cognitive biases and effects

A list I keep coming back to stay informed and neutral as possibly needed.

1. Too Much Information

1.1. We notice things already primed in memory or repeated often

1. Availability heuristic: A mental shortcut that relies on immediate examples that come to mind when evaluating a specific topic, concept, or decision.
2. Attentional bias: The tendency to pay attention to some things while simultaneously ignoring others. This impacts both the accuracy of memories and decision-making ability.
3. Illusory truth effect: The tendency to believe information to be correct after repeated exposure, regardless of its actual veracity.
4. Mere exposure effect: A psychological phenomenon where people tend to develop a preference for things merely because they are familiar with them.
5. Context effect: The influence of environmental factors on one’s perception of a stimulus.
6. Cue-dependent forgetting: The inability to recall information without the presence of memory cues that were available when the information was encoded.
7. Mood-congruent memory bias: The tendency to recall information more easily when the emotional content matches one’s current emotional state.
8. Frequency illusion: The phenomenon in which people who just learn or notice something start seeing it everywhere.
9. Baader-Meinhof Phenomenon: Another name for frequency illusion, where after noticing something for the first time, there is a tendency to notice it more often.
10. Empathy gap: The tendency to underestimate the influence of visceral drives on their own attitudes, preferences, and behaviors.
11. Omission bias: The tendency to judge harmful actions as worse than equally harmful omissions or inactions.
12. Base rate fallacy: The tendency to ignore base rate information and focus on specific information relating to the individual case.

1.2. Bizarre, funny, visually-striking, or anthropomorphic things stick out more than non-bizarre/unfunny things

1. Bizarreness effect: The tendency of bizarre material to be better remembered than common material.
2. Humor effect: The tendency of humorous items to be more easily remembered than non-humorous ones.
3. Von Restorff effect: The tendency for an item that “stands out like a sore thumb” to be more likely to be remembered than other items.
4. Picture superiority effect: The notion that concepts that are learned by viewing pictures are more easily and frequently recalled than concepts that are learned by viewing their written word form.
5. Self-relevance effect: The tendency for information relating to oneself to be better remembered than other information.
6. Negativity bias: The notion that things of a more negative nature have a greater effect on one’s psychological state than neutral or positive things.

1.3. We notice flaws in others more easily than we notice flaws in ourselves

1. Bias blind spot: The tendency to see oneself as less biased than other people.
2. Naive cynicism: The tendency to expect more egocentric bias in others than in oneself.
3. Naive realism: The belief that we see reality as it really is, objectively and without bias.

1.4. We notice when something has changed

1. Anchoring: The tendency to rely too heavily on the first piece of information offered when making decisions.
2. Conservation: The understanding that certain properties of an object remain the same despite changes in appearance.
3. Contrast effect: The enhancement or diminishment of a weight or other measurement when compared to a recently observed contrasting object.
4. Distinction bias: The tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.
5. Focusing effect: The tendency to place too much importance on one aspect of an event, causing an error in accurately predicting the utility of a future outcome.
6. Framing effect: Drawing different conclusions from the same information, depending on how it is presented.
7. Money illusion: The tendency to think of currency in nominal rather than real terms.
8. Weber-Fechner law: The perception of change in a given stimulus is proportional to the initial stimulus.

1.5. We are drawn to details that confirm our own existing beliefs

1. Confirmation bias: The tendency to search for, interpret, and recall information in a way that confirms one’s preexisting beliefs.
2. Congruence bias: The tendency to test hypotheses exclusively through direct testing, instead of testing possible alternative hypotheses.
3. Post-purchase rationalization: The tendency to persuade oneself through rational argument that a purchase was good value.
4. Choice-support bias: The tendency to remember one’s choices as better than they actually were.
5. Selective perception: The tendency for expectations to affect perception.
6. Observer-expectancy effect: When a researcher’s cognitive bias causes them to subconsciously influence the participants of an experiment.
7. Experimenter’s bias: The tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment.
8. Observer effect: Changes that the act of observation will make on a phenomenon being observed.
9. Exception bias: The tendency to give undue weight to a few apparently special cases.
10. Ostrich effect: The tendency to ignore negative situations by metaphorically burying one’s head in the sand.
11. Subjective validation: The perception that something is true if a subject’s belief demands it to be true.
12. Continued influence effect: The tendency to believe previously learned misinformation even after it has been corrected.
13. Semmelweis reflex: The tendency to reject new evidence that contradicts established paradigms.

