Cognitive Bias Codex PDF

THE COGNITIVE BIAS CODEX Too Much Information We notice things already primed in memory or repeated often o Availability Heuristic: A mental shortcut that relies on immediate examples that come to mind when evaluating a specifi...

THE COGNITIVE BIAS CODEX Too Much Information We notice things already primed in memory or repeated often o Availability Heuristic: A mental shortcut that relies on immediate examples that come to mind when evaluating a specific topic, concept, method, or decision. This can lead to biased decisions based on recent or memorable information1. o Attentional Bias: The tendency to pay attention to some things while simultaneously ignoring others. This bias affects not only what we perceive but also the decisions we make based on those perceptions2. o Illusory Truth Effect: The tendency to believe false information to be correct after repeated exposure. Repetition increases the perception of truth, even if the information is initially known to be false3. o Mere-Exposure Effect: A psychological phenomenon where people tend to develop a preference for things merely because they are familiar with them. Repeated exposure to a stimulus increases liking for it4. o Context Effect: The influence of environmental factors on one’s perception of a stimulus. This effect shows how context can alter our understanding and interpretation of information5. o Cue-Dependent Forgetting: The failure to recall information without memory cues. This type of forgetting occurs because the cues present during learning are not available during recall6. o Mood-Congruent Memory Bias: The tendency to recall memories that are consistent with one’s current mood. For example, when happy, one is more likely to remember other happy events7. o Frequency Illusion: Also known as the Baader-Meinhof Phenomenon, it is a cognitive bias where something you recently learned or noticed suddenly appears everywhere. This is due to selective attention and confirmation bias8. o Baader-Meinhof Phenomenon: The experience of learning something new and then seeing it frequently shortly after. This is a specific instance of the frequency illusion8. o Empathy Gap: The inability to understand or predict the behavior of others when in a different emotional state. This bias can lead to misunderstandings and misjudgments of others’ actions9. o Omission Bias: The tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions). This bias can affect decision-making and moral judgments9. o Base Rate Fallacy: Ignoring statistical information (base rates) in favor of specific information. This can lead to incorrect conclusions by focusing on anecdotal evidence rather than broader statistical data9. Bizarre, funny, visually striking, or anthropomorphic things stick out more than non- bizarre/unfunny things o Bizarreness Effect: The tendency to remember bizarre or unusual information better than common information because it stands out and is more distinctive. o Humor Effect: The phenomenon where humorous items are more likely to be remembered than non-humorous ones, as humor enhances attention and memory retention. o Von Restorff Effect: Also known as the “isolation effect,” it predicts that an item that stands out from a group of similar items is more likely to be remembered.  o Picture Superiority Effect: The tendency for pictures and images to be more easily remembered than words. This effect is due to the dual coding of visual and verbal information, making visual information more memorable. o Self-Relevance Effect: The tendency to better remember information that is personally relevant or related to oneself. This effect highlights the bias we have towards information that we can relate to our own experiences. o Negativity Bias: The cognitive bias where negative events, emotions, or interactions have a greater impact on one’s psychological state and processes than neutral or positive ones. This means we tend to focus more on negative information We notice when something has changed o Anchoring: The tendency to rely too heavily on the first piece of information encountered when making decisions. o Conservatism: The tendency to revise one’s beliefs insufficiently when presented with new evidence, sticking too closely to initial beliefs. o Contrast Effect: The enhancement or diminishment of perception, cognition, or performance when comparing two stimuli, making them seem more different than they are. o Distinction Bias: The tendency to view two options as more distinctive when evaluating them together than when evaluating them separately. o Focusing Effect: The tendency to place too much importance on one aspect of an event or situation, ignoring other relevant factors. o Framing Effect: The way information is presented (positive or negative) influences how people react to it. o Money Illusion: The tendency to think of money in nominal terms rather than real terms, ignoring the effects of inflation. o Weber–Fechner Law: A principle stating that the perceived change in a stimulus is proportional to the initial stimulus, meaning larger changes are needed to notice differences as the stimulus increases. We are drawn to details that confirm our own existing belief o Confirmation Bias: The tendency to search for, interpret, and remember information that confirms one’s existing beliefs. o Congruence Bias: The tendency to test one’s initial hypothesis repeatedly while neglecting to test alternative hypotheses. o Post-Purchase Rationalization: Convincing oneself that a purchase was a good decision, even if it wasn’t, to avoid feeling regret. o Choice-Supportive Bias: Remembering one’s choices as better than they were, often by downplaying the negatives of the chosen option and emphasizing the positives. o Selective Perception: The tendency to notice and remember information that aligns with one’s existing beliefs and to ignore information that contradicts them. o Observer-Expectancy Effect: When a researcher’s expectations subconsciously influence the participants of an experiment, affecting the results. o Experimenter’s Bias: When a researcher’s expectations or beliefs unintentionally influence the outcome of an experiment. o Observer Effect: The phenomenon where observing a situation or phenomenon changes it. o Expectation Bias: When people’s expectations about the outcome of an event influence their perception and interpretation of the information.  