Biases

Actor-Observer Bias

Need to Act Fast

Personality, Influence
Description

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), 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).
Futher Reading
- https://www.verywellmind.com/what-is-the-actor-observer-bias-2794813
- https://en.wikipedia.org/wiki/Actor-observer_bias
Ambiguity Effect

Need to Act Fast

Probability, Avoidance
Description

The tendency to avoid options for which the probability of a favorable outcome is unknown.
Futher Reading
- https://en.wikipedia.org/wiki/Ambiguity_effect
Anchoring Effect

Too Much Information

Decision Making, Reasoning
Description

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).
Futher Reading
Anecdotal Fallacy

Not Enough Meaning

Experience, Evidence
Description

The tendency to use personal experience or an isolated example instead of a sound argument or compelling evidence.
Futher Reading
- https://en.wikipedia.org/wiki/Anecdotal_evidence
Anthropomorphism

Not Enough Meaning

Personification, Perception
Description

The tendency to characterize animals, objects, and abstract concepts as possessing human-like traits, emotions, and intentions.
Futher Reading
- https://en.wikipedia.org/wiki/Anthropomorphism#Psychology_of_Anthropomorphism
Appeal to Novelty

Need to Act Fast

Fallacy
Description

A fallacy in which one prematurely claims that an idea or proposal is correct or superior, exclusively because it is new and modern.
Futher Reading
- https://en.wikipedia.org/wiki/Appeal_to_novelty
Appeal to Probability

Not Enough Meaning

Probability, Fallacy
Description

The logical fallacy of taking something for granted because it would probably be the case (or might possibly be the case).
Futher Reading
- https://en.wikipedia.org/wiki/Appeal_to_probability
Attentional Bias

Too Much Information

Perception, Frequency
Description

The tendency of perception to be affected by recurring thoughts.
Futher Reading
- https://www.verywellmind.com/what-is-an-attentional-bias-2795027
- https://en.wikipedia.org/wiki/Attentional_bias
Authority Bias

Not Enough Meaning

Attribution, Authority
Description

The tendency to attribute greater accuracy to the opinion of an authority figure (unrelated to its content) and be more influenced by that opinion.
Futher Reading
- https://en.wikipedia.org/wiki/Authority_bias
Automation Bias

Not Enough Meaning

Automation, Decision Making
Description

The tendency to depend excessively on automated systems which can lead to erroneous automated information overriding correct decisions.
Futher Reading
- https://en.wikipedia.org/wiki/Automation_bias
Availability Heuristic

Too Much Information

Memory, Evaluation
Description

A mental shortcut that relies on immediate examples that come to a given person’s mind when evaluating a specific topic, concept, method or decision.
Futher Reading
Baader-Meinhof Phenomenon

Too Much Information

Attention, Frequency
Description

The illusion where something that has recently come to one’s attention suddenly seems to appear with improbable frequency shortly afterwards.
Futher Reading
- https://dqydj.com/baader-meinhof-phenomenon-frequency-bias/
Backfire Effect

Need to Act Fast

Evidence, Belief
Description

The reaction to disconfirming evidence by strengthening one’s previous beliefs.
Futher Reading
- https://en.wikipedia.org/wiki/Backfire_effect
Bandwagon Effect

Not Enough Meaning

Group, Belief
Description

The tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behavior.
Futher Reading
- https://en.wikipedia.org/wiki/Bandwagon_effect
Barnum Effect

Need to Act Fast

Personality, Acceptance
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Barnum_effect
Base Rate Fallacy

Not Enough Meaning

Fallacy, Focus
Description

The tendency to ignore general information and focus on information only pertaining to the specific case, even when the general information is more important.
Futher Reading
- https://en.wikipedia.org/wiki/Base_rate_fallacy
Belief Bias

Need to Act Fast

Evaluation
Description

An effect where someone’s evaluation of the logical strength of an argument is biased by the believability of the conclusion.
Futher Reading
- https://en.wikipedia.org/wiki/Belief_bias
Bias Blind Spot

Too Much Information

Identify
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Bias_blind_spot
Bizarreness Effect

Too Much Information

Memory
Description

Bizarre material is better remembered than common material.
Futher Reading
- https://en.wikipedia.org/wiki/Bizarreness_effect
Cheerleader Effect

Not Enough Meaning

Group, Attractiveness
Description

The tendency for people to appear more attractive in a group than in isolation.
Futher Reading
- https://en.wikipedia.org/wiki/Cheerleader_effect
Choice Supportive Bias

Too Much Information

Selection, Options
Description

The tendency to retroactively ascribe positive attributes to an option one has selected and/or to demote the forgone options.
Futher Reading
- https://en.wikipedia.org/wiki/Choice-supportive_bias
Clustering Illusion

