200 Cognitive Biases

1–10: Attention, Perception & Memory Distortions

1. Anchoring Bias
   Relying too heavily on the first piece of information (the "anchor") we receive when making decisions.

2. Attentional Bias
   Tendency to pay more attention to certain stimuli while neglecting others, often because of our current emotional state or expectations.

3. Availability Heuristic
   Estimating likelihood or frequency of events based on how easily examples come to mind (recent, vivid, dramatic).

4. Baader–Meinhof Phenomenon (Frequency Illusion)
   Once you notice something, you start seeing it everywhere, creating the illusion it's suddenly more frequent.

5. Change Blindness
   Failing to notice even large changes in a visual scene when our attention is directed elsewhere.

6. Confirmation Bias
   Seeking or interpreting evidence in ways that confirm our preexisting beliefs, and ignoring disconfirming data.

7. Context Effect
   Cognitive perception of stimuli is influenced by the surrounding environment or context.

8. 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).

9. Egocentric Bias
   Over-focusing on our own perspective and experiences, making it difficult to see situations through others' eyes.

10. Illusory Truth Effect
    Repeated statements feel more true over time, simply because we've heard them often.

11–20: Judgment under Uncertainty

1. Ambiguity Effect
   Avoiding options for which missing information makes the probability of outcomes seem 'unknown.'

2. Base Rate Neglect
   Ignoring general (statistical) information in favor of specifics or anecdotes when estimating probabilities.

3. Belief Bias
   Judging the strength of an argument by the plausibility of its conclusion rather than how strongly it's supported.

4. Clustering Illusion
   Seeing patterns in random data (e.g., 'hot streaks' in coin tosses).

5. 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").

6. 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'").

7. Hindsight Bias
   After an event, believing we "knew it all along" or that it was easily predictable.

8. 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.

9. Law of the Instrument
   Overreliance on a familiar tool or approach ("If all you have is a hammer, everything looks like a nail.").

10. Survivorship Bias
    Focusing on successes or survivors while overlooking those that did not survive (creating a skewed perspective).

21–30: Social & Group Dynamics

1. Actor–Observer Bias
   We attribute our own actions to external circumstances, but others' actions to their character or disposition.

2. Authority Bias
   Being overly influenced by authority figures or experts, sometimes beyond rational justification.

3. Bandwagon Effect (Social Proof)
   Doing or believing things just because many other people do.

4. Bystander Effect
   In a group, individuals are less likely to help someone in distress because they assume someone else will.

5. Collective Effort Model
   People in groups often reduce individual effort if they believe their contributions aren't personally critical.

6. False Consensus Effect
   Overestimating how much other people share our own attitudes and behaviors.

7. Illusion of Transparency
   Tendency to overestimate others' ability to know our emotional states or intentions.

8. Ingroup Bias
   Showing preferential treatment and judgments toward members of one's own group over outsiders.

9. Outgroup Homogeneity Effect
   Seeing members of other groups as more similar to each other than they really are.

10. 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

1. Dunning–Kruger Effect
   Incompetent individuals overestimate their skill; experts may underestimate their relative competence.

2. Effort Justification
   Placing greater value on outcomes that required more work, even if they aren't inherently better.

3. Extrinsic Incentive Error
   Believing others are more motivated by money or external rewards than they actually are—underestimating intrinsic motivations.

4. IKEA Effect
   People value something they partially created more than a similar product they didn't help make.

5. Illusion of Control
   Overestimating one's influence over external events, especially in random outcomes.

6. Moral Licensing
   After doing something morally good, feeling "licensed" to act in a self-indulgent or less moral way.

7. Planning Fallacy
   Underestimating the time, costs, and risks of future actions, often leading to missed deadlines or budget overruns.

8. Projection Bias
   Assuming that our current preferences or values will remain constant in the future.

9. Self-Serving Bias
   Attributing successes to our own skill, and failures to external factors.

10. Sunk Cost Fallacy
    Continuing a behavior or endeavor because of previously invested resources (time, money) rather than cutting losses.

41–50: Emotional & Affective Biases

1. Affect Heuristic
   Making decisions based on our emotions ("gut feeling") rather than objective evidence.

2. Empathy Gap
   Underestimating the influence of emotional and visceral states on our behavior when we're not currently experiencing them.

