A cognitive bias

Cognitive bias

A cognitive bias is a pattern of deviation in judgment that occurs in particular situations. Implicit in the concept of a "pattern of deviation" is a standard of comparison; this may be the judgment of people outside those particular situations, or may be a set of independently verifiable...

 is a pattern of poor judgment, often triggered by a particular situation. Identifying "poor judgment," or more precisely, a "deviation in judgment," requires a standard for comparison, i.e. "good judgment". In scientific investigations of cognitive bias

Cognitive bias

A cognitive bias is a pattern of deviation in judgment that occurs in particular situations. Implicit in the concept of a "pattern of deviation" is a standard of comparison; this may be the judgment of people outside those particular situations, or may be a set of independently verifiable...

, the source of "good judgment" is that of people outside the situation hypothesized to cause the poor judgment, or, if possible, a set of independently verifiable facts. The existence of most of the particular cognitive biases listed below has been verified empirical

Empirical

The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....

ly in psychology

Psychology

Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...

 experiments.

Cognitive biases, like many behaviors, are influenced by evolution and natural selection pressure. Some are presumably adaptive and beneficial, for example, because they lead to more effective actions in given contexts or enable faster decisions, when faster decisions are of greater value for reproductive success and survival. Others presumably result from a lack of appropriate mental mechanisms, i.e. a general fault in human brain structure, or from the misapplication of a mechanism that is adaptive (beneficial) under different circumstances.

Cognitive bias is a general term that is used to describe many distortions in the human mind that are difficult to eliminate and that lead to perceptual distortion, inaccurate judgment, or illogical interpretation.

Decision-making and behavioral biases

Many of these biases are studied for how they affect belief formation, business decisions, and scientific research.

• Anchoring
  Anchoring
  Anchoring or focalism is a cognitive bias that describes the common human tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions.-Background:...
  
  – the common human tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions.
• Attentional Bias
  Attentional bias
  Several types of cognitive bias occur due to an attentional bias. One example is when a person does not examine all possible outcomes when making a judgment about a correlation or association...
  
  – implicit cognitive bias defined as the tendency of emotionally dominant stimuli in one's environment to preferentially draw and hold attention.
• Backfire effect - Evidence disconfirming our beliefs only strengthens them.
• Bandwagon effect
  Bandwagon effect
  The bandwagon effect is a well documented form of groupthink in behavioral science and has many applications. The general rule is that conduct or beliefs spread among people, as fads and trends clearly do, with "the probability of any individual adopting it increasing with the proportion who have...
  
  – the tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink
  Groupthink
  Groupthink is a psychological phenomenon that occurs within groups of people. It is the mode of thinking that happens when the desire for harmony in a decision-making group overrides a realistic appraisal of alternatives. Group members try to minimize conflict and reach a consensus decision without...
  
   and herd behavior
  Herd behavior
  Herd behavior describes how individuals in a group can act together without planned direction. The term pertains to the behavior of animals in herds, flocks and schools, and to human conduct during activities such as stock market bubbles and crashes, street demonstrations, sporting events,...
  
  .
• Bias blind spot
  Bias blind spot
  The bias blind spot is the cognitive bias of failing to compensate for one's own cognitive biases. The term was created by Emily Pronin, a social psychologist from Princeton University's Department of Psychology, with colleagues Daniel Lin and Lee Ross...
  
  – the tendency to see oneself as less biased than other people.
• Choice-supportive bias
  Choice-supportive bias
  In cognitive science, choice-supportive bias is the tendency to retroactively ascribe positive attributes to an option one has selected. It is a cognitive bias....
  
  – the tendency to remember one's choices as better than they actually were.
• Confirmation bias
  Confirmation bias
  Confirmation bias is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true.David Perkins, a geneticist, coined the term "myside bias" referring to a preference for "my" side of an issue...
  
  – the tendency to search for or interpret information in a way that confirms one's preconceptions.
• Congruence bias
  Congruence bias
  Congruence bias is a type of cognitive bias similar to confirmation bias. Congruence bias occurs due to people's overreliance on direct testing of a given hypothesis, and a neglect of indirect testing.-Examples:...
  
  – the tendency to test hypotheses exclusively through direct testing, in contrast to tests of possible alternative hypotheses.
• Contrast effect
  Contrast effect
  A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition and related performance as a result of immediately previous or simultaneous exposure to a stimulus of lesser or greater value in the same dimension...
  
  – the enhancement or diminishing of a weight or other measurement when compared with a recently observed contrasting object.
• Denomination effect
  Denomination effect
  The denomination effect is a theoretical form of cognitive bias relating to currency, whereby people are less likely to spend larger bills than their equivalent value in smaller bills. It was proposed by Priya Raghubir and Joydeep Srivastava in their 2009 paper "Denomination Effect".Joffe-Walt,...
  
  – the tendency to spend more money when it is denominated in small amounts (e.g. coins) rather than large amounts (e.g. bills).
• Distinction bias
  Distinction bias
  Distinction bias , is the tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately....
  
  – the tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.
• Empathy gap
  Empathy gap
  A hot-cold empathy gap is a cognitive bias in which a person underestimates the influences of visceral drives, and instead attributes behavior primarily to other, nonvisceral factors....
  
