Explore Cognitive Biases
Discover the psychological patterns, mental shortcuts, and decision traps that shape human judgment. Grounded in research, written as stories.
Survivorship bias
You study the winners and build your strategy around them — but the failures that never became visible are doing most of the shaping.
Swimmer's Body Illusion
Swimmers have great bodies because of genetics, not just training. Mistaking selection for causation quietly warps every choice that follows.
Clustering illusion
The tendency to perceive meaningful patterns, such as streaks or clusters, in random or noisy data.
Social Proof
Social proof is the tendency to assume that the behavior of others reflects the correct course of action in a given situation.
Sunk Cost Fallacy
The money is gone either way — but loss aversion keeps people pouring more in. Recognising the fallacy is the first move toward cutting free.
Reciprocity
Reciprocity is a cognitive bias where feeling obliged to return a favor, gift, or concession leads people to comply with requests they might otherwise refuse.
Confirmation bias
The tendency to search for, interpret, focus on, and remember information in a way that confirms one's preconceptions while ignoring or discounting contradictory evidence.
Authority bias
A title or uniform can override the actual evidence in your head. Authority bias makes expert-sounding sources feel true before you've checked them.
Contrast effect
A mediocre salary feels generous after a bad offer. Contrast effect means context — not reality — is setting your reference point.
availability heuristic
The first number in a negotiation pulls every counter-offer toward it. Anchoring shows why the opening bid matters more than logic suggests.
It Will Get Worse Before It Gets Better Fallacy
The tendency to interpret worsening conditions as a sign that an eventual improvement is imminent, leading one to persist with ineffective or harmful actions.
Story Bias
A vivid narrative beats a spreadsheet every time — even when the data is more reliable. Story bias explains why coherence feels like truth.
Why Human Minds Make Predictable Mistakes
Information & Attention
How attention filters, prioritizes, or overlooks available information.
Meaning & Interpretation
How the mind fills gaps, explains events, and finds patterns.
Decisions & Action
How urgency, limited time, and practical pressure shape choices.
Memory & Recall
How experiences are encoded, reconstructed, and remembered.
Hindsight bias
Hindsight bias is the tendency to perceive past events as having been more predictable than they actually were before they occurred.
Overconfidence effect
The overconfidence effect is a cognitive bias in which a person's subjective confidence in their judgments exceeds the objective accuracy of those judgments.
Chauffeur Knowledge
Confident-sounding detail is easy to mistake for depth. Chauffeur knowledge describes what fluency looks like when expertise isn't actually there.
Illusion of control
The tendency to overestimate one's degree of influence over external events that are actually determined by chance or outside one's control.
Incentive Super-Response Tendency
Incentive Super-Response Tendency is the cognitive bias where people change their behavior to maximize a reward, often undermining the original purpose of the incentive.
Regression to Mean Fallacy
Extreme results tend to moderate on their own — but we credit the intervention. Regression to the mean catches out managers, coaches, and clinicians alike.
Outcome bias
The tendency to judge a decision by its eventual outcome instead of the quality of the decision at the time it was made.
Paradox of Choice / Less Is More
More options feel like freedom, but past a threshold they produce paralysis and regret. Paradox of choice shows why fewer decisions are often better ones.
Liking Bias
Liking bias is the tendency to favor people we like, making us more likely to comply with their requests, buy from them, or help them, often overriding objective evaluation.
Endowment effect
The tendency for people to demand much more to give up an object than they would be willing to pay to acquire it.
Coincidence
The tendency to perceive meaningful connections between unrelated events, interpreting random coincidences as significant.
Groupthink
Agreement feels safer than accuracy inside a tight-knit group. Groupthink describes how social pressure quietly replaces critical thinking.
Neglect of probability
The tendency to disregard or underweight probability information when making decisions under uncertainty, focusing instead on the magnitude or emotional salience of outcomes.
Scarcity Error
Scarcity Error is the tendency to overvalue items or opportunities merely because they are perceived as scarce or limited.
Base rate fallacy
The probability of a single event feels large regardless of how common the outcome actually is. Base rate neglect is why rare events feel inevitable.