3. Framing Effect
   Being influenced by how information is presented (gain vs. loss framing) rather than just the facts themselves.

4. Hedonic Adaptation
   Tendency to quickly return to a relatively stable level of happiness despite major positive or negative events.

5. Negativity Bias
   Giving more weight to negative experiences or information than positive ones of equal intensity.

6. Pessimism Bias
   Overestimating the likelihood of negative outcomes, relative to probabilities.

7. Positivity Bias (Optimism Bias)
   Overestimating the likelihood of positive outcomes, relative to probabilities.

8. Priming
   Exposure to a stimulus influences responses to subsequent stimuli, often unconsciously.

9. Reactive Devaluation
   Devaluing proposals or ideas merely because they originate from an adversary or disliked source.

10. Rosy Retrospection
    Remembering past events as more positive than they actually were.

51–60: Decision & Behavior Traps

1. Choice-Supportive Bias
   Remembering chosen options as better than they really were, and rejected options as worse.

2. Decoy Effect
   Preferences for options change when a third, asymmetrically dominated option is introduced.

3. Distinction Bias
   Viewing two options as more dissimilar when simultaneously evaluating them than when separately evaluating them.

4. Endowment Effect
   Placing higher value on things we own simply because we own them.

5. Fear of Missing Out (FOMO)
   Anxiety that not experiencing something (a trend or event) will lead to regret or lost opportunities.

6. Hyperbolic Discounting
   Preferring smaller, sooner rewards to larger, later rewards, irrationally undervaluing future gains.

7. Irrational Escalation
   Continuing a decision even when rational analysis suggests a better alternative, often due to prior investment.

8. Menu Dependence
   Choices depend on how options are grouped or compared, not just on their absolute value.

9. Regret Aversion
   Avoiding taking actions for fear that whatever happens, we'll regret making the "wrong" choice.

10. Status Quo Bias
    Preferring things to stay the same by doing nothing or by sticking with a previous decision.

61–70: Communication & Language Effects

1. Authority Suggestion Effect
   The way language from an authority figure can override individual judgment (akin to Authority Bias).

2. Euphemism Treadmill
   New, mild terms for a concept eventually take on the negative connotations of the old term.

3. Labeling Effect
   Assigning a label to a person or thing influences how we perceive them or it afterward.

4. Name Letter Effect
   People prefer letters in their own name and will make decisions biased toward them (e.g., brand names, locations).

5. Rhyme-as-Reason Effect
   Rhyming statements seem more truthful (e.g., "If it doesn't fit, you must acquit").

6. Sapir–Whorf Hypothesis (Linguistic Relativity)
   The language we use shapes how we think and perceive reality.

7. Semantic Priming
   Words we read or hear can prime us to interpret subsequent information in aligned ways.

8. Weasel Words
   The strategic use of vague or ambiguous language to create an impression without making a firm statement.

9. Wording Effect
   The specific phrasing in surveys or polls can influence participants' responses.

10. Zeigarnik Effect
    People remember uncompleted or interrupted tasks better than completed ones—can be language- or context-driven.

71–80: Social Interaction & Identity

1. Cheerleader Effect
   Individuals appear more attractive in a group than they do alone.

2. Displacement of Conflict
   Redirecting conflict from a powerful target to a safer or more convenient one.

3. Double Standard
   Judging the same action differently depending on who performs it or other group identifiers.

4. Ethnocentrism
   Evaluating other cultures or groups according to the standards of one's own culture, often with a sense of superiority.

5. Group Attribution Error
   Believing that group members' characteristics and preferences are all related or individually similar.

6. Halo Effect
   Overall positive impression of a person (or brand) colors our judgments about their other traits or products.

7. Horns Effect (Reverse Halo)
   Negative initial impression spills over into judgments about other aspects of a person or thing.

8. Identifiable Victim Effect
   We respond more strongly to specific individuals in crisis than to large, abstract groups.

9. Social Desirability Bias
   Answering questions or behaving in ways that are viewed favorably by others, rather than truthfully.

10. 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

1. Cryptomnesia
   Mistaking a memory for a novel idea ("unconscious plagiarism").

2. Google Effect (Digital Amnesia)
   Forgetting information that can easily be looked up online.

3. Illusory Correlation
   Perceiving a relationship between variables (often people, events, or behaviors) even when no such relationship exists.