  - the tendency to underestimate the influence or strength of feelings, in either oneself or others.
• Endowment effect
  Endowment effect
  In behavioral economics, the endowment effect is a hypothesis that people value a good or service more once their property right to it has been established. In other words, people place a higher value on objects they own than objects that they do not...
  
  – "the fact that people often demand much more to give up an object than they would be willing to pay to acquire it".
• Experimenter's
  Experimenter's bias
  In experimental science, experimenter's bias is subjective bias towards a result expected by the human experimenter. David Sackett, in a useful review of biases in clinical studies, states that biases can occur in any one of seven stages of research:...
  
   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.
• Focusing effect – the tendency to place too much importance on one aspect of an event; causes error in accurately predicting the utility of a future outcome.
• Framing effect
  Framing (social sciences)
  A frame in social theory consists of a schema of interpretation — that is, a collection of anecdotes and stereotypes—that individuals rely on to understand and respond to events. In simpler terms, people build a series of mental filters through biological and cultural influences. They use these...
  
  – drawing different conclusions from the same information, depending on how that information is presented.
• Hostile media effect
  Hostile media effect
  The hostile media effect, sometimes called the hostile media phenomenon, refers to the finding that people with strong biases toward an issue perceive media coverage as biased against their opinions, regardless of the reality...
  
  - the tendency to see a media report as being biased due to one's own strong partisan views.
• Hyperbolic discounting
  Hyperbolic discounting
  In behavioral economics, hyperbolic discounting is a time-inconsistent model of discounting.Given two similar rewards, humans show a preference for one that arrives sooner rather than later. Humans are said to discount the value of the later reward, by a factor that increases with the length of the...
  
  – the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs, where the tendency increases the closer to the present both payoffs are.
• Illusion of control
  Illusion of control
  The illusion of control is the tendency for people to overestimate their ability to control events, for instance to feel that they control outcomes that they demonstrably have no influence over. The effect was named by psychologist Ellen Langer and has been replicated in many different contexts. It...
  
  – the tendency to overestimate one's degree of influence over other external events.
• Impact bias
  Impact bias
  The impact bias, a form of which is the durability bias, in affective forecasting, is the tendency for people to overestimate the length or the intensity of future feeling states....
  
  – the tendency to overestimate the length or the intensity of the impact of future feeling states.
• Information bias – the tendency to seek information even when it cannot affect action.
• 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.
• Loss aversion
  Loss aversion
  In economics and decision theory, loss aversion refers to people's tendency to strongly prefer avoiding losses to acquiring gains. Some studies suggest that losses are twice as powerful, psychologically, as gains....
  
  – "the disutility of giving up an object is greater than the utility associated with acquiring it". (see also Sunk cost effects
  Sunk cost
  In economics and business decision-making, sunk costs are retrospective costs that have already been incurred and cannot be recovered. Sunk costs are sometimes contrasted with prospective costs, which are future costs that may be incurred or changed if an action is taken...
  
   and Endowment effect
  Endowment effect
  In behavioral economics, the endowment effect is a hypothesis that people value a good or service more once their property right to it has been established. In other words, people place a higher value on objects they own than objects that they do not...
  
  ).
• Mere exposure effect – the tendency to express undue liking for things merely because of familiarity with them.
• Money illusion
  Money illusion
  In economics, money illusion refers to the tendency of people to think of currency in nominal, rather than real, terms. In other words, the numerical/face value of money is mistaken for its purchasing power...
  
  – the tendency to concentrate on the nominal (face value) of money rather than its value in terms of purchasing power.
• Moral credential effect
  Moral credential
  An individual's track record as a good egalitarian individual can establish an unconscious ethical certification, endorsement, or license within that individual and this will increase their likelihood of making less egalitarian decisions later. This moral credentialing effect occurs even when the...
  
  – the tendency of a track record of non-prejudice to increase subsequent prejudice.
• Negativity bias
  Negativity bias
  Negativity bias is the name for a psychological phenomenon by which humans pay more attention to and give more weight to negative rather than positive experiences or other kinds of information...
  
  – the tendency to pay more attention and give more weight to negative than positive experiences or other kinds of information.
• Neglect of probability
  Neglect of probability
  The neglect of probability bias, a type of cognitive bias, is the tendency to completely disregard probability when making a decision under uncertainty and is one simple way in which people regularly violate the normative rules for decision making....
  
  – the tendency to completely disregard probability when making a decision under uncertainty.
• Normalcy bias
  Normalcy bias
  The normalcy bias, or normality bias, refers to a mental state people enter when facing a disaster. It causes people to underestimate both the possibility of a disaster occurring and its possible effects...
  
  – the refusal to plan for, or react to, a disaster which has never happened before.
• Omission bias
  Omission bias
  The omission bias is an alleged type of cognitive bias. It is the tendency to judge harmful actions as worse, or less moral than equally harmful omissions . It is contentious as to whether this represents a systematic error in thinking, or is supported by a substantive moral theory...
  
  – the tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions).
• Outcome bias
  Outcome bias
  The outcome bias is an error made in evaluating the quality of a decision when the outcome of that decision is already known.-Overview:One will often judge a past decision by its ultimate outcome instead of based on the quality of the decision at the time it was made, given what was known at that...
  