o Ostrich Effect: The tendency to avoid potentially negative information by “burying one’s head in the sand.” o Subjective Validation: The tendency to believe vague or general statements are true, especially if they are personally meaningful. o Continued Influence Effect: The tendency for misinformation to continue to influence thoughts and memories even after it has been corrected. o Semmelweis Reflex: The tendency to reject new evidence or knowledge because it contradicts established norms or beliefs. We notice flaws in others more easily than we notice flaws in ourselves o Bias Blind Spot: The tendency to see oneself as less biased than other people, even though everyone has biases. o Naïve Cynicism: The belief that other people are more selfish or biased than they are, often assuming others have bad intentions without enough evidence. o Naïve Realism: The belief that we see the world exactly as it is, and that people who disagree with us must be uninformed, irrational, or biased. Not Enough Meaning We tend to find stories and patterns even when looking at sparse data o Confabulation: Creating false memories without intending to deceive, often filling in gaps in memory with fabricated details. o Clustering Illusion: Seeing patterns in random events, like thinking a series of coin flips must balance out. o Insensitivity to Sample Size: Ignoring the size of a sample when judging the reliability of its results, like thinking a small survey is as accurate as a large one. o Neglect of Probability: Ignoring the actual chances of an event happening, often overestimating or underestimating risks. o Anecdotal Fallacy: Using personal stories or isolated examples as evidence for a general claim, instead of relying on broader data. o Illusion of Validity: Overestimating the accuracy of one’s predictions or judgments, especially when the data seems consistent. o Masked-Man Fallacy: If if you know something about someone in one context, you must know it in all contexts, like thinking you know who someone is just because you recognize their voice. o Recency Illusion: Believing that something you’ve only recently noticed is new, even if it has been around for a long time. o Gambler’s Fallacy: Believing that past random events affect the likelihood of future random events, like thinking a coin is “due” to land on heads. o Hot-Hand Fallacy: Believing that a person who has experienced success in a random event is more likely to continue succeeding. o Illusory Correlation: Perceiving a relationship between two variables when none exists, like thinking that wearing a lucky shirt causes your team to win. o Pareidolia: Seeing familiar patterns, like faces, in random objects, such as clouds or rock formations. o Anthropomorphism: Attributing human characteristics to non-human entities, like thinking your pet understands complex emotions We fill in characteristics from stereotypes, generalities, and prior histories  o Group Attribution Error: Believing that the characteristics or behaviors of one group member reflect the entire group, or that a group’s decision reflects the preferences of all its members. o Ultimate Attribution Error: Attributing negative behaviors of outgroup members to their character, while attributing positive behaviors to external factors, and doing the opposite for ingroup members. o Stereotyping: Having a fixed, oversimplified, and often incorrect idea about a group of people. o Essentialism: The belief that certain categories (like gender or race) have an underlying essence that makes them what they are. o Functional Fixedness: The tendency to see objects as only working in a particular way, which limits creativity in problem-solving. o Moral Credential Effect: Feeling licensed to act in a less ethical way after having previously demonstrated moral behavior. o Just-World Hypothesis: The belief that the world is fair, and people get what they deserve, leading to victim-blaming. o Argument from Fallacy: If if an argument contains a fallacy, its conclusion must be false. o Authority Bias: Placing more trust in the opinions of authority figures, regardless of the content. o Automation Bias: Relying too heavily on automated systems, assuming they are always correct. o Bandwagon Effect: Adopting beliefs or behaviors because many other people do. o Placebo Effect: Experiencing a real improvement in condition due to believing that a treatment will work, even if the treatment has no therapeutic effect. We imagine things and people we're familiar with or fond of as better o Out-Group Homogeneity Bias: The tendency to see members of an out-group (a group you don’t belong to) as more like each other than they really are, while seeing members of your own group as more diverse. o Cross-Race Effect: The tendency to recognize faces of people more easily from your own race compared to faces of people from other races. o In-Group Favoritism: Preferring and giving better treatment to people who belong