4. Leveling and Sharpening
   When recounting memories, we drop details that seem irrelevant (leveling) but focus heavily on unusual details (sharpening).

5. Memory Inhibition
   Recall of certain details is inhibited by exposure to related but misleading or distracting information.

6. Misattribution of Memory
   Attributing a memory to the wrong source or confusing an imagined event with reality.

7. Misinformation Effect
   Post-event information can distort recall of the original event (especially in eyewitness testimony).

8. Peak–End Rule
   We judge experiences largely based on how they felt at their peak (best or worst) and how they ended.

9. Recall Bias
   Systematic errors in memory due to personal beliefs, time passage, or emotional factors.

10. 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

1. Just-World Hypothesis
   Belief that the world is fair; people get what they deserve, and deserve what they get.

2. Outrage Bias
   Tendency to become disproportionately angry or outraged at minor offenses, especially online.

3. System Justification
   Defending and rationalizing the status quo, even at personal or collective cost.

4. Tyranny of Small Decisions
   Many small, individually rational decisions can lead to undesirable collective outcomes.

5. Ultimate Attribution Error
   Attributing negative outgroup behavior to dispositional causes while excusing the same behavior by ingroup members as situational.

6. Worse-Than-Average Effect
   Believing we are worse than average at tasks we're not confident in (opposite of the better-than-average effect).

7. Zero-Sum Bias
   Viewing situations as zero-sum (one side's gain is another's loss) even if they're not.

8. Decency Gap
   Demanding higher moral standards from opponents while making excuses for lapses in one's own side.

9. Binding Bias
   Overvaluing group cohesion or loyalty to the extent that it overrides personal moral judgments.

10. 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

1. Temporal Discounting
   Valuing immediate rewards disproportionately more than future rewards (similar to Hyperbolic Discounting).

2. Present Bias
   Focusing on immediate wants or needs at the expense of long-term goals.

3. Ziegarnik–Lewin Effect
   Unfinished goals or tasks dominate our attention, but finishing them can abruptly reduce motivation.

4. Future Blindness
   Underestimating potential changes or disruptions that might happen over time, leading to overconfidence.

5. Expectation Escalation
   Upwardly adjusting what we consider "normal" or "adequate" once a higher standard is reached.

6. Procrastination
   Delaying tasks despite expecting to be worse off for the delay; often linked to anxiety and poor impulse control.

7. Time-Saving Bias
   Overestimating the time saved by faster tasks and underestimating time saved by slower tasks.

8. Punctuality Fallacy
   Assuming that success depends on perfect timing, neglecting other critical factors such as quality or synergy.

9. Reminiscence Bump
   People tend to recall many memories from adolescence and early adulthood because of that period's significance.

10. Transient Bias
    Over-focusing on current conditions and forgetting that life circumstances are fluid.

111–120: Risk Assessment & Management

1. Action Bias
   Preference for action over inaction, even if inaction would produce a better outcome.

2. Black Swan Blindness
   Ignoring or downplaying low-probability, high-impact events until after they occur.

3. Dread Risk
   Overestimating the risk of a dramatic, publicized event (plane crash, terrorism) vs. more likely yet mundane risks (car accidents).

4. Zero-Risk Bias
   Prefer reducing a small risk to zero over larger overall risk reductions elsewhere.

5. Exponential Growth Bias
   Underestimating how quickly exponential processes grow (e.g., compound interest, viral spread).

6. House-Money Effect
   Taking more risks with money or resources perceived as "house money" (winnings or windfalls).

7. Sudden-Death Aversion
   Avoiding high-risk/high-reward "sudden-death" scenarios, even when they could maximize chances of success.

8. Toxic Handling
   One individual in a group handles all negativity and stress, skewing risk perceptions for everyone else.

9. Generalization of Failure
   After one failure, seeing all risk-taking as more likely to fail.

10. Ambiguity Aversion
    Preferring known probabilities over unknown probabilities, even if the unknown could be advantageous.

