The list was compiled from LessWrong as well as personal notes, collected from the Philosopher's Toolkit and other sources. Rationality is characteristic of thinking and acting optimally.
Tendency to overemphasize the influence of their personality and underemphasize the influence of their situation.
Tendency to neglect relevant data when making judgments of a correlation or association.
Tendency to retroactively ascribing to one's choices to be more informed than they were when they were made.
Tendency to interpret information in a way that confirms one's preconceptions.
Tendency to test hypotheses exclusively through direct testing, in contrast to tests of possible alternative hypotheses.
Tendency to remember high values and high likelihoods/probabilities/frequencies as lower than they actually were and low ones as higher than they actually were. Based on the evidence, memories are not extreme enough.
Tendency to claim more responsibility for themselves for the results of a joint action than an outside observer would. Recalling the past in a self-serving manner. Like remembering one's exam grades as being better than they were.
Tendency to overestimate the length or the intensity of the impact of future feeling states.
Tendency to seek information even when it cannot affect action.
Tendency to blame failures on oneself while attributing successes to situational factors; opposite of self-serving bias.
Tendency to recall information congruent with one's current mood.
Tendency to judge harmful actions as worse, or less moral, than equally harmful omissions.
Tendency to attribute successes to internal characteristics while blaming failures on outside forces. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way beneficial to their interests.
Tendency to like things to stay relatively the same.
Tendency to overestimating one's desirable qualities, and underestimating undesirable qualities, relative to other people. Also known as the Lake Wobegon effect.
Tendency of focusing on what has survived to the present and ignoring what must have been lost.
Tendency for people to view themselves as relatively variable in terms of personality, behavior and mood while viewing others as much more predictable.
Tendency to want to finish a given unit of a task or an item with strong effects on the consumption of food in particular.
Tendency to steer the search for causes based on the knowledge of a subject's disease in a medical study.
Tendency to distort memories towards stereotypes. "Black-sounding" names being misremembered as names of criminals.
Preference for reducing a small risk to zero over a greater reduction in a larger risk.
Tendency to attribute greater accuracy to the opinion of an authority figure and be more influenced by that opinion.
Tendency to overestimate the contribution of lasting traits and dispositions, as opposed to situational effects, in determining people's behavior.
Tendency to alter responses in the direction they perceive desired by the investigator.
Tendency of evading questions that may embarrass or invade privacy.
Tendency to assume that others share the same or similar thoughts, beliefs, values, or positions.
Tendency to incorrectly remember one's past attitudes and behaviour as resembling present attitudes and behaviour.
Tendency to see past events as predictable, based on knowledge of later events. Also known as the "I-knew-it-all-along" effect.
Tendency to be over-optimistic about the outcome of planned actions.
Tendency to judge a decision by its eventual outcome instead of based on the quality of the decision at the time it was made.
Tendency to test hypotheses with positive rather than negative examples, thus risking to miss obvious disconfirming tests.
Tendency to overestimate the probability of good things happening to them.
Tendency of humans to tend to agree with each other, and hold back objections or dissent even when the group is wrong.
Tendency to behave similarly to others in a group, even if doing so goes against your own judgment.
Tendency to give preferential treatment to others they perceive to be members of their own groups.
Tendency of people to see members of their own group as being relatively more varied than members of other groups.
Tendency for group members to spend more time and energy discussing information that all members are already familiar with (i.e., shared information), and less time and energy discussing information that only some members are aware of.
Assuming that an idea has merit simply because many people believe it or practice it.
Tendency to avoid options for which missing information makes the probability seem "unknown".
Tendency to remember bizarre material better than common material.
Tendency for individuals to less likely offer help in an emergency situation when other people are present.
That cognition and memory are dependent on context, such that out-of-context memories are more difficult to retrieve than in-context memories.
Example: Recall time and accuracy for a work-related memory will be lower at home, and vice versa.
Enhancement or diminishment of a weight or other measurement when compared with recently observed contrasting object.
Tendency for people of one race to have difficulty identifying members of a race other than their own.
When people are incompetent in the strategies they adopt to achieve success and satisfaction, they suffer a dual burden, not only do they reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the ability to realize it. Instead, they are left with the mistaken impression that they are doing just fine.
Tendency for people to overestimate the degree to which others agree with them.
Tendency to give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically for them, but are in fact vague and general enough to apply to a wide range of people. Also known as the Barnum Effect. Like Horoscopes.
Tendency to process information toward conclusions that suit some end or goal.
That self-generated information is remembered best. People are better able to recall memories of statements that they have generated than similar statements generated by others.
Tendency to forget information that can be found readily online by using Internet search engines.
Tendency for a person's positive or negative traits to "spill over" from one area of their personality to another in others' perceptions of them.