Gambler's fallacy
The tendency to believe that past independent random events influence the likelihood of future outcomes, when in reality each event's probability remains unchanged.
anchoring bias
The first price you see reshapes every estimate that follows — even an obviously random one. Anchoring bias runs deeper than most people expect.
Loss aversion
Loss aversion is the tendency for people to prefer avoiding losses over acquiring equivalent gains.
Social Loafing
In a group, individual effort fades as collective size grows. Social loafing explains why adding people to a project doesn't always add output.
Exponential Growth
Humans evolved to track linear change — exponential curves consistently catch us off guard, with expensive consequences.
Winner's Curse
The winner's curse is the tendency for the winning bidder in an auction to overpay, especially when the item's true value is uncertain and bidders have similar estimates.
Fundamental attribution error
The tendency to overemphasize personality-based explanations for others' behavior while underestimating situational influences.
False Causality
False causality is the cognitive error of inferring a causal relationship between two events merely because they occur together or in sequence, without proper evidence.
Halo effect
The halo effect is a cognitive bias where a positive (or negative) impression of one trait influences overall judgments of a person, product, or organization.
Alternative Paths
Alternative Paths bias is the tendency to focus on a single, salient course of action while neglecting other viable alternatives to achieve a goal.
Forecast Illusion
Forecasts feel precise but the confidence intervals tell a different story. Forecast illusion reveals how certainty is performed, not earned.
Conjunction fallacy
The tendency to judge a conjunction of two events as more probable than one of the constituent events alone.
framing effect
The tendency to draw different conclusions from the same information depending on how that information is presented.
Action bias
Action bias is the tendency to take action when faced with a problem or uncertainty, even when inaction would lead to a better outcome or when no clear problem exists.
Omission bias
The tendency to judge harmful actions (commissions) as morally worse than equally harmful inactions (omissions).
Self-serving bias
The tendency to attribute one's successes to internal factors (e.
Hedonic Treadmill
The hedonic treadmill (or hedonic adaptation) is the tendency for people to return to a relatively stable level of happiness despite major positive or negative life events.
Selection bias
Selection bias occurs when a sample is not randomly selected, causing it to differ systematically from the target population.
Association Bias
Association bias is the tendency to perceive a causal or meaningful connection between two events that merely co-occur, even when no such link exists.
Beginner's Luck
Beginner's luck is the tendency to attribute early success in a novel activity to personal skill rather than chance, leading to overconfidence and increased risk‑taking.
Cognitive dissonance
Cognitive dissonance is the uncomfortable mental state that arises when a person holds two conflicting beliefs, attitudes, or when their behavior contradicts their beliefs.
Hyperbolic discounting
Hyperbolic discounting is the tendency to prefer smaller, immediate rewards over larger, delayed ones, leading to time‑inconsistent choices.
Because Justification
Adding a reason — any reason — dramatically increases compliance. Explanations work even when they explain nothing.
Decision Fatigue
Decision fatigue is the deterioration in the quality of decisions made by an individual after a prolonged session of decision making.
Contagion Bias
Objects feel contaminated once associated with something unpleasant — even when no physical trace remains. Contagion bias is disgust as logic.
Problem with Average
Averages conceal as much as they reveal. The problem with average shows why a single summary statistic can make a population invisible.
Motivation Crowding
Pay people to do something they love and they may stop loving it. Motivation crowding explains how external rewards can erode internal drive.
Twaddle Tendency
The tendency to mistake verbose, elaborate language for meaningful insight, using excessive talk to mask a lack of substance or understanding.
Will Rogers Phenomenon
Move a low-performer to a better group and the group average rises — but nothing improved. The Will Rogers phenomenon lives in how we draw our categories.
Information bias
Information bias is the tendency to seek information even when it cannot affect action or improve decision outcomes.
Effort justification
Effort justification is the tendency to assign greater value to an outcome when substantial effort has been expended to obtain it.
The Law of Small Numbers
The tendency to draw strong conclusions from small sample sizes, ignoring the greater variability expected in small samples.
Observer-expectancy effect
Researchers unconsciously steer participants toward expected results. Observer expectancy effect is why double-blind design became a scientific standard.
Simple Logic
Logic that looks valid on the surface often rests on an unstated assumption. Simple logic bias catches out people who skip the check.
