Brain Waves

By Steven Pinker
W.W. Norton, 660 pp.

Reading any 600-page treatise isn’t exactly effortless, no matter how absorbing. It is work for the mind. Reading one on how the mind actually works is enough to grind the mental gears. Steven Pinker’s account of the latest thinking in cognitive psychology is learned, instructive, clever and charming, but reading it gives the strange sensation that portions of your brain are being plucked out one by one and rotated in front of your eyes for close inspection.

It’s not an unpleasant sensation, merely disorienting. That’s the idea. Pinker invites us to examine everything from our basic instincts to our highest mental faculties from a novel perspective. The book is didactic in the best sense: it gives you all sorts of things to think about. It makes you think about them in ways that would never have occurred to you. And it makes work for the mind feel like play.

Pinker’s explanations are based on three rather simple ideas. The first is that the human mind is best thought of as a computational mechanism. Some people have trouble with this one. A computer is a mechanism, but the human mind possesses properties and capabilities that mechanisms do not, such as a sense of self. True enough, but Pinker points out that the logic is fuzzy. Just because there are machines that have no minds does not mean the mind is not a machine. There are organs that have no sense of their own identity – your skin, for example – but it doesn’t follow that the brain is not an organ.

The mind, Pinker argues, is a confederacy of different capacities, some reflective and some not, but all are designed to solve different types of problems, all interacting with one another. Processing visual input from the retina is not the same type of thinking as lying convincingly to one’s wife in order to throw her a surprise party, but the healthy brain is remarkably adept at both. Many of these functions are localized in specific pockets of tissue. Neuropsychology is rife with cases such as the brain-damaged patient who processes visual information perfectly, who knows exactly what his wife looks like, but who is convinced the woman he lives with is an imposter.

The second core idea is that the architecture of the mind displays a design, which prompts the twin questions of how it was designed and for what. Pinker’s answer is that it was crafted by adaptive pressure for the same things that natural selection designed every other living organism on the planet: survival and procreative success. Until recently, evolutionary biology concentrated on anatomy. It’s largely been a matter of sorting fossilized femurs and parsing different species of trilobite. But the same analytical bent can be productively applied to why humans think the way they do. How the Mind Works is human psychology and neuroscience run through the sieve of Darwinism.

The third key idea is that the workings of the mind can be understood by picking them apart. The process is called reverse-engineering. Building a better mousetrap means designing one from the ground up. That’s engineering. Figuring out how a mousetrap works if you’ve never seen one before requires dismantling a few of them. That’s reverse-engineering.

Here’s how the technique works, at least in Pinker’s hands. Take a familiar and universal human feature, say the absence of sexual attraction between brother and sister. Show how crucially cognition is implicated. (In the case of incest, it’s not just the act that’s repulsive, it’s the very thought of the act.) Then demonstrate how nature would have programmed that behavior into the deepthink of humankind as a means of regulating reproductive behaviour. Everything we know or do is just the result of eons of hominid evolution.

For the most part, the arguments are pretty convincing. So what makes Steven Pinker so smart? Well, he has the book-learning, as they used to say. He was educated at McGill and Harvard Universities and is now the director of the Centre for Cognitive Neuroscience at the Massachusetts Institute of Technology. Credentials aside, he has a natural talent for explaining things in a way that is both clear and persuasive.

Not perfectly persuasive, however. The theory he advances is so big as to be pliant around the edges. Anything that can’t quite be accommodated is explained away in terms that fold in on themselves. For example, the pleasure humans take in singing and dancing – surely products of higher brain functions – isn’t easily accounted for in terms of selective Darwinian pressure. Pinker suggests that the artistic sensibility is just a happy dividend. The brain wasn’t designed with art in mind any more than a mousetrap is designed to snap the fingers of unsuspecting toddlers, but the blueprints of any machine never exhaust what it will actually do.

By the same token, if Pinker is to be believed, the design of the mind’s machinery places outer limits on what it is capable of understanding. Why can’t we quite grasp how it’s possible for an amalgam of biochemical processors to develop a sense of identity – an awareness of you, us, me? Pinker argues it’s because we’re not programmed to do so. The mystery of consciousness will forever elude us because we’re not equipped to comprehend it.

Now, there’s a theory with built-in flexibility. Its inability to solve its thorniest question is invoked as a sign of its sophistication. Unfortunately, it doesn’t ring true. If the neuroscientists can’t crack their central problem, it’s probably not because it’s impossible to do so. It’s more likely that further heavy thinking is still required and yet to come.

Back to the drawing board, I’m

Montreal Gazette January 31, 1998