  – 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.
• Planning fallacy
  Planning fallacy
  The planning fallacy is a tendency for people and organizations to underestimate how long they will need to complete a task, even when they have experience of similar tasks over-running. The term was first proposed in a 1979 paper by Daniel Kahneman and Amos Tversky...
  
  – the tendency to underestimate task-completion times.
• Post-purchase rationalization
  Post-purchase rationalization
  Post-purchase rationalization is a cognitive bias whereby someone who purchases an expensive product or service overlooks any faults or defects in order to justify their purchase...
  
  – the tendency to persuade oneself through rational argument that a purchase was a good value.
• Pseudocertainty effect
  Pseudocertainty effect
  The pseudocertainty effect is a concept from prospect theory. It refers to people's tendency to perceive an outcome as certain while in fact it is uncertain...
  
  – the tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.
• Reactance
  Reactance (psychology)
  Reactance is an emotional reaction in direct contradiction to rules or regulations that threaten or eliminate specific behavioral freedoms.Reactance can occur when someone is heavily pressured to accept a certain view or attitude. Reactance can cause the person to adopt or strengthen a view or...
  
  – 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.
• Restraint bias – the tendency to overestimate one's ability to show restraint in the face of temptation.
• Selective perception
  Selective perception
  Selective perception may refer to any number of cognitive biases in psychology related to the way expectations affect perception.For instance, several studies have shown that students who were told they were consuming alcoholic beverages perceived themselves as being "drunk", exhibited fewer...
  
  – the tendency for expectations to affect perception.
• Semmelweis reflex
  Semmelweis reflex
  The Semmelweis reflex or "Semmelweis effect" is a metaphor for the reflex-like tendency to reject new evidence or new knowledge because it contradicts established norms, beliefs or paradigms...
  
  – the tendency to reject new evidence that contradicts a paradigm.
• Social comparison bias
  Social comparison bias
  Stated simply, social comparison bias is that, when making hiring decisions, people tend to favour potential candidates who don't compete with their own particular strengths....
  
  – the tendency, when making hiring decisions, to favour potential candidates who don't compete with one's own particular strengths.
• Status quo bias
  Status quo bias
  The status quo bias is a cognitive bias for the status quo; in other words, people tend not to change an established behavior unless the incentive to change is compelling...
  
  – the tendency to like things to stay relatively the same (see also loss aversion
  Loss aversion
  In economics and decision theory, loss aversion refers to people's tendency to strongly prefer avoiding losses to acquiring gains. Some studies suggest that losses are twice as powerful, psychologically, as gains....
  
  , endowment effect
  Endowment effect
  In behavioral economics, the endowment effect is a hypothesis that people value a good or service more once their property right to it has been established. In other words, people place a higher value on objects they own than objects that they do not...
  
  , and system justification
  System justification
  System justification theory is a scientific theory within social psychology that proposes people have a motivation to defend and bolster the status quo, that is, to see it as good, legitimate, and desirable....
  
  ).
• Unit bias — the tendency to want to finish a given unit of a task or an item. Strong effects on the consumption of food in particular.
• Wishful thinking
  Wishful thinking
  Wishful thinking is the formation of beliefs and making decisions according to what might be pleasing to imagine instead of by appealing to evidence, rationality or reality...
  
  – the formation of beliefs and the making of decisions according to what is pleasing to imagine instead of by appeal to evidence or rationality.
• Zero-risk bias
  Zero-risk bias
  Zero-risk bias occurs when individuals value complete elimination of a risk, however small, to a reduction in a greater risk. That is, individuals may prefer small benefits that are certain to large ones that are uncertain, regardless of the size of the "certain" benefit.An example is the Delaney...
  
  – preference for reducing a small risk to zero over a greater reduction in a larger risk.

Biases in probability and belief

Many of these biases are often studied for how they affect business and economic decisions and how they affect experimental research.

• Ambiguity effect
  Ambiguity effect
  The ambiguity effect is a cognitive bias where decision making is affected by a lack of information, or "ambiguity". The effect implies that people tend to select options for which the probability of a favorable outcome is known, over an option for which the probability of a favorable outcome is...
  
  – the tendency to avoid options for which missing information makes the probability seem "unknown."
• Anchoring effect
  Anchoring
  Anchoring or focalism is a cognitive bias that describes the common human tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions.-Background:...
  
  – the tendency to rely too heavily, or "anchor," on a past reference or on one trait or piece of information when making decisions (also called "insufficient adjustment").
• Attentional bias
  Attentional bias
  Several types of cognitive bias occur due to an attentional bias. One example is when a person does not examine all possible outcomes when making a judgment about a correlation or association...
  
  – the tendency to neglect relevant data when making judgments of a correlation or association.
• Availability heuristic
  Availability heuristic
  The availability heuristic is a phenomenon in which people predict the frequency of an event, or a proportion within a population, based on how easily an example can be brought to mind....
  
