200 Cognitive Biases

1–10: Attention, Perception & Memory Distortions Anchoring Bias Relying too heavily on the first piece of information (the “anchor”) we receive when making decisions. Attentional Bias Tendency to pay more attention to certain stimuli while neglecting others, often because of our current emotional state or expectations. Availability Heuristic Estimating likelihood or frequency of events based on how easily examples come to mind (recent, vivid, dramatic). Baader–Meinhof Phenomenon (Frequency Illusion) Once you notice something, you start seeing it everywhere, creating the illusion it’s suddenly more frequent. Change Blindness Failing to notice even large changes in a visual scene when our attention is directed elsewhere. Confirmation Bias Seeking or interpreting evidence in ways that confirm our preexisting beliefs, and ignoring disconfirming data. Context Effect Cognitive perception of stimuli is influenced by the surrounding environment or context. Contrast Effect Perception of something is affected by comparisons to something else (e.g., an object seems bigger if it’s placed near smaller objects). Egocentric Bias Over-focusing on our own perspective and experiences, making it difficult to see situations through others’ eyes. Illusory Truth Effect Repeated statements feel more true over time, simply because we’ve heard them often. 11–20: Judgment under Uncertainty Ambiguity Effect Avoiding options for which missing information makes the probability of outcomes seem ‘unknown.’ Base Rate Neglect Ignoring general (statistical) information in favor of specifics or anecdotes when estimating probabilities. Belief Bias Judging the strength of an argument by the plausibility of its conclusion rather than how strongly it’s supported. Clustering Illusion Seeing patterns in random data (e.g., ‘hot streaks’ in coin tosses). Conjunction Fallacy Judging the conjunction of events as likelier than a single general event (e.g., “Linda is a bank teller and activist” seeming likelier than just “Linda is a bank teller”). Gambler’s Fallacy Believing that past random events affect the probabilities in the random event at hand (“I’ve flipped five heads, so a tail is ‘due’”). Hindsight Bias After an event, believing we “knew it all along” or that it was easily predictable. Hot-Hand Fallacy Thinking someone who experiences success (e.g., making consecutive basketball shots) has a greater chance of further success, even in purely random sequences. Law of the Instrument Overreliance on a familiar tool or approach (“If all you have is a hammer, everything looks like a nail.”). Survivorship Bias Focusing on successes or survivors while overlooking those that did not survive (creating a skewed perspective). 21–30: Social & Group Dynamics Actor–Observer Bias We attribute our own actions to external circumstances, but others’ actions to their character or disposition. Authority Bias Being overly influenced by authority figures or experts, sometimes beyond rational justification. Bandwagon Effect (Social Proof) Doing or believing things just because many other people do. Bystander Effect In a group, individuals are less likely to help someone in distress because they assume someone else will. Collective Effort Model People in groups often reduce individual effort if they believe their contributions aren’t personally critical. False Consensus Effect Overestimating how much other people share our own attitudes and behaviors. Illusion of Transparency Tendency to overestimate others’ ability to know our emotional states or intentions. Ingroup Bias Showing preferential treatment and judgments toward members of one’s own group over outsiders. Outgroup Homogeneity Effect Seeing members of other groups as more similar to each other than they really are. Social Comparison Bias Disliking or feeling competitive with someone we perceive as “better” or more talented in some area we care about. 31–40: Motivation & Self-Perception Dunning–Kruger Effect Incompetent individuals overestimate their skill; experts may underestimate their relative competence. Effort Justification Placing greater value on outcomes that required more work, even if they aren’t inherently better. Extrinsic Incentive Error Believing others are more motivated by money or external rewards than they actually are—underestimating intrinsic motivations. IKEA Effect People value something they partially created more than a similar product they didn’t help make. Illusion of Control Overestimating one’s influence over external events, especially in random outcomes. Moral Licensing After doing something morally good, feeling “licensed” to act in a self-indulgent or less moral way. Planning Fallacy Underestimating the time, costs, and risks of future actions, often leading to missed deadlines or budget overruns. Projection Bias Assuming that our current preferences or values will remain constant in the future. Self-Serving Bias Attributing successes to our own skill, and failures to external factors. Sunk Cost Fallacy Continuing a behavior or endeavor because of previously invested resources (time, money) rather than cutting losses. 