Kluge: The Haphazard Construction of the Human Mind

so consistently vulnerable to error.

In the pages to come I’ll consider why our memory so often fails us, and why we often believe things that aren’t true but disbelieve things that are. I’ll consider how it is that half of all Americans can believe in ghosts and how almost four million can sincerely believe that they’ve been abducted by space aliens. I’ll look at how we spend (and often waste) our money, why the phenomenon of throwing good money after bad is so widespread, and why we inevitably find meat that is 80 percent lean much more appealing than meat that is 20 percent fat. I’ll examine the origins of languages and explain why they are replete with irregularity, inconsistency, and ambiguity — and, for that matter, why a sentence like People people left left ties us in knots even though it’s only four words long. I’ll also look at what makes us happy, and why. It’s often been said that pleasure exists to guide the species, but why, for example, do we spend so many hours watching television when it does our genes so little good? And why is mental illness so widespread, affecting, at one time or another, almost half the population? And why on earth cant money buy happiness?

Kluge, kluge, kluge. In every case, I’ll show that we can best understand our limitations by considering the role of evolutionary inertia in shaping the human mind.

This is not to say that every cognitive quirk is without redeeming value. Optimists often find some solace in even the worst of our mental limitations; if our memory is bad, it is only to protect us from emotional pain; if our language is ambiguous, it is only to enable us to say no without explicitly saying “no.”

Well, sort of; there’s a difference between being able to exploit ambiguity (say, for purposes of poetry or politeness) and being stuck with it. When our sentences can be misunderstood even when we want them to be clear — or when our memory fails us even when someone’s life is at stake (for example, when an eyewitness gives testimony at a criminal trial) — real human cognitive imperfections cry out to be addressed.

I don’t mean to chuck the baby along with its bath — or even to suggest that kluges outnumber more beneficial adaptations. The biologist Leslie Orgel once wrote that “Mother Nature is smarter than you are,” and most of the time it is. No single individual could ever match what nature has done, and most of nature’s designs are sensible, even if they aren’t perfect. But it’s easy to get carried away with this line of argument. When the philosopher Dan Dennett tells us that “time and again, biologists baffled by some apparently futile or maladroit bit of bad design in nature have eventually come to see that they have underestimated the ingenuity, the sheer brilliance, the depth of insight to be discovered in Mother Nature’s creations,” he’s cheerleading. In an era in which machines can beat humans in intellectual endeavors ranging from chess to statistical analysis, it is possible to contemplate other ways in which physical systems might solve cognitive problems, and nature doesn’t always come out on top. Instead of assuming that nature is always ingenious, it pays to take each aspect of the mind on its own, to sort the truly sublime from the cases in which nature really could have done better.

Whether kluges outnumber perfections or perfections outnumber kluges, kluges tell us two things that perfections can’t. First, they can give special insight into our evolutionary history; when we see perfection, we often can’t tell which of many converging factors might have yielded an ideal solution; often it is only by seeing where things went wrong that we can tell how things were built in the first place. Perfection, at least in principle, could be the product of an omniscient, omnipotent designer; imperfections not only challenge that idea but also offer specific forensic clues, a unique opportunity to reconstruct the past and to better understand human nature. As the late Stephen Jay Gould noted, imperfections, “remnants of the past that don’t make sense in present terms — the useless, the odd, the peculiar, the incongruous — are the signs of history.”

And second, kluges can give us clues into how we can improve ourselves. Whether we are 80 percent perfect or 20 percent perfect (numbers that are really meaningless, since it all depends on how you count), humans do show room for improvement, and kluges can help lead the way. By taking an honest look in the mirror, in recognizing our limitations as well as our strengths, we have a chance to make the most of the noble but imperfect minds we did evolve.

2. MEMORY

Your memory is a monster; you forget — it doesn’t. It simply files things away. It keeps things for you, or hides things from you — and summons them to your recall with a will of its own. You think you have a memory; but it has you!

— JOHN IRVING

MEMORY IS, I BELIEVE, the mother of all kluges, the single factor most responsible for human cognitive idiosyncrasy.

Our memory is both spectacular and a constant source of disappointment: we can recognize photos from our high school yearbooks decades later — yet find it impossible to remember what we had for breakfast yesterday. Our memory is also prone to distortion, conflation, and simple failure. We can know a word but not be able to remember it when we need it (think of a word that starts with a, meaning “a counting machine with beads”),[5] or we can learn something valuable (say, how to remove tomato sauce stains) and promptly forget it. The average high school student spends four years memorizing dates, names, and places, drill after drill, and yet a significant number of teenagers can’t even identify the century in which World War I took place.

I’m one to talk. In my life, I have lost my house keys, my glasses, my cell phone, and even a passport. I’ve forgotten where I parked, left the house without remembering my keys, and on a particularly sad day, left a leather jacket (containing a second cell phone) on a park bench. My mother once spent an hour looking for her car in the garage at an unfamiliar airport. A recent Newsweek article claims that people typically spend 55 minutes a day “looking for things they know they own but can’t find.”

Memory can fail people even when their lives are at stake. Skydivers have been known to forget to pull the ripcord to open their parachute (accounting, by one estimate, for approximately 6 percent of skydiving deaths), scuba divers have forgotten to check their oxygen level, and more than a few parents have inadvertently left their babies in locked cars. Pilots have long known that there’s only one way to fly: with a checklist, relying on a clipboard to do what human memory can’t, which is to keep straight the things that we have do over and over again. (Are the flaps down? Did I check the fuel gauge? Or was that last time?) Without a checklist, it’s easy to forget not just the answers but also the questions.

Why, if evolution is usually so good at making things work well, is our memory so hit-or-miss?

The question becomes especially pointed when we compare the fragility of our memory with the robustness of the memory in the average computer. Whereas my Mac can store (and retrieve) my complete address book, the locations of all the countries in Africa, the complete text of every email message I ever sent, and all the photographs I’ve taken since late 1999 (when I got my first digital camera), not to mention the first 3,000 digits of pi, all in perfect detail, I still struggle with the countries in Africa and can scarcely even remember whom I last emailed, let alone exactly what I said. And I never got past the first ten digits of pi (3.1415926535) — even though I was just the sort of nerd who’d try to memorize more.[6]

Human memory for photographic detail is no better; we can recognize the main elements of a photo we’ve seen before, but studies show that people often don’t notice small or even fairly large changes in the background.[7] And I for one could never ever recall the details of a photograph, no matter how long I sat and stared at it beforehand. I can still remember the handful of phone numbers I memorized as a child, when I had loads of free time, but it took me almost a year to learn my wife’s cell phone number by heart.

Worse, once we do manage to encode a memory, it’s often difficult to revise it. Take, for instance, the trouble I have with the name of my dear colleague Rachel. Five years after she got divorced and reverted to her maiden name (Rachel K.), I still sometimes stumble and refer to her by her former married name (Rachel C.) because the earlier habit is so strong. Whereas computer memory is precise, human memory is in many ways a recalcitrant mess.