121–130: Cultural, Ideological & Media-Driven Biases

1. Cultural Bias
   Interpreting and judging phenomena in terms particular to one's own culture.

2. Denomination Effect
   Spending more freely with smaller currency denominations or digital credits than large bills.

3. Herding
   Copying the masses' behavior, often driven by media, social networks, or cultural norms.

4. Groupthink
   Desire for group cohesion leads to suppressing dissenting viewpoints and critical thinking.

5. Illusory Superiority (Better-Than-Average Effect)
   Overestimating our own qualities and abilities relative to others.

6. Media Equation
   People tend to treat media (like computers or TV) as if they were real people, applying social rules to them.

7. Meme Theory (Thought Contagion)
   Ideas spread like viruses, replicating through social and cultural transmission.

8. Normalization of Deviance
   Gradual process by which unacceptable practices or standards become acceptable over time.

9. Punctuated Equilibrium in Culture
   Long periods of cultural stability followed by sudden shifts, often triggered by external events.

10. Socio-Centric Thinking
    Viewing issues primarily through the lens of one's social group or ideology, ignoring broader perspectives.

131–140: Mental Shortcuts & Heuristics

1. Affect Heuristic
   Quick judgments based on emotional reactions rather than factual analysis (overlaps with "Affect Bias").

2. Availability Cascade
   Self-reinforcing process where a collective belief gains plausibility through repeated public discussion.

3. Cognitive Ease
   Preferencing ideas that are easy to process or recall over those that require more mental effort.

4. Fluency Heuristic
   If one option is processed more fluently (faster, more familiar), we judge it to be superior.

5. Forer Effect (Barnum Effect)
   Seeing vague, general personality descriptions as uniquely applicable to ourselves.

6. Length Implication Heuristic
   Longer messages or lists can appear more credible simply because they are more detailed.

7. Mere Exposure Effect
   People develop a preference for things simply because they're familiar.

8. Occam's Razor Misapplication
   Over-simplifying solutions or dismissing complex truth by appealing to "the simplest explanation."

9. Processing Difficulty Effect
   Occasionally, harder-to-read or decipher text can lead to better recall or deeper processing (counterintuitive effect).

10. Scarcity Heuristic
    Perceiving things as more valuable if they are scarce or limited.

141–150: Errors in Explanation & Causality

1. Anthropomorphism
   Attributing human traits or intentions to non-human entities or events.

2. Circular Reasoning
   Using the conclusion as a premise without offering real evidence.

3. Correlation vs. Causation Error
   Mistaking correlation for causation or failing to consider third variables or reverse causation.

4. Curse of Knowledge
   Once we know something, we find it hard to imagine not knowing it—making it difficult to teach or explain.

5. Distorted Definition of Randomness
   Expecting random sequences to look more orderly or more 'patterned' than they truly are.

6. Essentialism
   Believing that certain things have an unchanging 'essence' that dictates how they will behave or be perceived.

7. Focusing Effect
   Overemphasizing a single factor at the expense of others when explaining outcomes.

8. Fundamental Attribution Error
   Attributing others' behavior too much to personality and not enough to context—(Actor–Observer Bias is a related phenomenon).

9. Hasty Generalization
   Drawing a broad conclusion from a tiny sample.

10. 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

1. Bike-Shedding
   Spending disproportionate time on trivial issues while neglecting more complex, important ones.

2. Blaming the Victim
   Finding reasons why the victim of a misfortune is responsible, often to preserve a sense of justice.

3. Boundary Effect
   Overlooking how changes near boundary conditions (limits) can invalidate certain assumptions or methods.

4. Broken Window Theory (misused cognitively)
   Extrapolating from small signs of disorder that major problems must exist or will develop if not corrected.

5. Cobra Effect
   Solutions that exacerbate the problem they're trying to solve due to misguided incentives.

6. Defensive Decision-Making
   Choosing the option that protects against the worst outcome for oneself, rather than aiming for the best overall outcome.

7. Escalation of Commitment
   Similar to the Sunk Cost Fallacy—continuing on a failing path to justify resources already spent.

8. Goal Dilution
   When multiple goals are pursued simultaneously, motivation and effectiveness toward each goal can be diluted.

9. Parkinson's Law of Triviality
   Similar to Bike-Shedding—time spent on an issue is inversely proportional to its actual importance.

10. 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

1. Bubble Thinking
   Collective psychological phenomenon where asset prices rise far above fundamental value, driven by group euphoria.