  – estimating what is more likely by what is more available in memory, which is biased toward vivid, unusual, or emotionally charged examples.
• Availability cascade
  Availability cascade
  An availability cascade is a self-reinforcing cycle that explains the development of certain kinds of collective beliefs. A novel idea or insight, usually one that seems to explain a complex process in a simple or straightforward manner, gains rapid currency in the popular discourse by its very...
  
  – 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").
• Base rate neglect
  Base rate fallacy
  The base rate fallacy, also called base rate neglect or base rate bias, is an error that occurs when the conditional probability of some hypothesis H given some evidence E is assessed without taking into account the "base rate" or "prior probability" of H and the total probability of evidence...
  
  or Base rate fallacy – the tendency to base judgments on specifics, ignoring general statistical information.
• Belief bias
  Belief bias
  Belief bias is a cognitive bias in which someone's evaluation of the logical strength of an argument is biased by their belief in the truth or falsity of the conclusion...
  
  – an effect where someone's evaluation of the logical strength of an argument is biased by the believability of the conclusion.
• Clustering illusion
  Clustering illusion
  The clustering illusion refers to the tendency erroneously to perceive small samples from random distributions to have significant "streaks" or "clusters", caused by a human tendency to underpredict the amount of variability likely to appear in a small sample of random or semi-random data due to...
  
  – the tendency to see patterns where actually none exist. Also referred to as "patternicity" by author Michael Shermer.
• Conjunction fallacy
  Conjunction fallacy
  The conjunction fallacy is a logical fallacy that occurs when it is assumed that specific conditions are more probable than a single general one.The most often-cited example of this fallacy originated with Amos Tversky and Daniel Kahneman:...
  
  – the tendency to assume that specific conditions are more probable than general ones.
• Forward Bias - the tendency to create models based on past data which are validated only against that past data.
• Frequency illusion - the illusion in which a word, a name or other thing that has recently come to one's attention suddenly appears "everywhere" with improbable frequency (see also recency illusion
  Recency illusion
  The Recency illusion is the belief or impression that something is of recent origin when it is in fact long-established.The term was invented by Arnold Zwicky, a linguist at Stanford University who was primarily interested in examples involving words, meanings, phrases, and grammatical constructions...
  
  ). Sometimes called "The Baader-Meinhof phenomenon".
• Gambler's fallacy
  Gambler's fallacy
  The Gambler's fallacy, also known as the Monte Carlo fallacy , and also referred to as the fallacy of the maturity of chances, is the belief that if deviations from expected behaviour are observed in repeated independent trials of some random process, future deviations in the opposite direction are...
  
  – the tendency to think that future probabilities are altered by past events, when in reality they are unchanged. Results from an erroneous conceptualization of the Law of large numbers
  Law of large numbers
  In probability theory, the law of large numbers is a theorem that describes the result of performing the same experiment a large number of times...
  
  . 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."
• Hindsight bias
  Hindsight bias
  Hindsight bias, or alternatively the knew-it-all-along effect and creeping determinism, is the inclination to see events that have already occurred as being more predictable than they were before they took place. It is a multifaceted phenomenon that can affect different stages of designs,...
  
  – sometimes called the "I-knew-it-all-along" effect, the tendency to see past events as being predictable at the time those events happened.(sometimes phrased as "Hindsight is 20/20")
• Illusory correlation
  Illusory correlation
  Illusory correlation is the phenomenon of seeing the relationship one expects in a set of data even when no such relationship exists. When people form false associations between membership in a statistical minority group and rare behaviors, this would be a common example of illusory correlation...
  
  – inaccurately perceiving a relationship between two events, either because of prejudice or selective processing of information.
• Just-world hypothesis – the tendency for people to want to believe that the world is fundamentally just, causing them to rationalize an otherwise inexplicable injustice as deserved by the victim(s).
• Observer-expectancy effect
  Observer-expectancy effect
  The observer-expectancy effect is a form of reactivity, in which a researcher's cognitive bias causes them to unconsciously influence the participants of an experiment...
  
  – 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
  Subject-expectancy effect
  The subject-expectancy effect, is a form of reactivity that occurs in scientific experiments or medical treatments when a research subject or patient expects a given result and therefore unconsciously affects the outcome, or reports the expected result...
  
  ).
• Optimism bias
  Optimism bias
  Optimism bias is the demonstrated systematic tendency for people to be overly optimistic about the outcome of planned actions. This includes over-estimating the likelihood of positive events and under-estimating the likelihood of negative events. Along with the illusion of control and illusory...
  
  – the tendency to be over-optimistic about the outcome of planned actions.
• Ostrich effect
  Ostrich effect
  In behavioral finance, the ostrich effect is the avoidance of apparently risky financial situations by pretending they do not exist. The name comes from the common legend that ostriches bury their heads in the sand to avoid danger....
  
  – ignoring an obvious (negative) situation.
• Overconfidence effect
  Overconfidence effect
  The overconfidence effect is a well-established bias in which someone's subjective confidence in their judgments is reliably greater than their objective accuracy, especially when confidence is relatively high. For example, in some quizzes, people rate their answers as "99% certain" but are wrong...
  
  – 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.
• Positive outcome bias
  Valence effect
  The valence effect of prediction is the tendency for people to simply overestimate the likelihood of good things happening rather than bad things. Valence refers to the positive or negative emotional charge something has....
  
