Why Do We Believe in Misinformation? The Truth About the 'Gullible Brain' Revealed by 'Thinking, Fast and Slow': An AI Book Review

Thinking, Fast and Slow, by Daniel Kahneman, 2012

"The new virus is a government conspiracy," "5G causes disease," "Vaccines contain microchips"—why do so many people believe these claims that flood the internet? Are they simply being deceived because they are "ignorant"? No, that is not actually the case. The problem lies in the "very structure of the brain" that we all share.

Psychologist Daniel Kahneman, who won the Nobel Prize in Economic Sciences in 2002, wrote the book "Thinking, Fast and Slow," which is one of the most important books for understanding why fake news and conspiracy theories are so easy to spread. For many years, we have depicted humans as "rational agents (Econs)," beings who calmly evaluate information and logically judge truth or falsehood. However, Kahneman, along with his long-time ally Amos Tversky, fundamentally overturned this premise and pioneered a new field called "behavioral economics." What they revealed was the shocking fact of how irrational our judgments are, how filled they are with predictable biases, and how surprisingly easily we are led by misinformation.

The core of this book is the story of two characters living inside our heads. One is "System 1," an impatient protagonist who is impulsive, intuitive, and judges things with lightning speed. This System 1 is the very culprit that spreads conspiracy theories without checking, judges the content of articles based only on headlines, and reacts instantly to emotional misinformation. The other is "System 2," a wise sage who is careful, logical, and deliberative, but unfortunately, extremely lazy. Our daily lives are driven almost entirely by the strange cooperative (or conflicting) relationship between these two. And unfortunately, fake news and pseudoscience are designed to skillfully exploit the weaknesses in this brain structure.

In this book review, we will explore the important concepts of the book from the perspective of why conspiracy theories and pseudoscience are so easy to permeate our thinking. The battle between System 1 and System 2, the many predictable cognitive biases, the psychology of loss aversion (prospect theory), and the "two selves" created by memory distortion. This knowledge should become the strongest weapon for seeing through misinformation and honing critical thinking.

Part 1: The Runaway Intuition and the Negligence of Reason — The Battle Between System 1 and System 2

Behind the scenes of our consciousness, two different thinking systems are always at work. To make them easier to understand, Kahneman named them "System 1" and "System 2." This does not refer to specific parts of the brain, but is a clever metaphor that characterizes modes of thinking 4.

Character Introduction: The Impatient Hero "System 1" and the Lazy Sage "System 2"

System 1 (Fast Thinking)

System 1 is an automatic, effortless mode of thinking 2. Feeling that a beautiful view is "beautiful," recognizing a friend's face in an instant, understanding simple sentences, and driving on a familiar road are all the work of System 1 2. This is the default mode that is always running while we are awake, processing the vast majority of the cognitive load in our daily lives 5. This is because it is surprisingly efficient. The source of our impressions, intuitions, and intentions lies in this System 1 8. It also includes innate skills essential for survival, such as the ability to instantly sense danger when facing a wild animal or a spider 9.

System 2 (Slow Thinking)

On the other hand, System 2 is a conscious, effortful mode of thinking 4. For example, solving complex calculation problems like "17x24," parking in a tight space, or preparing tax return documents are the turn of System 2 9. System 2 is the conscious, rational self that we think of as "ourselves" 11. However, its greatest characteristic is that it is "lazy." Activating System 2 requires a great deal of mental energy, and our brains are instinctively designed to conserve energy 2.

The Strange Coexistence of the Two Systems

How do these two systems work together? Basically, the hardworking System 1 constantly sends "suggestions" such as impressions, intuitions, intentions, and emotions to System 2 11. And the lazy System 2 usually approves those suggestions without making almost any corrections 9. System 2 is only fully mobilized when System 1 faces a problem it cannot handle, that is, when it encounters a question it cannot answer 5. Although the final decision-making power lies with System 2, that authority is often abandoned 9. System 1 is hardworking but careless, and System 2 is cautious but lazy. The relationship is such that when System 1 can no longer handle things, it finally asks System 2 for help, and System 2 reluctantly gets up, saying, "I have no choice" 7.

