The Undoing Project: A Friendship that Changed the World (181 POCHE)

by Michael Lewis

when the story was about perseverance in the face of incredible adversity, as it often was, it was hard not to grow attached to it.

a big part of a consultant’s job was to feign total certainty about uncertain things.

A perfect answer didn’t exist, but statistics could get you to some answer that was at least a bit better than simply guessing.

He suggested a new definition of the nerd: a person who knows his own mind well enough to mistrust it.

Freshly exposed to the human mind, Morey couldn’t help but notice how strangely it operated. When it opened itself to information that might be useful in evaluating an amateur basketball player, it also opened itself to being fooled by the very illusions that had made the model such a valuable tool in the first place.

The human mind was just bad at seeing things it did not expect to see, and a bit too eager to see what it expected to see.

“Confirmation bias is the most insidious because you don’t even realize it is happening,”

the mind’s best trick of all was to lead its owner to a feeling of certainty about inherently uncertain things.

In some strange way people, at least when they were judging other people, saw what they expected to see and were slow to see what they hadn’t seen before.

Simply knowing about a bias wasn’t sufficient to overcome it:

You never knew

people were endlessly complicated and interesting.”

Why does that picture so often seem to be imposed by the mind upon the world around it, rather than by the world upon the mind?

How does a person turn the shards of memory into a coherent life story?

Why does a person’s understanding of what he sees change with the contex...

Psychology wasn’t like physics, or even economics. It lacked a single persuasive theory to organize itself around, or even an agreed-upon set of rules for discussion.

If an officer thought a soldier physically impressive, he also found him impressive in other ways. Switch the order of assessment, and the same problem occurred: If a person was first judged to be generally great, he was then judged to be stronger than he actually was.

“When someone says something, don’t ask yourself if it is true. Ask what it might be true of.”

Our decisions, Clyde Coombs thought, might be treated as a collection of judgments about the similarity between two things: the ideal in our head, and the object on offer.

“The directionality and asymmetry of similarity relations are particularly noticeable in similes and metaphors,”

When people compared one thing to another—two people, two places, two numbers, two ideas—they did not pay much attention to symmetry.

If the mind, when it compares two things, essentially counts up the features it notices in each of them, it might also judge those things to be at once more similar and more dissimilar to each other than some other pair of things.

When people picked coffee over tea, and tea over hot chocolate, and then turned around and picked hot chocolate over coffee—they weren’t comparing two drinks in some holistic manner. Hot drinks didn’t exist as points on some mental map at fixed distances from some ideal. They were collections of features. Those features might become more or less noticeable; their prominence in the mind depended on the context in which they were perceived. And the choice created its own context: Different

features might assume greater prominence in the mind when the coffee was being compared to tea (caffeine) than when it was being compared to hot chocolate (sugar). And what was true of drinks might also be true of people, and ideas, and emotions.

By changing the context in which two things are compared, you submerge certain features and force others to the surface.

Things are grouped together for a reason, but, once they are grouped, their grouping causes them to seem more like each other than they otherwise would. That is, the mere act of classification reinforces stereotypes. If you want to weaken some stereotype, eliminate the classification.

Error wasn’t merely instructive; it was the key that might unlock the deep nature of the mechanism.

“Reforms always create winners and losers,” Danny explained, “and the losers will always fight harder than the winners.”

education was knowing what to do when you don’t know,”

when a person calculates the odds of some situation, he does not do advanced statistics. He just behaves as if he does.

probability was not a given.

made—even when those people were trained statisticians. People

mistook even a very small part of a thing for the whole.

Even statisticians tended to leap to conclusions from inconclusively smal...

the smaller the sample, the lower the likelihood that it would mirror the broader population.

“People’s intuitions about random sampling appear to satisfy the law of small numbers, which asserts that the law of large numbers applies to small numbers as well,”

psychologists had so much faith in small samples that they assumed that whatever had been learned from either group must be generally true, even if one lesson seemed to contradict the other.

It turned out to be true. If you wanted to know whether you had cancer or not, you were better off using the algorithm that the researchers had created than you were asking the radiologist to study the X-ray.

‘People are not so complicated. Relationships between people are complicated.’

The way the creative process works is that you first say something, and later, sometimes years later, you understand what you said. And in our case it was foreshortened.

Subjective probability meant: the odds you assign to any given situation when you are more or less guessing.

“The decisions we make, the conclusions we reach, and the explanations we offer are usually based on our judgments of the likelihood of uncertain events such as success in a new job, the outcome of an election, or the state of a market.” In these and many other uncertain situations, the mind did not naturally calculate the correct odds.

The more the basketball player resembles your mental model of an NBA player, the more likely you will think him to be an NBA player.

The correct answer is “the smaller hospital.” The smaller the sample size, the more likely that it is unrepresentative of the wider population.

The more easily people can call some scenario to mind—the more available it is to them—the more probable they find it to be.

Any fact or incident that was especially vivid, or recent, or common—or anything that happened to preoccupy a person—was likely to be recalled with special ease, and so be disproportionately weighted in any judgment.

Human judgment was distorted by … the memorable

people don’t know what they don’t know, but that they don’t bother to factor their ignorance into their judgments.

The stories we make up, rooted in our memories, effectively replace probability judgments.

“There is much evidence showing that, once an uncertain situation has been perceived or interpreted in a particular fashion, it is quite difficult to view it in any other way.”