  – the tendency of one to overestimate the probability of a favorable outcome coming to pass in a given situation (see also wishful thinking
  Wishful thinking
  Wishful thinking is the formation of beliefs and making decisions according to what might be pleasing to imagine instead of by appealing to evidence, rationality or reality...
  
  , optimism bias
  Optimism bias
  Optimism bias is the demonstrated systematic tendency for people to be overly optimistic about the outcome of planned actions. This includes over-estimating the likelihood of positive events and under-estimating the likelihood of negative events. Along with the illusion of control and illusory...
  
  , and valence effect
  Valence effect
  The valence effect of prediction is the tendency for people to simply overestimate the likelihood of good things happening rather than bad things. Valence refers to the positive or negative emotional charge something has....
  
  ).
• Pareidolia
  Pareidolia
  Pareidolia is a psychological phenomenon involving a vague and random stimulus being perceived as significant. Common examples include seeing images of animals or faces in clouds, the man in the moon or the Moon rabbit, and hearing hidden messages on records played in reverse...
  
  – 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
  Man in the Moon
  The Man in the Moon is an imaginary figure resembling a human face, head or body, that observers from some cultural backgrounds typically perceive in the bright disc of the full moon...
  
  , and hearing hidden message
  Hidden message
  A hidden message is information that is not immediately noticeable, and that must be discovered or uncovered and interpreted before it can be known...
  
  s on records played in reverse.
• Pessimism bias
  Pessimism bias
  Pessimism bias is an effect in which people exaggerate the likelihood that negative things will happen to them. It contrasts with optimism bias, which is a more general, systematic tendency to underestimate personal risks and overestimate the likelihood of positive life events. Depressed people are...
  
  – the tendency for some people, especially those suffering from depression, to overestimate the likelihood of negative things happening to them.
• Primacy effect – the greater ease of recall of initial items in a sequence compared to items in the middle of the sequence.
• Recency effect – the greater ease of recall of items at the end of a sequence compared to items earlier in the sequence.
• Recency bias – a cognitive bias that results from disproportionate salience of recent stimuli or observations — the tendency to weigh recent events more than earlier events (see also peak-end rule
  Peak-end rule
  According to the peak-end rule, we judge our past experiences almost entirely on how they were at their peak and how they ended. Other information is not lost, but it is not used. This includes net pleasantness or unpleasantness and how long the experience lasted.In one experiment, one group of...
  
  ).
• Recency illusion
  Recency illusion
  The Recency illusion is the belief or impression that something is of recent origin when it is in fact long-established.The term was invented by Arnold Zwicky, a linguist at Stanford University who was primarily interested in examples involving words, meanings, phrases, and grammatical constructions...
  
  - the illusion that a phenomenon, typically a word or language usage, that one has just begun to notice is a recent innovation (see also frequency illusion).
• Disregard of regression toward the mean
  Regression toward the mean
  In statistics, regression toward the mean is the phenomenon that if a variable is extreme on its first measurement, it will tend to be closer to the average on a second measurement, and—a fact that may superficially seem paradoxical—if it is extreme on a second measurement, will tend...
  
  – the tendency to expect extreme performance to continue.
• Stereotyping – expecting a member of a group to have certain characteristics without having actual information about that individual.
• Subadditivity effect
  Subadditivity effect
  The subadditivity effect is the tendency to judge probability of the whole to be less than the probabilities of the parts.For instance, subjects in one experiment judged the probability of death from cancer in the United States was 18%, the probability from heart attack was 22%, and the probability...
  
  – the tendency to judge probability of the whole to be less than the probabilities of the parts.
• Subjective validation
  Subjective validation
  Subjective validation, sometimes called personal validation effect, is a cognitive bias by which a person will consider a statement or another piece of information to be correct if it has any personal meaning or significance to them...
  
  – perception that something is true if a subject's belief demands it to be true. Also assigns perceived connections between coincidences.
• Well travelled road effect
  Well travelled road effect
  The well travelled road effect is a cognitive bias in which travellers will estimate the time taken to traverse routes differently depending on their familiarity with the route. Frequently travelled routes are assessed as taking a shorter time than unfamiliar routes...
  
  – underestimation of the duration taken to traverse oft-traveled routes and over-estimate the duration taken to traverse less familiar routes.

Social biases

Most of these biases are labeled as attributional bias

Attributional bias

In psychology, an attributional bias is a cognitive bias that affects the way we determine who or what was responsible for an event or action...

es.

• Actor–observer bias – the tendency for explanations of other individuals' behaviors to overemphasize the influence of their personality and underemphasize the influence of their situation (see also Fundamental attribution error
  Fundamental attribution error
  In social psychology, the fundamental attribution error describes the tendency to over-value dispositional or personality-based explanations for the observed behaviors of others while under-valuing situational explanations for those behaviors...
  
  ), and for explanations of one's own behaviors to do the opposite (that is, to overemphasize the influence of our situation and underemphasize the influence of our own personality).
• Dunning–Kruger effect – a twofold bias. On one hand the lack of metacognitive ability
  Metacognition
  Metacognition is defined as "cognition about cognition", or "knowing about knowing." It can take many forms; it includes knowledge about when and how to use particular strategies for learning or for problem solving...
  
   deludes people, who overrate their capabilities. On the other hand, skilled people underrate their abilities, as they assume the others have a similar understanding.
• Egocentric bias
  Egocentric bias
  Egocentric bias occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would credit them....
  
  – occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would.
• Forer effect
  Forer effect
  The Forer effect is 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...
  
  (aka Barnum effect) – the tendency to 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. For example, horoscope
  Horoscope
  In astrology, a horoscope is a chart or diagram representing the positions of the Sun, Moon, planets, the astrological aspects, and sensitive angles at the time of an event, such as the moment of a person's birth. The word horoscope is derived from Greek words meaning "a look at the hours" In...
  
  s.
• False consensus effect
  False consensus effect
  In psychology, the false consensus effect is a cognitive bias whereby a person tends to overestimate how much other people agree with him or her. There is a tendency for people to assume that their own opinions, beliefs, preferences, values and habits are 'normal' and that others also think the...
  
  – the tendency for people to overestimate the degree to which others agree with them.
• Fundamental attribution error
  Fundamental attribution error
  In social psychology, the fundamental attribution error describes the tendency to over-value dispositional or personality-based explanations for the observed behaviors of others while under-valuing situational explanations for those behaviors...
  
  – the tendency for people to over-emphasize personality-based explanations for behaviors observed in others while under-emphasizing the role and power of situational influences on the same behavior (see also actor-observer bias
  Actor-observer bias
  The actor-observer asymmetry touches on the fundamental questions of how people gain access to their own and other people's minds and whether those modes of access are distinct....
  
  , group attribution error
  Group attribution error
  The group attribution error is a group-serving, attributional bias identical to the fundamental attribution error except that it occurs between different groups rather than different individuals....
  
  , positivity effect
  Positivity effect
  In psychology and cognitive science, the positivity effect is the tendency of people, when evaluating the causes of the behaviors of a person they like or prefer, to attribute the person's inherent disposition as the cause of their positive behaviors and the situations surrounding them as the cause...
  
  , and negativity effect
  Negativity effect
  In psychology, the negativity effect is the tendency of people, when evaluating the causes of the behaviors of a person they dislike, to attribute their positive behaviors to the environment and their negative behaviors to the person's inherent nature...
  
  ).
• Halo effect
  Halo effect
  The halo effect is a cognitive bias whereby one trait influences another trait or traits of that person or object. This is very common among physically attractiveness...
  
  – the tendency for a person's positive or negative traits to "spill over" from one area of their personality to another in others' perceptions of them (see also physical attractiveness stereotype
  Physical attractiveness stereotype
  The physical attractiveness stereotype is a term that psychologists use to refer to the tendency to assume that people who are physically attractive also possess other socially desirable personality traits....
  
  ).
• Illusion of asymmetric insight
  Illusion of asymmetric insight
  The illusion of asymmetric insight is a cognitive bias that involves the fact that people perceive their knowledge of others to surpass other people's knowledge of themselves...
  
  – people perceive their knowledge of their peers to surpass their peers' knowledge of them.
• Illusion of transparency
  Illusion of transparency
  The illusion of transparency is a tendency for people to overestimate the degree to which their personal mental state is known by others. Another manifestation of the illusion of transparency is a tendency for people to overestimate how well they understand others' personal mental states...
  
  – people overestimate others' ability to know them, and they also overestimate their ability to know others.
• Illusory superiority
  Illusory superiority
  Illusory superiority is a cognitive bias that causes people to overestimate their positive qualities and abilities and to underestimate their negative qualities, relative to others. This is evident in a variety of areas including intelligence, performance on tasks or tests, and the possession of...
  
  – overestimating one's desirable qualities, and underestimating undesirable qualities, relative to other people. (Also known as "Lake Wobegon effect," "better-than-average effect," or "superiority bias").
• Ingroup bias
  Ingroup bias
  In-group–out-group bias, also called intergroup bias, refers to the phenomenon of in-group favoritism, a preference and affinity for one’s in-group over the out-group, or anyone viewed as outside the in-group. This can be expressed in evaluation of others, linking, allocation of resources and many...
  
  – the tendency for people to give preferential treatment to others they perceive to be members of their own groups.
• Just-world phenomenon
  Just-world phenomenon
  The just world hypothesis describes a cognitive bias in which people believe that the world they live in is one in which actions have appropriate and predictable consequences. This phenomenon has been widely studied by social psychologists since Melvin J. Lerner conducted seminal work on the belief...
  
  – the tendency for people to believe that the world is just and therefore people "get what they deserve."
• Moral luck
  Moral luck
  Moral luck describes circumstances whereby a moral agent is assigned moral blame or praise for an action or its consequences even though it is clear that said agent did not have full control over either the action or its consequences...
  
  – the tendency for people to ascribe greater or lesser moral standing based on the outcome of an event rather than the intention
• Outgroup homogeneity bias
  Outgroup homogeneity bias
  The outgroup homogeneity effect is one's perception of out-group members as more similar to one another than are in-group members. I.e. "they are alike; we are diverse". The outgroup homogeneity effect, or "relative outgroup homogeniety" has been explicitly contrasted with the "outgroup...
  