Tendency to perceive news coverage as biased against your position on an issue.
That humorous items are more easily remembered than non-humorous ones, which might be explained by the distinctiveness of humor, the increased cognitive processing time to understand the humor, or the emotional arousal caused by the humor.
Tendency to report flattering beliefs about oneself and believe that one is above average.
A smaller percentage of items are remembered in a longer list, but as the length of the list increases, the absolute number of items remembered increases as well.
Tendency to express undue liking for things merely because they are familiar with them.
Memory becoming less accurate because of interference from post-event information.
That memory recall is higher for the last items of a list when the list items were received via speech than when they were received through writing.
Tendency of being more certain than is justified, given your priors and the evidence available.
That being shown some items from a list and later retrieving one item causes it to become harder to retrieve the other items.
The notion that concepts that are learned by viewing pictures are more easily and frequently recalled than are concepts that are learned by viewing their written word form counterparts.
That older adults favor positive over negative information in their memories.
Tendency to weigh initial events more than subsequent events.
That information that takes longer to read, and is processed with more difficulty, is more easily remembered.
Tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.
Tendency to weigh recent events more than earlier events.
That memories relating to the self are better recalled than similar information relating to others.
That information is better recalled if exposure to it is repeated over a long span of time rather than a short one.
Tendency to overestimate the amount that other people notice your appearance or behavior.
Tendency to judge probability of the whole to be less than the probabilities of the parts.
Diminishment of the recency effect because a sound item is appended to the list that the subject is not required to recall.
Tendency to perceive recent events to have occurred more remotely and remote events appear to have occurred more recently.
The fact that you more easily remember information you have read by rewriting it instead of rereading it.
State of being more uncertain than is justified, given your priors and the evidence you are aware of.
That the "gist" of what someone has said is better remembered than the verbatim wording. This is because memories are representations, not exact copies.
Tendency to remember an item that "stands out like a sore thumb", more than other items.
That uncompleted or interrupted tasks are remembered better than completed ones.
Tendency of placing too much importance on one aspect of an event; causes error in accurately predicting the utility of a future outcome.
Tendency to demand much more to give up an object than they would be willing to pay to acquire it.
That a person in a group has diminished recall for the words of others who spoke immediately before himself, if they take turns speaking.
Assumption that specific conditions are more probable than general ones.
Assumption that something simple for one system will be simple for others.
Assumption that individual random events are influenced by previous random events. Ex: I've flipped heads with this coin five times consecutively, so the chance of tails coming out on the sixth flip is much greater than heads.
Assumption that the way you see the world reflects the way the world really is.
Assumption that other people are more like you than they actually are.
Assumption that because nothing is certain, everything is equally uncertain. It does not take into account that some things are more certain than others.
The Sophisticate: "The world isn't black and white. No one does pure good or pure bad. Therefore, no one is better than anyone else." The Zetet: "Knowing only gray, you conclude that all grays are the same shade. You mock the simplicity of the two-color view, yet you replace it with a one-color view."
Underestimating task-completion times.
Letting past investments interfere with decision-making in the present.
Occurs when an argument leaps directly from capability to actuality, without considering the necessary intermediate of motive.
A vulnerability to over-interpretation and our predilection for compact stories over raw truths.
Error of using a simple polarized scheme for deciding a complex issue/ each piece of evidence about the question is individually categorized as supporting exactly one of the two opposing positions.
Related to not taking into account the idea that a small sample size is not always reflective of a whole population and that sample populations with certain characteristics, e.g. made up of repeat job seekers, are not reflective of the whole population.
Error of thinking that if something is worse than the problem currently being discussed, then the problem currently being discussed isn't that important at all. In other words: nothing matters if it's not literally the worst thing happening
Tendency to perceive the knowledge of their peers to surpass their peers' knowledge of them.
Tendency to believe they can control or at least influence outcomes that they clearly cannot.
Tendency to perceive self-generated preferences as instead being caused by insightful, effective and benevolent agents.
Tendency to identify as true statements familiar statements over unfamiliar ones.
Tendency to perceive patterns where actually none exist.
Tendency to notice something everywhere after having learnt about it. Also known as the Baader-Meinhof Phenomenon.
Tendency to overestimate others' ability to know them, and they also overestimate their ability to know others. Misleading impression that your words convey more to others than they really do.
Mental shortcut where highly untypical situations are classified as absurd or impossible.
Mental shortcut basing a decision on an emotional reaction rather than a calculation.
Mental shortcut that treats easily recalled information as important or more important than alternative solutions which are not as readily recalled.
Mental shortcut where people judge the probability or frequency of a hypothesis by considering how much the hypothesis resembles available data as opposed to using a Bayesian calculation.