Confirmation bias makes us filter information through existing beliefs:
<ul>
<li>We unconsciously seek evidence supporting our views</li>
<li>Contradictory information gets downplayed or reinterpreted</li>
<li>Google searches with biased terms produce biased results</li>
<li>Echo chambers form when we surround ourselves with agreement</li>
<li>Even opposing groups both believe evidence supports their side</li>
</ul>
This bias explains polarization in politics, persistence of superstitions, and why changing minds is so difficult. Our brains act more like lawyers defending pre-existing positions than judges weighing evidence objectively.

Confirmation Bias

The sunk cost fallacy keeps us invested in losing propositions:<ul><li>Past investments are already gone and cannot be recovered</li><li>Rational decisions consider only future costs and benefits</li><li>Emotional attachment to previous investments clouds judgment</li><li>Fear of wasting prior investments leads to greater losses</li><li>Admitting failure feels more painful than continuing to invest</li></ul>This fallacy explains why people stay in bad relationships, continue watching boring movies, keep wearing uncomfortable clothes, and persist with failing projects. Recognizing that past investments are irrecoverable helps make better forward-looking decisions.

Sunk Cost Fallacy

The halo effect causes one positive trait to influence unrelated judgments:<ul><li>Attractive people are perceived as more intelligent and competent</li><li>Successful products create perception of company-wide excellence</li><li>Likable individuals receive benefit of doubt in unrelated areas</li><li>First impressions color subsequent evaluations of unrelated traits</li><li>Marketing effectively leverages this bias through brand association</li></ul>This mental shortcut explains why good-looking politicians get more votes, why we assume successful companies are good at everything, and why we're surprised when admired individuals have significant failings in other areas.

Halo Effect

Outcome bias causes us to evaluate decisions based on results rather than process:<ul><li>Good decisions can produce bad outcomes through bad luck</li><li>Poor decisions can yield good results through good luck</li><li>Decision quality should be judged by the information available at decision time</li><li>Fortune and misfortune often override decision quality</li><li>Hindsight creates illusion that outcomes were predictable</li></ul>This bias distorts performance evaluation in business, explains why we celebrate lucky risk-takers over careful planners, and creates incentives for reckless behavior when it happens to succeed. Focusing on process quality rather than outcomes leads to better long-term decision-making.

Outcome Bias

Social proof drives us to follow others' actions as a decision shortcut:
<ul>
<li>Others' behavior serves as evidence of correct action</li>
<li>Uncertainty increases reliance on social signals</li>
<li>We unconsciously imitate those around us</li>
<li>Consensus creates assumption of correctness</li>
<li>Marketing leverages this bias through testimonials and popularity claims</li>
</ul>
This tendency explains why restaurants seat patrons in windows, why laugh tracks work, why bestseller lists boost sales, and why peer pressure remains powerful throughout life. When unsure what to do, humans instinctively look to others for guidance.

Social Proof

Whether we like it or not, we are puppets of our emotions. We make complex decisions by consulting our feelings, not our thoughts.

If you think you can predict the future, think again.

The Dunning-Kruger effect explains why incompetence often features high confidence:
<ul>
<li>Novices lack knowledge to evaluate their own performance</li>
<li>Expertise includes recognizing the complexity of a domain</li>
<li>Knowledge reveals how much more there is to learn</li>
<li>Confidence peaks early before declining and then rising again</li>
<li>True experts often underestimate their relative ability</li>
</ul>
This cognitive bias explains why debates between experts and novices are so frustrating, why incompetent people don't seek improvement, and why superficial knowledge creates greater certainty than deep understanding.

Dunning-Kruger Effect

Thinking is more interesting than knowing, but less interesting than looking.

Survivorship bias distorts reality by showing only winners:<ul><li>Successes become highly visible while failures disappear</li><li>Hidden graveyards of failed attempts remain unseen</li><li>Common advice often suffers from this selective focus</li><li>Impossible skills seem achievable when we only see success</li><li>Accurate judgment requires examining the full dataset</li></ul>This bias affects multiple domains: business case studies, investment strategies, diet programs, and self-help advice. Without considering the entire sample—especially failures—conclusions will be dangerously skewed toward overoptimism.

