ONE OF SEVEN WAYS OF SEEING
Recognize the shortcuts that quietly shape your judgment.
Support theory models how an event’s description affects its judged probability. Listing possibilities separately can draw attention to outcomes people overlook when they assess a broad category, so equivalent descriptions can receive different probability estimates.
Support theory models probability judgments as responses to descriptions of events. Listing an event’s components can increase its judged probability, while listing alternatives can reduce it. Extensions examine why a combined description may receive less support than its separately assessed parts, including repacking and anchoring as possible mechanisms.
People often rate themselves above an average peer. Support theory suggests that the comparison draws on more evidence about oneself than about a vaguely defined group. Naming a specific peer, changing the direction of comparison, or defining the trait more clearly can alter the judgment; motivation may also shape which evidence comes to mind.
A winner selected from many random attempts may have an impressive record without repeatable skill. Taleb’s monkey example asks whether the selection process, including unseen failures, supports a prediction of future success.
Survivorship bias occurs when a sample includes only people or things that passed a selection process, omitting those that failed or disappeared. Conclusions drawn from that sample may misstate success rates, risks, or the traits associated with success. Abraham Wald’s analysis of damage to returning warplanes illustrates why missing cases matter.
This chapter discusses survivorship bias and related concepts such as data mining, overfitting, and regression to the mean, emphasizing that in fields with high randomness like finance, track records are often due to luck rather than skill. It contrasts this with professions like dentistry or music where randomness is low and past performance is a reliable indicator of competence.
Survivorship bias occurs when we focus on the successful outcomes (e.g., companies that show earnings increases) while ignoring the many failures, leading to overestimating the probability of success. This cognitive bias distorts our perception of skill versus randomness.
Even a population composed entirely of incompetent managers will produce a small number with great track records due to randomness. This makes it difficult to distinguish skill from luck based solely on past performance.
The swimmer's body illusion occurs when people mistake selection for an effect of an activity. Elite swimmers may have physical traits that helped them reach that level, so their appearance alone does not show what swimming will do for everyone. A related selection effect can make long-term gamblers remember unusually lucky beginnings.
Daniel Kahneman explains the dual-process model of the mind: System 1 (fast, automatic, intuitive) and System 2 (slow, deliberate, analytical). He describes how heuristics and biases arise from System 1's reliance on shortcuts and its tendency to substitute easy questions for hard ones, leading to predictable errors in judgment and decision-making.
Noise refers to unwanted variability in judgments that should be identical, measured by standard deviation. The text illustrates how even when bias is unknown, noise can be identified and addressed to improve decision-making systems.
Taboo trade-offs occur when sacred values (e.g., lives, children, honor) are pitted against secular ones (e.g., money), triggering moral outrage and punitive attributions. This concept explains why people resist quantifying certain values and treat such comparisons as morally degrading.
The bias of perceiving causal relationships between unrelated events, leading to superstitious behaviors even among rational professionals. This is illustrated by a trader who unconsciously repeated a specific entrance and tie after a profitable day, attributing the outcome to these arbitrary actions.
This label describes dismissing a technology without adequately examining its prospects. The Warner anecdote from 1927 illustrates the risk, though a technology’s later success does not prove that every earlier objection was unreasonable.
Taleb criticizes the assumption that action must follow a known endpoint. His account emphasizes exploration, trial and error, and outcomes that emerge without a complete plan.
The tendency to avoid actions that are easily imagined otherwise (e.g., selling a lottery ticket close to the drawing) due to the anticipation of intense regret if things go wrong, even when objective probabilities remain unchanged.
This basketball study grouped consecutive shots into blocks and compared the observed hit counts with those expected under a constant, independent hit probability. Its reported tests generally did not detect departures from that model.
Philip Tetlock's research examines how experts make predictions and reason about historical counterfactuals, revealing a general tendency toward theory-driven reasoning and biases like overconfidence and belief perseverance, particularly among those favoring parsimony and explanatory closure.
