Thinking, Fast and Slow

by Daniel Kahneman

“Lady Macbeth effect.”

“The sight of all these people in uniforms does not prime creativity.”

“The world makes much less sense than you think. The coherence comes mostly from the way your mind works.”

Cognitive strain is affected by both the current level of effort and the presence of unmet demands.

You are also likely to be relatively casual and superficial in your thinking. When you feel strained, you are more likely to be vigilant and suspicious, invest more effort in what you are doing,

but you also are less intuitive and less creative than usual.

The lesson of figure 5 is that predictable illusions inevitably occur if a judgment is based on an impression of cognitive ease or strain.

cognitive ease.

cognitive ease

If you care about being thought credible and intelligent, do not use complex language where simpler language will do.

In addition to making your message simple, try to make it memorable. Put your ideas in verse if you can; they will be more likely to be taken as truth.

but the proportion dropped to 35% when the font was barely legible. You read this correctly: performance was better with the bad font. Cognitive strain, whatever its source, mobilizes System 2, which is more likely to reject the intuitive answer suggested by System 1.

the mere exposure effect.

Indeed, the mere exposure effect is actually stronger for stimuli

The mere exposure effect occurs, Zajonc claimed, because the repeated exposure of a stimulus is followed by nothing bad. Such a stimulus will eventually become a safety signal, and safety is good. Obviously,

After they hatched, the chicks consistently emitted fewer distress calls when exposed to the tone they had heard while inhabiting the shell.

creativity is associative memory that works exceptionally well. He made up a test, called the Remote Association Test (RAT), which is still often used in studies of creativity.

They found that putting the participants in a good mood before the test by having them think happy thoughts more than doubled accuracy. An even more striking result is that unhappy subjects were completely incapable of performing the intuitive task accurately; their guesses were no better than random.

good mood, intuition, creativity, gullibility, and increased reliance on System 1 form a cluster.

sadness, vigilance, suspicion, an analytic approach, and increased effort also go together.

“I’m in a very good mood today, and my System 2 is weaker than usual. I should be extra careful.”

We (System 2) knew this was a ludicrous idea, but our System 1 had made it seem almost normal to meet Jon in strange places.

Finding such causal connections is part of understanding a story and is an automatic operation

A story in Nassim Taleb’s The Black Swan illustrates this automatic search for causality. He reports that bond prices initially rose on the day of Saddam Hussein’s capture in his hiding place in Iraq. Investors were apparently seeking safer assets that morning, and the Bloomberg News service flashed this headline:

rules of associative coherence tell us what happened.

Your mind is ready and even eager to identify agents, assign them personality traits and specific intentions, and view their actions as expressing individual propensities.

Here again, the evidence is that we are born prepared to make intentional attributions:

The prominence of causal intuitions is a recurrent theme in this book because people are prone to apply causal thinking inappropriately, to situations that require statistical reasoning.

The system and the machine are fictions; my reason for using them is that they fit the way we think about causes.

When uncertain, System 1 bets on an answer, and the bets are guided by experience.

System 1 does not keep track of alternatives that it rejects, or even of the fact that there were alternatives. Conscious doubt is not in the repertoire of System 1; it requires maintaining incompatible interpretations in mind at the same time, which demands mental effort.

Uncertainty and doubt are the domain of System 2.

The moral is significant: when System 2 is otherwise engaged, we will believe almost anything.

System 1 is gullible and biased to believe, System 2 is in charge of doubting and unbelieving, but System 2 is sometimes busy, and often lazy.

Indeed, there is evidence that people are more likely to be influenced by empty persuasive messages, such as commercials,...

The operations of associative memory contribute to a general confirmation bias. When asked, “Is Sam friendly?” different instances of Sam’s behavior will come to mind than w...

(and scientists, quite often) seek data that are likely to be compatible with the beliefs they currently hold.

The confirmatory bias of System 1 favors uncritical acceptance of suggestions and exaggeration of the likelihood of extreme and improbable events.

The halo effect is also an example of suppressed ambiguity: like the word bank, the adjective stubborn is ambiguous and will be interpreted in a way that makes it coherent with the context.

The sequence in which we observe characteristics of a person is often determined by chance.

The consistency I had enjoyed earlier was spurious; it produced a feeling of cognitive ease, and my System 2 was happy to lazily accept the final grade.

decorrelate error!

The Wisdom of Crowds,

this is the kind of task in which individuals do very poorly, but pools of individual judgments do remarkably well. Some individuals greatly overestimate the true number, others underestimate it, but when many judgments are averaged, the average tends to be quite accurate.

However, the magic of error reduction works well only when the observations are independent and their errors uncorrelated. If the observers share a bias, the aggregation of judgments will not reduce it.

Allowing the observers to influence each other effectively reduces the size of the sample, and with it the precision of the group estimate.

To derive the most useful information from multiple sources of evidence, you should always try to make these source...

The principle of independent judgments (and decorrelated errors) has immediate applications for the conduct of meetings, an activity in which executives in organizations spend a great deal of their working days. A simple rule can help: before an issue is discussed, all members of the committee should be asked to write a very brief summary of their position. This procedure makes good use of the value of the diversity of knowledge and opinion in the group. The standard practice of open discussion gives too much weight to the opinions of those who speak early and assertively, causing others to line up behind them.

System 1 excels at constructing the best possible story that incorporates ideas currently activated, but it does not (cannot) allow for information it does not have. The measure of success for System 1 is the coherence of the story it manages to create. The amount and

When information is scarce, which is a common occurrence, System 1 operates as a machine for jumping to conclusions.