence Research"

Duncan concludes by stating that the one sure thing in these sorts of studies is change. What he means by this is that what is generally accepted now will change as research progress and we are at this point [of understanding intelligence] now but will be racing ahead with new knowledge and discoveries into the future.

Because I have studied neuroscience and psychology, some of the information was review. However, a lot was a new way to look at things I had heard before. I thoroughly enjoyed reading the book and would suggest it to anyone looking for a way to start understanding the neurophysiology of intelligence. As a recommendation for potential readers, I would say that the book is easy enough to read without a background in this topic but being familiar with basic psychology and neurophysiology will certainly help. I would also state that having a basic understanding of how research (particularly on animals) will make the examples and cited studies more meaningful.