Barnum effect
The Barnum effect (also known as the Forer effect) is the tendency for individuals to rate vague, general personality descriptions as highly accurate for themselves personally.
Volunteer's Folly
People who volunteer for hard tasks differ from those who don't — but we credit the task, not the selection. Volunteer's folly in one sentence.
Affect Heuristic
Mood shapes which facts feel relevant before reasoning begins. The affect heuristic makes emotional state a data input, not just noise.
Introspection Illusion
Introspection frequently misreports the actual cause of a choice. The introspection illusion gives us stories, not access to our own processes.
Inability to Shut Up
The tendency to keep multiple options open rather than committing to a single choice, driven by fear of losing alternatives.
Sleeper Effect
A weak source can make an argument more persuasive over time, not less. The sleeper effect is why debunking today doesn't always hold tomorrow.
Alternative Blindness
Alternative blindness is the cognitive tendency to overlook or undervalue alternative options when evaluating a decision, focusing narrowly on the presented choice.
Social comparison bias
The tendency to favor individuals who do not threaten one's own standing or abilities when making decisions about assistance, evaluation, or resource allocation.
Serial position effect
The serial position effect is the tendency to recall items at the beginning (primacy) and end (recency) of a list better than items in the middle.
Not invented here
Internally built ideas feel better than outside solutions — regardless of quality. Not-invented-here bias costs teams problems already solved.
The Black Swan
A Black Swan event is an unpredictable, rare occurrence with massive impact and retrospective predictability.
Domain Dependence
Domain dependence is the tendency to apply knowledge or reasoning strategies only within the context in which they were learned, failing to transfer them to unrelated domains.
False consensus effect
The false consensus effect is the tendency for individuals to overestimate how much other people share their beliefs, attitudes, and behaviors.
In-Group Out-Group Bias
The tendency to favor members of one's own group (in-group) over those of other groups (out-groups), often based on minimal or arbitrary criteria.
Ambiguity Aversion
Ambiguity aversion is the tendency to prefer options with known probabilities over those with unknown probabilities, even when the expected outcomes are identical.
Default effect
The tendency to accept the pre‑set or default option when presented with a choice among alternatives.
Fear of Regret
Fear of regret is the tendency to anticipate feeling regret and let that anticipation guide choices, often leading to a preference for inaction or maintaining the status quo.
Salience Effect
What stands out gets acted on; what blends in gets ignored. Salience effect explains why memorable detail drives decisions more than representative data.
House-Money Effect
The tendency to treat money obtained as a windfall or unexpected gain more loosely than money earned through effort, leading to disproportionate spending or risk‑taking.
Procrastination
Procrastination is the voluntary delay of an intended action despite expecting to be worse off for the delay.
Identifiable victim effect
A face and a name unlock generosity that statistics alone cannot. The identifiable victim effect shows why a story of one outweighs a report of millions.
Illusion of Attention
The illusion of attention is the mistaken belief that we perceive all relevant stimuli in our visual field, when in fact attention limits perception and we can miss obvious events.
Strategic Misrepresentation
Cost and time estimates are systematically low because the distortion is deliberate. Strategic misrepresentation is optimism with an incentive.
Overthinking
Overthinking is a cognitive error where excessive analysis or rumination interferes with decision‑making or action, often leading to paralysis or worsened outcomes.
Planning fallacy
The tendency to underestimate the time, costs, and risks of future actions while overestimating the benefits, despite knowing that past similar tasks have taken longer.
Professional Deformation
Every profession trains a lens — and that lens keeps reappearing even when it doesn't fit. Professional deformation is expertise becoming a blind spot.
Zeigarnik effect
Uncompleted or interrupted tasks are remembered better than completed ones.
Illusion of Skill
The illusion of skill is the tendency to overestimate the role of personal ability and underestimate the influence of chance in determining outcomes.
Feature-Positive Effect
The feature-positive effect is a cognitive bias where people give more weight to the presence of a feature than to its absence when making judgments or decisions.
Cherry Picking
Cherry picking is the selective presentation of information that supports a desired conclusion while ignoring or omitting contradictory evidence.
Fallacy of the Single Cause
The fallacy of the single cause is the error of attributing a complex event to a single factor, ignoring the multitude of contributing factors.
