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Sources and Methodology

Every bias entry in DebiasDaily is informed by established cognitive-science research. Where available, we prioritize peer-reviewed studies and supplement them with reputable academic books and explanatory sources. This page lists the key sources and explains how the catalogue is built and maintained.

Peer-reviewed research

Journal articles and studies published in peer-reviewed outlets. These form the primary research foundation for the bias entries.

Judgment under Uncertainty: Heuristics and Biases

Amos Tversky, Daniel Kahneman (1974) — Science

The seminal paper introducing the heuristics-and-biases framework, covering availability, representativeness, and anchoring.

Anchoring BiasAvailability HeuristicRepresentativeness Heuristic
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The Framing of Decisions and the Psychology of Choice

Amos Tversky, Daniel Kahneman (1981) — Science

Classic paper demonstrating how the framing of choices as gains or losses systematically alters preferences.

Framing EffectLoss Aversion
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Individual Differences in Reasoning: Implications for the Rationality Debate?

Keith E. Stanovich, Richard F. West (2000) — Behavioral and Brain Sciences

Theoretical foundation for the System 1 / System 2 distinction and belief-bias effects used throughout the bias catalogue.

Foundation for 'fast vs. slow' thinking framework
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Planting Misinformation in the Human Mind: A 30-Year Investigation of the Malleability of Memory

Elizabeth F. Loftus (2005) — Learning & Memory

Research on how post-event information alters memory, foundational for the Misinformation Effect and False Memory entries.

Misinformation EffectFalse MemorySource Monitoring ErrorSuggestibility
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When More Pain Is Preferred to Less: Adding a Better End

Daniel Kahneman, Barbara L. Fredrickson, Charles A. Schreiber, Donald A. Redelmeier (1993) — Psychological Science

Original experiment demonstrating that retrospective evaluations of painful experiences depend on peak and end moments, not duration.

Peak-End Rule
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Illusory Correlation in Interpersonal Perception: A Cognitive Basis of Stereotypic Judgments

David L. Hamilton, Robert K. Gifford (1976) — Journal of Experimental Social Psychology

Classic experiments showing how people perceive relationships between rare or distinctive events that are statistically unrelated.

Illusory CorrelationStereotyping
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The Spotlight Effect in Social Judgment: An Egocentric Bias in Estimates of the Salience of One's Own Actions and Appearance

Thomas Gilovich, Victoria Husted Medvec, Kenneth Savitsky (2000) — Journal of Personality and Social Psychology

Seminal experiments demonstrating that people systematically overestimate how much others notice their appearance and behavior.

Spotlight Effect
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The Bystander Effect: A Meta-Analytic Review on Bystander Intervention in Dangerous and Non-Dangerous Emergencies

Peter Fischer, Joachim I. Krueger, Tobias Greitemeyer, Claudia Vogrincic, Andreas Kastenmüller (2011) — Psychological Bulletin

Comprehensive meta-analysis confirming the bystander effect and identifying boundary conditions.

Bystander Effect
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Do People Have Insight Into Their Abilities? A Metasynthesis

Ethan M. Zell, Zlatan Krizan (2014) — Perspectives on Psychological Science

Meta-analysis confirming the Dunning-Kruger effect and discussing its implications for self-assessment.

Dunning-Kruger Effect
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You Don't Know Me, But I Know You: The Illusion of Asymmetric Insight

Emily Pronin, Daniel Y. Lin, Lee Ross (2002) — Journal of Personality and Social Psychology

Experiments demonstrating that people believe they understand others better than others understand them, and that people are more aware of their own biases than of their own unbiased thinking.

Bias Blind Spot
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A Theory of Social Comparison Processes

Leon Festinger (1954) — Human Relations

Original theory proposing that people evaluate their own opinions and abilities by comparing themselves to others.