What happens when System 2 slacks off? — The Source of Cognitive Bias

This power dynamic is the root of many errors in human judgment. Let's look at a famous problem introduced in the book: 'A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much is the ball?'

Many people immediately answer '10 cents.' This is the answer intuitively derived by System 1. However, if you pause for a moment to activate System 2 and double-check, you should realize that the correct answer is '5 cents' (if the ball is 5 cents, the bat is $1.05, totaling $1.10). This simple problem brilliantly demonstrates how impulsively System 1 provides answers and how easily System 2 tends to accept them without question 2.

Herein lies the central conflict structure of the book.System 1, due to its speed and automaticity, becomes the source of many systematic errors, or 'cognitive biases' 2.Normally, System 2 should take on the role of verifying and correcting those errors. However, due to its inherent laziness, many errors go unnoticed and become our formal beliefs and judgments 2.

The fundamental flaw in human judgment is not the existence of the emotional and intuitive System 1 itself. Rather, the core of the problem lies in the fact thatSystem 2, which should be rational, is cognitively lazy. We are not so much irrational as we are creatures who'find it burdensome' to be rational. Correct logical thinking is a costly activity for our brains, and it is the arduous task of overriding default intuitions through conscious effort. Therefore, to make better judgments, it is important not only to strive to 'think better,' but also to create environments and mechanisms that lower the cognitive cost of engaging System 2 or automate better choices.

Part 2: Why Do We Repeat the Same Mistakes? — The Traps of Heuristics and Biases

How does System 1 make quick judgments? The secret lies in'mental shortcuts' called 'heuristics'. This is a habit of thought where, instead of answering a difficult question, we replace it with a much easier one 12. This efficient mechanism becomes a breeding ground for many predictable biases.

The 'Invisible Threads' That Manipulate Your Judgment: Representative Biases

Anchoring Effect

A phenomenon where the first number presented, even if irrelevant, bites into your thinking like an 'anchor' and distorts subsequent judgments 12. There are experimental results showing that the first amount suggested in price negotiations, real estate prices, or even the number rolled on a die by a judge can influence sentencing decisions 4. It is difficult to escape this powerful effect, but Kahneman advises: 'When the first number is presented, it is better to get into the habit of thinking carefully before answering rather than responding immediately' 4.

Availability Heuristic

A tendency to judge the frequency or probability of an event based on how easily that instance can be recalled 13. The probabilities of dramatic but rare events that are widely reported in the media, such as plane crashes or shark attacks, tend to be overestimated, while common but mundane risks like diabetes or strokes tend to be underestimated 4. The book states: 'If you are asked the probability of California being hit by a tsunami within the next 30 years, you will conjure up an image of a tsunami. (Omitted) And you will overestimate the probability of occurrence' 4.

The Illusion of Causality and the Craving for Narrative

System 1 has a strong impulse to find causal relationships even in random events. It automatically constructs a coherent (but often incorrect) story to understand the world 4. For example, a typical case is forcing an explanation of a day's stock price fluctuations by linking them to the day's biggest news (such as 'the arrest of Hussein') 4. This is related to the principle Kahneman calls 'WYSIATI (What You See Is All There Is)'. We construct reality with only the limited information at hand and ignore what we do not know 12.

Overconfidence and Hindsight Bias

We hold excessive confidence in our own judgments and think back on past events as if we 'knew it all along'

However, it should be added that some of the research cited in this book, especially studies regarding the 'priming effect,' have been subject to criticism for being difficult to replicate within the subsequent 'replication crisis' in psychology as well 15. This demonstrates that science is a self-correcting process and speaks to the importance of maintaining a critical perspective when reading the insights in this book.

Cognitive biases are neither signs of stupidity nor random errors. They are predictable and systematic side effects of a highly efficient cognitive system optimized for survival, rather than statistical truth. They are the price we pay for speed and efficiency. These heuristics worked well in most cases in the ancestral environments where humanity evolved. However, in modern society, which is flooded with complex statistics and information, these same shortcuts produce systematic errors, or biases. Fighting bias is not about obtaining a 'smarter' brain, but about recognizing that your own mental shortcuts are prone to failure

Part 3: The Pain of Loss is Twice as Strong as the Joy of Gain — The Impact of Prospect Theory

Among the achievements of Kahneman and Tversky, what is considered particularly groundbreaking is Prospect Theory . This theory overturns the model of the 'rational agent' that maximizes utility, which has been assumed by traditional economics, and describes how real humans make decisions under conditions of uncertainty 3.