Intention-to-Treat Error
Excluding non-compliant participants erases exactly why they dropped out. Intention-to-treat error distorts what treatments actually achieve.
Actor-observer bias
The actor-observer bias is the tendency to attribute other people's actions to their internal traits while attributing our own actions to external circumstances.
Additive bias
The tendency to favor adding elements rather than removing them when solving problems, even when subtraction would be more effective.
Aesthetic–usability effect
People tend to perceive aesthetically pleasing designs as more usable, even when actual functionality is unchanged.
Agent detection bias
The tendency to interpret ambiguous or uncertain stimuli as being caused by an intentional, intelligent agent.
Ambiguity effect
The tendency to avoid options for which the probability of a favorable outcome is unknown, even when the unknown probability could be favorable.
Anthropocentric thinking
The tendency to use human analogies as a basis for reasoning about other, less familiar, biological phenomena.
Anthropomorphism
Anthropomorphism is the attribution of human characteristics, emotions, or intentions to non-human entities such as animals, objects, or abstract concepts.
Assumed similarity bias
Assumed similarity bias is the tendency to overestimate how similar other people are to oneself in traits, attitudes, or behaviors.
Attentional bias
Attentional bias is the preferential processing of certain stimuli due to their relevance to an individual's current concerns, emotions, or motivations.
Attribute substitution
Attribute substitution occurs when a complex judgment is replaced by a simpler, related heuristic attribute, often without conscious awareness.
Automation bias
Automation bias is the tendency to rely excessively on automated systems, allowing their output to override correct judgments or contradictory information.
Availability cascade
An availability cascade is a self-reinforcing process in which a belief gains plausibility through its repeated expression in public discourse.
Backfire effect
Correcting a false belief can make it stick harder. The backfire effect shows why evidence alone is a surprisingly weak tool for changing minds.
Ballot order effect
Candidates listed first on a ballot tend to receive a small but statistically significant boost in votes compared with those appearing later.
Bandwagon effect
The tendency to adopt beliefs or behaviors because many other people are doing so.
Belief bias
Belief bias is the tendency to judge the logical strength of an argument based on how believable its conclusion seems, rather than on the argument's formal validity.
Ben Franklin effect
Doing someone a favour makes you like them more — not less. The Ben Franklin effect reverses the expected direction of obligation and warmth.
Berkson's paradox
Berkson's paradox is a statistical phenomenon where a spurious negative association appears between two variables when conditioning on a common effect or selection criterion.
Bias blind spot
The tendency to see oneself as less biased than other people, or to be able to identify more cognitive biases in others than in oneself.
Bizarreness effect
Bizarre or unusual material is remembered better than common, ordinary material.
Boundary extension
Boundary extension is the tendency to remember the background of a scene as being larger or more expansive than it actually was.
Cheerleader effect
The cheerleader effect is the perceptual bias whereby individuals are judged as more attractive when seen in a group than when viewed alone.
Childhood amnesia
Childhood amnesia is the inability of adults to retrieve episodic memories from early childhood, typically before the age of three to four years.
Choice-supportive bias
The tendency to remember one's choices as better than they actually were.
Common source bias
When all sources trace back to one original claim, you have an echo, not corroboration. Common source bias is how one error multiplies into consensus.
Compassion fade
The tendency to behave more compassionately toward a small number of identifiable victims than toward a large number of anonymous ones.
Congruence bias
Congruence bias is the tendency to test hypotheses only by seeking confirming evidence, while neglecting to test alternative hypotheses that could falsify them.
Conservatism bias
The tendency to insufficiently revise one's belief when presented with new evidence.
Context neglect bias
The tendency to neglect the human, social, and situational context when evaluating or solving technological problems.
Courtesy bias
The tendency to express opinions that are more socially acceptable than one's true beliefs in order to avoid offending others.
Cross-race effect
The tendency for people to recognize faces of their own race more accurately than faces of other races.
Cryptomnesia
Cryptomnesia is a memory bias where a person mistakenly believes a thought, idea, or creation is original, when it is actually a forgotten memory.
Cue-dependent forgetting
Cue-dependent forgetting occurs when information is harder to recall because the contextual cues present at encoding are absent or different at retrieval.
Curse of knowledge
When better-informed people find it extremely difficult to think about problems from the perspective of lesser-informed people.
