Kluge: The Haphazard Construction of the Human Mind (Houghton Mifflin; 2008)

— 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.* And what is recent is rarely fully debugged. Instead of an objective machine for discovering and encoding Truth with a capital T, our human capacity for belief is haphazard, scarred by evolution and contaminated by emotions, moods, desires, goals, and simple self-interest — and surprisingly vulnerable to the idiosyncrasies of memory. Moreover, evolution has left us distinctly gullible, which smacks more of evolutionary shortcut than good engineering. All told, though the systems that underlie our capacity for belief are powerful, they are also subject to superstition, manipulation, and fallacy. This is not trivial stuff: beliefs, and the imperfect neural tools we use to evaluate them, can lead to family conflicts, religious disputes, and even war.