Not Enough Meaning

Pattern
Description

The tendency to overestimate the importance of small runs, streaks, or clusters in large samples of random data (that is, seeing phantom patterns).
Futher Reading
- https://en.wikipedia.org/wiki/Clustering_illusion
Confabulation

Not Enough Meaning

Memory, Misinterpretation
Description

A memory error defined as the production of fabricated, distorted, or misinterpreted memories about oneself or the world.
Futher Reading
- https://en.wikipedia.org/wiki/Confabulation
Confirmation Bias

Too Much Information

Research, Belief, Reasoning, Interpretation
Description

The tendency to search for, interpret, focus on and remember information in a way that confirms one’s preconceptions.
Futher Reading
Congruence Bias

Too Much Information

Research, Hypothesis
Description

The tendency of people to over-rely on testing their initial hypothesis (the most congruent one) while neglecting to test alternative hypotheses.
Futher Reading
- https://en.wikipedia.org/wiki/Congruence_bias
Conjunction Fallacy

Need to Act Fast

Perception, Probability
Description

The tendency to assume that specific conditions are more probable than a more general version of those same conditions. For example, subjects in one experiment perceived the probability of a woman being both a bank teller and a feminist as more likely than the probability of her being a bank teller.
Futher Reading
- https://en.wikipedia.org/wiki/Conjunction_fallacy
Conservatism Bias

Not Enough Meaning

Belief, Evidence
Description

The tendency to revise one’s belief insufficiently when presented with new evidence.
Futher Reading
- https://en.wikipedia.org/wiki/Conservatism_%28belief_revision%29
Consistency Bias

Not Enough Meaning

Memory
Description

Incorrectly remembering one’s past attitudes and behaviour as resembling present attitudes and behaviour.
Futher Reading
- https://fs.blog/2016/08/commitment-consistency-bias/
- https://uxdesign.cc/deadly-biases-every-designer-needs-to-live-with-94a3ac519c99
Context Effect

Too Much Information

Memory, Recall, Context
Description

Cognition and memory are dependent on context, such that out-of-context memories are more difficult to retrieve than in-context memories (e.g., recall time and accuracy for a work-related memory will be lower at home, and vice versa).
Futher Reading
- https://en.wikipedia.org/wiki/Cue-dependent_forgetting
Continued Influence Effect

Too Much Information

Belief, Misinformation, Influence
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Continued_influence_effect
Contrast Effect

Too Much Information

Perception, Contrast
Description

The enhancement or reduction of a certain stimulus’ perception when compared with a recently observed, contrasting object.
Futher Reading
- https://en.wikipedia.org/wiki/Contrast_effect
Cross-Race Effect

Not Enough Meaning

Race, Identity
Description

The tendency for people of one race to have difficulty identifying members of a race other than their own.
Futher Reading
- https://en.wikipedia.org/wiki/Cross-race_effect
Cryptomnesia

What Should We Remember?

Misattribution
Description

A form of misattribution where a memory is mistaken for imagination, because there is no subjective experience of it being a memory.
Futher Reading
- https://en.wikipedia.org/wiki/Cryptomnesia
Curse of Knowledge

Not Enough Meaning

Perspective
Description

When better-informed people find it extremely difficult to think about problems from the perspective of lesser-informed people.
Futher Reading
- https://en.wikipedia.org/wiki/Curse_of_knowledge
Declinism

Not Enough Meaning

Predisposition, Negativity
Description

The predisposition to view the past favorably (rosy retrospection) and future negatively.
Futher Reading
- https://en.wikipedia.org/wiki/Declinism
Decoy Effect

Need to Act Fast

Preference
Description

Preferences for either option A or B change in favor of option B when option C is presented, which is completely dominated by option B (inferior in all respects) and partially dominated by option A.
Futher Reading
- https://uxdesign.cc/ux-psychology-2-increasing-conversions-with-the-decoy-effect-272500321df7
- https://en.wikipedia.org/wiki/Decoy_effect
Defensive Attribution Hypothesis

Need to Act Fast

Attribution, Hypothesis
Description

Attributing more blame to a harm-doer as the outcome becomes more severe or as personal or situational similarity to the victim increases.
Futher Reading
- https://en.wikipedia.org/wiki/Defensive_attribution_hypothesis
Denomination Effect

Not Enough Meaning

Money
Description

The tendency to spend more money when it is denominated in small amounts (e.g., coins) rather than large amounts (e.g., bills).
Futher Reading
- https://en.wikipedia.org/wiki/Denomination_effect
Disposition Effect

Need to Act Fast

Value
Description

The tendency to sell an asset that has accumulated in value and resist selling an asset that has declined in value.
Futher Reading
- https://en.wikipedia.org/wiki/Disposition_effect
Distinction Bias

Too Much Information

Perception, Evaluation
Description

The tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.
Futher Reading
- https://en.wikipedia.org/wiki/Distinction_bias
Dunning Kruger Effect

Need to Act Fast

Estimation, Ability
Description

The tendency for unskilled individuals to overestimate their own ability and the tendency for experts to underestimate their own ability.
Futher Reading
Duration Neglect

What Should We Remember?

