How the Mind Works (Penguin Press Science) (Paperback)

Pinker marries Darwin's theory of evolution to the latest developments in neuroscience and computation. He shows in detail how the process of natural selection shaped our entire neurological networks; how the struggle for survival selects from among our genes those most fit to flourish in our environment. Nature has produced in us bodies, brains and minds attuned to coping intelligently with whatever our environment demands. Housed in our bodies, our minds structure neural networks into adaptive programmes for handling our perceptions. Pinker concludes, "The mind is a system of organs of computation, designed by natural selection to solve the kinds of problems our ancestors faced in their foraging way of life."

Our beliefs and desires are information, allowing us to create meaning. "Beliefs are inscriptions in memory, desires are goal inscriptions, thinking is computation, perceptions are inscriptions triggered by sensors, trying is executing operations triggered by a goal." Pinker writes that the mind has a 'design stance' for dealing with artefacts, a 'physical stance' for dealing with objects, and an 'intentional stance' for dealing with people. "Causal and inferential roles tend to be in sync because natural selection designed both our perceptual and our inferential modules to work accurately, most of the time, in this world." With this down-to-earth kind of explanation, there is no need to invoke mysterious intangible powers: "We don't need spirits or occult forces to explain intelligence." Pinker sums up the recent amazing developments in neurobiology and cognitive science. This book, like those by his colleagues Daniel Dennett ('Darwin's dangerous idea' and 'Consciousness explained') and Richard Dawkins ('River out of Eden' and 'Unweaving the rainbow'), should be required reading. They are all Darwinians, but then why shouldn't they be? It is just like saying that all physicists are Einsteinians nowadays, or that all poets and playwrights are Shakespeareans, or that all osteopaths are Stillians. Their books make Karl Popper, so hostile to Darwin, and Californian gurus like Fritjof Capra, sadly outdated.

By giving coherent, intelligible accounts of the ways in which our bodies and minds have evolved, writers like Pinker can help us to understand better how and why our bodies work in the ways they do.

The computational bits left me feeling out of my depth at several points, but also feeling reassured that this wasn't science lite. And while the evolutionary bits were less challenging - and easier to read - they offered more than enough food for thought.

Apparently some people find the computation plus evolution theory controversial. Others find the ideas old hat. And Pinker himself seems to rub plenty of people up the wrong way for various reasons. Myself, I find the arguments fresh and convincing, and Pinker very enjoyable to read. He covers an awful lot of ground with great gusto, he packs the detail in and makes his points with wry humour.

A book to read once to get the gist and a second time to get the detail.

Pinker uses evolutionary roots as the foundation for his presentation. Like it or not, our genes carry a large part of our mental processes. The mind is not a "blank slate," but is born with vast supply of historical information on which to build as it matures. The "cultural environment" so dear to some commentators makes only a small contribution to who we become as adults. Even a child's peer groups influence its development more than does parental input, and by a huge margin. This situation arises because the mind is an algorithmic processor. It is essentially independent of an individual's environment, with a built-in learning capability to select from the wide spectrum of inputs. To Pinker, this essentially unconstrained process is part of the evolutionary path. Children's independence reflects the need of natural selection to sort among "what is" to arrive at what "will be" in the future. There are certainly no guarantees of how development will proceed over generations.

The computational image is based on "problem-solving." When to take a step, avoid predators, seek a mate, find food. Clearly, as Pinker states, computational mind processes are as universal as brains. Therefore, in Pinker's view, each brain develops modules for dealing with these issues. Like any powerful computer, he stresses, the mind depends on parallel processing for flexibility. How else, for example, could the brain control breathing while also thinking about a Mozart string trio? As humans evolved, they either added new problem-solving modules, or improved on the inherited ones. This is an algorithmic process - adding small instructions over time as adaptations to changing conditions. It is clearly a universal evolutionary process that has achieved enormous expression in the human species. Each acquired "tactic" could be passed down through generations, with each successful transmission building on an inherited base.

"The mind is not the brain, but what the brain does," is the key statement of the book. Pinker supports this image with numerous examples of mind/brain functions. Why our brain "sees" a three-dimensional image in a stereographic display when we know the photographs are two dimensional is but one of many instances he cites. The various factors he proposes must not be considered as independent entities, he stresses. The algorithmic processes form a whole, but not one based neither on conflicting elements nor particularly complementary ones. Weightings of importance take place continually, but even the expression of an idea is not a mental "victory" for that particular idea. The human mind's greatest attribute is its flexibility.

As with any of the recent works on cognition, Pinker's analysis isn't the final word. Given the complexity of the mind, that is clearly an impossible goal. Yet Pinker has broached many new concepts in this book. All deserve further careful study. Pinker avoids dogmatism with his elegant treatment. This book is required in furthering your own thinking about our place in nature and deserves respect and attention. He welcomes serious studies in the subject, even if the work appears to refute his ideas. But he insists that the refutation must rely on solid science and not traditional dogmas. [stephen a. haines - Ottawa, Canada]