List of All Cognitive Biases

A

• Abilene Paradox

  A group collectively decides on a course of action that is counter to the preferences of all individuals in the group.

• Absent-Mindedness

  We fail to remember information due to lack of attention during encoding or retrieval.

• Action Bias

  We prefer to "do something" rather than nothing, even when inaction would be the statistically better choice (common in investing and sports).

• Actor-Observer Bias

  We attribute our own actions to situational factors while attributing others' actions to their character.

• Affect Heuristic

  We rely on our current emotions ("gut feelings") to make quick decisions, judging risks/benefits based on how we feel.

• Ambiguity Bias

  We avoid options where the probability of outcomes is unknown, preferring known probabilities even if less favorable.

• Ambiguity Effect

  We avoid options where the probability of a favorable outcome is unknown, preferring options with known probabilities.

• Anchoring

  We rely too heavily on the first piece of information we encounter (the "anchor") when making decisions.

• Anecdotal Fallacy

  We give more weight to personal stories and anecdotes than to statistical evidence.

• Anthropomorphism

  We attribute human characteristics, emotions, or intentions to non-human entities.

• Appeal to Novelty

  We assume that something new is automatically better than something old.

• Appeal to Probability Fallacy

  We assume that because something is possible, it is therefore inevitable or likely.

• Argument from Fallacy

  We assume that if an argument contains a logical fallacy, its conclusion must be false.

• Attentional Bias

  We pay more attention to certain things while ignoring others, often based on our current emotional state or concerns.

• Authority Bias

  We attribute greater accuracy and weight to the opinions of authority figures.

• Automation Bias

  We favor suggestions from automated systems over contradictory information from non-automated sources.

• Availability Heuristic

  We overestimate the likelihood of events that come easily to mind, often due to recent exposure or emotional impact.

B

• Backfire Effect

  When confronted with evidence against our beliefs, we sometimes strengthen those beliefs instead of changing them.

• Bandwagon Effect

  We adopt beliefs or behaviors because many others do so.

• Base Rate Fallacy

  We ignore general statistical information (base rates) in favor of specific information about an individual case.

• Belief Revision

  We inadequately update our beliefs when presented with new evidence, either over- or under-revising.

• Bias Blind Spot

  We recognize cognitive biases in others but fail to see them in ourselves.

• Bizarreness Effect

  We remember bizarre or unusual material better than common material.

C

• Cheerleader Effect

  We perceive individuals as more attractive when they are in a group than when alone.

• Chesterton's Fence

  We should understand why something exists before removing it, as it may serve a purpose we're unaware of.

• Choice-Supportive Bias

  We remember our choices as better than they actually were.

• Clustering Illusion

  We see patterns in random events or data where none actually exist.

• Confabulation

  We unconsciously create false memories or explanations to fill gaps in our memory without intending to deceive.

• Confirmation Bias

  We search for, interpret, and recall information in a way that confirms our preexisting beliefs.

• Congruence Bias

  We test hypotheses exclusively through direct testing, neglecting to test alternative hypotheses.

• Conjunction Fallacy

  We judge the conjunction of two events as more probable than one of the events alone.

• Conservatism Bias

  We insufficiently revise our beliefs when presented with new evidence.

• Context Effect

  Our perception of stimuli is influenced by the surrounding context or environment.

• Continued Influence Effect

  Misinformation continues to influence our thinking even after it has been corrected.

• Contrast Effect

  We perceive things differently depending on what we've recently been exposed to for comparison.

• Courtesy Bias

  We tend to give opinions that are socially acceptable to avoid offending others, rather than stating our true beliefs (often skews survey data).

• Cross-Race Effect

  We have difficulty recognizing faces of people from races other than our own.

• Cryptomnesia

  We mistakenly believe a memory is a new, original idea, forgetting that we learned it from someone else.

• Cue-Dependent Forgetting

  We fail to recall information without memory cues that were present when the memory was encoded.

• Curse of Knowledge

  Once we know something, we find it hard to imagine what it's like not to know it.

D

• Declinism

  We believe that society or institutions are in decline and that the past was better.

• Decoy Effect

  Our preference between two options changes when a third, asymmetrically dominated option is introduced.

• Defensive Attribution Hypothesis

  We attribute more blame to a harm-doer as the severity of the outcome increases, to protect our belief in a controllable world.

• Delmore Effect

  We are more likely to set goals in areas where we are already competent rather than where we need improvement.

• Denomination Effect

  We are less likely to spend large bills than their equivalent value in smaller denominations.

• Disposition Effect

  We sell assets that have increased in value while holding assets that have decreased in value.

• Distinction Bias

  We view two options as more different when evaluating them simultaneously than when evaluating them separately.