Duration, Value
Description

The neglect of the duration of an episode in determining its value.
Futher Reading
- https://en.wikipedia.org/wiki/Duration_neglect
Egocentric Bias

Need to Act Fast

Responsibility
Description

Occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would credit them with.
Futher Reading
- https://en.wikipedia.org/wiki/Egocentric_bias
Endowment Effect

Need to Act Fast

Demand
Description

The tendency for people to demand much more to give up an object than they would be willing to pay to acquire it.
Futher Reading
- https://en.wikipedia.org/wiki/Endowment_effect
Extrinsic Incentives Bias

Not Enough Meaning

Attribution
Description

An exception to the fundamental attribution error, when people view others as having (situational) extrinsic motivations and (dispositional) intrinsic motivations for oneself.
Futher Reading
- https://en.wikipedia.org/wiki/Extrinsic_incentives_bias
Fading Affect Bias

What Should We Remember?

Emotion, Memory
Description

A bias in which the emotion associated with unpleasant memories fades more quickly than the emotion associated with positive events.
Futher Reading
- https://en.wikipedia.org/wiki/Fading_affect_bias
False Consensus Effect

Need to Act Fast

Estimation
Description

The tendency for people to overestimate the degree to which others agree with them.
Futher Reading
- https://www.verywellmind.com/what-is-the-false-consensus-effect-2795030
- https://en.wikipedia.org/wiki/False_consensus_effect
False Memory

What Should We Remember?

Misattribution, Memory
Description

A form of misattribution where imagination is mistaken for a memory.
Futher Reading
- https://en.wikipedia.org/wiki/Confabulation
Framing Effect

Too Much Information

Belief, Reasoning
Description

Drawing different conclusions from the same information, depending on how that information is presented.
Futher Reading
Functional Fixedness

Not Enough Meaning

Tradition
Description

Limits a person to using an object only in the way it is traditionally used.
Futher Reading
- https://www.verywellmind.com/what-is-functional-fixedness-2795484
- https://en.wikipedia.org/wiki/Functional_fixedness
Fundamental Attribution Error

Need to Act Fast

Observation, Personality
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Fundamental_attribution_error
Gambler’s Fallacy

Not Enough Meaning

Probability, Fallacy
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Gambler%27s_fallacy
Generation Effect

Need to Act Fast

Memory, Recall
Description

That self-generated information is remembered best. For instance, people are better able to recall memories of statements that they have generated than similar statements generated by others.
Futher Reading
- https://en.wikipedia.org/wiki/Generation_effect
Google Effect

What Should We Remember?

Information
Description

The tendency to forget information that can be found readily online by using Internet search engines.
Futher Reading
- https://en.wikipedia.org/wiki/Google_effect
Group Attribution Error

Not Enough Meaning

Attribution, Decision Making, Group
Description

The biased belief that the characteristics of an individual group member are reflective of the group as a whole or the tendency to assume that group decision outcomes reflect the preferences of group members, even when information is available that clearly suggests otherwise.
Futher Reading
- https://en.wikipedia.org/wiki/Group_attribution_error
Halo Effect

Not Enough Meaning

Personality, Perception, Identity
Description

The tendency for a person’s positive or negative traits to ‘spill over’ from one personality area to another in others’ perceptions of them (see also physical attractiveness stereotype).
Futher Reading
Hard–Easy Effect

Need to Act Fast

Estimation, Ability
Description

The tendency to overestimate one’s ability to accomplish hard tasks, and underestimate one’s ability to accomplish easy tasks.
Futher Reading
- https://en.wikipedia.org/wiki/Hard%E2%80%93easy_effect
Hindsight Bias

Not Enough Meaning

Predictability
Description

Sometimes called the ‘I-knew-it-all-along’ effect, the tendency to see past events as being predictable at the time those events happened.
Futher Reading
Hot-Hand Fallacy

Not Enough Meaning

Belief, Fallacy
Description

The belief that a person who has experienced success with a random event has a greater chance of further success in additional attempts.
Futher Reading
- https://en.wikipedia.org/wiki/Hot_hand
Hyperbolic Discounting

Need to Act Fast

Reasoning
Description

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.
Futher Reading
- https://blog.usejournal.com/most-common-cognitive-biases-visualised-explained-ad94574f8054
- https://en.wikipedia.org/wiki/Hyperbolic_discounting
Identifiable Victim Effect