Subjectivity of Value: The Value Function

The core of Prospect Theory lies in the value function, which shows that the way we perceive value is subjective and has three important characteristics 4.

Reference Dependence

We do not evaluate the value of things based on absolute standards, but rather judge them based on changes from a certain 'reference point,' that is, whether it is a gain or a loss 4. For example, if the expected bonus amount was 1 million yen (reference point) and you actually received 500,000 yen, even though you objectively gained 500,000 yen, psychologically you feel like you 'lost 500,000 yen' 4. The same 80,000 yen salary is a joy for someone who expected 70,000 yen, but a disappointment for someone who expected 90,000 yen.

Loss Aversion

This is the most powerful insight of Prospect Theory. It is the principle that 'losses are felt more intensely than gains' 4. Specifically, the pain of losing 10,000 yen is said to be felt about twice as strongly as the joy of gaining 10,000 yen 19. Borrowing an example from the book, if you compare the 'joy of suddenly receiving 100,000 yen as a windfall' with the 'sadness of suddenly being charged a 100,000 yen fine by the police for a traffic violation,' the psychological impact of the latter is far greater 4. This psychology of extreme loss aversion explains the status quo bias (the tendency to dislike change) and the endowment effect, where we place a high value on things we own and find it difficult to let them go.

Diminishing Sensitivity

Sensitivity to gains and losses becomes duller as we move away from the reference point 4. The joy of gaining 100 yen from 0 yen is felt much more strongly than the joy of 1,100 yen from 1,000 yen. Similarly, a 50 yen price increase for a 500 yen bento feels like a significant loss, but there is little resistance to adding a 1,000 yen option when buying a 1 million yen car 20.

Distortion of Probability: The Probability Weighting Function

Furthermore, we cannot evaluate probabilities objectively. We have a tendency to overestimate very low probabilities (which is why we buy lottery tickets) and underestimate very high probabilities (which is why we might not wear a seatbelt for short distances) 16. Because of this, we take seemingly contradictory actions: buying insurance out of fear of the slight possibility of suffering a large loss, while simultaneously buying lottery tickets dreaming of the slight possibility of gaining a large reward.

Applications to Real Life: Marketing and Investment

These principles are utilized everywhere in our daily lives. In marketing, phrases like “limited time offer” or “free for now only” frame “not buying now” as a loss, stimulating our loss aversion 3. Money-back guarantees reduce the risk of loss associated with the decision to purchase, lowering the hurdle to buying 19.

In the world of investment, prospect theory clearly explains irrational behavior. Investors have a tendency to sell stocks that are showing a profit early to lock in gains (risk aversion in the gain domain), while being unable to “cut losses” on stocks that are losing money, leaving them to languish (risk seeking in the loss domain) 21. This is behavior aimed at avoiding the pain of realizing a loss.

Our economic choices and life decisions are not so much the result of rational calculations of future wealth, but are rather dominated by immediate emotional desires to avoid the pain of loss, using the status quo as a benchmark. Value is not an objective thing, but a deeply emotional and context-dependent construct. This insight may have been formed during the process of evolution. Potential gains might only make a situation slightly better, but significant losses, such as losing all one's food, were directly linked to death. This deep emotional response for survival still governs our judgments in abstract domains like modern stock markets and consumer behavior.

Part 4: The Paradox of Experience and Memory — The “Two Selves” That Determine Your Happiness

Toward the end of the book, Kahneman poses the most profound and philosophical question. It is the concept of the “two selves” that exist within us.

The other self: The experiencing self vs. the remembering self

The experiencing self is the self that lives in the present moment, answering the question, “Does it hurt now?” 14. On the other hand, the remembering self is the storyteller that weaves the narrative of our lives, keeps records, and evaluates the whole, answering the question, “How was it, on the whole?” 14.