2. Not Enough Meaning

2.1. We tend to find stories and data when looking at sparse data

1. Confabulation: The production of fabricated, distorted, or misinterpreted memories without the conscious intention to deceive.
2. Clustering illusion: The tendency to see patterns in random sequences.
3. Insensitivity to sample size: The tendency to under-expect variation in small samples.
4. Neglect of Probability: The tendency to completely disregard probability when making a decision under uncertainty.
5. Anecdotal fallacy: Using personal experience or an isolated example instead of sound arguments or compelling evidence.
6. Illusion of validity: Believing that our judgments are accurate, especially when available information is consistent or inter-correlated.
7. Masked man fallacy: The belief that if A=B, then any property of A must also be a property of B.
8. Recency illusion: The belief that things you have noticed only recently are in fact recent.
9. Gambler’s fallacy: The mistaken belief that if something happens more frequently than normal during a given period, it will happen less frequently in the future.
10. Illusory correlation: Seeing a relationship between two variables when no such relationship exists.
11. Pareidolia: The tendency to see patterns in random stimuli (such as seeing faces in clouds).
12. Anthropomorphism: The tendency to attribute human characteristics to non-human things.

2.2. We fill in characteristics from stereotypes, generalities, and prior histories

1. Group attribution error: The tendency to believe the characteristics of an individual group member are reflective of the group as a whole.
2. Ultimate attribution error: The tendency to attribute positive acts by in-group members to their personality and negative acts to the environment, while attributing the opposite for out-group members.
3. Stereotyping: Expecting a group or person to have certain qualities without having real information about the individual.
4. Essentialism: Believing that things have a set of characteristics that make them what they are.
5. Functional fixedness: The inability to look beyond an object’s common use to see its potential other uses.
6. Moral credential effect: The belief that having done something good allows one to do something bad without losing moral standing.
7. Just-world hypothesis: The tendency to believe that the world is fundamentally fair and people get what they deserve.
8. Argument from fallacy: Assuming that if an argument for a conclusion is fallacious, then the conclusion is false.
9. Authority bias: The tendency to attribute greater weight to the opinions of an authority figure.
10. Automation bias: The tendency to depend more on automated systems and their outputs than is appropriate.
11. Bandwagon effect: The tendency to believe things because many other people believe them.
12. Placebo effect: A beneficial effect produced by a treatment that cannot be attributed to the properties of the treatment itself.

2.3. We think we know what other people are thinking

1. Illusion of transparency: The tendency to overestimate how well other people can discern our emotional state.
2. Curse of knowledge: When better-informed people find it difficult to think about problems from the perspective of lesser-informed people.
3. Spotlight effect: The tendency to overestimate how much other people notice our appearance or behavior.
4. Extrinsic incentive error: When people think others are more motivated by external rewards than they actually are.
5. Illusion of external agency: The tendency to view our own actions as originating from external influences rather than personal choice.
6. Illusion of asymmetric insight: People perceive their knowledge of others to surpass other people’s knowledge of them.

2.4. We imagine things and people we’re familiar with or fond of as better

1. Out-group homogeneity bias: The tendency to see members of out-groups as more similar to each other than members of in-groups.
2. Cross-race effect: The tendency to more easily recognize faces of one’s own race.
3. In-group bias: The tendency to favor members of one’s own group over those in other groups.
4. Halo effect: The tendency for an impression created in one area to influence opinion in another area.
5. Cheerleader effect: The phenomenon where people appear more attractive in a group than in isolation.
6. Positivity effect: The tendency to remember pleasant items more accurately than unpleasant ones.
7. Not invented here: Aversion to using products, research, or knowledge from external origins.
8. Reactive devaluation: Devaluing proposals only because they purportedly originated with an adversary.
9. Well-traveled road effect: The tendency to underestimate the duration of familiar journeys.

2.5. We simplify probabilities and numbers to make them easier to think about

1. Mental accounting: Treating money differently depending on its source or intended use.
2. Appeal to probability fallacy: The assumption that because something is possible, it is inevitable.
3. Normalcy bias: The refusal to plan for, or react to, a disaster which has never happened before.
4. Murphy’s Law: The adage that “anything that can go wrong, will go wrong.”
5. Zero-sum bias: The belief that a situation is zero-sum when it is actually non-zero-sum.
6. Survivorship bias: Concentrating on people or things that “survived” some process while overlooking those that didn’t.
7. Subadditivity effect: The tendency to judge probability of the whole to be less than the probabilities of the parts.
8. Denomination effect: The tendency to spend more money when it’s denominated in small amounts.
9. Magic number 7+-2: The observation that humans can only hold 7 (plus or minus 2) items in working memory.