Need to Act Fast

Punishment
Description

The tendency of individuals to offer greater aid when a specific, identifiable person (’victim’) is observed under hardship, as compared to a large, vaguely defined group with the same need.
Futher Reading
- https://en.wikipedia.org/wiki/Identifiable_victim_effect
Ikea Effect

Need to Act Fast

Value
Description

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 product.
Futher Reading
Illusion of Asymmetric Insight

Not Enough Meaning

Perception
Description

People perceive their knowledge of their peers to surpass their peers’ knowledge of them.
Futher Reading
- https://en.wikipedia.org/wiki/Illusion_of_asymmetric_insight
Illusion of Control

Need to Act Fast

Estimation, Control
Description

The tendency to overestimate one’s degree of influence over other external events.
Futher Reading
- https://en.wikipedia.org/wiki/Illusion_of_control
Illusion of Transparency

Not Enough Meaning

Estimation
Description

The tendency for people to overestimate the degree to which their personal mental state is known by others, and to overestimate how well they understand others’ personal mental states.
Futher Reading
- https://dscout.com/people-nerds/cognitive-biases-user-research
- https://en.wikipedia.org/wiki/Illusion_of_transparency3
Illusion of Validity

Not Enough Meaning

Estimation
Description

The tendency to overestimate the accurracy of one’s judgments, especially when available information is consistent or inter-correlated.
Futher Reading
- https://en.wikipedia.org/wiki/Illusion_of_validity
Illusory Correlation

Not Enough Meaning

Perception, Relation
Description

Inaccurately perceiving a relationship between two unrelated events.
Futher Reading
- https://en.wikipedia.org/wiki/Illusory_correlation
Illusory Superiority

Need to Act Fast

Estimation, Desirability
Description

Overestimating one’s desirable qualities, and underestimating undesirable qualities, relative to other people.
Futher Reading
- https://en.wikipedia.org/wiki/Illusory_superiority
Illusory Truth Effect

Too Much Information

Belief, Frequency
Description

The tendency to believe false information to be correct after repeated exposure.
Futher Reading
- https://en.wikipedia.org/wiki/Illusory_truth_effect
Impact Bias

Not Enough Meaning

Estimation
Description

The tendency to overestimate the length or the intensity of the impact of future feeling states.
Futher Reading
- https://en.wikipedia.org/wiki/Impact_bias
In-Group Bias

Not Enough Meaning

Pattern, Group
Description

A pattern of favoring members of one’s in-group over out-group members. This can be expressed in evaluation of others, in allocation of resources, and in many other ways.
Futher Reading
- https://en.wikipedia.org/wiki/In-group_favoritism
Information Bias

Need to Act Fast

Information
Description

The tendency to seek information even when it cannot affect action.
Futher Reading
- https://en.wikipedia.org/wiki/Information_bias_(psychology)
Insensitivity to Sample Size

Not Enough Meaning

Research, Probability
Description

People judge the probability of obtaining a sample statistic without respect to the sample size
Futher Reading
- https://en.wikipedia.org/wiki/Insensitivity_to_sample_size
Just World Hypothesis

Not Enough Meaning

Belief, Rationalization, Hypothesis
Description

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).
Futher Reading
- https://en.wikipedia.org/wiki/Just-world_hypothesis
Law of Narrative Gravity

Too Much Information

Press, Narrative, Perception
Description

The public and press are drawn to narratives, and the more widely accepted (or massive) a narrative, the more it attracts and shapes the perception of facts.
Futher Reading
- https://www.wired.com/2017/03/the-invisible-force-that-warps-what-you-read-in-the-news/
Law of the Instrument

Need to Act Fast

Tool, Method
Description

An over-reliance on a familiar tool or methods, ignoring or under-valuing alternative approaches.
Futher Reading
- https://en.wikipedia.org/wiki/Law_of_the_instrument
Law of Triviality

Need to Act Fast

Triviality
Description

The tendency to give disproportionate weight to trivial issues. Also known as bikeshedding, this bias explains why an organization may avoid specialized or complex subjects, such as the design of a nuclear reactor, and instead focus on something easy to grasp or rewarding to the average participant, such as the design of an adjacent bike shed.
Futher Reading
- https://en.wikipedia.org/wiki/Law_of_triviality
Leveling and Sharpening

What Should We Remember?

Memory
Description

Memory distortions introduced by the loss of details in a recollection over time, often concurrent with sharpening or selective recollection of certain details that take on exaggerated significance in relation to the details or aspects of the experience lost through leveling. Both biases may be reinforced over time, and by repeated recollection or re-telling of a memory.
Futher Reading
- https://en.wikipedia.org/wiki/Leveling_and_sharpening
Levels-of-Processing Effect

What Should We Remember?

