Rationality: What It Is, Why It Seems Scarce, Why It Matters

by Steven Pinker

lodestar

How can we make sense of making sense—and its opposite?

Commentaries by the thousands have lamented our shortfall of reason, and it’s become conventional wisdom that people are simply irrational. In social science and the media, the human being is portrayed as a caveman out of time, poised to react to a lion in the grass with a suite of biases, blind spots, fallacies, and illusions.

Just as citizens should grasp the basics of history, science, and the written word, they should command the intellectual tools of sound reasoning. These include logic, critical thinking, probability, correlation and causation, the optimal ways to adjust our beliefs and commit to decisions with uncertain evidence, and the yardsticks for making rational choices alone and with others.

Many act as if rationality is obsolete—as if the point of argumentation is to discredit one’s adversaries rather than collectively reason our way to the most defensible beliefs.

A major theme of this book is that none of us, thinking alone, is rational enough to consistently come to sound conclusions: rationality emerges from a community of reasoners who spot each other’s fallacies.

realism and reason are ideals that must be singled out and defended.

Our species has dated the origin of the universe, plumbed the nature of matter and energy, decoded the secrets of life, unraveled the circuitry of consciousness, and chronicled our history and diversity. We have applied this knowledge to enhance our own flourishing, blunting the scourges that immiserated our ancestors for most of our existence. We have postponed our expected date with death from thirty years of age to more than seventy (eighty in developed countries), reduced extreme poverty from ninety percent of humanity to less than nine, slashed the rates of death from war twentyfold and from famine a hundredfold.

The San engage in persistence hunting, which puts to use our three most conspicuous traits: our two-leggedness, which enables us to run efficiently; our hairlessness, which enables us to dump heat in hot climates; and our big heads, which enable us to be rational. The San deploy this rationality to track the fleeing animals from their hoofprints, effluvia, and other spoor, pursuing them until they keel over from exhaustion and heat stroke.7 Sometimes the San track an animal along one of its habitual pathways, or, when a trail goes cold, by searching in widening circles around the last known prints. But often they track them by reasoning.

The San don’t just pigeonhole animals into categories but make finer-grained logical distinctions. They tell individuals apart within a species by reading their hoofprints, looking for telltale nicks and variations. And they distinguish an individual’s permanent traits, like its species and sex, from transient conditions like fatigue, which they infer from signs of hoof-dragging and stopping to rest.

Yet for all the deadly effectiveness of the San’s technology, they have survived in an unforgiving desert for more than a hundred thousand years without exterminating the animals they depend on. During a drought, they think ahead to what would happen if they killed the last plant or animal of its kind, and they spare the members of the threatened species.

It is unthinkable for a San hunter not to share meat with an empty-handed bandmate, or to exclude a neighboring band driven from their drought-stricken territory, since they know that memories are long and some day fortunes may reverse.

Despite our ancient capacity for reason, today we are flooded with reminders of the fallacies and follies of our fellows. People gamble and play the lottery, where they are guaranteed to lose, and fail to invest for their retirement, where they are guaranteed to win. Three quarters of Americans believe in at least one phenomenon that defies the laws of science, including psychic healing (55 percent), extrasensory perception (41 percent), haunted houses (37 percent), and ghosts (32 percent)—which also means that some people believe in houses haunted by ghosts without believing in ghosts.

Human intuition doesn’t grasp exponential (geometric) growth, namely something that rises at a rising rate, proportional to how large it already is, such as compound interest, economic growth, and the spread of a contagious disease.20 People mistake it for steady creep or slight acceleration, and their imaginations don’t keep up with the relentless doubling.

People with a shaky grasp of exponential growth have been found to save less for retirement and to take on more credit-card debt, two roads to penury.

insouciance

confirmation bias: the bad habit of seeking evidence that ratifies a belief and being incurious about evidence that might falsify it.

Guinness Book of World Records for the highest score on an intelligence test. Vos Savant wrote that you should switch: the odds of the car being behind Door 2 are two in three, compared with one in three for Door 1. The column drew ten thousand letters, a thousand of them from PhDs, mainly in mathematics and statistics, most of whom said she was wrong. Here are some examples:

They werent "mansplaining" as Pinker imagines. They were stating the facts. Your chances improve from 33% to 50% even if you dont switch, switching doesnt improve ypur chances, your and her logic is false here , the woke tone makes it cringe not right.