A cognitive bias where a pattern is identified in data after the fact by focusing on a subset of data that supports a hypothesis, while ignoring the larger context where no pattern exists.
Telling someone who is merely hot-tempered but not angry to 'cool down' can actually trigger genuine anger. This cognitive bias describes how an incorrect accusation of anger can create the very emotion it claims exists.
The human mind operates analogically, not logically, by patterning new information with past experiences to draw conclusions quickly. This plausible reasoning was evolutionarily advantageous, favoring survival over logical consistency.
Taleb describes Yevgenia Krasnova’s attachment to a favorite novel as a form of friendship. Her refusal to hear it analyzed illustrates how personal affection can shape a reader’s response to criticism.
The Baltimore Stockbroker parable illustrates survivorship bias, where a streak of correct predictions is achieved by sending different predictions to many people and only continuing with those who received correct ones, making the broker appear brilliant despite having no skill.
Ellenberg introduces attempts to find hidden messages in the Torah through equidistant letter sequences. The broader statistical question is how to distinguish evidence of a code from patterns found by searching many possibilities; this excerpt stops before the worked example and critique.
The bandwagon effect describes adopting a belief or behavior because it is popular. Other people’s choices can provide useful information, but popularity can also substitute for checking the reasons behind a choice.
The cognitive bias of selectively applying skepticism to certain domains (e.g., religion) while uncritically accepting authority in others (e.g., economics, science), often due to confirmation bias.
A confident story about a market movement can outrun the evidence. Taleb’s Bloomberg example separates two questions: whether a change is unusual and whether the proposed cause actually explains it.
This study compared students’ forecasts of happiness in a future relationship with happiness reported by students already in relationships. The excerpt reports similar forecasts and group averages for falling in love; it describes the breakup groups without providing their results.
The studies described here found overextreme forecasts among Dutch and American lawyers: low probabilities understated success and high probabilities overstated it. Discrimination was poorer in the American sample, especially for forecasts made far from trial.
The Cemetery of Letters refers to the bias of silent evidence, where we only see the successes (e.g., published books) and ignore the vast number of failures (e.g., unpublished manuscripts), leading to an overestimation of the uniqueness of successful individuals.
The paradox of choice suggests that having too many options can lead to decision paralysis and dissatisfaction, as demonstrated by Sheena Iyengar's jam experiment where a smaller selection led to higher purchase rates than a larger one.
The conjunction effect occurs when a combination of events is judged more probable than a broader event that contains it. A plausible added cause can make a narrower scenario feel more likely. Support theory relates this to how descriptions make supporting possibilities accessible.
Survivorship bias and missing evidence can make a plausible causal story look more convincing than it is. Taleb urges caution with 'because': ask what evidence is absent and whether the explanation distinguishes causation from luck.
Humans are naturally drawn to the tangible, visible, and concrete while ignoring the abstract and unseen, leading to cognitive biases like confirmation bias and neglect of silent evidence. This results in a superficial understanding of uncertainty and randomness.
The zero price effect is the extra appeal an offer can gain when its price falls to nothing. Ariely describes experiments in which people switched toward a free item even though the price gap between the available options stayed the same. A free offer can still cost time, require another purchase, or displace something you would value more.
Munger argues that layers of investment fees, consultants, and trading costs can consume a foundation’s returns. He discusses low-cost indexing and concentrated long-term ownership as different alternatives, and uses a historical three-percent cost estimate to show how fees and donations can shrink assets.
Our brains have inherent biases that distort perception and thinking, such as confirmation bias and inattentional blindness. Awareness of these biases can help us avoid irrational beliefs and make better decisions.
The default fund is a choice architecture tool where a pre-selected option is the automatic outcome if no active choice is made. The Swedish premium pension plan used a default fund (AP7) but nudged participants to actively choose their own portfolios, resulting in two-thirds making active choices.
People often evaluate evidence by focusing on its strength (extremeness) rather than its weight (reliability), leading to overconfidence when strength is high and weight low, and underconfidence when weight is high and strength low.