Social Comparison Bias
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The "False Consensus Effect": An Egocentric Bias in Social Perception and Attribution Processes

Lee Ross, David Greene, Pamela House (1977) — Journal of Experimental Social Psychology

Classic paper demonstrating that people overestimate the extent to which others share their beliefs and behaviors.

False Consensus Effect
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The Intuitive Psychologist and His Shortcomings: Distortions in the Attribution Process

Lee Ross (1977) — Advances in Experimental Social Psychology

Foundational review of the tendency to attribute others' behavior to disposition while ignoring situational factors.

Fundamental Attribution ErrorActor-Observer Bias
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Self-Serving Biases in the Attribution of Causality: Fact or Fiction?

Dale T. Miller, Michael Ross (1975) — Psychological Bulletin

Early empirical demonstration that people attribute success internally and failure externally.

Self-Serving Bias
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Social Categorization and Intergroup Behaviour

Henri Tajfel, Michael G. Billig, R. P. Bundy, Claude Flament (1971) — European Journal of Social Psychology

Minimal group paradigm experiments showing that mere categorization into groups produces in-group favoritism.

In-Group BiasOut-Group Homogeneity Bias
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Stereotypes and Prejudice: Their Automatic and Controlled Components

Patricia G. Devine (1989) — Journal of Personality and Social Psychology

Demonstrates that stereotypes are automatically activated even among low-prejudice individuals.

StereotypingImplicit Bias
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No Reduction in Hindsight Bias After Complete Information and Repeated Testing

Rüdiger F. Pohl, Hellmut Hell (1996) — Organizational Behavior and Human Decision Processes

Investigates the cognitive mechanisms behind hindsight bias as a consequence of memory reconstruction.

Hindsight Bias
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The Trouble With Overconfidence

Don A. Moore, Paul J. Healy (2008) — Psychological Review

Comprehensive review distinguishing overprecision, overplacement, and overestimation as three forms of overconfidence.

Overconfidence Bias
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Exploring the "Planning Fallacy": Why People Underestimate Their Task Completion Times

Roger Buehler, Dale Griffin, Michael Ross (1994) — Journal of Personality and Social Psychology

Experiments showing people underestimate task completion times even when they have relevant past experience.

Planning Fallacy
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Can There Ever Be Too Many Options? A Meta-Analytic Review of Choice Overload

Benjamin Scheibehenne, Rainer Greifeneder, Peter M. Todd (2010) — Journal of Consumer Research

Meta-analysis examining when and why more choices lead to worse outcomes.

Choice Overload
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Experimental Tests of the Endowment Effect and the Coase Theorem

Daniel Kahneman, Jack L. Knetsch, Richard H. Thaler (1990) — Journal of Political Economy

Seminal experiments demonstrating that losses loom larger than gains and that ownership increases valuation.

Loss AversionEndowment EffectStatus Quo Bias
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Adding Asymmetrically Dominated Alternatives: Violations of Regularity and the Similarity Hypothesis

Joel Huber, John W. Payne, Christopher Puto (1982) — Journal of Consumer Research

Classic experiments showing how adding an asymmetrically dominated option changes preferences between two alternatives.

Decoy EffectAsymmetric Dominance
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The Serial Position Effect of Free Recall

Bennet B. Murdock (1962) — Journal of Experimental Psychology

Foundational experiment demonstrating primacy and recency effects in memory recall.

Serial Position Effect
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Life Is Pleasant—and Memory Helps to Keep It That Way!

W. Richard Walker, John J. Skowronski, Catherine E. Thompson (2003) — Review of General Psychology

Research showing that negative emotional intensity fades faster than positive emotional intensity in autobiographical memories.

Fading Affect Bias
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Change Detection

Ronald A. Rensink (2002) — Annual Review of Psychology

Review of change detection and change blindness, and their implications for visual attention and awareness.

Change BlindnessInattentional Blindness
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A Constant Error in Psychological Ratings

Edward L. Thorndike (1920) — Journal of Applied Psychology

Original paper documenting the halo effect in military officer evaluations.