41–50: Emotional & Affective Biases Affect Heuristic Making decisions based on our emotions (“gut feeling”) rather than objective evidence. Empathy Gap Underestimating the influence of emotional and visceral states on our behavior when we’re not currently experiencing them. Framing Effect Being influenced by how information is presented (gain vs. loss framing) rather than just the facts themselves. Hedonic Adaptation Tendency to quickly return to a relatively stable level of happiness despite major positive or negative events. Negativity Bias Giving more weight to negative experiences or information than positive ones of equal intensity. Pessimism Bias Overestimating the likelihood of negative outcomes, relative to probabilities. Positivity Bias (Optimism Bias) Overestimating the likelihood of positive outcomes, relative to probabilities. Priming Exposure to a stimulus influences responses to subsequent stimuli, often unconsciously. Reactive Devaluation Devaluing proposals or ideas merely because they originate from an adversary or disliked source. Rosy Retrospection Remembering past events as more positive than they actually were. 51–60: Decision & Behavior Traps Choice-Supportive Bias Remembering chosen options as better than they really were, and rejected options as worse. Decoy Effect Preferences for options change when a third, asymmetrically dominated option is introduced. Distinction Bias Viewing two options as more dissimilar when simultaneously evaluating them than when separately evaluating them. Endowment Effect Placing higher value on things we own simply because we own them. Fear of Missing Out (FOMO) Anxiety that not experiencing something (a trend or event) will lead to regret or lost opportunities. Hyperbolic Discounting Preferring smaller, sooner rewards to larger, later rewards, irrationally undervaluing future gains. Irrational Escalation Continuing a decision even when rational analysis suggests a better alternative, often due to prior investment. Menu Dependence Choices depend on how options are grouped or compared, not just on their absolute value. Regret Aversion Avoiding taking actions for fear that whatever happens, we’ll regret making the “wrong” choice. Status Quo Bias Preferring things to stay the same by doing nothing or by sticking with a previous decision. 61–70: Communication & Language Effects Authority Suggestion Effect The way language from an authority figure can override individual judgment (akin to Authority Bias). Euphemism Treadmill New, mild terms for a concept eventually take on the negative connotations of the old term. Labeling Effect Assigning a label to a person or thing influences how we perceive them or it afterward. Name Letter Effect People prefer letters in their own name and will make decisions biased toward them (e.g., brand names, locations). Rhyme-as-Reason Effect Rhyming statements seem more truthful (e.g., “If it doesn’t fit, you must acquit”). Sapir–Whorf Hypothesis (Linguistic Relativity) The language we use shapes how we think and perceive reality. Semantic Priming Words we read or hear can prime us to interpret subsequent information in aligned ways. Weasel Words The strategic use of vague or ambiguous language to create an impression without making a firm statement. Wording Effect The specific phrasing in surveys or polls can influence participants’ responses. Zeigarnik Effect People remember uncompleted or interrupted tasks better than completed ones—can be language- or context-driven. 71–80: Social Interaction & Identity Cheerleader Effect Individuals appear more attractive in a group than they do alone. Displacement of Conflict Redirecting conflict from a powerful target to a safer or more convenient one. Double Standard Judging the same action differently depending on who performs it or other group identifiers. Ethnocentrism Evaluating other cultures or groups according to the standards of one’s own culture, often with a sense of superiority. Group Attribution Error Believing that group members’ characteristics and preferences are all related or individually similar. Halo Effect Overall positive impression of a person (or brand) colors our judgments about their other traits or products. Horns Effect (Reverse Halo) Negative initial impression spills over into judgments about other aspects of a person or thing. Identifiable Victim Effect We respond more strongly to specific individuals in crisis than to large, abstract groups. Social Desirability Bias Answering questions or behaving in ways that are viewed favorably by others, rather than truthfully. Spiral of Silence Individuals may stay silent if they believe their views are in the minority, thereby reinforcing that perceived majority view. 81–90: Memory, Recall, & Information Processing Cryptomnesia Mistaking a memory for