  – individuals see members of their own group as being relatively more varied than members of other groups.
• Projection bias – the tendency to unconsciously assume that others (or one's future selves) share one's current emotional states, thoughts and values.
• Self-serving bias
  Self-serving bias
  A self-serving bias occurs when people attribute their successes to internal or personal factors but attribute their failures to situational factors beyond their control. The self-serving bias can be seen in the common human tendency to take credit for success but to deny responsibility for failure...
  
  – the tendency to claim more responsibility for successes than failures. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way beneficial to their interests (see also group-serving bias
  Group-serving bias
  Group-serving bias is identical to self-serving bias except that it takes place between groups rather than individuals, under which group members make dispositional attributions for their group's successes and situational attributions for group failures, and vice versa for outsider groups.For...
  
  ).
• System justification
  System justification
  System justification theory is a scientific theory within social psychology that proposes people have a motivation to defend and bolster the status quo, that is, to see it as good, legitimate, and desirable....
  
  – the tendency to defend and bolster the status quo. Existing social, economic, and political arrangements tend to be preferred, and alternatives disparaged sometimes even at the expense of individual and collective self-interest. (See also status quo bias
  Status quo bias
  The status quo bias is a cognitive bias for the status quo; in other words, people tend not to change an established behavior unless the incentive to change is compelling...
  
  .)
• Trait ascription bias
  Trait ascription bias
  Trait ascription bias is the tendency for people to view themselves as relatively variable in terms of personality, behavior and mood while viewing others as much more predictable in their personal traits across different situations...
  
  – the tendency for people to view themselves as relatively variable in terms of personality, behavior, and mood while viewing others as much more predictable.
• Ultimate attribution error
  Ultimate attribution error
  The ultimate attribution error is a term in social psychology which refers to a bias people commonly have towards members of an outgroup. Specifically, they view negative acts committed by outgroup members as a stable trait of the outgroup, and view positive acts committed by outgroup members as...
  
  – similar to the fundamental attribution error, in this error a person is likely to make an internal attribution to an entire group instead of the individuals within the group.

Memory errors and biases

• Cryptomnesia
  Cryptomnesia
  Cryptomnesia occurs when a forgotten memory returns without it being recognised as such by the subject, who believes it is something new and original...
  
  – a form of misattribution where a memory is mistaken for imagination.
• Egocentric bias
  Egocentric bias
  Egocentric bias occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would credit them....
  
  – recalling the past in a self-serving manner, e.g., remembering one's exam grades as being better than they were, or remembering a caught fish as being bigger than it was.
• False memory
  Confabulation
  Confabulation is the process in which a memory is remembered falsely. Confabulations are indicative of a complicated and intricate process that can be led astray at any given point during encoding, storage, or recall of a memory. Two distinct types of confabulation are often distinguished...
  
  – a form of misattribution where imagination is mistaken for a memory.
• Hindsight bias
  Hindsight bias
  Hindsight bias, or alternatively the knew-it-all-along effect and creeping determinism, is the inclination to see events that have already occurred as being more predictable than they were before they took place. It is a multifaceted phenomenon that can affect different stages of designs,...
  
  – filtering memory of past events through present knowledge, so that those events look more predictable than they actually were; also known as the "I-knew-it-all-along effect."
• Positivity effect
  Positivity effect
  In psychology and cognitive science, the positivity effect is the tendency of people, when evaluating the causes of the behaviors of a person they like or prefer, to attribute the person's inherent disposition as the cause of their positive behaviors and the situations surrounding them as the cause...
  
  – older adults remember relatively more positive than negative things, compared with younger adults
• Reminiscence bump
  Reminiscence bump
  The reminiscence bump is the tendency for older adults to have increased recollection for events that occurred during their adolescence and early adulthood...
  
  – the effect that people tend to recall more personal events from adolescence and early adulthood than from other lifetime periods.
• Rosy retrospection
  Rosy retrospection
  Rosy retrospection refers to the finding that subjects later rate past events more positively than they had actually rated them when the event occurred, reminiscent of the Latin phrase memoria praeteritorum bonorum ....
  
  – the tendency to rate past events more positively than they had actually rated them when the event occurred.
• Self-serving bias
  Self-serving bias
  A self-serving bias occurs when people attribute their successes to internal or personal factors but attribute their failures to situational factors beyond their control. The self-serving bias can be seen in the common human tendency to take credit for success but to deny responsibility for failure...
  
  – perceiving oneself responsible for desirable outcomes but not responsible for undesirable ones.
• Suggestibility
  Suggestibility
  Suggestibility is the quality of being inclined to accept and act on the suggestions of others.A person experiencing intense emotions tends to be more receptive to ideas and therefore more suggestible. Generally, suggestibility decreases as age increases...
  
  – a form of misattribution where ideas suggested by a questioner are mistaken for memory.
• Telescoping effect
  Telescoping effect
  In psychology and cognitive science, the telescoping effect is people's tendency to perceive recent events as being more remote than they are, and to perceive distant events as being more recent than they are. More specifically, the former is known as backward telescoping, and the latter as forward...
  