Halo EffectHorn Effect
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Frequency and the Conference of Referential Validity

Lynn Hasher, David Goldstein, Thomas Toppino (1977) — Journal of Verbal Learning and Verbal Behavior

Demonstrates that repeated exposure to a statement increases its perceived truthfulness.

Illusory Truth EffectMere Exposure Effect
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The Fallacy of Personal Validation: A Classroom Demonstration of Gullibility

Bertram R. Forer (1949) — Journal of Abnormal and Social Psychology

Classic demonstration showing that people accept vague, generic personality descriptions as uniquely accurate when they believe the descriptions are tailored to them.

Forer/Barnum Effect
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Attitudinal Effects of Mere Exposure

Robert B. Zajonc (1968) — Journal of Personality and Social Psychology

Classic paper on how repeated exposure increases liking without conscious awareness.

Mere Exposure EffectFamiliarity Bias
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Bad Is Stronger Than Good

Roy F. Baumeister, Ellen Bratslavsky, Catrin Finkenauer, Kathleen D. Vohs (2001) — Review of General Psychology

Comprehensive review demonstrating that negative events have greater psychological impact than positive ones of equal intensity.

Negativity Bias
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Projection Bias in Predicting Future Utility

George Loewenstein, Ted O'Donoghue, Matthew Rabin (2003) — The Quarterly Journal of Economics

Theoretical and empirical work on how people project current preferences onto future states.

Projection BiasEmpathy Gap
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The Optimism Bias

Tali Sharot (2011) — Current Biology

Neuroscience and behavioral evidence for the tendency to overestimate positive outcomes and underestimate negative ones.

Optimism Bias
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Logic and Human Reasoning: An Assessment of the Deduction Paradigm

Jonathan St B. T. Evans (2002) — Psychological Bulletin

Influential review covering how prior beliefs interfere with logical syllogistic reasoning.

Belief Bias
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The Psychology of Sunk Cost

Hal R. Arkes, Catherine Blumer (1985) — Organizational Behavior and Human Decision Processes

Classic experiments showing that prior investment influences current decisions even when the investment is irrecoverable.

Sunk Cost Fallacy
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Behavioral Study of Obedience

Stanley Milgram (1963) — Journal of Abnormal and Social Psychology

Landmark obedience experiments demonstrating the power of perceived authority to override personal conscience.

Authority BiasObedience to Authority
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Cryptomnesia: Delineating Inadvertent Plagiarism

Alan S. Brown, Dana R. Murphy (1989) — Journal of Experimental Psychology: Learning, Memory, and Cognition

Three experiments demonstrating that people inadvertently reproduce others' ideas while genuinely believing them to be original, due to source-memory failures.

Cryptomnesia
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The Third-Person Effect in Communication: The Impact of Media Bias on Subjective Assessments of Others and Self

W. Phillips Davison (1983) — Public Opinion Quarterly

Original paper introducing the third-person effect — the perception that mass-communicated messages have greater influence on others than on oneself.

Third-Person Effect
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Defensive Attribution: Effects of Severity and Relevance on the Assignment of Blame

Ellen Walster (1966) — Journal of Personality and Social Psychology

Experiments showing that people blame accident victims less when they are similar to the observer and when the accident is severe, consistent with a self-protective bias.

Defensive Attribution
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The Symbiosis of Social and Cognitive Automation Biases: Consequences for Human-Computer Teamwork

Raja Parasuraman, Victor Riley (1997) — Human Factors

Review of research on automation misuse and disuse, including the tendency for people to over-rely on automated systems even when they are incorrect.

Automation Bias
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Availability Cascades and Risk Regulation

Timur Kuran, Cass R. Sunstein (1999) — Stanford Law Review

Analysis of self-reinforcing processes by which an expressed perception triggers a chain reaction that increases its plausibility through rising availability in public discourse.

