If you want to find schizophrenia, go to a psychology department. Not among the staff (although some do seem to hear voices inaudible to the rest of us) but within the subject. It has gone from describing varieties of religious experience to censusing them, from phrenology to scanning brains and DNA, and at last—coming full circle—to explaining belief in Darwinian terms. Psychology is a journey from the arts to the sciences and back again.
How the Mind Works is a route map across the Great Divide, an ambitious attempt to explain how we act, think, and feel in terms of cognitive science. Steven Pinker believes that the voyage of discovery is more or less complete; or, at least, we have got about as far as we will. In spite of an escape clause of the kind familiar to consumers of health foods (“We don’t understand how the mind works”), his agenda is clear. It is presented in the forceful manner expected of the author of The Language Instinct. The mind works in a particular way, he says, because of evolution.
The mind is almost as hard to define as the soul. Four years after The Origin of Species, the Reverend Charles Kingsley was the first to use evolution to metaphysical ends: in The Water Babies a drowned chimney sweep is reborn, meets Darwin and Huxley, and evolves a moral sense lacking in his earthly self. After all, if evolution could produce that miracle, the Englishman, why could it not produce the greater miracle, the soul? Ethics, religion, and science were neatly reconciled.
Steven Pinker transcends the Water Babies school of brain science, but in some places only just. He is as keen on what evolution can do as was Charles Kingsley. That, in the broad sense, the mind evolved is not at all surprising. It had as little choice in the matter as did the kidney. Because of evolution, the parent of creatures as unlikely as the tree-kangaroo and the AIDS virus, the human brain does unexpected and at first sight mysterious things. Those who study it have long ignored its past: according to this book, “the study of the mind is still mostly Darwin-free, sometimes defiantly so.”
Pinker does his best to put the balance right. To demystify the mysteries of seeing, gambling, laughing, and (possibly) falling in love we need to understand the brain’s antecedents. History may not contain everything the brain does, but it defines the limits within which it is obliged to work. Take those irritating “magic eye” books that at first sight seem just a set of textured pages. Suddenly, from each a giraffe or a racing car pops out. They come from our ability to see in stereo, perhaps a relic of a life surrounded by millions of identical leaves from which a juicy insect had to be distinguished.
Is Pinker’s—notably daring—title sensible, or does it promise too much? How, for example, does television work? To a child it is obvious: press the button and it comes on. An adult has a deeper understanding, and an engineer knows how to fix it. Ask an executive and there is another response. The hard-faced men who did well out of Mrs. Thatcher understand why sports programs on British TV rake in millions when they used to be free. A producer would talk of continuity or cameras. Only a small or unduly stupid child thinks that the actors are behind the screen, but the popularity of TV and movie theme parks shows that many viewers find it hard to separate image from reality.
The Simpsons works because, inter alia, American viewers are not as stupid as advertisers once assumed, because its creator has marvelous talent, because Rupert Murdoch hyped the series in his newspapers, and because the brain can be fooled into thinking that a series of still pictures is a moving image. None of those facts alone is enough to understand its success.
How the Mind Works, though, attempts a universal exegesis of the set within the skull, a mental theory of everything. Such a doctrine may soon appear for physics (or so some physicists proclaim) but it must surely be far away for psychology. As a result How the Mind Works is two, if not more, different books. The first, an exploration of cognitive science, succeeds. The second, in which human nature—human society, indeed—is explained by natural selection, is less persuasive. It is worth remembering that Darwin himself, cautious as always, wrote in 1859: “I have nothing to do with the origin of the primary mental powers, any more than with life itself.”
Pinker is an entertaining guide to the workings of what he calls the “connectoplasm” that makes us what we are. To him, psychology is engineering in reverse: if you understand the structure of the brain, you have at least a hope of comprehending why it thinks. There is much on neural networks, on brain damage, on illusion, even on consciousness. Some is familiar, most not; and all is explained with energy and style.
The brain is the ultimate lying machine. Television, whatever its weaknesses, is at least honest. Switch it on, and it bursts into color. We all know that those myriad hues are based on three simple pigments, red, blue and green. Together, that makes white—elementary physics. Where, though, do the black parts of the picture come from? The screen, switched off, is dim gray, not coal black. The brain copes, Pinker explains, by telling fibs: it fills in black instead of gray where it expects it to be.