Information
Description

That different methods of encoding information into memory have different levels of effectiveness.
Futher Reading
- https://en.wikipedia.org/wiki/Levels-of-processing_effect
List-Length Effect

What Should We Remember?

Memory
Description

A smaller percentage of items are remembered in a longer list, but as the length of the list increases, the absolute number of items remembered increases as well. For example, consider a list of 30 items (‘L30’) and a list of 100 items (‘L100’). An individual may remember 15 items from L30, or 50%, whereas the individual may remember 40 items from L100, or 40%. Although the percent of L30 items remembered (50%) is greater than the percent of L100 (40%), more L100 items (40) are remembered than L30 items.
Futher Reading
- https://link.springer.com/article/10.3758/s13421-010-0007-6
Loss Aversion

Need to Act Fast

Perception
Description

The perceived disutility of giving up an object is greater than the utility associated with acquiring it.
Futher Reading
- https://blog.usejournal.com/most-common-cognitive-biases-visualised-explained-ad94574f8054
- https://en.wikipedia.org/wiki/Loss_aversion
Mere Exposure Effect

Too Much Information

Frequency, Familiarity, Preference
Description

People tend to develop a preference for things merely because they are familiar with them.
Futher Reading
- https://en.wikipedia.org/wiki/Mere-exposure_effect
Misinformation Bias

What Should We Remember?

Memory
Description

Memory becoming less accurate because of interference from post-event information.
Futher Reading
- https://www.verywellmind.com/what-is-the-misinformation-effect-2795353
- https://en.wikipedia.org/wiki/Misinformation_effect
Modality Effect

What Should We Remember?

Memory, Recall, Speech
Description

That memory recall is higher for the last items of a list when the list items were received via speech than when they were received through writing.
Futher Reading
- https://en.wikipedia.org/wiki/Modality_effect
Money Illusion

Not Enough Meaning

Money
Description

The tendency to concentrate on the nominal value (face value) of money rather than its value in terms of purchasing power.
Futher Reading
- https://en.wikipedia.org/wiki/Money_illusion
Mood-Congruent Memory Bias

Too Much Information

Mood, Context
Description

The improved recall of information congruent with one’s current mood.
Futher Reading
- https://en.wikipedia.org/wiki/State-dependent_memory
Moral Credential Effect

Not Enough Meaning

Morality
Description

Occurs when someone who does something good gives themselves permission to be less good in the future.
Futher Reading
- https://en.wikipedia.org/wiki/Moral_credential
Moral Luck

Not Enough Meaning

Morality
Description

The tendency for people to ascribe greater or lesser moral standing based on the outcome of an event.
Futher Reading
- https://en.wikipedia.org/wiki/Moral_luck
Naïve Cynicism

Too Much Information

Expectation
Description

Expecting more egocentric bias in others than in oneself.
Futher Reading
- https://en.wikipedia.org/wiki/Na%C3%AFve_cynicism
Naïve Realism

Too Much Information

Belief
Description

The belief that we see reality as it really is – objectively and without bias; that the facts are plain for all to see; that rational people will agree with us; and that those who don’t are either uninformed, lazy, irrational, or biased.
Futher Reading
- https://en.wikipedia.org/wiki/Na%C3%AFve_realism_%28psychology%29
Negativity Bias

Too Much Information

Negativity, Memory, Recall
Description

Humans have a greater recall of unpleasant memories compared with positive memories.
Futher Reading
- https://en.wikipedia.org/wiki/Negativity_bias
Neglect of Probability

Not Enough Meaning

Probability, Decision Making
Description

The tendency to completely disregard probability when making a decision under uncertainty.
Futher Reading
- https://en.wikipedia.org/wiki/Neglect_of_probability
Next-in-Line Effect

What Should We Remember?

Recall
Description

When taking turns speaking in a group using a predetermined order (e.g. going clockwise around a room, taking numbers, etc.) people tend to have diminished recall for the words of the person who spoke immediately before them.
Futher Reading
- https://en.wikipedia.org/wiki/Next-in-line_effect
Normalcy Bias

Not Enough Meaning

Cognitive Dissonance, Belief
Description

The refusal to plan for, or react to, a disaster which has never happened before.
Futher Reading
- https://en.wikipedia.org/wiki/Normalcy_bias
Not Invented Here

Not Enough Meaning

Aversion, Group
Description

Aversion to contact with or use of products, research, standards, or knowledge developed outside a group.
Futher Reading
- https://en.wikipedia.org/wiki/Not_invented_here
- https://www.kooslooijesteijn.net/blog/design-better-avoiding-cognitive-biases
Observer-Expectancy Effect