Availability Cascade
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Moral Luck

Bernard Williams, Thomas Nagel (1976) — Cambridge University Press

Seminal philosophical work examining how moral judgement is influenced by factors beyond an agent's control, challenging the assumption that moral responsibility depends solely on choice.

Moral Luck
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"Naive cynicism" in everyday theories of responsibility assessment: On biased assumptions of bias

Justin Kruger, Thomas Gilovich (1999) — Journal of Personality and Social Psychology

Four studies demonstrating that people expect others — but not themselves — to make motivationally biased responsibility assessments, a tendency the authors term naive cynicism.

Naïve Cynicism
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Google Effects on Memory: Cognitive Consequences of Having Information at Our Fingertips

Betsy Sparrow, Jenny Liu, Daniel M. Wegner (2011) — Science

Landmark study showing that the availability of digital information reduces the likelihood of encoding it into long-term memory.

Google Effect
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When Corrections Fail: The Persistence of Political Misconceptions

Brendan Nyhan, Jason Reifler (2010) — Political Behavior

Research demonstrating that factual corrections can sometimes increase misperceptions among ideologically committed groups.

Backfire Effect
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The illusion of moral decline

Adam M. Mastroianni, Daniel T. Gilbert (2023) — Nature

Large-scale cross-national research showing that the widespread perception of moral decline is an illusion produced by biased exposure to negative information and biased memory for past events.

Declinism
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A Meta-Analysis of the Effect of Time Pressure on Human Performance

J. A. Szalma, P. A. Hancock, S. Quinn (2008) — Proceedings of the Human Factors and Ergonomics Society Annual Meeting

Quantitative review of 125 studies showing that time pressure has a small but detrimental effect on performance, with effects varying by task type — facilitating speed but impairing accuracy.

Time-Pressure Effect
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The Placebo Effect in Clinical Practice

Ted J. Kaptchuk (2015) — Annual Review of Clinical Psychology

Comprehensive review of the placebo effect, its mechanisms, clinical implications, and ethical considerations in medical practice.

Placebo Effect
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Time Perception Under Stress

David Eagleman, Amy N. Bhatt (2019) — Frontiers in Psychology

Research on how stress and arousal alter time perception, including the mechanisms behind subjective time dilation during high-pressure situations.

Tachypsychia
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Interpersonal Perception

C. Neil Macrae, Charles Stangor (2013) — Annual Review of Psychology

Review of how people form impressions of others, including cognitive mechanisms underlying interpersonal perception and judgement.

Interpersonal Effects
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Cognitive Dissonance and the Benjamin Franklin Effect

Jack W. Brehm (1956) — Journal of Personality and Social Psychology

Research demonstrating that doing a favour for someone can increase liking through cognitive dissonance reduction — the mechanism underlying the Benjamin Franklin Effect.

Benjamin Franklin Effect
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Overcoming Organizational Defenses: Facilitating Organizational Learning

Chris Argyris (1990) — Allyn & Bacon

Analysis of how organisational defensive routines create traps that prevent adaptation and learning, including escalation of commitment and groupthink.

Organisational Traps
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The relation of strength of stimulus to rapidity of habit-formation

Robert M. Yerkes, John D. Dodson (1908) — Journal of Comparative Neurology and Psychology

Original paper establishing the inverted-U relationship between arousal and performance, later known as the Yerkes-Dodson law.

Peak Performance Effect
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Academic books

Books from academic presses and leading scholars that synthesize and extend the peer-reviewed literature.

Heuristics and Biases: The Psychology of Intuitive Judgment

Thomas Gilovich, Dale Griffin, Daniel Kahneman (eds.) (2002) — Cambridge University Press

Edited volume collecting key research on judgment heuristics and systematic biases in human reasoning.