Intuitive probability is driven by imaginability: the easier something is to visualize, the likelier it seems. This entraps us into what Tversky and Kahneman call the conjunction fallacy, in which a conjunction is more intuitively probable than either of its elements.

People will of course think a president will resign after protests instead of all by himself without reason to be more likely. Your reasoning is absurd here.

highly intelligent Amanda who marches for Black Lives Matter

She isnt intelligent nope.

Disagreement is necessary in deliberations among mortals. As the saying goes, the more we disagree, the more chance there is that at least one of us is right.

Rationality rejecters can refuse to play the game. They can say, “I don’t have to justify my beliefs to you. Your demands for arguments and evidence show that you are part of the problem.” Instead of feeling any need to persuade, people who are certain they are correct can impose their beliefs by force.

In theocracies and autocracies, authorities censor, imprison, exile, or burn those with the wrong opinions. In democracies the force is less brutish, but people still find means to impose a belief rather than argue for it. Modern universities—oddly enough, given that their mission is to evaluate ideas—have been at the forefront of finding ways to suppress opinions, including disinviting and drowning out speakers, removing controversial teachers from the classroom, revoking offers of jobs and support, expunging contentious articles from archives, and classifying differences of opinion as punishable harassment and discrimination.

And another reason not to blow off persuasion is that you will have left those who disagree with you no choice but to join the game you are playing and counter you with force rather than argument. They may be stronger than you, if not now then at some time in the future. At that point, when you are the one who is canceled, it will be too late to claim that your views should be taken seriously because of their merits.

A man is sentenced to be hanged for offending the sultan, and offers a deal to the court: if they give him a year, he will teach the sultan’s horse to sing, earning his freedom. When he returns to the dock, a fellow prisoner says, “Are you crazy? You’re only postponing the inevitable. In a year there will be hell to pay.” The man replies, “I figure over a year, a lot can happen. Maybe the sultan will die, and the new sultan will pardon me. Maybe I’ll die; in that case I would have lost nothing. Maybe the horse will die; then I’ll be off the hook. And who knows? Maybe I’ll teach the horse to sing!”

libertarian paternalism by the legal scholar Cass Sunstein and the behavioral economist Richard Thaler in their book Nudge.

In the game of Chicken, made famous in the James Dean classic Rebel Without a Cause, two teenage drivers approach each other at high speed on a narrow road and whoever swerves first loses face (he is the “chicken”).29 Since each one knows that the other does not want to die in a head-on crash, each may stay the course, knowing the other has to swerve first. Of course when both are “rational” in this way, it’s a recipe for disaster (a paradox of game theory we will return to in chapter 8). So is there a strategy that wins at Chicken? Yes—relinquish your ability to swerve by conspicuously locking the steering wheel, or by putting a brick on the gas pedal and climbing into the back seat, leaving the other guy no choice but to swerve. The player who lacks control wins. More precisely, the first player to lack control wins: if both lock their wheels simultaneously . . .

The art of political rhetoric is to hide, euphemize, or reframe taboo tradeoffs. Finance ministers can call attention to the lives a budgetary decision will save and ignore the lives it costs. Reformers can redescribe a transaction in a way that tucks the tit for tat in the background: advocates for the women in red-light districts speak of sex workers exercising their autonomy rather than prostitutes selling their bodies; advertisers of life insurance (once taboo) describe the policy as a breadwinner protecting a family rather than one spouse betting that the other will die.37

When you combine self-interest and sociality with impartiality—the interchangeability of perspectives—you get the core of morality.45 You get the Golden Rule, or the variants that take note of George Bernard Shaw’s advice “Do not do unto others as you would have others do unto you; they may have different tastes.”

“Those who are governed by reason desire nothing for themselves which they do not also desire for the rest of humankind.”

Despite its lack of coolth, we should, and in many nonobvious ways do, follow reason. Merely asking why we should follow reason is confessing that we should. Pursuing our goals and desires is not the opposite of reason but ultimately the reason we have reason.

When a future self might act irrationally, a present self can outsmart it. When a rational argument slips into fallacy or sophistry, an even more rational argument exposes it.

And then there’s my favorite, the Yiddish As di bubbe volt gehat beytsim volt zi gevain mayn zaidah, “If my grandmother had balls, she’d be my grandfather.”