Decoy effect
The decoy effect occurs when the addition of a third, clearly inferior option (the decoy) shifts people's preference toward one of the original options that dominates the decoy.
Defensive attribution hypothesis
The tendency to assign more blame for a mishap to people who are perceived as dissimilar to the judge.
Denomination effect
The tendency to spend more money when it is denominated in small amounts (e.
Disposition effect
The tendency to sell assets that have increased in value and keep assets that have decreased in value.
Distinction bias
The tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.
Domain neglect
Domain neglect is the tendency to overlook relevant knowledge from a specific domain when solving problems that require interdisciplinary thinking.
Dunning–Kruger effect
The Dunning–Kruger effect is a cognitive bias where people with low ability at a task overestimate their competence, while people with high ability tend to underestimate theirs.
Duration neglect
Pain at the peak registers more strongly than duration. Duration neglect explains why a long ordeal is remembered as less severe than a brief intense one.
Egocentric bias
People overweight their own role in shared events — and so does everyone else. Egocentric bias is why responsibility totals exceed 100 percent.
Embodiment bias
Embodiment bias refers to the tendency to attribute meaning or properties to objects or events based on one's own bodily states, capacities, or characteristics (e.
End-of-history illusion
The age-independent belief that one will change less in the future than one has changed in the past.
Escalation of commitment
The further in you are, the harder it becomes to justify walking away. Escalation of commitment is sunk cost plus social identity operating together.
Euphoric recall
Euphoric recall is the tendency to remember past experiences more favorably than they actually were, while downplaying or forgetting negative aspects.
Experimenter's
What the researcher expects tends to appear in the data — not through fraud, but through the hundreds of small decisions that shape an experiment.
Extension neglect
Extension neglect is the tendency to ignore or underweight the size of a sample when judging the likelihood, representativeness, or significance of an outcome.
Extrinsic incentives bias
Extrinsic incentives bias is the tendency to explain others' actions by external rewards or pressures while explaining one's own actions by internal drives or motivations.
Fading affect bias
A bias in which the emotion associated with unpleasant memories fades more quickly than the emotion associated with pleasant ones.
False memory
A false memory is a recollection of an event that did not actually occur, where imagination or suggestion is mistaken for a genuine memory.
False uniqueness bias
People tend to overestimate how differently they think and behave compared with their peers. False uniqueness bias is individuality as cognitive error.
Fluency heuristic
Processing ease feels like truth. Fluency heuristic explains why clearly written claims — regardless of their accuracy — tend to win on first impression.
Frequency illusion
Notice a new car model and suddenly it seems to be everywhere. Frequency illusion is the brain flagging recent learning as evidence of prevalence.
Functional fixedness
A cognitive bias that leads individuals to perceive objects only in terms of their typical functions, limiting creative problem solving.
G. I. Joe fallacy
The tendency to think that merely knowing about a cognitive bias is enough to prevent it from influencing one's judgments or decisions.
Gender bias
Gender bias is the tendency to favor one gender over another based on stereotypes or assumptions, often operating unconsciously.
Generation effect
The generation effect is the finding that information is better remembered when it is self‑generated rather than merely read or heard.
Google effect
The tendency to forget information that can be easily retrieved via online search engines.
Group attribution error
When something goes wrong in a group, the whole group gets blamed — even bystanders. Group attribution error scales individual behaviour upward.
Groupshift
Groups shift toward more extreme positions than members would hold alone. Group polarisation shows how discussion amplifies rather than moderates.
Hard–easy effect
The tendency to overestimate one's ability to accomplish hard tasks, and underestimate one's ability to accomplish easy tasks.
Hostile attribution bias
The tendency to interpret others' ambiguous or benign actions as intentionally hostile.
Hot-cold empathy gap
The tendency to underestimate the influence of visceral drives (e.
Hot-hand fallacy
The hot-hand fallacy is the belief that a person who has experienced success with a random event has a greater chance of further success in additional attempts.
Illusion of asymmetric insight
The illusion of asymmetric insight is a cognitive bias in which individuals believe they understand others better than others understand them.
Illusion of explanatory depth
The tendency to believe one understands how something works better than one actually does, especially for explanatory knowledge.