• Doubling-back Aversion

  We tend to avoid returning to a previous location or state, even when retracing our steps is the most efficient path.

• Dunning-Kruger Effect

  People with low ability overestimate their competence, while those with high ability underestimate theirs.

• Duration Neglect

  We judge experiences based on their peak intensity and end, ignoring their duration.

E

• Effort Justification

  We value outcomes more highly when we've had to put significant effort into achieving them.

• Egocentric Bias

  We rely too heavily on our own perspective and overestimate our role in events.

• Empathy Gap

  We underestimate the influence of emotional states on our own and others' behavior and decisions.

• Endowment Effect

  We value things we own more highly than things we don't, simply because we own them.

• Escalation of Commitment

  We increase commitment to a decision despite evidence that it was wrong, especially when responsible for it.

• Essentialism

  We believe that certain categories have an underlying essence that determines their characteristics.

• Expectation Bias

  We see what we expect to see in data or observations.

• Experimenter's Bias

  Experimenters' expectations unconsciously influence the outcome of their research.

• Extrinsic Incentive Error

  We believe others are more motivated by external rewards than intrinsic satisfaction, while seeing ourselves as the opposite.

F

• Fading Affect Bias

  The emotion associated with negative memories fades faster than the emotion associated with positive memories.

• False Consensus Effect

  We overestimate the extent to which others share our beliefs, values, and behaviors.

• False Memory

  We remember events that never actually occurred, or remember them very differently from how they happened.

• Focusing Effect

  We place too much importance on one aspect of an event, causing errors in predicting future outcomes.

• Forer Effect (Barnum Effect)

  We believe vague, general personality descriptions are highly accurate and specifically tailored to us.

• Framing Effect

  We draw different conclusions from the same information depending on how it's presented.

• Frequency Illusion (Baader-Meinhof Phenomenon)

  Once we notice something for the first time, we tend to notice it more often, leading us to believe it's suddenly everywhere.

• Functional Fixedness

  We see objects only in terms of their traditional uses, limiting creative problem-solving.

• Fundamental Attribution Error

  We overemphasize personal characteristics and underemphasize situational factors when explaining others' behavior.

G

• Gambler's Fallacy

  We believe that past random events affect the probability of future random events.

• Generation Effect

  We remember information better when we generated it ourselves than when we simply read it.

• Google Effect (Digital Amnesia)

  We are less likely to remember information that can be easily accessed online.

• Group Attribution Error

  We assume that an individual's characteristics reflect the group they belong to, or that group decisions reflect all members' preferences.

H

• Halo Effect

  We let one positive trait influence our overall impression of a person or thing.

• Hard-Easy Effect

  We are overconfident on easy tasks and underconfident on difficult tasks.

• Hick’s Law

  The time it takes to make a decision increases logarithmically with the number and complexity of choices (critical in UX design).

• Hindsight Bias

  After learning an outcome, we believe we would have predicted it all along ("I knew it all along").

• Hot-Hand Fallacy

  We believe that a person who has experienced success has a greater chance of further success ("on a streak").

• Humor Effect

  We remember humorous information better than non-humorous information.

• Hyperbolic Discounting

  We prefer smaller, immediate rewards over larger, later rewards, with preferences changing over time.

I

• Identifiable Victim Effect

  We respond more strongly to a single, identifiable person in need than to a large, anonymous group.

• IKEA Effect

  We place disproportionately high value on products we partially created ourselves.

• Illusion of Asymmetric Insight

  We believe we know others better than they know us, and that we know ourselves better than others know themselves.

• Illusion of Control

  We overestimate our ability to control events, especially random outcomes.

• Illusion of External Agency

  We believe that good or bad outcomes are caused by external agents rather than chance.

• Illusion of Transparency

  We overestimate the degree to which our internal states are known by others.

• Illusion of Validity

  We overestimate our ability to interpret and predict outcomes based on data, especially when information is consistent.

• Illusory Correlation

  We perceive a relationship between variables when no such relationship exists.

• Illusory Superiority

  We overestimate our own qualities and abilities relative to others (also called "Lake Wobegon effect").

• Illusory Truth Effect

  We tend to believe information is true after repeated exposure, regardless of its actual validity.

• Impact Bias

  We overestimate the length and intensity of future emotional reactions to events.

• Implicit Associations

  We automatically associate concepts in memory, influencing judgments and behavior without conscious awareness.

• Implicit Stereotypes

  We unconsciously attribute certain qualities to members of social groups without awareness.

• In-Group Bias

  We favor members of our own group over those in other groups.

• Information Bias

  We seek information even when it cannot affect our decision or action.

• Insensitivity to Sample Size

  We fail to appreciate that small samples are less reliable than large samples.