Having a dishonest body part leads to both problems and opportunities. The brain is immeasurably more complex than anything made by man (as indeed is the tongue). No computer could list the facts we know without noticing: that when Edna goes to church, her head goes with her, or that zebras in the wild never wear underwear. No computer has common sense: if there’s a bag in your car with a gallon of milk in it, there’s a gallon of milk in your car, but if you—with your gallon of blood—were to get in, it would seem odd to you (but not to the most advanced analytical engine) to say that there is a gallon of blood in the driver’s seat.
Pinker’s book ranges widely in its search for the nature of thought. Fossils, artificial intelligence, Dr. Strangelove, binocular vision, literature, kibbutzim, all (perhaps too much) human life is there. Most of it, it seems, is explainable by Darwin. On the way through the neural jungle, Pinker comes up with an endless series of extraordinary facts. We find crumpled balls of paper to be the same, although their shapes are very different, but faces to be different, although their shapes are almost the same. A simple calculation based on the average numbers of words per sentence and the number of choices that could sensibly be made for each word shows that there are a hundred times more meaningful sentences than the number of seconds since the beginning of the universe. Altruism is simple: in the absence of refrigerators, the best place for a hunter to store meat is in the bodies of other hunters, who will then be able to kill, and share, the next meal. Sixty-two percent of toddlers will eat imitation dog feces crafted from peanut butter and odorous cheese.
The strength of How the Mind Works is in its deconstruction of the mechanism of the brain from the evidence of what it can and cannot do. Much of it is straight science. The explanation of the mind’s eye—three-dimensional vision—is the clearest I know, but pulls few punches. Why is turning a photograph upside down immediately apparent, while switching it left to right is scarcely noticed? Read this book (with considerable concentration) to find out.
In any discussion of the mind, the arts faculty gets a say. It is odd that physics and chemistry make do with scientists, while psychology needs Thinkers. Steven Pinker, quite rightly, sees himself as among the former group; but in his book the thinkers get a look-in. In general, they are not much help. Pinker uses humor (much of it Jewish and all of it funny) to illustrate his more ticklish points. Another story comes to mind. Two American Jews go into a nightclub in Tel Aviv to find a comic making cracks in Hebrew to an appreciative audience. One of the Americans breaks into uproarious laughter. The other asks him—as neither speaks He-brew—why he is laughing. “Why not?” he answers. “I trust these people.”
That is the essence of science. Even though I do not understand quantum mechanics or the nerve cell membrane, I trust those who do. Most scientists are quite ignorant about most sciences, but all use a shared grammar that allows them to recognize their craft when they see it. The motto of the Royal Society of London is Nullius in verba: trust not in words. Observation and experiment are what count, not opinion and introspection. The study of the mind has been invaded by both. Few working scientists have much sympathy for those who try to interpret nature in metaphysical terms. For most wearers of white coats, philosophy is to science as pornography is to sex: it is cheaper, easier, and some people seem, bafflingly, to prefer it. Outside psychology it plays almost no part in the functions of the research machine.
Brain scientists—Steven Pinker included—are defensive about their flirtation with the mystics. They know that they cannot afford a relationship with their subject as austere as that of the physicist Lord Rutherford with his; he claimed that “if your experiment needs statistics, you should have done a better experiment.” Even biologists see that as unfair; in the messy world of real life, statistics reveal the general through the mists of the particular. Psychologists, with minds of their own to deal with, may need yet another level of explanation. The cynical view that if their science needs philosophy they should do better science is less than reasonable. It may mean, though, that large parts of their enterprise are for the time being beyond the limits of science altogether.
As Pinker says, to interpret the brain too literally from the behavior of its owners would be to argue that rocks are smarter than cats because rocks always go away when you kick them. Some questions of the mind remain unanswered and perhaps unanswerable. When it comes to “What is it like to be a bat?” or (as much debated by those who believe in things called qualia, subjective experiences of, for instance, color) “Might your experience of red be the same as my experience of green?” Pinker is refreshingly frank—he admits that it “beats the heck out of me.” If others wish to coin words to describe things of that kind, so what? That is what the arts faculty is for.