Illusion of learning
The illusion of learning is a metacognitive bias where individuals mistakenly believe they have understood or learned material simply because it feels familiar or easy to process.
Illusion of transparency
You assume your discomfort is obvious to everyone in the room — it usually isn't. Illusion of transparency overestimates how much leaks outward.
Illusion of validity
The tendency to overestimate the accuracy of one's judgments, especially when the available information is consistent or inter-correlated.
Illusory correlation
Illusory correlation is the perception of a relationship between two variables when no such relationship exists or when it is weaker than perceived.
Illusory superiority
The tendency for individuals to overestimate their positive qualities and abilities while underestimating their negative ones relative to others.
Illusory truth effect
The tendency to judge a statement as true simply because it feels familiar or has been encountered before, regardless of its actual accuracy.
Impact bias
The tendency to overestimate the length or the intensity of the impact of future feeling states.
Implicit association
Implicit association refers to the automatic mental links between concepts that influence the speed of categorizing related items, as measured by reaction time differences.
Impostor Syndrome
High achievers believe they are one mistake away from being found out. Impostor syndrome is not low confidence — it is competence without ownership.
Ingroup bias
The tendency for people to give preferential treatment to others they perceive as members of their own social groups.
Insensitivity to sample size
The tendency to underestimate the variability that can occur in small samples, leading to overconfident judgments based on limited data.
Intentionality bias
The tendency to judge human actions as intentional rather than accidental.
Just-world fallacy
The just-world fallacy is the tendency to believe that the world is fundamentally fair, leading people to rationalize injustice by assuming victims deserved their fate.
Law of the instrument
When you hold a hammer, problems start to look like nails. Law of the instrument describes how a preferred tool colonises your entire view of a situation.
Less-is-better effect
The tendency to prefer a smaller option when options are evaluated separately, but not when they are evaluated jointly.
Leveling and sharpening
Memory preserves sharp peaks and smooths flat background. Leveling and sharpening is how recall reshapes — and distorts — the original event.
Levels-of-processing effect
Information processed at a deeper semantic level is retained far better. Levels of processing effect is why meaning aids memory more than repetition.
Memory inhibition
Being shown some items from a list makes it harder to retrieve the other items.
Mere exposure effect
The tendency to express undue liking for things merely because of familiarity with them.
Misinformation effect
The misinformation effect is a memory distortion where exposure to incorrect information after an event reduces the accuracy of later recall of that event.
Misinterpreted-effort hypothesis
Effort is treated as a proxy for quality — harder-to-read text seems more credible. Misinterpreted effort hypothesis tracks this distortion.
Modality effect
The channel through which information arrives shapes what gets remembered. Modality effect shows that hearing and reading leave different traces in memory.
Money illusion
The tendency to focus on the nominal (face) value of money rather than its real purchasing power after accounting for inflation or deflation.
Mood-congruent memory bias
The tendency to recall information that matches one's current emotional state more easily than information that does not match that state.
Moral credential
One good deed can feel like a moral credit — making a second lapse seem acceptable. Moral credential effect is ethical accounting that never balances.
Moral luck
Moral judgement acts as if effort alone explains results. Moral luck makes praise and blame inconsistent by design — luck does most of the work.
Motonormativity
Movement is the default healthy state; deviating from it draws suspicion. Motonormativity is a bias built into how health itself is defined.
Naïve cynicism
Naïve cynicism is the tendency to expect others to exhibit more egocentric bias than oneself.
Naïve realism
Everyone assumes their perceptions are objective and sees disagreement as evidence of the other person's bias. Naive realism is the lens that hides itself.
Negativity bias
Bad experiences register more vividly and last longer than equivalent good ones. Negativity bias is evolution's precautionary principle, still running.
Next-in-line effect
When taking turns speaking in a group with a predetermined order, people tend to have poorer recall for the words spoken by the person who spoke immediately before them.
Normalcy bias
When danger arrives, the default assumption is that things are normal. Normalcy bias delays exactly the responses that crises require.
Objectivity illusion
The objectivity illusion is the tendency for people to believe they are more objective and less biased than others.
Optimism bias
The tendency to overestimate the likelihood of positive events and underestimate the likelihood of negative events affecting oneself.