a novel idea (“unconscious plagiarism”). Google Effect (Digital Amnesia) Forgetting information that can easily be looked up online. Illusory Correlation Perceiving a relationship between variables (often people, events, or behaviors) even when no such relationship exists. Leveling and Sharpening When recounting memories, we drop details that seem irrelevant (leveling) but focus heavily on unusual details (sharpening). Memory Inhibition Recall of certain details is inhibited by exposure to related but misleading or distracting information. Misattribution of Memory Attributing a memory to the wrong source or confusing an imagined event with reality. Misinformation Effect Post-event information can distort recall of the original event (especially in eyewitness testimony). Peak–End Rule We judge experiences largely based on how they felt at their peak (best or worst) and how they ended. Recall Bias Systematic errors in memory due to personal beliefs, time passage, or emotional factors. Telescoping Effect Events from the past seem more recent than they are (forward telescoping) or more distant (backward telescoping). 91–100: Moral, Ethical, & Political Biases Just-World Hypothesis Belief that the world is fair; people get what they deserve, and deserve what they get. Outrage Bias Tendency to become disproportionately angry or outraged at minor offenses, especially online. System Justification Defending and rationalizing the status quo, even at personal or collective cost. Tyranny of Small Decisions Many small, individually rational decisions can lead to undesirable collective outcomes. Ultimate Attribution Error Attributing negative outgroup behavior to dispositional causes while excusing the same behavior by ingroup members as situational. Worse-Than-Average Effect Believing we are worse than average at tasks we’re not confident in (opposite of the better-than-average effect). Zero-Sum Bias Viewing situations as zero-sum (one side’s gain is another’s loss) even if they’re not. Decency Gap Demanding higher moral standards from opponents while making excuses for lapses in one’s own side. Binding Bias Overvaluing group cohesion or loyalty to the extent that it overrides personal moral judgments. Apologies as Admission In some cultures or contexts, apologizing is perceived as admission of guilt, discouraging genuine remorse or relationship repair. 101–110: Time, Planning & Future-Oriented Biases Temporal Discounting Valuing immediate rewards disproportionately more than future rewards (similar to Hyperbolic Discounting). Present Bias Focusing on immediate wants or needs at the expense of long-term goals. Ziegarnik–Lewin Effect Unfinished goals or tasks dominate our attention, but finishing them can abruptly reduce motivation. Future Blindness Underestimating potential changes or disruptions that might happen over time, leading to overconfidence. Expectation Escalation Upwardly adjusting what we consider “normal” or “adequate” once a higher standard is reached. Procrastination Delaying tasks despite expecting to be worse off for the delay; often linked to anxiety and poor impulse control. Time-Saving Bias Overestimating the time saved by faster tasks and underestimating time saved by slower tasks. Punctuality Fallacy Assuming that success depends on perfect timing, neglecting other critical factors such as quality or synergy. Reminiscence Bump People tend to recall many memories from adolescence and early adulthood because of that period’s significance. Transient Bias Over-focusing on current conditions and forgetting that life circumstances are fluid. 111–120: Risk Assessment & Management Action Bias Preference for action over inaction, even if inaction would produce a better outcome. Black Swan Blindness Ignoring or downplaying low-probability, high-impact events until after they occur. Dread Risk Overestimating the risk of a dramatic, publicized event (plane crash, terrorism) vs. more likely yet mundane risks (car accidents). Zero-Risk Bias Prefer reducing a small risk to zero over larger overall risk reductions elsewhere. Exponential Growth Bias Underestimating how quickly exponential processes grow (e.g., compound interest, viral spread). House-Money Effect Taking more risks with money or resources perceived as “house money” (winnings or windfalls). Sudden-Death Aversion Avoiding high-risk/high-reward “sudden-death” scenarios, even when they could maximize chances of success. Toxic Handling One individual in a group handles all negativity and stress, skewing risk perceptions for everyone else. Generalization of Failure After one failure, seeing all risk-taking as more likely to fail. Ambiguity Aversion Preferring known probabilities over unknown probabilities, even if the unknown could be advantageous. 