Crucially, it is this “remembering self” that governs our decision-making. We make future choices based not on the experience itself, but on the “memory” of the experience.

The tyranny of memory: The peak-end rule and duration neglect

And this remembering self is governed by two powerful biases.

The peak-end rule

The memory of an experience is determined almost entirely by the average of the most emotionally intense moment (the peak) and the final moment (the end) of that experience 7.

Duration neglect

How long the experience lasted has almost no effect on the memory-based evaluation 14.

The shocking experiments introduced in this book illustrate this principle. In experiments involving colonoscopies or submerging hands in cold water, subjects preferred the procedure that ended slightly more comfortably, even if it was objectively longer and involved more total pain 22. This means their 'remembering self' chose to force extra pain upon the 'experiencing self,' just to create a better 'memory.' This highlights a serious conflict of interest between the two selves.

What is happiness?

This distinction poses a fundamental question for us. Which self's happiness should we maximize? The 'experiencing self' that lives in moment-to-moment well-being, or the 'remembering self' that pursues satisfaction in the narrative of life 14?

This question has a major impact on how we think about vacations, relationships, and life satisfaction. We often make choices that become good stories later (a plus for the remembering self), even if they involve stress or discomfort in the moment (a minus for the experiencing self).

Perhaps we are not so much living our lives as we are constructing and editing memories of them. Our decision-maker, the 'remembering self,' acts like a dictatorial storyteller, prioritizing narrative consistency (a good peak and a satisfying ending) over the total amount of happiness actually lived by the 'experiencing self.' This suggests that to be 'happy,' we may need to consciously make choices that are kind to the 'experiencing self,' even if they don't make for the best 'story,' challenging the very way we pursue a 'good life.'

Conclusion: Overcoming Misinformation — 'System 2 Training' Through Critical Thinking

The human mind depicted in 'Thinking, Fast and Slow' is like a 'cognitive minefield' laid out by the efficient but error-prone System 1 and supervised by the powerful but lazy System 2. Conspiracy theories, fake news, and pseudoscience are traps cleverly set at the most explosive points within this very minefield.

Sensational headlines stimulate System 1, confirmation bias makes us collect only information that fits our beliefs, and the availability heuristic makes us mistake impressive misinformation for the truth. Our value judgments are distorted by loss aversion, making the imaginary loss of 'vaccine risks' feel greater than the real loss of 'disease risks'.

However, the book's message is not a pessimistic one that 'humans are foolish and it can't be helped.' Rather, it is a practical guidebook for recognizing the weaknesses in our thinking and countering them.

The key to fighting misinformation and pseudoscience is not to eliminate System 1, but to know when to doubt it and consciously activate System 2.

Specifically, the following strategies are effective:

• Adopting an 'outside view': Instead of relying on your intuition or emotional reactions, make judgments based on reliable statistical data and expert consensus. Develop the habit of asking, 'How is this information evaluated among experts?'

• Applying a 'pre-mortem': Before believing a claim, verify it from the opposite perspective by asking, 'If this information were misinformation, what signs would there be?' This allows you to escape the trap of confirmation bias.

• Diversifying information sources: System 1 mistakes information seen or heard repeatedly for the truth (mere exposure effect). That is why it is necessary to intentionally expose yourself to different perspectives and opposing information sources, and make an effort to break out of echo chambers.

• Recognizing emotional reactions: When you feel strong anger, fear, or anxiety, that is the sign to stop and activate System 2. By asking yourself, 'Why does this information make me feel so agitated?', you can see through manipulation.

The greatest lesson 'Thinking, Fast and Slow' gives us is a call for intellectual humility. It teaches us to reduce our certainty in our own intuition and beliefs just a little, and to start from the premise that 'I, too, could be deceived.' Being attracted to conspiracy theories or pseudoscience is not a problem for specific people only. It is a structural vulnerability of the cognitive system that we all possess.

By understanding how the mind works, we can make slightly better judgments. And in a modern society where misinformation and pseudoscience are rampant, that small difference becomes the decisive factor in distinguishing truth from fake news. This book does not give us a new brain, but it does give us a far superior 'instruction manual for thinking' to avoid being misled by misinformation.

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