Why Is It So Hard to Be Rational? | The New Yorker

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• For some reason, I took a class on health policy, and I was appalled by the idea that hospital administrators should take costs into account when providing care. (Shouldn’t doctors alone decide what’s best for their patients?)

• He pointed out that my dad was a doctor, and explained that I was engaging in “motivated reasoning.” My gut was telling me what to think, and my brain was figuring out how to think it. This felt like thinking, but wasn’t.

• Like Greg, I read a collection of rationality blogs—Marginal Revolution, Farnam Street, Interfluidity, Crooked Timber. I haunted the Web sites of the Social Science Research Network and the National Bureau of Economic Research, where I could encounter just-published findings; I internalized academic papers on the cognitive biases that slant our thinking, and learned a simple formula for estimating the “expected value” of my riskier decisions.

• I adopted his habit of tracking what I knew and how well I knew it, so that I could separate my well-founded opinions from my provisional views. Bad investors, Greg told me, often had flat, loosely drawn maps of their own knowledge, but good ones were careful cartographers, distinguishing between settled, surveyed, and unexplored territories.

• This summer, on my phone, I read a blog post by the economist Arnold Kling, who noted that an unusually large number of books about rationality were being published this year, among them Steven Pinker’s “Rationality: What It Is, Why It Seems Scarce, Why It Matters” (Viking) and Julia Galef’s “The Scout Mindset: Why Some People See Things Clearly and Others Don’t” (Portfolio).

• And yet rationality has sharp edges that make it hard to put at the center of one’s life. It’s possible to be so rational that you are cut off from warmer ways of being—like the student Bazarov, in Ivan Turgenev’s “Fathers and Sons,” who declares, “I look up to heaven only when I want to sneeze.”

• “RATIONAL, adj.: Devoid of all delusions save those of observation, experience and reflection,” Ambrose Bierce wrote, in his “Devil’s Dictionary.”

• It’s possible that you are trying to appear rational only because you want to impress people; or that you are more rational about some things (your job) than others (your kids); or that your rationality gives way to rancor as soon as your ideas are challenged. Perhaps you irrationally insist on answering difficult questions yourself when you’d be better off trusting the expert consensus.

• We want to live in a more rational society, but not in a falsely rationalized one. We want to be more rational as individuals, but not to overdo it. We need to know when to think and when to stop thinking, when to doubt and when to trust. Rationality is one of humanity’s superpowers. How do we keep from misusing it?

• We can practice the instrumental rationality of means and ends (how do I get what I want?) and the value rationality of purposes and goals (do I have good reasons for wanting what I want?). We can pursue the rationality of affect (am I cool, calm, and collected?) or develop the rationality of habit (do I live an ordered, or “rationalized,” life?). Rationality was obviously useful, but Weber worried that it was turning each individual into a “cog in the machine,” and life into an “iron cage.”

• For Aristotle, rationality was what separated human beings from animals. For the authors of “The Rationality Quotient,” it’s a mental faculty, parallel to but distinct from intelligence, which involves a person’s ability to juggle many scenarios in her head at once, without letting any one monopolize her attention or bias her against the rest.

• It’s because some people are better jugglers than others that the world is full of “smart people doing dumb things”: college kids getting drunk the night before a big exam, or travellers booking flights with impossibly short layovers.

• Pinker, a cognitive and evolutionary psychologist, sees it instrumentally, as “the ability to use knowledge to attain goals.” By this definition, to be a rational person you have to know things, you have to want things, and you have to use what you know to get what you want. Intentions matter: a person isn’t rational, Pinker argues, if he solves a problem by stumbling on a strategy “that happens to work.”

• Introspection is key to rationality. A rational person must practice what the neuroscientist Stephen Fleming, in “Know Thyself: The Science of Self-Awareness” (Basic Books), calls “metacognition,” or “the ability to think about our own thinking”—“a fragile, beautiful, and frankly bizarre feature of the human mind.”

• As we perform increasingly familiar tasks, we monitor our performance less rigorously; this happens when we drive, or fold laundry, and also when we think thoughts we’ve thought many times before. Studying for a test by reviewing your notes, Fleming writes, is a bad idea, because it’s the mental equivalent of driving a familiar route.

• “Experiments have repeatedly shown that testing ourselves—forcing ourselves to practice exam questions, or writing out what we know—is more effective,” he writes. The trick is to break the illusion of fluency, and to encourage an “awareness of ignorance.”

• Most of us stay informed straightforwardly—by taking in new information. Rationalists do the same, but self-consciously, with an eye to deliberately redrawing their mental maps.

• fresh facts and opinions aren’t uniformly significant. In recent decades, rationalists confronting this problem have rallied behind the work of Thomas Bayes

• There are many ways to explain Bayesian reasoning—doctors learn it one way and statisticians another—but the basic idea is simple. When new information comes in, you don’t want it to replace old information wholesale. Instead, you want it to modify what you already know to an appropriate degree. The degree of modification depends both on your confidence in your preëxisting knowledge and on the value of the new data.

• Bayesian reasoners begin with what they call the “prior” probability of something being true, and then find out if they need to adjust it.