121–130: Cultural, Ideological & Media-Driven Biases Cultural Bias Interpreting and judging phenomena in terms particular to one’s own culture. Denomination Effect Spending more freely with smaller currency denominations or digital credits than large bills. Herding Copying the masses’ behavior, often driven by media, social networks, or cultural norms. Groupthink Desire for group cohesion leads to suppressing dissenting viewpoints and critical thinking. Illusory Superiority (Better-Than-Average Effect) Overestimating our own qualities and abilities relative to others. Media Equation People tend to treat media (like computers or TV) as if they were real people, applying social rules to them. Meme Theory (Thought Contagion) Ideas spread like viruses, replicating through social and cultural transmission. Normalization of Deviance Gradual process by which unacceptable practices or standards become acceptable over time. Punctuated Equilibrium in Culture Long periods of cultural stability followed by sudden shifts, often triggered by external events. Socio-Centric Thinking Viewing issues primarily through the lens of one’s social group or ideology, ignoring broader perspectives. 131–140: Mental Shortcuts & Heuristics Affect Heuristic Quick judgments based on emotional reactions rather than factual analysis (overlaps with “Affect Bias”). Availability Cascade Self-reinforcing process where a collective belief gains plausibility through repeated public discussion. Cognitive Ease Preferencing ideas that are easy to process or recall over those that require more mental effort. Fluency Heuristic If one option is processed more fluently (faster, more familiar), we judge it to be superior. Forer Effect (Barnum Effect) Seeing vague, general personality descriptions as uniquely applicable to ourselves. Length Implication Heuristic Longer messages or lists can appear more credible simply because they are more detailed. Mere Exposure Effect People develop a preference for things simply because they’re familiar. Occam’s Razor Misapplication Over-simplifying solutions or dismissing complex truth by appealing to “the simplest explanation.” Processing Difficulty Effect Occasionally, harder-to-read or decipher text can lead to better recall or deeper processing (counterintuitive effect). Scarcity Heuristic Perceiving things as more valuable if they are scarce or limited. 141–150: Errors in Explanation & Causality Anthropomorphism Attributing human traits or intentions to non-human entities or events. Circular Reasoning Using the conclusion as a premise without offering real evidence. Correlation vs. Causation Error Mistaking correlation for causation or failing to consider third variables or reverse causation. Curse of Knowledge Once we know something, we find it hard to imagine not knowing it—making it difficult to teach or explain. Distorted Definition of Randomness Expecting random sequences to look more orderly or more ‘patterned’ than they truly are. Essentialism Believing that certain things have an unchanging ‘essence’ that dictates how they will behave or be perceived. Focusing Effect Overemphasizing a single factor at the expense of others when explaining outcomes. Fundamental Attribution Error Attributing others’ behavior too much to personality and not enough to context—(Actor–Observer Bias is a related phenomenon). Hasty Generalization Drawing a broad conclusion from a tiny sample. Post Hoc Ergo Propter Hoc Assuming that because one thing happened after another, it was caused by the other (“after this, therefore because of this”). 151–160: Problem-Solving & Strategy Pitfalls Bike-Shedding Spending disproportionate time on trivial issues while neglecting more complex, important ones. Blaming the Victim Finding reasons why the victim of a misfortune is responsible, often to preserve a sense of justice. Boundary Effect Overlooking how changes near boundary conditions (limits) can invalidate certain assumptions or methods. Broken Window Theory (misused cognitively) Extrapolating from small signs of disorder that major problems must exist or will develop if not corrected. Cobra Effect Solutions that exacerbate the problem they’re trying to solve due to misguided incentives. Defensive Decision-Making Choosing the option that protects against the worst outcome for oneself, rather than aiming for the best overall outcome. Escalation of Commitment Similar to the Sunk Cost Fallacy—continuing on a failing path to justify resources already spent. Goal Dilution When multiple goals are pursued simultaneously, motivation and effectiveness toward each goal can be diluted. Parkinson’s Law of Triviality Similar to Bike-Shedding—time spent on an issue is inversely proportional to its actual importance. Tragedy of the Commons Individuals, acting independently in self-interest, can deplete shared resources, harming everyone in the long run. 161–170: Economic & Market Biases Bubble Thinking Collective psychological phenomenon where asset prices rise far above fundamental value, driven by group euphoria. Diminishing Sensitivity Gains or losses have diminishing psychological impact as their absolute amount grows (related to Prospect