184 Cognitive biases
Functional fixedness
Limits a person to using an object only in the way it is traditionally used.
Illusion of control
The tendency to overestimate one's degree of influence over other external events.
Hard-easy effect
Based on a specific level of task difficulty, the confidence in judgments is too conservative and not extreme enough
Regressive bias
A certain state of mind wherein high values and high likelihoods are overestimated while low values and low likelihoods are underestimated.[5][70][71][unreliable source?]
Ben Franklin effect
A person who has performed a favor for someone is more likely to do another favor for that person than they would be if they had received a favor from that person.
Availability cascade
A self-reinforcing process in which a collective belief gains more and more plausibility through its increasing repetition in public discourse (or "repeat something long enough and it will become true").
Illusory truth effect
A tendency to believe that a statement is true if it is easier to process, or if it has been stated multiple times, regardless of its actual veracity. These are specific cases of truthiness.
Pareidolia
A vague and random stimulus (often an image or sound) is perceived as significant, e.g., seeing images of animals or faces in clouds, the man in the moon, and hearing non-existent hidden messages on records played in reverse.
Contrast effect
The enhancement or reduction of a certain perception's stimuli when compared with a recently observed, contrasting object.
Look-elsewhere effect
An apparently statistically significant observation may have actually arisen by chance because of the size of the parameter space to be searched.
Belief bias
An effect where someone's evaluation of the logical strength of an argument is biased by the believability of the conclusion.
Law of the instrument
An over-reliance on a familiar tool or methods, ignoring or under-valuing alternative approaches. "If all you have is a hammer, everything looks like a nail."
Not invented here
Aversion to contact with or use of products, research, standards, or knowledge developed outside a group. Related to IKEA effect.
Exaggerated expectation
Based on the estimates, real-world evidence turns out to be less extreme than our expectations (conditionally inverse of the conservatism bias).
Illusion of validity
Belief that furtherly acquired information generates additional relevant data for predictions, even when it evidently does not.
Survivorship bias
Concentrating on the people or things that "survived" some process and inadvertently overlooking those that didn't because of their lack of visibility.
Reactive devaluation
Devaluing proposals only because they purportedly originated with an adversary.
Hyperbolic discounting
Discounting is the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs. Hyperbolic discounting leads to choices that are inconsistent over time - people make choices today that their future selves would prefer not to have made, despite using the same reasoning. Also known as current moment bias, present-bias, and related to Dynamic inconsistency.
Stereotyping
Expecting a member of a group to have certain characteristics without having actual information about that individual.
Framing effect
Drawing different conclusions from the same information, depending on how that information is presented
Overconfidence effect
Excessive confidence in one's own answers to questions. For example, for certain types of questions, answers that people rate as "99% certain" turn out to be wrong 40% of the time.[5][64][65][66]
Ostrich effect
Ignoring an obvious (negative) situation.
Illusory correlation
Inaccurately perceiving a relationship between two unrelated events.
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.
Subjective validation
Perception that something is true if a subject's belief demands it to be true. Also assigns perceived connections between coincidences.
Decoy effect
Preferences for either option A or B change in favor of option B when option C is presented, which is similar to option B but in no way better.
Negativity bias or Negativity effect
Psychological phenomenon by which humans have a greater recall of unpleasant memories compared with positive memories.[57][58] (see also actor-observer bias, group attribution error, positivity effect, and negativity effect).[59]
Rhyme as reason effect
Rhyming statements are perceived as more truthful. A famous example being used in the O.J Simpson trial with the defense's use of the phrase "If the gloves don't fit, then you must acquit."
Hindsight bias
Sometimes called the "I-knew-it-all-along" effect, the tendency to see past events as being predictable at the time those events happened.
Hot-hand fallacy
The "hot-hand fallacy" (also known as the "hot hand phenomenon" or "hot hand") is the fallacious belief that a person who has experienced success with a random event has a greater chance of further success in additional attempts.