Ostrich effect
The tendency to avoid acknowledgment of an obviously bad situation to avoid the bad feelings that may come with acknowledgment of the situation.
Outgroup favoritism
Outgroup favoritism is the tendency for members of socially disadvantaged groups to express positive attitudes or preferences toward groups other than their own.
Outgroup homogeneity bias
Individuals perceive members of social groups they do not belong to (outgroups) as more similar to each other than members of their own group (ingroup).
Pareidolia
Pareidolia is the tendency to perceive meaningful patterns, such as faces, in random or ambiguous visual or auditory stimuli.
Part-list cueing effect
The part-list cueing effect occurs when being shown some items from a previously learned list later impairs recall of the remaining, non-cued items.
Peak–end rule
The worst moment and the final moment of an experience shape how it is remembered — duration barely registers. Peak-end rule gives endings outsized weight.
Perky effect
The Perky effect refers to the phenomenon where a faint visual perception can influence or be confused with mental imagery, causing imagined images to be shaped by real stimuli.
Pessimism bias
The tendency to overestimate the likelihood that negative events will occur.
Picture superiority effect
The picture superiority effect is the tendency for information presented as images to be remembered more easily and frequently than the same information presented as words.
Plan continuation bias
Plan continuation bias is the tendency to persist with an original plan of action even when new information indicates that the plan is no longer appropriate or effective.
Plant blindness
The tendency to ignore plants in their environment and a failure to recognize and appreciate the utility of plants to life on earth.
Present bias
Present bias is the tendency to overvalue immediate rewards relative to future ones when making decisions involving trade-offs across time.
Primacy effect
The tendency to better remember items that appear at the beginning of a list compared to those in the middle.
Pro-innovation bias
The tendency to have excessive optimism about an invention or innovation's usefulness for society while overlooking its limitations and weaknesses.
Probability matching
People match their choices to probability rather than always picking the best option. Probability matching trades certainty for intuitive fairness.
Projection bias
Projection bias is the tendency to overestimate how much one's future self will share one's current preferences, thoughts, and values.
Proportionality bias
The tendency to assume that large or significant events must have correspondingly large or significant causes.
Pseudocertainty effect
A certain small gain feels safer than a gamble with higher expected value — but only when framed as gains. Pseudocertainty reverses with loss framing.
Puritanical bias
Pleasure is treated as morally suspicious and restraint as inherently virtuous. Puritanical bias shapes health, productivity, and social policy quietly.
Pygmalion effect
The phenomenon whereby others' expectations of a target person affect the target person's performance.
Quantification bias
The tendency to give greater weight to information that can be measured or quantified while undervaluing aspects that are difficult to measure.
Reactive devaluation
Reactive devaluation is the tendency to devalue a proposal simply because it is believed to originate from an adversary.
Recency effect
A cognitive bias where items presented at the end of a list are recalled more easily than those in the middle.
Recency illusion
The recency illusion is the mistaken belief that a phenomenon one has just noticed is itself recent, when in fact it has existed for a longer time.
Reminiscence bump
The tendency to recall more personal memories from adolescence and early adulthood than from other life periods.
Repetition blindness
Repetition blindness is the reduced ability to notice a second occurrence of a visual target when it appears shortly after the first in a rapid sequence.
Restraint bias
The tendency to overestimate one's ability to resist temptation.
Rhyme as reason effect
The tendency to perceive rhyming statements as more truthful or accurate than non-rhyming statements with similar meaning.
Risk compensation
Risk compensation (also known as the Peltzman effect) is the tendency for people to take greater risks when they perceive their safety to have increased.
Rosy retrospection
The tendency to remember past events as more positive than they actually were.
Salience bias
The most visible option drives decisions regardless of relevance. Salience bias makes prominence do the work that evidence should.
Saying is believing effect
Saying something out loud moves your private beliefs in that direction. Saying-is-believing effect is persuasion turned inward.
Scope neglect
Scope neglect (also called scope insensitivity) is the tendency to evaluate a problem or solution without adequately considering its scale or magnitude.
Selective perception
Selective perception is the tendency for expectations, beliefs, or motivations to influence what information a person notices and interprets.
Self-relevance effect
Memories that are personally relevant to the self are recalled more accurately than similar information that is not self-related.