Theory). Disposition Effect Tendency to sell assets that have increased in value while holding assets that have dropped in value, seeking to avoid loss realization. End of History Illusion Underestimating how much our preferences and values will change in the future. Hedonic Framing Splitting gains and combining losses to maximize perceived outcomes (e.g., listing multiple benefits separately, grouping costs together). Money Illusion Focusing on nominal dollar amounts rather than real purchasing power (ignoring inflation or deflation). Prospect Theory (Loss Aversion) We feel the pain of losses more strongly than the pleasure of equivalent gains. Reference Price Effect A perceived “fair” or “normal” price serves as a reference; deviations feel like gains or losses. Restraint Bias Overestimating our capacity to resist temptation, which can lead to exposing ourselves to unnecessary risks. Weber–Fechner Law Perceived change in a stimulus is proportional to the initial intensity of that stimulus (applies to money, weight, brightness, etc.). 171–180: Technology, Tools & Environment Biases Automation Bias Over-relying on automated systems (algorithms, software) even when they are flawed or incomplete. Digital Divide Fallacy Ignoring that not all user bases have equal technological access or skill, skewing usage or adoption data. Feature Creep Overcomplicating products or systems by adding unnecessary features (can confuse or alienate users). Generational Bias Assuming technological or cultural changes are inferior or superior based solely on generational identity. Not-Invented-Here Syndrome Avoiding or undervaluing external ideas/technologies because they weren’t developed in-house. Online Disinhibition Effect People say or do things online they wouldn’t do face to face, often due to perceived anonymity. Overconfidence in Tools Trusting technology’s readouts or numeric data without cross-checking or common sense. Platform Effect Believing a certain platform’s popularity or structure implies inherent superiority or inevitability. Seductive Detail Effect Irrelevant but interesting features or data can distract from the core purpose, reducing learning or clarity. Technological Lock-In Once a technology is adopted widely, switching becomes expensive or complicated, even if superior alternatives exist. 181–190: Ethics, Morality & Relationship to Others Altruism Bias Overestimating the benevolence of our own motives, underestimating others’ cynicism or self-interest. Defensive Attribution Explaining others’ misfortunes by blaming them for the situation, to protect our own sense of invulnerability. Empathy Gap in Morality Difficulty in understanding the moral choices of people in drastically different emotional states or contexts. Ethical Fading Situations in which the moral aspects of a decision are overlooked or ‘faded out’ under pressure. Licensing Effect in Ethics Doing one ‘good deed’ can make people feel they have a moral license to do something not-so-good afterward. Moral Credential Effect Accumulating “moral credits” from past good deeds to rationalize or excuse future questionable actions. Prejudice Blindness Underestimating the extent of one’s own biases or discriminatory behavior. Psychological Numbing** Diminished emotional response when facing large-scale problems (e.g., statistics on famine or disasters). Self-Righteousness Bias Viewing one’s own moral stance as inherently superior, while dismissing legitimate points of others. Slippery Slope Fearing that a small first step will lead to a chain of related (and often extreme) events, though sometimes the chain is improbable. 191–200: Meta-Biases & Self-Reflection Blind-Spot Bias Recognizing the impact of biases in others’ judgments while failing to see the impact of biases on one’s own judgments. Bias Blindness in Groups Groups believe they are less biased than other groups, ignoring their own group-level blind spots. Cynicism Bias Overestimating selfishness or malicious intent in others, ignoring the possibility of honest mistakes or benign motives. Double-Counting Fallacy Mistaking two pieces of evidence that are not truly independent as separate confirmations of a hypothesis. Falsification Neglect Not actively looking for ways to prove our beliefs wrong, contrary to the scientific ideal of falsification. Gradual Decay of Bias Awareness Even if we learn about biases, over time, we revert to old patterns unless we continuously practice reflection. Hindsight Overcorrection Sometimes, trying to avoid hindsight bias makes us overcorrect and assume we knew less than we did. Instrumental Rationalization Using superficial “rational” arguments to justify a pre-chosen conclusion, rather than letting logic guide the conclusion. Noble Cause Corruption Rationalizing unethical behavior in the name of a “greater good,” ignoring immediate harm. Third-Person Effect Believing that media or biases affect others more than they affect us, underestimating our own susceptibility.