The “smartest people in the world” claim from the Yang Gang is a mild example of the argument from authority. The authority being deferred to is often religious, as in the gospel song and bumper sticker “God said it, I believe it, that settles it.” But it can also be political or academic. Intellectual cliques often revolve around a guru whose pronouncements become secular gospel. Many academic disquisitions begin, “As Derrida has taught us . . .”—or Foucault, or Butler, or Marx, or Freud, or Chomsky. Good scientists disavow this way of talking, but they are sometimes raised up as authorities by others.

It’s often said that the Scientific Revolution of the seventeenth century was launched when people first appreciated that statements about the physical world are empirical and can be established only by observation, not scholastic argumentation.

waxed

wroth;

Is the human brain a big deep learning network? Certainly not, for many reasons, but the similarities are illuminating. The brain has around a hundred billion neurons connected by a hundred trillion synapses, and by the time we are eighteen we have been absorbing examples from our environments for more than three hundred million waking seconds. So we are prepared to do a lot of pattern-matching and associating, just like these networks. The networks are tailor-made for the fuzzy family resemblance categories that make up so much of our conceptual repertoire. Neural networks thus provide clues about the portion of human cognition that is rational but not, technically speaking, logical. They demystify the inarticulate yet sometimes uncanny mental power we call intuition, instinct, inklings, gut feelings, and the sixth sense.

A thousand stories which the ignorant tell, and believe, die away at once, when the computist takes them in his gripe. —Samuel Johnson1

The availability bias may affect the fate of the planet. Several eminent climate scientists, having crunched the numbers, warn that “there is no credible path to climate stabilization that does not include a substantial role for nuclear power.”21 Nuclear power is the safest form of energy humanity has ever used. Mining accidents, hydroelectric dam failures, natural gas explosions, and oil train crashes all kill people, sometimes in large numbers, and smoke from burning coal kills them in enormous numbers, more than half a million per year. Yet nuclear power has stalled for decades in the United States and is being pushed back in Europe, often replaced by dirty and dangerous coal. In large part the opposition is driven by memories of three accidents: Three Mile Island in 1979, which killed no one; Fukushima in 2011, which killed one worker years later (the other deaths were caused by the tsunami and from a panicked evacuation); and the Soviet-bungled Chernobyl in 1986, which killed 31 in the accident and perhaps several thousand from cancer, around the same number killed by coal emissions every day.22

bugbears

believe journalists have not given enough thought to the way that media coverage can activate our cognitive biases and distort our understanding.

The press is an availability machine. It serves up anecdotes which feed our impression of what’s common in a way that is guaranteed to mislead.

Availability-driven ignorance can be corrosive. A looping mental newsreel of catastrophes and failures can breed cynicism about the ability of science, liberal democracy, and institutions of global cooperation to improve the human condition. The result can be a paralyzing fatalism or a reckless radicalism: a call to smash the machine, drain the swamp, or empower a demagogue who promises “I alone can fix it.”36

As the physicist Len Mlodinow pointed out in The Drunkard’s Walk: How Randomness Rules Our Lives, the country has more than six thousand fund managers, and modern mutual funds have been around for about forty years.

The cluster illusion makes us think that random processes are nonrandom and vice versa. When Tversky and Kahneman showed people (including statisticians) the results of real strings of coin flips, like TTHHTHTTTT, which inevitably have runs of consecutive heads or tails, they thought the coin was rigged. They would say a coin looked fair only if it was rigged to prevent the runs, like HTHTTHTHHT, which “looks” random even though it isn’t.64 I witnessed a similar illusion when I worked in an auditory perception lab. The participants had to detect faint tones, which were presented at random times so they couldn’t guess when a tone would come. Some said the random-event generator must be broken because the tones came in bursts. They didn’t realize that that’s what randomness sounds like.

The cluster illusion, like other post hoc fallacies in probability, is the source of many superstitions: that bad things happen in threes, people are born under a bad sign, or an annus horribilis means the world is falling apart. When a series of plagues is visited upon us, it does not mean there is a God who is punishing us for our sins or testing our faith. It means there is not a God who is spacing them apart.

Extraordinary claims require extraordinary evidence. —Carl Sagan

flub

Everyone complains about his memory, and no one complains about his judgment. —La Rochefoucauld