  – the effect that recent events appear to have occurred more remotely and remote events appear to have occurred more recently.
• Von Restorff effect
  Von Restorff effect
  The Von Restorff effect , also called the isolation effect, predicts that an item that "stands out like a sore thumb" is more likely to be remembered than other items....
  
  – the tendency for an item that "stands out like a sore thumb" to be more likely to be remembered than other items.

Common theoretical causes of some cognitive biases

• Bounded rationality
  Bounded rationality
  Bounded rationality is the idea that in decision making, rationality of individuals is limited by the information they have, the cognitive limitations of their minds, and the finite amount of time they have to make a decision...
  
  – limits on optimization and rationality
• Attribute substitution
  Attribute substitution
  Attribute substitution is a psychological process thought to underlie a number of cognitive biases and perceptual illusions. It occurs when an individual has to make a judgment that is computationally complex, and instead substitutes a more easily calculated heuristic attribute...
  
  – making a complex, difficult judgment by unconsciously substituting an easier judgment
• Attribution theory, especially:
  • Salience
    Salience (neuroscience)
    The salience of an item – be it an object, a person, a pixel, etc – is the state or quality by which it stands out relative to its neighbours...
    
    
• Cognitive dissonance
  Cognitive dissonance
  Cognitive dissonance is a discomfort caused by holding conflicting ideas simultaneously. The theory of cognitive dissonance proposes that people have a motivational drive to reduce dissonance. They do this by changing their attitudes, beliefs, and actions. Dissonance is also reduced by justifying,...
  
  , and related:
  • Impression management
    Impression management
    In sociology and social psychology, impression management is a goal-directed conscious or unconscious process in which people attempt to influence the perceptions of other people about a person, object or event; they do so by regulating and controlling information in social interaction...
    
    
  • Self-perception theory
    Self-perception theory
    Self-perception theory is an account of attitude change developed by psychologist Daryl Bem. It asserts that people develop their attitudes by observing their behaviour and concluding what attitudes must have caused them. The theory is counterintuitive in nature, as the conventional wisdom is that...
    
    
• Heuristic
  Heuristic
  Heuristic refers to experience-based techniques for problem solving, learning, and discovery. Heuristic methods are used to speed up the process of finding a satisfactory solution, where an exhaustive search is impractical...
  
  s, including:
  • Availability heuristic
    Availability heuristic
    The availability heuristic is a phenomenon in which people predict the frequency of an event, or a proportion within a population, based on how easily an example can be brought to mind....
    
    – estimating what is more likely by what is more available in memory, which is biased toward vivid, unusual, or emotionally charged examples
  • Representativeness heuristic
    Representativeness heuristic
    The representativeness heuristic is a psychological term describing a phenomenon wherein people judge the probability or frequency of a hypothesis by considering how much the hypothesis resembles available data as opposed to using a Bayesian calculation. While often very useful in everyday life, it...
    
    – judging probabilities on the basis of resemblance
  • Affect heuristic
    Affect heuristic
    The affect heuristic is a heuristic in which current affect influences decisions. Simply put, it is a "rule of thumb" instead of a deliberative decision...
    
    – basing a decision on an emotional reaction rather than a calculation of risks and benefits
• Introspection illusion
  Introspection illusion
  The introspection illusion is a cognitive illusion in which people wrongly think they have direct insight into the origins of their mental states, while treating others' introspections as unreliable...
  
  
• Adaptive bias
  Adaptive bias
  Adaptive bias is the idea that the human brain has evolved to reason adaptively, rather than truthfully or even rationally, and that cognitive bias may have evolved as a mechanism to reduce the overall cost of cognitive errors as opposed to merely reducing the number of cognitive errors, when faced...
  
  
• Misinterpretations or misuse of statistics
  Misuse of statistics
  A misuse of statistics occurs when a statistical argument asserts a falsehood. In some cases, the misuse may be accidental. In others, it is purposeful and for the gain of the perpetrator. When the statistical reason involved is false or misapplied, this constitutes a statistical fallacy.The false...
  
  .

Methods for dealing with cognitive biases

Reference class forecasting

Reference class forecasting

Reference class forecasting is the method of predicting the future, through looking at similar past situations and their outcomes.Reference class forcasting predicts the outcome of a planned action based on actual outcomes in a reference class of similar actions to that being forecast. The theories...

 was developed by Daniel Kahneman

Daniel Kahneman

Daniel Kahneman is an Israeli-American psychologist and Nobel laureate. He is notable for his work on the psychology of judgment and decision-making, behavioral economics and hedonic psychology....

, Amos Tversky

Amos Tversky

Amos Nathan Tversky, was a cognitive and mathematical psychologist, a pioneer of cognitive science, a longtime collaborator of Daniel Kahneman, and a key figure in the discovery of systematic human cognitive bias and handling of risk. Much of his early work concerned the foundations of measurement...

, and Bent Flyvbjerg

Bent Flyvbjerg

Bent Flyvbjerg is the first Chair and BT Professor of Major Programme Management at Oxford University's Saïd Business School and is Founding Director of the University's BT Centre for Major Programme Management. He was previously Professor of Planning at Aalborg University, Denmark and Chair of...

to eliminate or reduce the impact of cognitive biases on decision making.