2. Diminishing Sensitivity
   Gains or losses have diminishing psychological impact as their absolute amount grows (related to Prospect Theory).

3. Disposition Effect
   Tendency to sell assets that have increased in value while holding assets that have dropped in value, seeking to avoid loss realization.

4. End of History Illusion
   Underestimating how much our preferences and values will change in the future.

5. Hedonic Framing
   Splitting gains and combining losses to maximize perceived outcomes (e.g., listing multiple benefits separately, grouping costs together).

6. Money Illusion
   Focusing on nominal dollar amounts rather than real purchasing power (ignoring inflation or deflation).

7. Prospect Theory (Loss Aversion)
   We feel the pain of losses more strongly than the pleasure of equivalent gains.

8. Reference Price Effect
   A perceived "fair" or "normal" price serves as a reference; deviations feel like gains or losses.

9. Restraint Bias
   Overestimating our capacity to resist temptation, which can lead to exposing ourselves to unnecessary risks.

10. 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

1. Automation Bias
   Over-relying on automated systems (algorithms, software) even when they are flawed or incomplete.

2. Digital Divide Fallacy
   Ignoring that not all user bases have equal technological access or skill, skewing usage or adoption data.

3. Feature Creep
   Overcomplicating products or systems by adding unnecessary features (can confuse or alienate users).

4. Generational Bias
   Assuming technological or cultural changes are inferior or superior based solely on generational identity.

5. Not-Invented-Here Syndrome
   Avoiding or undervaluing external ideas/technologies because they weren't developed in-house.

6. Online Disinhibition Effect
   People say or do things online they wouldn't do face to face, often due to perceived anonymity.

7. Overconfidence in Tools
   Trusting technology's readouts or numeric data without cross-checking or common sense.

8. Platform Effect
   Believing a certain platform's popularity or structure implies inherent superiority or inevitability.

9. Seductive Detail Effect
   Irrelevant but interesting features or data can distract from the core purpose, reducing learning or clarity.

10. 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

1. Altruism Bias
   Overestimating the benevolence of our own motives, underestimating others' cynicism or self-interest.

2. Defensive Attribution
   Explaining others' misfortunes by blaming them for the situation, to protect our own sense of invulnerability.

3. Empathy Gap in Morality
   Difficulty in understanding the moral choices of people in drastically different emotional states or contexts.

4. Ethical Fading
   Situations in which the moral aspects of a decision are overlooked or 'faded out' under pressure.

5. Licensing Effect in Ethics
   Doing one 'good deed' can make people feel they have a moral license to do something not-so-good afterward.

6. Moral Credential Effect
   Accumulating "moral credits" from past good deeds to rationalize or excuse future questionable actions.

7. Prejudice Blindness
   Underestimating the extent of one's own biases or discriminatory behavior.

8. Psychological Numbing
   Diminished emotional response when facing large-scale problems (e.g., statistics on famine or disasters).

9. Self-Righteousness Bias
   Viewing one's own moral stance as inherently superior, while dismissing legitimate points of others.

10. 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

1. Blind-Spot Bias
   Recognizing the impact of biases in others' judgments while failing to see the impact of biases on one's own judgments.

2. Bias Blindness in Groups
   Groups believe they are less biased than other groups, ignoring their own group-level blind spots.

3. Cynicism Bias
   Overestimating selfishness or malicious intent in others, ignoring the possibility of honest mistakes or benign motives.

4. Double-Counting Fallacy
   Mistaking two pieces of evidence that are not truly independent as separate confirmations of a hypothesis.

5. Falsification Neglect
   Not actively looking for ways to prove our beliefs wrong, contrary to the scientific ideal of falsification.

6. Gradual Decay of Bias Awareness
   Even if we learn about biases, over time, we revert to old patterns unless we continuously practice reflection.

7. Hindsight Overcorrection
   Sometimes, trying to avoid hindsight bias makes us overcorrect and assume we knew less than we did.

8. Instrumental Rationalization
   Using superficial "rational" arguments to justify a pre-chosen conclusion, rather than letting logic guide the conclusion.

9. Noble Cause Corruption
   Rationalizing unethical behavior in the name of a "greater good," ignoring immediate harm.

10. Third-Person Effect
    Believing that media or biases affect others more than they affect us, underestimating our own susceptibility.