J

• Just-World Hypothesis

  We believe the world is fair and people get what they deserve, leading us to blame victims.

L

• Law of the Instrument

  We over-rely on a familiar tool or approach ("If you have a hammer, everything looks like a nail").

• Law of Triviality (Bike-Shedding Effect)

  We give disproportionate weight to trivial issues while neglecting more important but complex ones.

• Less-is-Better Effect

  We prefer a smaller, more complete option over a larger, less complete option when judged separately (but not together).

• Leveling and Sharpening

  When retelling events, we simplify (level) some details while emphasizing (sharpening) others.

• Levels of Processing Effect

  We remember information that has been processed at a deeper, more meaningful level better than shallowly processed information.

• List-Length Effect

  The longer a list, the smaller the proportion of items we recall from it.

• Loss Aversion

  We feel the pain of losing something more strongly than the pleasure of gaining something of equal value.

M

• Magic Number 7±2

  We can only hold about 7 (plus or minus 2) items in short-term memory at once.

• Masked Man Fallacy

  We assume that if we know something under one description, we should know it under all descriptions.

• Memory Inhibition

  Some memories actively interfere with or suppress the retrieval of other memories.

• Mental Accounting

  We treat money differently depending on where it comes from, where it's kept, or how it's spent.

• Mere Exposure Effect

  We develop a preference for things simply because we are familiar with them.

• Misattribution of Memory

  We attribute a memory to the wrong source or context, confusing fantasy with reality or one event with another.

• Misinformation Effect

  Our memory of an event becomes less accurate when we are exposed to misleading information after the event.

• Modality Effect

  We remember the final items of a list better when presented auditorily versus visually.

• Money Illusion

  We think of currency in nominal rather than real (inflation-adjusted) terms.

• Mood-Congruent Memory Bias

  We recall memories that match our current emotional state more easily.

• Moral Credential Effect

  We feel licensed to behave unethically after doing something good, as if we've earned moral credits.

• Moral Luck

  We judge people's moral responsibility based on outcomes that were outside their control.

• Murphy's Law

  We expect that if something can go wrong, it will go wrong.

N

• Naïve Cynicism

  We expect others to be more self-interested than they actually are.

• Naïve Realism

  We believe we see the world objectively and that people who disagree must be uninformed, irrational, or biased.

• Negativity Bias

  We give more psychological weight to negative experiences than positive ones of equal intensity.

• Neglect of Probability

  We disregard probability when making decisions under uncertainty, often focusing on outcomes instead.

• Next-in-Line Effect

  We have reduced recall for events just before our turn to perform, due to anxiety or preparation focus.

• Normalcy Bias

  We underestimate the possibility and impact of disasters, believing things will always function normally.

• Not Invented Here

  We avoid using or buying products, ideas, or knowledge from external sources.

O

• Observer Effect

  The act of observing something changes the thing being observed.

• Observer-Expectancy Effect

  A researcher's expectations can influence the participants' behavior in a study.

• Occam's Razor

  We prefer simpler explanations over more complex ones when both equally explain the data.

• Omission Bias

  We judge harmful actions as worse than equally harmful inactions (omissions).

• Optimism Bias

  We believe we are less likely to experience negative events and more likely to experience positive events than others.

• Ostrich Effect

  We avoid negative information by "burying our heads in the sand."

• Out-Group Homogeneity Bias

  We perceive members of other groups as more similar to each other than members of our own group.

• Outcome Bias

  We judge a decision based on its outcome rather than on the quality of the decision at the time it was made.

• Overconfidence Effect

  We have excessive confidence in our own answers, judgments, and abilities relative to our actual accuracy.

P

• Pareidolia

  We perceive meaningful images or patterns (like faces) in random or ambiguous stimuli.

• Part-List Cueing Effect

  Being shown some items from a list as cues can impair recall of the remaining items.

• Peak-End Rule

  We judge experiences based on how we felt at their most intense point and at the end, rather than the total experience.

• Pessimism Bias

  We overestimate the likelihood of negative outcomes.

• Picture Superiority Effect

  We remember pictures better than words.

• Placebo Effect

  We experience real changes in symptoms or conditions because we believe a treatment will work.

• Planning Fallacy

  We underestimate the time, costs, and risks of future actions while overestimating their benefits.

• Positivity Effect

  Older adults tend to favor positive over negative information in their memories and attention.

• Prejudice

  We hold preconceived opinions about individuals based on their membership in a particular group.

• Primacy Effect

  We remember the first items presented in a list better than those in the middle.

• Pro-Innovation Bias

  We overvalue an innovation's usefulness while undervaluing its limitations.

• Processing Difficulty Effect

  We remember information better when it requires more effort to process (also called "desirable difficulty").

• Projection Bias

  We assume our current preferences, thoughts, and values will remain the same in the future.