2.6. We project our current mindset and assumptions onto the past and future

• Self-consistency bias: The tendency to maintain consistency between our current attitudes and memories of past behaviors.
• Resistant bias: The tendency to resist changes to beliefs when presented with contradictory evidence.
• Projection bias: The tendency to overestimate how much our future selves will share our current preferences.
• Pro-innovation bias: The tendency to have an excessive optimism towards an innovation’s usefulness.
• Time-saving bias: Underestimating the time saved when increasing from a relatively low speed and overestimating time saved when increasing from a relatively high speed.
• Planning fallacy: The tendency to underestimate task-completion times.
• Pessimism bias: The tendency to overestimate the likelihood of negative events.
• Impact bias: Overestimating the length or intensity of future emotional states.
• Declinism: The belief that a society or institution is tending towards decline.
• Moral luck: The tendency to retroactively assign blame based on outcome rather than intent.
• Outcome bias: Judging a decision based on its outcome rather than how exactly the decision was made.
• Hindsight bias: The tendency to see past events as being predictable.
• Rosy retrospection: The tendency to rate past events more positively than they were rated when they occurred.
• Telescoping effect: The tendency to perceive recent events as being more remote in time and remote events as being more recent.

3. Need to Act Fast

3.1. We favor simple-looking options and complete information over complex, ambiguous options

1. Less-is-better effect: The tendency to prefer a smaller set of options over a larger one, even when the larger set objectively provides more value.
2. Occam’s razor: The tendency to prefer simpler explanations over more complex ones.
3. Conjunction fallacy: The assumption that specific conditions are more probable than general ones.
4. Delmore effect: The tendency to believe in a solution’s effectiveness proportional to its complexity.
5. Law of Triviality: The tendency to give disproportionate weight to trivial issues.
6. Bike-shedding effect: The tendency to focus on minor details while avoiding complex issues (another name for Law of Triviality).
7. Rhyme as reason effect: The tendency to judge rhyming statements as more truthful than non-rhyming ones.
8. Belief bias: The tendency to evaluate the logical strength of an argument based on the believability of its conclusion.
9. Information bias: The tendency to seek information even when it cannot affect action.
10. Ambiguity bias: The tendency to avoid options with unknown probabilities in favor of options with known probabilities.

3.2. To get things done, we tend to complete things we’ve invested time & energy in

1. Backfire effect: When presented with contradictory evidence, beliefs get stronger.
2. Endowment effect: The tendency to value things more highly simply because we own them.
3. Processing difficulty effect: The tendency to believe that information that is harder to process must be more valuable or important.
4. Pseudocertainty effect: The tendency to make risk-averse choices if the expected outcome is positive, but risk-seeking choices to avoid negative outcomes.
5. Disposition effect: The tendency to sell assets that have increased in value while keeping assets that have decreased in value.
6. Zero-risk bias: Preference for reducing a small risk to zero over a greater reduction in a larger risk.
7. Unit bias: The tendency to want to complete a unit of a task or an item.
8. IKEA effect: The tendency to place higher value on products that we partially created.
9. Loss aversion: The tendency to prefer avoiding losses over acquiring equivalent gains.
10. Generation effect: The tendency to better remember information when we’ve generated it ourselves.
11. Escalation of commitment: Continuing an endeavor due to previously invested resources.
12. Irrational escalation: Increasing investment in a decision despite new evidence suggesting it’s failing.
13. Sunk cost fallacy: Continuing an endeavor due to previously invested resources, even when it’s no longer worthwhile.

3.3. To act, we must be confident we can make an impact and feel what we do is important

1. Peltzman effect: The tendency to take greater risks when safety measures are in place.
2. Risk compensation: The tendency to take greater risks when perceived safety increases.
3. Effort Justification: The tendency to value outcomes that we had to work hard to achieve.
4. Trait ascription bias: The tendency to view ourselves as relatively variable in terms of personality, behavior and mood while viewing others as more predictable.
5. Defensive attribution hypothesis: Attributing more blame to a victim the more similar they are to ourselves.
6. Fundamental attribution error: The tendency to overemphasize personality-based explanations for others’ behaviors while underemphasizing situational explanations.
7. Illusory superiority: Overestimating one’s own qualities and abilities relative to others.
8. Illusion of control: The tendency to overestimate one’s control over external events.
9. Actor-observer bias: The tendency to attribute our own actions to external causes while attributing others’ behaviors to internal causes.
10. Self-serving bias: The tendency to claim more responsibility for successes than failures.
11. Barnum effect: The tendency to accept vague and general personality descriptions as uniquely applicable to ourselves.
12. Forer effect: Another name for the Barnum effect.
13. Optimism bias: The tendency to be overly optimistic about future outcomes.
14. Egocentric bias: The tendency to rely too heavily on our own perspective when considering others’.
15. Dunning-Kruger effect: When unskilled individuals mistakenly assess their ability to be much higher than it is.
16. Lake Wobegone effect: The tendency to overestimate one’s capabilities and see oneself as above average.
17. Hard-easy effect: The tendency to overestimate our ability to accomplish hard tasks and underestimate our ability to accomplish easy tasks.
18. False consensus effect: The tendency to overestimate how much others agree with us.
19. Third-person effect: Believing that mass communicated media messages have a greater effect on others than on themselves.
20. Social desirability bias: The tendency to answer questions in a manner that will be viewed favorably by others.
21. Overconfidence effect: Excessive confidence in one’s own answers to questions.