Survivorship Bias

Availability bias makes easily recalled examples seem more important:<ul><li>Vivid examples outweigh accurate statistics</li><li>Recent events seem more probable than distant ones</li><li>Emotionally charged incidents distort risk assessment</li><li>Media coverage amplifies availability of certain risks</li><li>Personal experiences overshadow broader patterns</li></ul>This bias explains why people fear terrorism more than heart disease, worry about shark attacks more than car accidents, and overestimate the likelihood of lottery wins. Our risk assessment follows ease of recall rather than actual probability.

Availability Bias

Authority bias leads us to overvalue the opinions of authority figures:
<ul>
<li>Titles and uniforms trigger automatic deference</li>
<li>Hierarchy outweighs actual expertise in decision-making</li>
<li>Critical thinking shuts down in presence of authority</li>
<li>Expertise in one area creates assumed expertise in unrelated fields</li>
<li>Passing the buck provides psychological relief from responsibility</li>
</ul>
This bias explains why celebrity endorsements work, why corporate hierarchies perpetuate bad decisions, and why intelligent people follow harmful orders. Evolution programmed us to avoid challenging leaders—a tendency that requires conscious override in many situations.

Authority Bias

The anchoring effect causes initial values to disproportionately influence judgments:<ul><li>First numbers create a reference point for all subsequent values</li><li>Arbitrary anchors affect estimates of unrelated figures</li><li>Higher initial prices make subsequent prices seem reasonable</li><li>Negotiation outcomes correlate strongly with opening offers</li><li>Awareness of the bias doesn't eliminate its influence</li></ul>This powerful cognitive bias explains why car dealers show you the expensive model first, why minimum payment amounts on credit cards increase debt, and why starting salary significantly influences lifetime earnings regardless of performance.

Anchoring Effect

Think you make rational decisions? Think again. This eye-opening book reveals how our minds are riddled with systematic thinking errors. Author Rolf Dobelli distills decades of cognitive research into 99 short chapters, each exposing a common mental mistake and how to avoid it. From why we overvalue things we already own to how experts consistently fail with predictions, these cognitive biases affect every aspect of life—investing, business, relationships, and everyday decisions. Once you recognize these thinking traps, you'll catch yourself falling for them and make dramatically better choices.

A world-class thinker counts the 100 ways in which humans behave irrationally, showing us what we can do to recognize and minimize these “thinking errors” to make better decisions and have a better life Despite the best of intentions, humans are notoriously bad—that is, irrational—when it comes to making decisions and assessing risks and tradeoffs. Psychologists and neuroscientists refer to these distinctly human foibles, biases, and thinking traps as “cognitive errors.” Cognitive errors are systematic deviances from rationality, from optimized, logical, rational thinking and behavior. We make these errors all the time, in all sorts of situations, for problems big and small: whether to choose the apple or the cupcake; whether to keep retirement funds in the stock market when the Dow tanks, or whether to take the advice of a friend over a stranger. The “behavioral turn” in neuroscience and economics in the past twenty years has increased our understanding of how we think and how we make decisions. It shows how systematic errors mar our thinking and under which conditions our thought processes work best and worst. Evolutionary psychology delivers convincing theories about why our thinking is, in fact, marred. The neurosciences can pinpoint with increasing precision what exactly happens when we think clearly and when we don’t.Drawing on this wide body of research, The Art of Thinking Clearly is an entertaining presentation of these known systematic thinking errors--offering guidance and insight into everything why you shouldn’t accept a free drink to why you SHOULD walk out of a movie you don’t like it to why it’s so hard to predict the future to why shouldn’t watch the news. The book is organized into 100 short chapters, each covering a single cognitive error, bias, or heuristic. Examples of these concepts include: Reciprocity, Confirmation Bias, The It-Gets-Better-Before-It-Gets-Worse Trap, and the Man-With-A-Hammer Tendency. In engaging prose and with real-world examples and anecdotes, The Art of Thinking Clearly helps solve the puzzle of human reasoning.

Rolf Dobelli is a Swiss author and businessman. He began his writing career as a novelist in 2002, but he is best known internationally for his bestselling non-fiction The Art of Thinking Clearly (2011, English 2013), for which The Times has called him "the self-help guru the Germans love".