Too Much Information

Research, Misinterpretation, Observation
Description

When a researcher expects a given result and therefore unconsciously manipulates an experiment or misinterprets data in order to find it.
Futher Reading
- https://medium.muz.li/6-common-cognitive-biases-uxers-should-know-750b8c7af1a8
- https://en.wikipedia.org/wiki/Observer-expectancy_effect
Omission Bias

Too Much Information

Decision Making
Description

The tendency to judge harmful actions (commissions) as worse, or less moral, than equally harmful inactions (omissions).
Futher Reading
- https://en.wikipedia.org/wiki/Omission_bias
Optimism Bias

Need to Act Fast

Estimation, Probability, Optimism
Description

The tendency to be over-optimistic, underestimating greatly the probability of undesirable outcomes and overestimating favorable and pleasing outcomes.
Futher Reading
- https://www.verywellmind.com/what-is-the-optimism-bias-2795031
- https://en.wikipedia.org/wiki/Optimism_bias
Ostrich Effect

Too Much Information

Avoidance
Description

The tendency to ignore an obvious (negative) situation.
Futher Reading
- https://en.wikipedia.org/wiki/Ostrich_effect
Out-Group Homogeneity

Not Enough Meaning

Perception, Group
Description

The perception of out-group members as more similar to one another than are in-group members, e.g. ’they are alike; we are diverse.’
Futher Reading
- https://en.wikipedia.org/wiki/Out-group_homogeneity
Outcome Bias

Not Enough Meaning

Decision
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Outcome_bias
Overconfidence Effect

Need to Act Fast

Confidence
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Overconfidence_effect
Pareidolia

Not Enough Meaning

Apophenia, Perception
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Pareidolia
Part-List Cueing Effect

What Should We Remember?

Retrieval
Description

That being shown some items from a list and later retrieving one item causes it to become harder to retrieve the other items.
Futher Reading
- https://en.wikipedia.org/wiki/Part-list_cueing_effect
Peak-End Rule

What Should We Remember?

Memory
Description

That people seem to perceive not the sum of an experience but the average of how it was at its peak (e.g., pleasant or unpleasant) and how it ended.
Futher Reading
- https://www.nngroup.com/articles/peak-end-rule/
Pessimism Bias

Not Enough Meaning

Estimation, Pessimism
Description

The tendency for some people, especially those suffering from depression, to overestimate the likelihood of negative things happening to them.
Futher Reading
- https://en.wikipedia.org/wiki/Pessimism_bias
Picture Superiority Effect

What Should We Remember?

Recall
Description

The notion that concepts that are learned by viewing pictures are more easily and frequently recalled than are concepts that are learned by viewing their written word form counterparts.
Futher Reading
- https://en.wikipedia.org/wiki/Picture_superiority_effect
Placebo Effect

Not Enough Meaning

Placebo, Benefit
Description

A phenomenon in which some people experience a benefit after the administration of an inactive ‘look-alike’ substance or treatment.
Futher Reading
- https://en.wikipedia.org/wiki/Placebo
Planning Fallacy

Not Enough Meaning

Estimation
Description

The tendency to underestimate one’s own task-completion times.
Futher Reading
- https://en.wikipedia.org/wiki/Planning_fallacy
Positivity Effect

Not Enough Meaning

Memory
Description

That older adults favor positive over negative information in their memories.
Futher Reading
- https://en.wikipedia.org/wiki/Positivity_effect
Pro Innovation Bias

Not Enough Meaning

Optimism
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Pro-innovation_bias
Projection Bias

Not Enough Meaning

Estimation
Description

The tendency to overestimate how much our future selves share one’s current preferences, thoughts and values, thus leading to sub-optimal choices.
Futher Reading
- https://en.wikipedia.org/wiki/Projection_bias
Pseudocertainty Effect

Need to Act Fast

Choice
Description

The tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.
Futher Reading
- https://en.wikipedia.org/wiki/Pseudocertainty_effect
Publication Bias

Too Much Information

Research, Decision Making
Description

A type of bias that occurs in published academic research when the outcome of an experiment or research study influences the decision whether to publish or otherwise distribute it.
Futher Reading
- https://en.wikipedia.org/wiki/Publication_bias
Reactance

Need to Act Fast

Perception, Constraint
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Reactance_(psychology)
Reactive Devaluation

Not Enough Meaning

Devaluation
Description

Devaluing proposals only because they purportedly originated with an adversary.
Futher Reading
- https://en.wikipedia.org/wiki/Reactive_devaluation
Recency Illusion