to your own group over those who don’t. o Halo Effect: The tendency to let one positive trait of a person influence your overall perception of them, making you think they have other positive traits as well. o Cheerleader Effect: The phenomenon where people appear more attractive when they are in a group than when they are alone. o Positivity Effect: The tendency, especially in older adults, to focus more on positive information and memories than on negative ones. o Not Invented Here: The tendency to reject ideas, products, or solutions that come from outside your own group or organization. o Reactive Devaluation: The tendency to devalue a proposal or idea simply because it comes from an opposing party or someone you don’t like. o Well-Traveled Road Effect: The tendency to underestimate the time it takes to travel familiar routes and overestimate the time it takes to travel unfamiliar routes We simplify probabilities and numbers to make them easier to think about o Mental Accounting: Treating money differently based on where it comes from or how it is intended to be used, even though money is interchangeable.  o Appeal to Probability Fallacy: Assuming that because something is likely to happen, it will happen. o Normalcy Bias: Underestimating the possibility or impact of a disaster because it hasn’t happened before, leading to inadequate preparation. o Murphy’s Law: The adage that anything that can go wrong will go wrong. o Zero Sum Bias: The belief that one person’s gain is another person’s loss, even when this isn’t true. o Survivorship Bias: Focusing on successful examples and ignoring those that failed, leading to incorrect conclusions. o Subadditivity Effect: Judging the probability of the whole to be less than the sum of its parts. o Denomination Effect: Being less likely to spend larger currency denominations than their equivalent value in smaller denominations. o The Magical Number 7 ± 2: The idea that the average person can hold about 7 (plus or minus 2) items in their short-term memory at once. We think we know what other people are thinking o Illusion of Transparency: The tendency to overestimate how much others can understand our thoughts, feelings, and emotions. We think our internal states are more obvious to others than they are. o Curse of Knowledge: When someone knows something, they find it hard to imagine not knowing it. This makes it difficult to explain things to others who don’t have the same knowledge. o Spotlight Effect: The belief that we are being noticed more than we really are. We think others are paying more attention to our actions and appearance than they do. o Extrinsic Incentive Error: The tendency to believe that others are motivated more by external rewards (like money) than by internal motivations (like personal satisfaction), while we see ourselves as motivated by internal factors. o Illusion of External Agency: The false belief that external forces or agents are responsible for our actions or outcomes, rather than recognizing our own role in creating those outcomes. o Illusion of Asymmetric Insight: The belief that we understand others better than they understand us, and that we know ourselves better than others know themselves. We project our current mindset and assumptions onto the past and future o Telescoping Effect: The tendency to perceive recent events as being more distant in time and distant events as being more recent. o Rosy Retrospection: Remembering past events as being more positive than they were. o Hindsight Bias: The tendency to believe, after an event has occurred, that we knew the outcome all along. o Outcome Bias: Judging a decision based on its outcome rather than the quality of the decision at the time it was made. o Moral Luck: When people are judged morally based on outcomes that were influenced by factors beyond their control. o Declinism: The belief that a society or institution is in decline, often viewing the past more favorably and the future more negatively. o Impact Bias: Overestimating the intensity and duration of our emotional reactions to future events. o Pessimism Bias: The tendency to overestimate the likelihood of negative outcomes and underestimate the likelihood of positive outcomes.  o Planning Fallacy: Underestimating the time, costs, and risks of future actions while overestimating the benefits. o Time-Saving Bias: Misestimating the time saved or lost when changing speed, often underestimating time saved at low speeds and overestimating time saved at high speeds. o Pro-Innovation Bias: Overvaluing new ideas or technologies simply because they are new. o Projection Bias: If others share the same beliefs, attitudes, and behaviors as oneself. o Restraint Bias: Overestimating one’s ability to control impulsive behavior. o Self-Consistency Bias: The tendency to perceive one’s past attitudes and behaviors as consistent with current attitudes and behaviors, even when they have changed. Need To Act Fast To act, we must be confident we can make an impact and feel what we do is important o Overconfidence Effect: The tendency to overestimate one’s abilities or the accuracy of one’s knowledge. o Social Desirability Bias: The tendency to answer questions in a way that will be viewed favorably by others. o Third-Person Effect: The belief that media messages affect others more than they affect oneself. o False Consensus Effect: The tendency to overestimate how much others agree with our own beliefs and behaviors. o Hard-Easy Effect: Overestimating success on difficult tasks and underestimating success on easy tasks. o Lake Wobegone Effect: The tendency to overestimate one’s abilities, thinking we are above average. o Dunning-Kruger Effect: When people with low ability at a task overestimate their ability. o Egocentric Bias: The tendency to rely too heavily on one’s own perspective and have a higher opinion of oneself. o Optimism Bias: The tendency to overestimate the likelihood of positive events and underestimate the likelihood of negative events. o Forer Effect: The tendency to believe vague, general statements are highly accurate for oneself. o Barnum Effect: Like the Forer Effect, where people believe general statements apply specifically to them. o Self-Serving Bias: The tendency to attribute positive events to oneself and negative events to external factors. o Actor-Observer Bias: The tendency to attribute our own actions to external factors but others’ actions to their character. o Illusion of Control: The belief that we have more control over events than we do. o Illusory Superiority: The belief that we are better than others in various aspects. o Fundamental Attribution Error: The tendency to attribute others’ actions to their character rather than situational factors. o Defensive Attribution Hypothesis: The tendency to attribute more blame to a person for their actions as the consequences become more severe. o Trait Ascription Bias: The tendency to view oneself as more variable in behavior than others.  o Effort Justification: The tendency to attribute greater value to an outcome that required a lot of effort to achieve. o Risk Compensation: The tendency to take greater risks when perceived safety increases. o Peltzman Effect: The theory that safety measures can lead to riskier behavior, offsetting the benefits of the safety measures. To stay focused, we favor the immediate, relatable thing in front of us o Hyperbolic Discounting: The tendency to prefer smaller, immediate rewards over larger, delayed rewards. People often choose a reward that comes sooner, even if it’s less valuable. o Appeal to Novelty: The belief that something is better simply because it is new. This fallacy assumes that newer ideas or products are superior just because they are recent. o Identifiable Victim Effect: The tendency to feel more empathy and willingness to help a specific, identifiable person in need, rather than a large, anonymous group of people with the same need To get things done, we tend to complete things we've invested time and energy in o Sunk Cost Fallacy: Continuing an endeavor because of previously invested resources (time, money, effort) even when it would be better to abandon it. o Irrational Escalation: Persisting with a decision or action despite negative outcomes, driven by the desire to justify past investments. o Escalation of Commitment: Increasing commitment to a failing course of action, often due to emotional attachment or the desire to avoid admitting failure. o Generation Effect: Remembering information better when you generate it yourself rather than just reading it. o Loss Aversion: The tendency to prefer avoiding losses over acquiring equivalent gains; losses feel more painful than gains feel good. o IKEA Effect: Valuing something more because you partially created or assembled it yourself. o Unit Bias: The tendency to think that a single unit of something is the right amount, leading to overconsumption if the unit is large. o Zero-Risk Bias: Preferring the complete elimination of a small risk over a greater overall reduction in risk. o Disposition Effect: The tendency to sell assets that have increased in value while keeping assets that have decreased in value. o Pseudocertainty Effect: Believing an outcome is certain when it is uncertain, especially in multi-stage decision-making. o Processing Difficulty Effect: The tendency to remember information better when it is harder to process, as the extra effort enhances memory retention. o Endowment Effect: Valuing something more highly simply because you own it. o Backfire Effect: When people strengthen their beliefs in the face of contradictory evidence To avoid mistakes, we aim to preserve autonomy and group status, and avoid irreversible decisions o System Justification: The tendency to defend and justify the existing social, economic, and political systems, even if they are unfair or disadvantageous to certain groups. o Reverse Psychology: A technique where you encourage someone to do something by suggesting they do the opposite, hoping they will react against your suggestion and do what you want.  o Reactance: The emotional reaction to being told what to do, which often leads to doing the opposite to assert one’s freedom. o Decoy Effect: When an additional, less attractive option is added to a set of choices, making one of the original options more appealing by comparison. o Social Comparison Effect: Evaluating oneself by comparing with others, which can influence self-esteem and behavior based on whether the comparison is with someone better or worse off. o Status Quo Bias: The preference to keep things the same rather than change, even if the change might be beneficial We favor simple–looking options and complete information over complex, ambiguous options o Ambiguity Bias: The tendency to avoid options or decisions that involve uncertainty or incomplete information, preferring those that are clearer and more well-defined. o Information Bias: The tendency to seek out more information even when it does not affect the decision-making process, often leading to overcomplication. o Belief Bias: Judging the strength of an argument based on how believable its conclusion is, rather than on the logic and evidence supporting it. o Rhyme-as-Reason Effect: The tendency to perceive rhyming statements as more truthful or accurate simply because they rhyme. o Bike-Shedding Effect: Spending excessive time on trivial issues while neglecting more important, complex ones, because the trivial issues are easier to understand and discuss. o Law of Triviality: The principle that people within an organization give disproportionate weight to trivial issues, often spending more time on minor details than on important matters. o Conjunction Fallacy: The error of believing that specific conditions are more probable than a single general one, like thinking that two events happening together is more likely than one of them happening alone. o Occam’s Razor: The principle that the simplest explanation, with the fewest assumptions, is usually the best one. o Less-Is-Better Effect: The phenomenon where a smaller or lesser option is preferred when evaluated separately, but not when compared directly with a larger or better option. What Should We Remember? We edit and reinforce some memories after the fact o Misattribution of Memory: Remembering something correctly but attributing it to the wrong source, like thinking you heard a story from a friend when you read it in a book. o Source Confusion: Mixing up where a memory or piece of information came from, such as thinking you saw something on TV when a friend told you about it. o Cryptomnesia: Believing a thought or idea is original when it is a forgotten memory, like thinking you came up with a joke that you actually heard from someone else. o False Memory: Recalling something that didn’t happen or remembering it differently from how it occurred, like thinking you attended an event that you only heard about. o Suggestibility: The tendency to accept and act on suggestions from others, which can lead to distorted or false memories, especially when influenced by leading questions or repeated information. o Spacing Effect: The phenomenon where learning is more effective when study sessions are spaced out over time rather than crammed into a short period  We discard specifics to form generalities o Implicit Association: Unconscious connections we make between different concepts, like associating certain groups of people with specific traits without realizing it. o Implicit Stereotypes: Unconscious beliefs about a group of people that influence our thoughts and actions without us being aware of them. o Stereotypical Bias: Distorted memories or judgments based on unfounded beliefs about certain groups, often related to race, gender, or other characteristics. o Prejudice: An unfair and unreasonable opinion or feeling, especially when formed without enough thought or knowledge, often leading to dislike or unjust treatment of certain people. o Negativity Bias: The tendency to focus more on negative experiences or information than on positive ones, making negative events seem more significant. o Fading Affect Bias: The phenomenon where negative emotions associated with memories fade faster than positive emotions, making past events seem more positive over time. We reduce events and lists to their key elements o Peak–End Rule: We judge an experience largely based on how we felt at its most intense point (the peak) and at its end, rather than the overall experience. o Leveling and Sharpening: When retelling a story, leveling involves omitting details to simplify it, while sharpening involves emphasizing certain details to make the story more vivid. o Misinformation Effect: When misleading information presented after an event alters our memory of the original event. o Serial Recall Effect: The ability to remember a list of items in the exact order they were presented. o List–Length Effect: The phenomenon where the probability of recalling an item decreases as the length of the list increases. o Duration Neglect: The tendency to overlook the length of an experience when evaluating how pleasant or unpleasant it was, focusing instead on the peak and end moments. o Modality Effect: The impact of the mode of presentation (e.g., visual or auditory) on memory recall, with auditory presentations often leading to better recall of the last items. o Memory Inhibition: The process of suppressing irrelevant or interfering memories to focus on relevant information. o Primacy Effect: The tendency to remember the first items in a list better than those in the middle. o Recency Effect: The tendency to remember the last items in a list better than those in the middle. o Part–Set Cueing Effect: When being presented with a subset of items from a list makes it harder to recall the remaining items. o Serial–Position Effect: The tendency to remember the first and last items in a series better than the middle items. o Suffix Effect: The phenomenon where an additional item at the end of a list (like a spoken word) reduces the recall of the last items in the list We store memories differently based on how they were experienced o Levels-of-Processing Effect: The idea that the depth at which you process information affects how well you remember it. Deeper, more meaningful processing leads to better memory. o Absent-Mindedness: Forgetting things because you are not paying attention or are distracted by other thoughts. o Testing Effect: The phenomenon where testing yourself on information helps you remember it better than just studying it. o Next-in-Line Effect: The tendency to forget information presented just before your turn to speak or perform because you are focused on preparing for your own turn. o Google Effect: The tendency to forget information that can be easily found online, relying on search engines instead of remembering it. o Tip of the Tongue Phenomenon: The frustrating feeling of knowing that you know a word or piece of information but being unable to recall it at the moment.