Hostile attribution bias
The "hostile attribution bias" is the tendency to interpret others' behaviors as having hostile intent, even when the behavior is ambiguous or benign.
Declinism
The belief that a society or institution is tending towards decline. Particularly, it is the predisposition to view the past favourably (rosy retrospection) and future negatively.
Loss aversion
The disutility of giving up an object is greater than the utility associated with acquiring it.[54] (see also Sunk cost effects and endowment effect).
Frequency illusion
The illusion in which a word, a name, or other thing that has recently come to one's attention suddenly seems to appear with improbable frequency shortly afterwards (not to be confused with the recency illusion or selection bias). This illusion may explain some examples of the Baader-Meinhof Phenomenon, when someone repeatedly notices a newly learned word or phrase shortly after learning it.
Recency illusion
The illusion that a word or language usage is a recent innovation when it is in fact long-established (see also frequency illusion).
Duration neglect
The neglect of the duration of an episode in determining its value
Forer effect or Barnum effect
The observation that individuals will give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically for them, but are in fact vague and general enough to apply to a wide range of people. This effect can provide a partial explanation for the widespread acceptance of some beliefs and practices, such as astrology, fortune telling, graphology, and some types of personality tests.
Irrational escalation
The phenomenon where people justify increased investment in a decision, based on the cumulative prior investment, despite new evidence suggesting that the decision was probably wrong. Also known as the sunk cost fallacy.
Backfire effect
The reaction to disconfirming evidence by strengthening one's previous beliefs. cf. Continued influence effect.
Normalcy bias
The refusal to plan for, or react to, a disaster which has never happened before.
Selective perception
The tendency for expectations to affect perception.
Experimenter's or expectation bias
The tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations.
Cheerleader effect
The tendency for people to appear more attractive in a group than in isolation.
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.[37]
IKEA effect
The tendency for people to place a disproportionately high value on objects that they partially assembled themselves, such as furniture from IKEA, regardless of the quality of the end result.
Pessimism bias
The tendency for some people, especially those suffering from depression, to overestimate the likelihood of negative things happening to them.
Dunning-Kruger effect
The tendency for unskilled individuals to overestimate their own ability and the tendency for experts to underestimate their own ability.
Moral credential effect
The tendency of a track record of non-prejudice to increase subsequent prejudice.
Attentional bias
The tendency of our perception to be affected by our recurring thoughts.
Conjunction fallacy
The tendency to assume that specific conditions are more probable than general ones.
Ambiguity effect
The tendency to avoid options for which missing information makes the probability seem "unknown".
Optimism bias
The tendency to be over-optimistic, overestimating favorable and pleasing outcomes (see also wishful thinking, valence effect, positive outcome bias).[62][63]
Continued influence effect
The tendency to believe previously learned misinformation even after it has been corrected. Misinformation can still influence inferences one generates after a correction has occurred. cf. Backfire effect
Anthropomorphism or personification
The tendency to characterize animals, objects, and abstract concepts as possessing human-like traits, emotions, and intentions.
Neglect of probability
The tendency to completely disregard probability when making a decision under uncertainty.[60]
Money illusion
The tendency to concentrate on the nominal value (face value) of money rather than its value in terms of purchasing power.[56]
Automation bias
The tendency to depend excessively on automated systems which can lead to erroneous automated information overriding correct decisions.
Bandwagon effect
The tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behavior.
Mere exposure effect
The tendency to express undue liking for things merely because of familiarity with them.[55]
Courtesy bias
The tendency to give an opinion that is more socially correct than one's true opinion, so as to avoid offending anyone.
Pro-innovation bias
The tendency to have an excessive optimism towards an invention or innovation's usefulness throughout society, while often failing to identify its limitations and weaknesses.
Base rate fallacy or Base rate neglect
The tendency to ignore base rate information (generic, general information) and focus on specific information (information only pertaining to a certain case).
Outcome bias
The tendency to judge a decision by its eventual outcome instead of based on the quality of the decision at the time it was made.