Confirmation BiasHindsight BiasOverconfidence BiasPlanning Fallacy
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Nudge: Improving Decisions About Health, Wealth, and Happiness

Richard H. Thaler, Cass R. Sunstein (2008) — Yale University Press

Applies behavioral economics to policy and choice architecture, showing how to counter biases without restricting freedom.

Status Quo BiasDefault EffectChoice OverloadPresent Bias
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Victims of Groupthink: A Psychological Study of Foreign-Policy Decisions and Fiascoes

Irving L. Janis (1972) — Houghton Mifflin

Foundational work introducing the groupthink phenomenon, analyzing how group cohesion and insulation can produce poor decisions in political and organizational contexts.

Groupthink
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Naive Realism in Intergroup Relations: Consequences of Conflict

Lee Ross, Andrew Ward (1996) — Conflicts and Resolutions in Social-Cultural and Political Life (Lawrence Erlbaum)

Theoretical account of naive realism as a source of intergroup conflict, showing how people's belief in their own objectivity makes disagreement seem irrational or malicious.

Naive Realism
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The Science of Reasoning

Jonathan St B. T. Evans (2007) — Psychology Press

Academic textbook on reasoning, deduction, and the cognitive mechanisms underlying logical and heuristic thinking.

Belief BiasMatching BiasConfirmation BiasLogical Reasoning biases
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Just-World Beliefs and Victim Blaming

Melvin J. Lerner (1980) — Plenum Press

Foundational work on the belief in a just world and its consequences for victim blaming and moral judgment.

Just-World Hypothesis
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General educational references

Accessible, general-audience books and references that explain the biases in plain language. They are informative and reputable, but they are not peer-reviewed primary research.

Thinking, Fast and Slow

Daniel Kahneman (2011) — Farrar, Straus and Giroux

Nobel laureate Daniel Kahneman's comprehensive book on the two systems of thought and the cognitive biases that arise from System 1 (fast, intuitive) vs. System 2 (slow, deliberate) thinking.

Confirmation BiasAnchoring BiasAvailability HeuristicHindsight BiasFraming EffectOverconfidence BiasSunk Cost FallacyOptimism BiasLoss AversionEndowment Effect
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The Psychology of Human Misjudgment

Charlie Munger (1995) — Harvard University (lecture transcript)

Warren Buffett's partner outlines 25 standard causes of human misjudgment, many mapping directly to known cognitive biases.

Confirmation BiasIncentive BiasSocial ProofAuthority BiasReciprocity Tendency
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Misbelief: What Makes Rational People Believe Irrational Things

Dan Ariely (2023) — HarperCollins

Explores why intelligent people fall for misinformation, conspiracy theories, and irrational beliefs.

Confirmation BiasMotivated ReasoningIllusory Truth EffectBandwagon Effect
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The Invisible Gorilla: How Our Intuitions Deceive Us

Christopher Chabris, Daniel Simons (2010) — Crown

Famous experiments on inattentional blindness, change blindness, and the illusion of attention.

Change BlindnessInattentional BlindnessIllusion of Attention
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Predictably Irrational: The Hidden Forces That Shape Our Decisions

Dan Ariely (2008) — HarperCollins

Behavioral economics experiments showing systematic deviations from rational choice across pricing, social norms, and self-control.

Anchoring BiasDecoy EffectEndowment EffectPresent BiasSocial Norms
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The Art of Thinking Clearly

Rolf Dobelli (2013) — Sceptre

99 short chapters each covering a cognitive error, designed for practical self-awareness.

Survivorship BiasSwimmer's Body IllusionClustering IllusionSocial ProofAuthority BiasSunk Cost FallacyReciprocityConfirmation BiasAvailability Heuristic
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You Are Not So Smart

David McRaney (2011) — Gotham Books

Accessible tour of self-delusion, covering biases like confirmation bias, hindsight bias, and the fundamental attribution error.