Erikson uses an exaggerated story about a Blue to illustrate how irrelevant detail can bury the point of a message. The practical question is which details help the audience understand or act.
Grant calls the gap between being impressed by a speaker and thinking critically about the material the dumbstruck effect. His examples show why enjoying a lecture is not a reliable measure of learning.
The Dunning–Kruger effect describes inflated self-assessments among low performers on particular tasks. Someone may lack both a skill and the knowledge needed to judge that skill accurately. It is a finding about calibration, not a rule that every beginner is arrogant or every expert underestimates their ability.
The durability bias is the tendency to overestimate how long emotional reactions to events will last. Research shows that even major life events often have less impact on long-term happiness than expected.
A cognitive bias where people prefer familiar solutions to problems even when those solutions are unlikely to work, analogous to looking for lost keys under a street lamp because it is well-lit, rather than where they were dropped.
People under time pressure or cognitive load often fail to correct their initial dispositional inferences about themselves, leading to biased self-judgments that ignore situational factors.
The ego default is our automatic tendency to protect and promote our self-image, often leading to harmful reactions when we perceive a threat to our status or identity.
The emotion default is reacting to a strong feeling before considering what an action will do. Parrish illustrates it with Sonny Corleone’s impulsive decisions in The Godfather.
The endowment effect describes our tendency to overvalue what we own simply because we own it, leading to a discrepancy between buying and selling prices. This bias is driven by emotional attachment, loss aversion, and an inability to see transactions from another's perspective.
Consumers often fail to invest in energy-efficient products (e.g., washing machines, vehicles) despite clear long-term savings, leading to the possibility that regulatory mandates can produce greater net benefits than market-based incentives like carbon taxes.
Kahneman connects optimism with entrepreneurship and overconfidence. This entry contains the chapter’s endnotes, rather than the main explanation of how optimism can encourage ventures while distorting judgments of success.
The envy/jealousy tendency is a deep-seated human drive, evolutionary in origin, that often outweighs greed in motivating behavior. It manifests strongly in competitive environments like universities and investment banks, where perceived inequities trigger intense emotions and social dynamics.
When our self-image is threatened, we instinctively waste energy making excuses instead of taking responsibility and solving the problem.
Taleb argues that reporting can use accurate fragments to misrepresent a person’s position. Drawing on his account of a discussion with David Cameron, he describes a conflict between journalists’ incentives and readers’ interests. He sees this as a structural failure that individual corrections cannot resolve. His proposed standard for disagreement is to represent an opponent’s meaning fairly before criticizing it.
The false consensus effect is the tendency to overestimate how common one's own opinions, choices, and attitudes are among others, often because people assume that others similarly construe situations. This cognitive bias can lead to misunderstandings and unwarranted negative inferences about others.
False polarization occurs when opposing partisans overestimate the differences in their views, underestimating common ground, due to naive realism and biased attributions. This misperception exacerbates conflict and hinders resolution.
The focusing illusion occurs when attention to one aspect of life makes it seem more important to overall well-being than it is in daily experience. Kahneman expresses it as: 'Nothing in life is as important as you think it is when you are thinking about it.'
Four common cognitive biases—narrow framing, confirmation bias, short-term emotion, and overconfidence—undermine decision quality. The WRAP process helps overcome them by widening options, reality-testing assumptions, attaining distance, and preparing to be wrong.
The fourfold pattern describes how people evaluate risky prospects differently based on the probability (high vs low) and the valence (gains vs losses) of outcomes, highlighting the asymmetry of losses and the nonlinear weighting of probabilities.
The fundamental computational bias refers to the pervasive tendency to contextualize information with prior knowledge and semantic associations, which is evolutionarily adaptive but can conflict with normative rationality in modern environments that require decontextualized reasoning. This bias, largely driven by System 1 processes, must sometimes be overridden by System 2 to handle abstract tasks in technological societies.
The gambler’s fallacy is the belief that a streak makes an independent random outcome due to reverse. A fair coin’s next toss does not become more likely to be tails just because earlier tosses were heads.