Omission bias
The tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions).[61]
Subadditivity effect
The tendency to judge probability of the whole to be less than the probabilities of the parts.[76]
Status quo bias
The tendency to like things to stay relatively the same (see also loss aversion, endowment effect, and system justification).[74][75]
Pseudocertainty effect
The tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.[69]
Berkson's paradox
The tendency to misinterpret statistical experiments involving conditional probabilities.
Sexual overperception bias / sexual underperception bias
The tendency to over-/underestimate sexual interest of another person in oneself.
Social desirability bias
The tendency to over-report socially desirable characteristics or behaviours in oneself and under-report socially undesirable characteristics or behaviours.[73]
Projection bias
The tendency to overestimate how much our future selves share one's current preferences, thoughts and values, thus leading to sub-optimal choices.[67][68][58]
Restraint bias
The tendency to overestimate one's ability to show restraint in the face of temptation.
Clustering illusion
The tendency to overestimate the importance of small runs, streaks, or clusters in large samples of random data (that is, seeing phantom patterns).
Impact bias
The tendency to overestimate the length or the intensity of the impact of future feeling states.[52]
Availability heuristic
The tendency to overestimate the likelihood of events with greater "availability" in memory, which can be influenced by how recent the memories are or how unusual or emotionally charged they may be.
Post-purchase rationalization
The tendency to persuade oneself through rational argument that a purchase was good value.
Focusing effect
The tendency to place too much importance on one aspect of an event.
Less-is-better effect
The tendency to prefer a smaller set to a larger set judged separately, but not jointly.
Semmelweis reflex
The tendency to reject new evidence that contradicts a paradigm.[28]
Anchoring or focalism
The tendency to rely too heavily, or "anchor", on one trait or piece of information when making decisions (usually the first piece of information acquired on that subject)
Choice-supportive bias
The tendency to remember one's choices as better than they actually were.
Identifiable victim effect
The tendency to respond more strongly to a single identified person at risk than to a large group of people at risk.
Conservatism (belief revision)
The tendency to revise one's belief insufficiently when presented with new evidence.
Confirmation bias
The tendency to search for, interpret, focus on and remember information in a way that confirms one's preconceptions.
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.
Information bias
The tendency to seek information even when it cannot affect action.[53]
Disposition effect
The tendency to sell an asset that has accumulated in value and resist selling an asset that has declined in value.
Denomination effect
The tendency to spend more money when it is denominated in small amounts (e.g., coins) rather than large amounts (e.g., bills).
Risk compensation / Peltzman effect
The tendency to take greater risks when perceived safety increases.
Congruence bias
The tendency to test hypotheses exclusively through direct testing, instead of testing possible alternative hypotheses.
Gambler's fallacy
The tendency to think that future probabilities are altered by past events, when in reality they are unchanged. The fallacy arises from an erroneous conceptualization of the law of large numbers. For example, "I've flipped heads with this coin five times consecutively, so the chance of tails coming out on the sixth flip is much greater than heads."
Insensitivity to sample size
The tendency to under-expect variation in small samples.
Planning fallacy
The tendency to underestimate task-completion times.[52]
Empathy gap
The tendency to underestimate the influence or strength of feelings, in either oneself or others.
Distinction bias
The tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.
Social comparison bias
The tendency, when making hiring decisions, to favour potential candidates who don't compete with one's own particular strengths.[72]
Reactance
The urge to do the opposite of what someone wants you to do out of a need to resist a perceived attempt to constrain your freedom of choice (see also Reverse psychology).
Time-saving bias
Underestimations of the time that could be saved (or lost) when increasing (or decreasing) from a relatively low speed and overestimations of the time that could be saved (or lost) when increasing (or decreasing) from a relatively high speed.
Observer-expectancy effect
When a researcher expects a given result and therefore unconsciously manipulates an experiment or misinterprets data in order to find it (see also subject-expectancy effect).
Curse of knowledge
When better-informed people find it extremely difficult to think about problems from the perspective of lesser-informed people.