• Consider the example of a patient who has tested positive for breast cancer—a textbook case used by Pinker and many other rationalists. The stipulated facts are simple. The prevalence of breast cancer in the population of women—the “base rate”—is one per cent. When breast cancer is present, the test detects it ninety per cent of the time. The test also has a false-positive rate of nine per cent: that is, nine per cent of the time it delivers a positive result when it shouldn’t. Now, suppose that a woman tests positive. What are the chances that she has cancer?

• When actual doctors answer this question, Pinker reports, many say that the woman has a ninety-per-cent chance of having it. In fact, she has about a nine-per-cent chance.

• The doctors have the answer wrong because they are putting too much weight on the new information (the test results) and not enough on what they knew before the results came in—the fact that breast cancer is a fairly infrequent occurrence.

• Start by imagining that we’ve tested a group of a thousand women: ten will have breast cancer, and nine will receive positive test results. Of the nine hundred and ninety women who are cancer-free, eighty-nine will receive false positives. Now you can allow yourself to focus on the one woman who has tested positive. To calculate her chances of getting a true positive, we divide the number of positive tests that actually indicate cancer (nine) by the total number of positive tests (ninety-eight). That gives us about nine per cent.

• Bayesian reasoning implies a few “best practices.” Start with the big picture, fixing it firmly in your mind. Be cautious as you integrate new information, and don’t jump to conclusions. Notice when new data points do and do not alter your baseline assumptions (most of the time, they won’t alter them), but keep track of how often those assumptions seem contradicted by what’s new. Beware the power of alarming news, and proceed by putting it in a broader, real-world context.

• In a sense, the core principle is mise en place. Keep the cooked information over here and the raw information over there; remember that raw ingredients often reduce over heat.

• a Bayesian assigns probabilities to these propositions. She doesn’t build an immovable world view; instead, by continually updating her probabilities, she inches closer to a more useful account of reality. The cooking is never done.

• The rationality community has its own lingua franca. If a rationalist wants to pay you a big compliment, she might tell you that you have caused her to “revise her priors”—that is, to alter some of her well-justified prior assumptions

• That same rationalist might talk about holding a view “on the margin”—a way of saying that an idea or fact will be taken into account, as a kind of tweak on a prior, the next time new information comes in

• She might speak about “updating” her opinions—a cheerful and forward-looking locution, borrowed from the statistical practice of “Bayesian updating,” which rationalists use to destigmatize the act of admitting a mistake.

• In Silicon Valley, people wear T-shirts that say “Update Your Priors,” but talking like a rationalist doesn’t make you one. A person can drone on about base rates with which he’s only loosely familiar, or say that he’s revising his priors when, in fact, he has only ordinary, settled opinions. Google makes it easy to project faux omniscience.

• There’s a difference between reading about surgery and actually being a surgeon, and the surgeon’s priors are what we really care about.

• Clearly, we want people in power to be rational. And yet the sense that rationalists are somehow unmoored from direct experience can make the idea of a rationalist with power unsettling.

• In a sketch by the British comedy duo Mitchell and Webb, a government minister charged with ending a recession asks his analysts if they’ve considered “killing all the poor.” “I’m not saying do it—I’m just saying run it through the computer and see if it would work,” he tells them. (After they say it won’t, he proposes “blue-skying” an even more senseless alternative: “Raise V.A.T. and kill all the poor.“) This caricature echoes a widespread skepticism of rationality as a value system.

• It’s up to rationalists to do the uncomfortable work of pointing out uncomfortable truths; sometimes in doing this they seem a little too comfortable.

• I’ve long admired my friend Greg for his rationality, but I’ve since updated my views. I think it’s not rationality, as such, that makes him curious, truthful, honest, careful, perceptive, and fair, but the reverse.

• In “Rationality,” “The Scout Mindset,” and other similar books, irrationality is often presented as a form of misbehavior, which might be rectified through education or socialization. This is surely right in some cases, but not in all.

• Similar events—a torn dollar bill found on the ground, a flat tire on the left side of the car rather than the right—could cast shadows over her mood for days, sometimes weeks. As a voter, a parent, a worker, and a friend, she was driven by emotion. She had a stormy, poetic, and troubled personality. I don’t think she would have been helped much by a book about rationality. In a sense, such books are written for the already rational.

• Greg tells me that, in his business, it’s not enough to have rational thoughts. Someone who’s used to pondering questions at leisure might struggle to learn and reason when the clock is ticking; someone who is good at reaching rational conclusions might not be willing to sign on the dotted line when the time comes.

• I know, rationally, that the coronavirus poses no significant risk to my small son, and yet I still hesitated before enrolling him in daycare for this fall, where he could make friends. You can know what’s right but still struggle to do it.

• Following through on your own conclusions is one challenge. But a rationalist must also be “metarational,” willing to hand over the thinking keys when someone else is better informed or better trained. This, too, is harder than it sounds.

• Still, like Gurri’s populists, rationalists may stage their own contrarian revolts, repeatedly finding that no one’s opinions but their own are defensible. In letting go, as in following through, one’s whole personality gets involved.

• The realities of rationality are humbling. Know things; want things; use what you know to get what you want. It sounds like a simple formula. But, in truth, it maps out a series of escalating challenges. In search of facts, we must make do with probabilities. Unable to know it all for ourselves, we must rely on others who care enough to know. We must act while we are still uncertain, and we must act in time—sometimes individually, but often together. For all this to happen, rationality is necessary, but not sufficient. Thinking straight is just part of the work.