Not Enough Meaning

Illusion, Perception
Description

The illusion that a phenomenon one has noticed only recently is itself recent. Often used to refer to linguistic phenomena; the illusion that a word or language usage that one has noticed only recently is an innovation when it is, in fact, long-established.
Futher Reading
- https://en.wikipedia.org/wiki/Recency_illusion
Restraint Bias

Not Enough Meaning

Estimation
Description

The tendency to overestimate one’s ability to show restraint in the face of temptation.
Futher Reading
- https://en.wikipedia.org/wiki/Restraint_bias
Rhyme as Reason Effect

Need to Act Fast

Perception
Description

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”.
Futher Reading
- https://en.wikipedia.org/wiki/Rhyme_as_reason_effect
Risk Compensation

Need to Act Fast

Risk, Perception
Description

The tendency to take greater risks when perceived safety increases.
Futher Reading
- https://en.wikipedia.org/wiki/Risk_compensation
Selection Bias

Too Much Information

Attention
Description

The tendency to notice something more when something causes us to be more aware of it, such as when we buy a car, we tend to notice similar cars more often than we did before. They are not suddenly more common – we just are noticing them more.
Futher Reading
- https://uxplanet.org/design-principles-selection-bias-bf51ff9ac69b
- https://en.wikipedia.org/wiki/Selection_bias
Selective Perception

Too Much Information

Perception, Belief
Description

The tendency not to notice and more quickly forget stimuli that cause emotional discomfort and contradict our prior beliefs.
Futher Reading
- https://en.wikipedia.org/wiki/Selective_perception
Self Relevance Effect

What Should We Remember?

Memory, Self
Description

That memories relating to the self are better recalled than similar information relating to others.
Futher Reading
- https://en.wikipedia.org/wiki/Self-reference_effect
Self-Serving Bias

Need to Act Fast

Responsibility, Evaluation
Description

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.
Futher Reading
- https://www.verywellmind.com/what-is-the-self-serving-bias-2795032
- https://en.wikipedia.org/wiki/Self-serving_bias
Semmelweis Reflex

Too Much Information

Evidence, Contradict
Description

The tendency to reject new evidence that contradicts a paradigm.
Futher Reading
- https://en.wikipedia.org/wiki/Semmelweis_reflex
Serial Position Effect

What Should We Remember?

Recall
Description

That items near the end of a sequence are the easiest to recall, followed by the items at the beginning of a sequence; items in the middle are the least likely to be remembered.
Futher Reading
- https://dscout.com/people-nerds/cognitive-biases-user-research
- https://en.wikipedia.org/wiki/Serial_position_effect
Social Comparison Bias

Need to Act Fast

Decision Making
Description

The tendency, when making decisions, to favour potential candidates who don’t compete with one’s own particular strengths.
Futher Reading
- https://en.wikipedia.org/wiki/Social_comparison_bias
Social Desirability Bias

Need to Act Fast

Desirability
Description

The tendency to over-report socially desirable characteristics or behaviours in oneself and under-report socially undesirable characteristics or behaviours.
Futher Reading
Source Confusion

What Should We Remember?

Memory
Description

Confusing episodic memories with other information, creating distorted memories.
Futher Reading
- https://en.wikipedia.org/wiki/Misattribution_of_memory
Spacing Effect

What Should We Remember?

Recall
Description

That information is better recalled if exposure to it is repeated over a long span of time rather than a short one.
Futher Reading
- https://en.wikipedia.org/wiki/Spacing_effect
Spotlight Effect

Not Enough Meaning

Estimation
Description

The tendency to overestimate the amount that other people notice your appearance or behavior.
Futher Reading
- https://en.wikipedia.org/wiki/Spotlight_effect
Status Quo Bias

Need to Act Fast

Preference
Description

The tendency to like things to stay relatively the same.
Futher Reading
- https://en.wikipedia.org/wiki/Status_quo_bias
Stereotypical Bias

What Should We Remember?

Memory, Stereotype
Description

Memory distorted towards stereotypes (e.g., racial or gender).
Futher Reading
- https://en.wikipedia.org/wiki/Implicit_stereotype
Stereotyping

Not Enough Meaning

Contradiction
Description

The tendency to reject new evidence that contradicts a paradigm.
Futher Reading
- https://en.wikipedia.org/wiki/Stereotype
Subadditivity Effect

Not Enough Meaning

Fallacy, Probability
Description

The tendency to judge the probability of the whole to be less than the probabilities of the parts.
Futher Reading
- https://en.wikipedia.org/wiki/Subadditivity_effect
Subjective Validation

Too Much Information

Perception, Belief, Coincidence
Description

Perception that something is true if a subject’s belief demands it to be true. Also assigns perceived connections between coincidences.
Futher Reading
- https://en.wikipedia.org/wiki/Subjective_validation
Suffix Effect

What Should We Remember?