3.4. To avoid mistakes, we aim to preserve autonomy and group status and avoid irreversible decisions

1. Status quo bias: The tendency to prefer things to stay the same.
2. Social comparison bias: Having a preference for or against someone based on how they compare to us.
3. Decoy effect: The tendency for preferences to change when presented with a third, less desirable option.
4. Reactance: The urge to do the opposite of what someone wants you to do.
5. Reverse psychology: Technique of advocacy of one message to trigger the response of adopting the contrary position.
6. System justification: The tendency to defend and bolster the status quo.

3.5. To stay focused, we favor the immediate, relatable thing in front of us

1. Identifiable victim effect: The tendency to respond more strongly to a single identified person at risk than to a large group of people at risk.
2. Appeal to novelty: The tendency to believe that new things are automatically better than old ones.
3. Hyperbolic discounting: The tendency to prefer immediate payoffs to later payoffs.

4. What Should We Remember?

4.1. We store memories differently based on how they are experienced

1. Tip of the tongue phenomenon: The feeling that a forgotten word or name is right on the verge of being remembered.
2. Google effect: The tendency to forget information that can be easily found online.
3. Next-in-line effect: The reduced ability to recall information about events that occurred while anxiously awaiting one’s turn to speak.
4. Testing effect: The finding that taking a test on material can be more beneficial for memory than studying.
5. Absent-mindedness: When attention lapses lead to memory failures.
6. Levels of processing effect: The tendency to remember information better when it has been processed more deeply and meaningfully.

4.2. We reduce events and lists to their key elements

1. Suffix effect: The impairment in recall of the last few items in a list when an irrelevant item is added to the end.
2. Serial position effect: The tendency to recall the first and last items in a series best, and the middle items worst.
3. Part-list cueing effect: When providing a portion of items from a list as memory cues makes it harder to recall the other items.
4. Recency effect: The tendency to better remember the most recently presented items in a series.
5. Primary effect: The tendency to better remember items that appear first in a series.
6. Memory inhibition: The ability to suppress irrelevant or unwanted memories to focus on relevant ones.
7. Modality effect: The tendency to have better memory recall for the last few items in a list when they are presented verbally rather than visually.
8. Duration neglect: The tendency to disregard the length of an experience when assessing its unpleasantness or pleasantness.
9. List-length effect: The observation that recognition performance decreases as the length of the list to be remembered increases.
10. Serial recall effect: The tendency for recall to be better when items are retrieved in the same order as they were learned.
11. Misinformation effect: When post-event information interferes with the memory of the original event.
12. Leveling and sharpening: Memory distortions where certain elements are diminished or emphasized when recalling a story.
13. Peak-end rule: The tendency to judge an experience largely based on how it was at its peak and at its end.

4.3. We discard specifics to form generalities

1. Fading affect bias: The tendency for negative emotions associated with memories to fade more quickly than positive emotions.
2. Negativity bias: The tendency to weight negative experiences more heavily than positive ones.
3. Prejudice: A preconceived opinion not based on actual experience.
4. Stereotypical bias: The tendency to remember information that confirms existing stereotypes and forget information that contradicts them.
5. Implicit stereotypes: The unconscious attribution of particular qualities to a member of a particular group.
6. Implicit association: The automatic association between mental representations of objects in memory.
7. Spacing effect: The phenomenon where learning is greater when studying is spread out over time rather than concentrated in a short period.
8. Suggestibility: The tendency to incorporate misleading information from external sources into personal memories.
9. False memory: The phenomenon where a person recalls something that did not happen or recalls it differently from the way it actually happened.
10. Cryptomnesia: When a forgotten memory returns without being recognized as such, leading to unintended plagiarism.
11. Source confusion: The inability to remember where, when, or how previously learned information was acquired.
12. Misattribution of memory: When memories are attributed to the wrong source; a type of source confusion where memories are mistakenly ascribed to a different origin.

And thanks to Mr John Manoogian III for this beautiful graphic.