Thinking, Fast and Slow

“One of the main functions of System 2 is to monitor and control thoughts and actions ‘suggested’ by System 1, allowing some to be expressed directly in behavior and suppressing or modifying others.” 

This quotation aptly expresses the core of the relationship between System 1 and System 2. It is significant because this basic relationship is foundational to many of the processes, biases, and other phenomena that are discussed throughout the book.

“Anything that makes it easier for the associative machine to run smoothly will also bias beliefs. A reliable way to make other people believe in falsehoods is frequent repetition, because familiarity is not easily distinguished from truth.” 

Kahneman identifies one of the primary techniques used by propogandists. He discusses the mechanism through which and reason why people believe what they repeatedly hear irrespective of truth or falsity. In essence, this quotation points to the psychological explanation of why something comes to be regarded as familiar and therefore preferred through mere exposure.

“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, when they are tired or depleted.”

The significance of this quotation is tied to Kahneman’s presentation of System 2 as a check on the easily manipulated System 1 and as depletable. As Kahneman explains it, System 1 immediately checks any information received against what it already knows and has stored, seeking to validate the new information. It is only when System 1 detects something that does not fit well that it triggers System 2’s engagement. Even at that stage, System 2’s tendency to avoid cognitive strain frequently allows System 1’s initial intuition to govern choices.

“The sequence in which we observe characteristics of a person is often determined by chance. Sequence matters, however, because the halo effect increases the weight of first impressions, sometimes to the point that subsequent information is mostly wasted.”

This passage illustrates the operation of one relatively well-known aspect of bias that arises from System 1 interacting with System 2 by shaping the information that is available. Through associative reasoning, which characterizes System 1, people generally form an initial impression in observing someone and then filter all subsequent information about that person in a way that promotes an all-good or all-bad vision of them to confirm the initial impression.

“[System 1’s] mental shotgun makes it easy to generate quick answers to difficult questions without imposing much hard work on your lazy System 2. […] The heuristic questions provide an off-the-shelf answer to each of the difficult target questions […]. The automatic processes of the mental shotgun and intensity matching often make available one or more answers to easy questions that can be mapped onto the target question.” 

The concepts expressed here are very significant to how System 1 provides a sense of confidence about matters of which a person actually has little understanding. By generating many possible responses to alternative (easier) questions, then borrowing one’s degree of intensity from another domain (related in some association), System 1 gives the illusion of intuitive understanding in response to a difficult question.

“Our predilection for causal thinking exposes us to serious mistakes in evaluating the randomness of truly random events.”

This quotation captures the essence of one of Kahneman’s key points: We frequently see causes or supposed evidence of causes that do not exist. Accepting blind luck’s role in determining outcomes to many situations may be unnerving, but it is nonetheless far more real than the nonexistent causes we frequently suspect.

“When an incorrect intuitive judgment is made, System 1 and System 2 should both be indicted. System 1 suggested the incorrect intuition and System 2 endorsed it and expressed it as a judgment. However, there are two possible reasons for the failure of System 2—ignorance or laziness.” 

The concepts expressed here are important to understanding the interaction between System 1 and System 2. This quote also explains why System 2 sometimes fails to check System 1, typically due to a lack of knowledge or a lack of effort.

“The test of learning psychology is whether your understanding of situations you encounter has changed, not whether you have learned a new fact.” 

This quotation reflects the depth and significance of the points that Kahneman is making, which are often more far-reaching and more practical than the writing’s amiable, accessible tone might suggest. Further, this quotation is practically useful in that it suggests a measure the reader might apply to determine whether they are actually grasping the concepts discussed: Do you see the events occurring around you differently, perhaps with more depth and a better ability to identify judgment errors that you would otherwise make or that you observe others making? Among the social sciences, psychology is one of very few with that level of immediate, individual utility.

“You build the best possible story from the information available to you, and if it is a good story, you believe it. Paradoxically, it is easier to construct a coherent story when you know little, when there are fewer pieces to fit into the puzzle. Our comforting conviction that the world makes sense rests on a secure foundation: our almost unlimited ability to ignore our own ignorance.” 

The operation of System 1, with its perennial quest for a causal narrative, leads to the seemingly counterintuitive fact that we often feel more certainty in our understanding and judgment of events or people when we have less information on which to base it. Once you account for WYSIATI, however, it makes sense: Simple stories are easily grasped, do not involve nuance or require careful evaluation, and can usually be constructed to coincide with preexisting beliefs. Thus, having less information allows System 1 to create a causal narrative that confirms existing beliefs without effort. In other words, it has all the emotional benefits of familiarity and cognitive ease. Gaining nonconforming knowledge or challenging assumptions, on the other hand, is likely to trigger the involvement of System 2, thereby requiring effort to resolve potentially unresolvable uncertainty or contradiction. WYSIATI, therefore, goes a long way toward explaining the conflicts and misunderstandings among people.

“A general limitation of the human mind is its imperfect ability to reconstruct past states of knowledge, or beliefs that have changed. Once you adopt a new view of the world (or any part of it), you immediately lose much of your ability to recall what you used to believe before your mind changed.” 

This point is important and often requires some effort to understand for the first time. Recognizing the limitation expressed in this quotation may undermine false certainty but probably promotes a greater awareness of the benefits of education, diversity, and other means of gaining perspectives different from our own.

“Stories of how businesses rise and fall strike a chord with readers by offering what the human mind needs: a simple message of triumph and failure that identifies clear causes and ignores the determining power of luck and the inevitability of regression.”