Recall
Description

Diminishment of the recency effect because a sound item is appended to the list that the subject is not required to recall.
Futher Reading
- https://coglab.cengage.com/labs/suffix_effect.shtml
Suggestibility

What Should We Remember?

Misattribution, Memory
Description

A form of misattribution where ideas suggested by a questioner are mistaken for memory.
Futher Reading
- https://en.wikipedia.org/wiki/Suggestibility#External
Sunk Cost Fallacy

Need to Act Fast

Fallacy, Decision Making
Description

In economics and business decision-making, a sunk cost (also known as retrospective cost) is a cost that has already been incurred and cannot be recovered.
Futher Reading
- https://uxdesign.cc/cognitive-bias-in-ux-the-user-side-and-the-designer-side-6f6ae0185779
- https://en.wikipedia.org/wiki/Sunk_cost
Survivorship Bias

Not Enough Meaning

Visibility
Description

Concentrating on the people or things that ‘survived’ some process and inadvertently overlooking those that didn’t because of their lack of visibility.
Futher Reading
- https://en.wikipedia.org/wiki/Survivorship_bias
- https://www.kooslooijesteijn.net/blog/design-better-avoiding-cognitive-biases
System Justification

Need to Act Fast

Status Quo
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/System_justification
Telescoping Effect

Not Enough Meaning

Time, Perception
Description

The tendency to displace recent events backwards in time and remote events forward in time, so that recent events appear more remote, and remote events, more recent.
Futher Reading
- https://en.wikipedia.org/wiki/Telescoping_effect
Testing Effect

What Should We Remember?

Memory
Description

The fact that you more easily remember information you have read by rewriting it instead of rereading it.
Futher Reading
- https://en.wikipedia.org/wiki/Testing_effect
Third-Person Effect

Need to Act Fast

Communication
Description

A hypothesized tendency to believe that mass communicated media messages have a greater effect on others than on themselves. As of 2020, the third-person effect has yet to be reliably demonstrated in a scientific context.
Futher Reading
- https://en.wikipedia.org/wiki/Third-person_effect
Time Saving Bias

Not Enough Meaning

Estimation
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Time-saving_bias
Tip-of-the-Tongue Phenomenon

What Should We Remember?

Recall, Memory
Description

When a subject is able to recall parts of an item, or related information, but is frustratingly unable to recall the whole item. This is thought to be an instance of ”blocking” where multiple similar memories are being recalled and interfere with each other.
Futher Reading
- https://en.wikipedia.org/wiki/Tip_of_the_tongue
Trait Ascription Bias

Need to Act Fast

Predictability, Personality
Description

The tendency for people to view themselves as relatively variable in terms of personality, behavior, and mood while viewing others as much more predictable.
Futher Reading
- https://en.wikipedia.org/wiki/Trait_ascription_bias
Ultimate Attribution Error

Not Enough Meaning

Attribution, Decision Making, Group
Description

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.
Futher Reading
- https://en.wikipedia.org/wiki/Ultimate_attribution_error
Unit Bias

Need to Act Fast

Consumption, Perception
Description

The standard suggested amount of consumption (e.g., food serving size) is perceived to be appropriate, and a person would consume it all even if it is too much for this particular person.
Futher Reading
- https://www.alleydog.com/glossary/definition.php?term=Unit%2520Bias
Von Restorff Effect

Too Much Information

Memory, Contrast
Description

That an item that sticks out is more likely to be remembered than other items.”
Futher Reading
- https://en.wikipedia.org/wiki/Von_Restorff_effect
Weber-Fechner Law

Too Much Information

Comparision, Pattern
Description

Difficulty in comparing small differences in large quantities.
Futher Reading
- https://en.wikipedia.org/wiki/Weber%E2%80%93Fechner_law
Well Travelled Road Effect

Not Enough Meaning

Estimation
Description

Travellers will estimate the time taken to traverse routes differently depending on their familiarity with the route.
Futher Reading
- https://en.wikipedia.org/wiki/Well_travelled_road_effect
Zeigarnik Effect

What Should We Remember?

Memory
Description

That uncompleted or interrupted tasks are remembered better than completed ones.
Futher Reading
- https://en.wikipedia.org/wiki/Zeigarnik_effect
Zero Sum Bias

Not Enough Meaning

Fallacy
Description

A bias whereby a situation is incorrectly perceived to be like a zero-sum game (i.e., one person gains at the expense of another).
Futher Reading
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153800/
- https://en.wikipedia.org/wiki/Zero-sum_thinking
Zero-Risk Bias

Need to Act Fast

Risk
Description

Preference for reducing a small risk to zero over a greater reduction in a larger risk.”
Futher Reading
- https://en.wikipedia.org/wiki/Zero-risk_bias

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