Confirmation BiasHindsight BiasFundamental Attribution ErrorSelf-Serving BiasSpotlight EffectBarnum Effect
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Cognitive Bias Codex (Wikipedia)

Various contributors (2016) — Wikipedia

Comprehensive, community-maintained list of cognitive biases with references to primary literature.

Reference for bias taxonomy and categorization
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Social Proof and Informational Social Influence

Robert B. Cialdini (2001) — Influence: Science and Practice (5th ed.)

Comprehensive treatment of how people look to others' behavior to guide their own, especially under uncertainty.

Social ProofBandwagon EffectConformity
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Methodology

Bias Selection Criteria

  1. Empirical support: The bias must have peer-reviewed experimental evidence demonstrating its existence and reproducibility.
  2. Everyday relevance: The bias should manifest in common decisions — work, relationships, finance, health, media consumption.
  3. Actionability: Recognizing the bias must enable a practical counter-strategy a person can apply in real time.
  4. Distinctiveness: Each entry represents a unique cognitive mechanism, not merely a synonym or subtype of another bias.
  5. Coverage balance: The biases span six categories (Core Thinking, Memory & Perception, Social, Decision-Making, Logical & Reasoning, Behavioral & Everyday) to ensure broad domain coverage.

Content Creation Process

  1. 1. Primary source identification: Locate the original experimental paper(s) or authoritative textbook treatment.
  2. 2. Definition drafting: Write a plain-language definition (~2-3 sentences) capturing the core mechanism without jargon.
  3. 3. 'Why it happens' explanation: Summarize the cognitive or evolutionary mechanism from the literature.
  4. 4. Concrete examples: Create 3 relatable, everyday scenarios where the bias operates (no laboratory-only examples).
  5. 5. Counter-steps: Derive 4 practical, evidence-informed techniques from the debiasing literature.
  6. 6. Tips: Add 4 concise, memorable heuristics for quick recall.
  7. 7. Human review: A maintainer verifies all content against the live source(s) before merging.

Source Verification Standards

  1. Every cited source is opened and read by a human maintainer (see EDUCATIONAL_SOURCES.md).
  2. URLs must use HTTPS and resolve without paywall or anti-bot barriers at verification time.
  3. Titles, publishers, and publication years must match the source exactly.
  4. No AI-generated citations are accepted without independent human verification.
  5. The catalogue does not claim professional or academic review beyond the maintainer's verification.
  6. Sources are added incrementally — entries without verified sources simply show no source section.

Quiz Design Principles

  1. Questions target recognition and application, not memorization of definitions.
  2. Scenarios mirror real-life contexts where the bias actually operates.
  3. Answer options include the correct identification plus plausible but incorrect alternatives representing related biases or common misconceptions.
  4. Feedback explains why the correct answer fits and briefly notes why distractors do not.

Ongoing Maintenance

  1. Correction reports via GitHub issues are reviewed and addressed in subsequent releases.
  2. ContentVersion and lastReviewedAt fields track substantive revisions and verification dates.
  3. New biases are added only when they meet all selection criteria and have verified sources.
  4. The bias catalogue version increments when entries are added, revised, or corrected.

Evidence-Strength Labels

Each bias entry in the catalogue displays an evidence-strength label indicating how well-supported the bias is by the cited research. Labels are derived from the quality and number of the entry's sources — never fabricated.

Well-established

Classic, widely-replicated finding supported by multiple peer-reviewed studies or textbook coverage.

Supported

Backed by peer-reviewed research or DOI-linked sources, but not a central replication target.

Context-dependent

Validated in specific contexts or originating from trade literature rather than broad empirical research.

Debated

Limited evidence, conflicting findings, or contested scientific status.

Per-Bias Sources

Each bias entry in the catalogue may include a "Sources and further reading"section with specific, verified references for that bias. Sources are added incrementally as maintainers verify them — entries without verified sources show no section rather than a placeholder.

To see sources for a specific bias, visit its detail page from the Biases Archive or from today's lesson.