In the context of discussing a then-recent book on the rise of Google, Kahneman explains that so much of Google’s success stemmed from luck, such that people are unlikely to glean any useful lesson from the story. This quotation identifies the psychological reasons why such books remain popular despite the impossibility of distilling a valuable lesson for others to adopt in their quest for success. System 1’s longing for causal explanation is so strong that people find it easy to believe there is value in such stories and analysis of them even though no evidence supports that view.

“Their own experience of exercising careful judgment on complex problems was far more compelling to them than an obscure statistical fact.” 

This statement epitomizes Kahneman’s concerns about reliance on intuitive judgments, including (or especially) those of others who purport to be experts. In this instance, he describes why stock traders did not react in any manner when he visited a firm and presented firm statistical analysis that demonstrated their performance was likely a matter of pure luck.

“Applying Apgar’s score, staff in the delivery rooms finally had consistent standards for determining which babies were in trouble, and the formula is credited for an important contribution to reducing infant mortality. The Apgar test is still used every day in every delivery room.”

This statement effectively summarizes the benefits of applying formulas. In contrast, relying on the intuitive assessments and judgments of individual experts can yield inconsistent and inefficient results.

“A more general lesson that I learned […] was do not simply trust intuitive judgment—your own or that of others—but do not dismiss it, either.”

This quotation, which occurs after Kahneman has consistently criticized intuitive judgments as frequently inaccurate, overconfident, and potentially harmful, marks a shift in the discussion of intuitive judgments. In the anecdote that precedes the quotation, he reveals a more nuanced position. In the chapter that follows it, we learn what Kahneman maintains are the necessary conditions for the development of expert intuition in certain fields.

“In a less regular, or low validity, environment, the heuristics of judgment are involved. System 1 is often able to produce quick answers to difficult questions by substitution, creating coherence where there is none.” 

This brief statement explains why Kahneman is skeptical of claims of certain types of self-proclaimed experts (such as stock-pickers) and also why people can feel sure of their intuitive responses despite major error. In essence, even where it is not possible to develop genuine expert intuition, people nonetheless believe that they do and convince others of the same.

“Unlike Econs, the Humans that psychologists know have a System 1. Their view of the world is limited by information that is available at a given moment (WYSIATI), and therefore they cannot be as logical and consistent as Econs.” 

This quotation succinctly expresses the reason why Tversky and Kahneman developed prospect theory: The prevailing theory undergirding behavioral economics failed to account for System 1, the dominant force guiding human decision-making which is neither conscious nor rational. It also shows why prospect theory was so impactful in economics and other fields.

“The fundamental ideas of prospect theory are that reference points exist, and that losses loom larger than corresponding gains.” 

This is one of several statements in the book that concisely and accurately summarizes prospect theory’s core insights. This one is made in the context of discussing financial traders’ false belief in their ability to pick stocks (which is effectively governed by chance for most people).

“Many stores in New York City sell lottery tickets, and business is good. The psychology of high prize lotteries is similar to the psychology of terrorism.” 

In Chapter 30 Kahneman describes his experience in Israel during the 2001-2004 terrorist bombings on buses. The unexpected juxtaposition between lotteries and terrorism in this quote makes it clear that winning the lottery and being victim to terrorism are extreme and extremely rare.

“As we have seen again and again, an important choice is controlled by an utterly inconsequential feature of the situation. This is embarrassing—it is not how we would wish to make important decisions. Furthermore, it is not how we experience the workings of our mind, but the evidence for these cognitive illusions is undeniable.”

This passage aptly expresses the importance of framing effects. It also expresses the high opposition to the obvious recognition of framing as a legitimate means of encouraging prosocial behavior. Of course, there is no way to pose a policy question that does not frame it. Kahneman simply urges that we understand the effects of framing in formulating such questions.

“Confusing experience with the memory of it is a compelling cognitive illusion—and it is substitution that makes us believe our past experience can be ruined. The experiencing self does not have a voice. The remembering self is sometimes wrong, but it is the one that keeps score and governs what we learn from living, and it is the one that makes decisions. What we learn from the past is to maximize the quality of our future memories.” 

Kahneman identifies the “remembering self” as having greater control than the experiencing self. This particular quotation clearly expresses the reasons why that is the case and describes the mechanism by which such control is exercised.

“It is only a slight exaggeration to say that happiness is the experience of spending time with people you love and who love you.” 

This quotation reflects Kahneman’s interest and participation in well-being research. It distills one of the ultimate lessons that he has taken from that work: that happiness derives from meaningful time spent with loved ones.

“Although Humans are not irrational, they often need help to make more accurate judgments and better decisions, and in some cases policies and institutions can provide that help.” 

This quotation advances the policy prescriptive vision that grows out of prospect theory, often expressed by those in the behavioral economics movement. It is a controversial argument, as Kahneman notes with some surprise, but also one that has gained significant traction in recent decades (as illustrated by Cass Sunstein serving in the Obama administration, for example).

“The acquisition of skills requires a regular environment, an adequate opportunity to practice, and rapid and unequivocal feedback about the correctness of thoughts and actions. When these conditions are fulfilled, skill eventually develops, and the intuitive judgments and choices that quickly come to mind will mostly be accurate. All of this is System 1, which means it occurs automatically and fast.” 

This passage succinctly summarizes Kahneman’s ultimate view of expertise and expert intuition. Despite assailing the errors of System 1 for most of the book ( and most of his career), Kahneman recognizes the value of expertise and lays this precise roadmap to obtaining it.