• Pseudocertainty Effect

  We make risk-averse choices when outcomes are framed as gains but risk-seeking choices to avoid sure losses.

R

• Reactance

  When we feel our freedom is threatened, we react by wanting the opposite of what we're being pushed to do.

• Reactive Devaluation

  We devalue proposals or ideas simply because they originate from an adversary or perceived opponent.

• Recency Effect

  We remember the most recently presented items in a list best.

• Recency Illusion

  We believe that something we recently noticed is a recent phenomenon, even if it has existed for a long time.

• Restraint Bias

  We overestimate our ability to resist temptation and control impulsive behavior.

• Rhyme as Reason Effect

  We perceive statements that rhyme as more truthful and accurate than non-rhyming statements.

• Risk Compensation (Peltzman Effect)

  We take more risks when we feel protected by safety measures, offsetting the benefits of those measures.

• Rosy Retrospection

  We remember past events more positively than we experienced them at the time.

S

• Selective Perception

  We filter what we see and hear based on our expectations and beliefs.

• Self-Consistency Bias

  We incorrectly remember our past attitudes and behaviors as similar to our current ones.

• Self-Relevance Effect

  We remember information better when it relates to ourselves.

• Self-Serving Bias

  We attribute successes to our own abilities and efforts, but attribute failures to external factors.

• Semmelweis Reflex

  We reflexively reject new evidence that contradicts established norms or beliefs.

• Serial Position Effect

  We remember items at the beginning and end of a list better than those in the middle.

• Serial Recall Effect

  We remember items in a sequence better when they are recalled in the order they were presented.

• Sexual Overperception Bias

  We (particularly men) tend to overestimate the sexual interest or flirtation of others based on neutral cues.

• Social Comparison Bias

  We favor potential candidates who don't compete with our own strengths when making hiring or selection decisions.

• Social Desirability Bias

  We present ourselves in a favorable light by over-reporting good behavior and under-reporting bad behavior.

• Source Confusion (Source Monitoring Error)

  We misattribute the source of a memory, confusing where, when, or how we learned something.

• Spacing Effect

  We learn and remember information better when study sessions are spaced out over time rather than massed together.

• Spotlight Effect

  We overestimate how much others notice our appearance or behavior.

• Status Quo Bias

  We prefer the current state of affairs and resist change, even when change would be beneficial.

• Stereotyping

  We assume that individuals possess certain characteristics based on their membership in a group.

• Subadditivity Effect

  We judge the probability of the whole as less than the sum of probabilities of its parts.

• Subjective Validation

  We perceive two unrelated events as connected because of our belief, expectation, or hypothesis that they should be.

• Suffix Effect

  Adding an item to the end of a list reduces recall of earlier items, especially in auditory memory.

• Suggestibility

  Our memories can be influenced and altered by suggestions from others, especially authority figures.

• Sunk Cost Fallacy

  We continue investing in something because of previously invested resources (time, money, effort), regardless of future value.

• Survivorship Bias

  We focus on successful examples while overlooking failures, leading to false conclusions.

• System Justification

  We defend and justify the existing social, economic, and political systems, even at personal cost.

T

• Telescoping Effect

  We displace recent events backward in time and remote events forward in time when recalling.

• Testing Effect

  We remember information better when we actively retrieve it through testing rather than simply restudying it.

• Third-Person Effect

  We believe that mass media messages have a greater effect on others than on ourselves.

• Time-Saving Bias

  We misestimate the time saved when increasing speed, overestimating savings at low speeds and underestimating at high speeds.

• Tip of the Tongue Phenomenon

  We experience a feeling of knowing something while being temporarily unable to retrieve it from memory.

• Trait Ascription Bias

  We view ourselves as more variable in personality across situations while viewing others as more predictable.

U

• Ultimate Attribution Error

  We attribute negative behaviors of outgroup members to their character while attributing their positive behaviors to external circumstances.

• Unit Bias

  We tend to consume a standard unit (one serving, one plate) regardless of the actual amount.

V

• Von Restorff Effect

  An item that stands out (is distinctive) from its surroundings is more likely to be remembered.

W

• Weber–Fechner Law

  We perceive changes in stimuli proportionally to their initial magnitude (a small change in a large stimulus is less noticeable).

• Well-Traveled Road Effect

  We underestimate the time taken to travel frequently used routes and overestimate time for unfamiliar routes.

Z

• Zeigarnik Effect

  We remember uncompleted or interrupted tasks better than completed ones.

• Zero-Risk Bias

  We prefer to completely eliminate a small risk rather than significantly reduce a larger risk.

• Zero-Sum Bias

  We mistakenly believe situations are zero-sum (one person's gain must be another's loss) when they are not.