Semmelweis reflex
The tendency to reject new evidence that contradicts an established paradigm or belief.
Sexual overperception bias
Sexual overperception bias is the tendency to perceive more sexual interest from another person than they actually express; sexual underperception bias is the opposite tendency.
Shared information bias
Groups discuss what everyone already knows, crowding out what only one person holds. Shared information bias is why meetings rarely surface what matters.
Social cryptomnesia
Groups claim credit for social progress while distancing from past wrongs. Social cryptomnesia is how movements get remembered without their people.
Social desirability bias
The tendency to over-report socially desirable characteristics or behaviours in oneself and under-report socially undesirable characteristics or behaviours.
Source confusion
Source confusion is a memory error in which a person incorrectly attributes the origin of a memory, mixing episodic details with information from other sources.
Spacing effect
Information is better recalled when exposure to it is repeated over a long span of time rather than massed together in a short period.
Spotlight effect
The tendency to overestimate how much other people notice one's appearance or behavior.
Status quo bias
The tendency to prefer things to stay relatively the same.
Stereotyping
Expecting a member of a group to have certain characteristics without having actual information about that individual.
Subadditivity effect
The tendency to judge the probability of a disjunction of mutually exclusive events as lower than the sum of the probabilities of its individual components.
Subjective validation
Subjective validation is the tendency to perceive vague or general statements as personally meaningful and accurate when they align with one's beliefs or expectations.
Suggestibility
Suggestibility is the tendency to accept and internalize ideas suggested by others, often mistaking them for personal memories.
Surrogation
Losing sight of the strategic construct that a measure is intended to represent, and subsequently acting as though the measure is the construct of interest.
System justification
The tendency to defend and bolster existing social, economic, and political arrangements, even when doing so conflicts with personal or collective interests.
Tachypsychia
Tachypsychia is an altered perception of time in which events seem to either slow down or speed up, typically occurring during high adrenaline or high stress states.
Teleological bias
Teleological bias is the tendency to attribute purpose or goal-directed intent to natural entities, events, or processes that lack such design.
Telescoping effect
Recent events feel closer than they are; distant ones feel further away. Telescoping effect distorts memory and every frequency estimate built on it.
Testing effect
The testing effect is the phenomenon where retrieving information from memory (e.
Third-person effect
The tendency to believe that mass-media messages influence others more than they influence oneself.
Time-saving bias
Time saved at high speeds is overestimated — so faster options feel more worthwhile than the maths supports. Time-saving bias shapes every commute.
Tip of the tongue
A word sits just out of reach: meaning there, label gone. Tip-of-the-tongue state maps the gap between semantic and phonological memory.
Trait ascription bias
The tendency to see one's own personality, behavior, and mood as more variable across situations than that of others.
Truth bias
People tend to assume that others are telling the truth unless they have clear reason to doubt.
Turkey illusion
The turkey illusion is the tendency to assume that a trend will continue without expecting sudden breaks or reversals.
Ultimate attribution error
Negative group outcomes get blamed on stable traits; identical outcomes in your own group get explained away. Ultimate attribution error scales prejudice.
Unconscious bias
Attitudes shaped by culture, experience, and exposure operate outside conscious awareness and shape judgment before any deliberate reasoning begins.
Value selection bias
The tendency to rely on existing numerical data when reasoning in an unfamiliar context, even if calculation or numerical manipulation is required.
Weber–Fechner law
A noticeable difference is a fixed ratio of the original — the same change feels large from a small base, trivial from a large one. Weber-Fechner law.
Well travelled road effect
The tendency to underestimate the duration taken to traverse oft‑travelled routes and overestimate the duration taken to traverse less familiar routes.
Women are wonderful effect
A tendency to associate more positive attributes with women than with men.
Worse-than-average effect
A tendency to believe oneself to be worse than others at tasks perceived as difficult.
Zero-risk bias
The preference for eliminating a small risk entirely, even when another option would produce a greater overall reduction in a larger risk but leave some residual risk.
Zero-sum bias
Resources and influence are assumed to be zero-sum even when they aren't — making cooperation feel like loss before any negotiation starts.
von Restorff effect
The von Restorff effect (also called the isolation effect) is the tendency for an item that stands out from its peers to be remembered better than other items.