John Duncan's "How Intelligence Happens"

John Duncan is assistant director of the MRC Cognition and Brain Sciences Unit in Cambridge, honorary professor of cognitive neuroscience at the Universities of Cambridge and Bangor, visiting professor at the University of Oxford, and fellow of the Royal Society and the British Academy. For the past thirty years, his research has focused on linking human mind to brain. He is known for his frontal-lobe theory of human intelligence, which has been covered in the media worldwide.

He applied the “Page 99 Test” to his new book, How Intelligence Happens, and reported the following:

How Intelligence Happens is the story of one of the great scientific mysteries. Human intelligence is among the most powerful forces on earth, building cities, plantations, microchips; it takes us from subatomic particles to the limits of the Universe. How can human thought emerge from a nervous system of billions of cells, essentially similar to the brains of many other animals? In the search for an answer, leads have come from many places – from the troubled science of intelligence testing, the study of how minds change after brain damage, the foundations of artificial intelligence, new methods for imaging human brain activity, and painstaking exploration of detailed activity in single nerve cells. In How Intelligence Happens I put together the parts of this story to show how brains solve human problems.

On p. 99 I am describing one of my first experiments. The question is simple. Almost childlike puzzles are often used in intelligence testing, and their properties are fascinating. A person who does well on these tests is also likely to succeed in many other kinds of activity, from laboratory tests of perception, memory or speed to complex life achievements. The tests are obviously important - but what do they measure in the brain? We now know that the answer concerns a specific brain system, combining fragments of thought and behaviour into the complex, goal-directed structures of human endeavour. The activity of this system can be seen with modern methods for brain imaging; it links closely to the needs of computers that solve problems in logic or plan and execute a day’s errands; and on p. 99, we see how damage to this system produces lost intelligence – a mind that is disorganized, fragmented, chaotic.

The story of How Intelligence Happens is like an early map of the world. It has parts that are relatively clear, parts that are sketchy, large parts simply labelled “unknown”. Sketchy though it is, however, an outline picture is beginning to form – a genuine, biological science of human intelligence and thought.

Learn more about How Intelligence Happens at the Yale University Press website.

--Marshal Zeringue