Kluge: The Haphazard Construction of the Human Mind

system would capture information in a single exposure, so we wouldn’t have to waste time with flash cards or lengthy memorization sessions. (Yes, I’ve heard the rumors about the existence of photographic memory, but no, I’ve never seen a well-documented case.)

There’s nothing wrong with mnemonics and no end to the possibilities; any cue can help. But when they fail, we can rely on a different sort of solution — arranging our life to accommodate the limits of our memory. I, for example, have learned through long experience that the only way to deal with my congenital absent-mindedness is to develop habits that reduce the demands on my memory. I always put my keys in the same place, position anything I need to bring to work by the front door, and so forth. To a forgetful guy like me, a PalmPilot is a godsend. But the fact that we can patch together solutions doesn’t mean that our mental mechanisms are well engineered; it is a symptorn of the opposite condition. It is only the clumsiness of human memory that necessitates these tricks in the first place.

Given the liabilities of our contextual memory, it’s natural to ask whether its benefits (speed, for example) outweigh the costs. I think not, and not just because the costs are so high, but because it is possible in principle to have the benefits without the costs. The proof is Google (not to mention a dozen other search engines). Search engines start with an underlying substrate of postal-code memory (the well-mapped information they can tap into) and build contextual memory on top. The postal-code foundation guarantees reliability, while the context on top hints at which memories are most likely needed at a given moment. If evolution had started with a system of memory organized by location, I bet that’s exactly what we’d have, and the advantages would be considerable. But our ancestors never made it to that part of the cognitive mountain; once evolution stumbled upon contextual memory, it never wandered far enough away to find another considerably higher peak. As a result, when we need precise, reliable memories, all we can do is fake it — kluging a poor man’s approximation of postal-code memory onto a substrate that doesn’t genuinely provide for it.

In the final analysis, we would be nowhere without memory; as Steven Pinker once wrote, “To a very great extent, our memories are ourselves.” Yet memory is arguably the mind’s original sin. So much is built on it, and yet it is, especially in comparison to computer memory, wildly unreliable.

In no small part this is because we evolved not as computers but as actors, in the original sense of the word: as organisms that act, entities that perceive the world and behave in response to it. And that led to a memory system attuned to speed more than reliability. In many circumstances, especially those requiring snap decisions, recency, frequency, and context are powerful tools for mediating memory. For our ancestors, who lived almost entirely in the here and now (as virtually all nonhuman life forms still do), quick access to contextually relevant memories of recent events or frequently occurring ones helped navigate the challenges of seeking food or avoiding danger. Likewise, for a rat or a monkey, it is often enough to remember related general information. Concerns about misattribution or bias in courtroom testimony simply don’t apply.

But today, courts, employers, and many other facets of everyday life make demands that our pre-hominid predecessors rarely faced, requiring us to remember specific details, such as where we last put our keys (rather than where we tend, in general, to put them), where we’ve gotten particular information, and who told us what, and when.

To be sure, there will always be those who see our limits as virtues. The memory expert Henry Roediger, for example, has implied that memory errors are the price we pay in order to make inferences. The Harvard psychologist Dan Schacter, meanwhile, has argued that the fractured nature of memory prepares us for the future: “A memory that works by piecing together bits of the past may be better suited to simulating future events than one that is a store of perfect records.” Another common suggestion is that we’re better off because we can’t remember certain things, as if faulty memory would spare us from pain.

These ideas sound nice on the surface, but I don’t see any evidence to support them. The notion that the routine failures of human memory convey some sort of benefit misses an important point: the things that we have trouble remembering arent the things we’d like to forget. It’s easy to glibly imagine some kind of optimal state wherein we’d remember only happy thoughts, a bit like Dorothy at the end of The Wizard of Oz. But the truth is that we generally can’t — contrary to Freud — repress memories that we find painful, and we don’t automatically forget them either. What we remember isn’t a function of what we want to remember, and what we forget isn’t a matter of what we want to forget; any war veteran or Holocaust survivor could tell you that. What we remember and what we forget are a function of context, frequency, and recency, not a means of attaining inner peace. It’s possible to imagine a robot that could automatically expunge all unpleasant memories, but we humans are just not built that way.

Similarly, there is no logical relation between having a capacity to make inferences and having a memory that is prone to errors. In principle, it is entirely possible to have both perfect records of past events and a capacity to make inferences about the future. That’s exactly how computer-based weather-forecasting systems work, for example; they extrapolate the future from a reliable set of data about the past. Degrading the quality of their memory wouldn’t improve their predictions, but rather it would undermine them. And there’s no evidence that people with an especially distortion-prone memory are happier than the rest of us, no evidence that they make better inferences or have an edge at predicting the future. If anything, the data suggest the opposite, since having an above-average memory is well correlated with general intelligence.

None of which is to say that there aren’t compensations. We can, for example, have a great deal of fun with what Freud called “free associations”; it’s entertaining to follow the chains of our memories, and we can put that to use in literature and poetry. If connecting trains of thought with chains of ought tickles your fancy, by all means, enjoy! But would we really and truly be better off if our memory was less reliable and more prone to distortion? It’s one thing to make lemonade out of lemons, another to proclaim that lemons are what you’d hope for in the first place.

In the final analysis, the fact that our ability to make inferences is built on rapid but unreliable contextual memory isn’t some optimal tradeoff. It’s just a fact of history: the brain circuits that allow us to make inferences make do with distortion-prone memory because that’s all evolution had to work with. To build a truly reliable memory, fit for the requirements of human deliberate reasoning, evolution would have had to start over. And, despite its power and elegance, that’s the one thing evolution just can’t do.

3. BELIEF

Alice laughed: “There’s no use trying,” she said; “one can’t be lieve impossible things.”

“I daresay you haven’t had much practice,” said the Queen. “When I was younger, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”

— LEWIS CARROLL, Alice’s Adventures in Wonderland

“You HAVE A NEED for other people to like and admire you, and yet you tend to be critical of yourself. While you have some personality weaknesses, you are generally able to compensate for them. You have considerable unused capacity that you have not turned to your advantage. Disciplined and self-controlled on the outside, you tend to be worrisome and insecure on the inside.”

Would you believe me if I told you that I wrote that description just for you? It’s actually a pastiche of horoscopes, constructed by a psychologist named Bertram Forer. Forer’s point was that we have a tendency to read too much into bland generalities, believing that they are (specifically) about us — even when they aren’t. Worse, we are even more prone to fall victim to this sort of trap if the bland description includes a few positive traits. Televangelists and late-night infomercials prey upon us in the same way — working hard to sound as if they are speaking to the individual listener rather than a crowd. As a species, we’re only too ready to be fooled. This chapter is, in essence, an investigation of why.

The capacity to hold explicit beliefs that we can talk about, evaluate, and reflect upon is, like language, a recently evolved innovation — ubiquitous in humans, rare or perhaps absent in most other species.[13] And what is recent is rarely fully debugged. Instead of an objective machine