List of cognitive biases


In psychology and cognitive science, cognitive biases are systematic patterns of deviation from norm and/or rationality in judgment. They are often studied in psychology, sociology and behavioral economics.
A memory bias is a cognitive bias that either enhances or impairs the recall of a memory, or that alters the content of a reported memory.
Explanations include information-processing rules, called heuristics, that the brain uses to produce decisions or judgments. Biases have a variety of forms and appear as cognitive bias, such as mental noise, or motivational bias, such as when beliefs are distorted by wishful thinking. Both effects can be present at the same time.
There are also controversies over some of these biases as to whether they count as useless or irrational, or whether they result in useful attitudes or behavior. For example, when getting to know others, people tend to ask leading questions which seem biased towards confirming their assumptions about the person. However, this kind of confirmation bias has also been argued to be an example of social skill; a way to establish a connection with the other person.
Although this research overwhelmingly involves human subjects, some studies have found bias in non-human animals as well. For example, loss aversion has been shown in monkeys and hyperbolic discounting has been observed in rats, pigeons, and monkeys.

Organization of cognitive biases

Although the reality of these biases is confirmed by reproducible research, there are often controversies about how to classify these biases or how to explain them. Several theoretical causes are known for some cognitive biases, which provides a classification of biases by their common generative mechanism. Gerd Gigerenzer has criticized the framing of cognitive biases as errors in judgment, and favors interpreting them as arising from rational deviations from logical thought. This list is organized based on the task-based classification proposed by. This classification defines 6 tasks, namely estimation, decision, hypothesis assessment, causal attribution, recall, and opinion reporting. The biases are further loosely classified into 5 sub-categories or "flavors":
  1. Association: a connection between different pieces of information
  2. Baseline: comparing something to a perceived standard or starting point
  3. Inertia: the reluctance to change something that is already in place
  4. Outcome: how well something aligns with an expected or hoped-for result
  5. Self-perspective: influenced by one's own personal point of view

    Estimation

In estimation or judgement tasks, people are asked to assess the value of a quantity.

Association

  • Aesthetic–usability effect: A tendency for people to perceive attractive things as more usable.
  • Attribute substitution: Occurs when a judgment has to be made that is computationally complex, and instead a more easily calculated heuristic attribute is substituted. This substitution is thought of as taking place in the automatic intuitive judgment system, rather than the more self-aware reflective system.
  • The availability heuristic is the tendency to overestimate the likelihood of events with greater "availability" in memory, which can be influenced by how recent the memories are or how unusual or emotionally charged they may be. There is a greater likelihood of recalling recent, nearby, or otherwise immediately available examples, and the imputation of importance to those examples over others.
  • Conjunction fallacy, the tendency to assume that specific conditions are more probable than a more general version of those same conditions.
  • Hot-cold empathy gap, the tendency to underestimate the influence of visceral drives on one's attitudes, preferences, and behaviors.
  • Tachypsychia: When time perceived by the individual either lengthens, making events appear to slow down, or contracts.
  • Time-saving bias, a tendency to underestimate the time that could be saved when increasing from a relatively low speed, and to overestimate the time that could be saved when increasing from a relatively high speed.
  • : Overestimating the significance of the present. It is related to chronological snobbery with possibly an appeal to novelty logical fallacy being part of the bias.

    Baseline

  • The anchoring bias, or focalism, is the tendency to rely too heavily—to "anchor"—on one trait or piece of information when making decisions.
  • Base rate fallacy or base rate neglect, the tendency to ignore general information and focus on information only pertaining to the specific case, even when the general information is more important.
  • Dunning–Kruger effect, the tendency for unskilled individuals to overestimate their own ability and the tendency for experts to underestimate their own ability.
  • Gambler's fallacy, the tendency to think that future probabilities are altered by past events, when in reality they are unchanged. The fallacy arises from an erroneous conceptualization of the law of large numbers. For example, "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."
  • Hard–easy effect, the tendency to overestimate one's ability to accomplish hard tasks, and underestimate one's ability to accomplish easy tasks.
  • Hot-hand fallacy, the belief that a person who has experienced success with a random event has a greater chance of further success in additional attempts.
  • Insensitivity to sample size, the tendency to under-expect variation in small samples.
  • Interoceptive bias or Hungry judge effect: The tendency for sensory input about the body itself to affect one's judgement about external, unrelated circumstances.
  • or Regressive bias: 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.
  • Subadditivity effect: The tendency to estimate that the likelihood of a remembered event is less than the sum of its mutually exclusive components.
  • Systematic bias: Judgement that arises when targets of differentiating judgement become subject to effects of regression that are not equivalent.
  • : The standard suggested amount of consumption is perceived to be appropriate, and a person would consume it all even if it is too much for this particular person.
  • Weber–Fechner law: Difficulty in perceiving and comparing small differences in large quantities.

    Inertia

  • Conservatism bias, the tendency to insufficiently revise one's belief when presented with new evidence.

    Outcome

  • : The tendency to expect or predict more extreme outcomes than those outcomes that actually happen.
  • Hedonic recall bias: The tendency for people who are satisfied with their wage to overestimate how much they earn, and conversely, for people who are unsatisfied with their wage to underestimate it.
  • Illusion of validity, the tendency to overestimate the accuracy of one's judgments, especially when available information is consistent or inter-correlated.
  • Impact bias: The tendency to overestimate the length or the intensity of the impact of future feeling states.
  • Outcome bias: The tendency to judge a decision by its eventual outcome instead of the quality of the decision at the time it was made.
  • Planning fallacy, the tendency for people to underestimate the time it will take them to complete a given task.
  • Restraint bias, the tendency to overestimate one's ability to show restraint in the face of temptation.
  • Sexual overperception bias, the tendency to overestimate sexual interest of another person in oneself, and sexual underperception bias, the tendency to underestimate it.

    Self-perspective

  • Curse of knowledge: When better-informed people find it extremely difficult to think about problems from the perspective of lesser-informed people.
  • Extrinsic incentives bias, an exception to the fundamental attribution error, where people view others as having extrinsic motivations, while viewing themselves as having intrinsic motivations.
  • False consensus effect, the tendency for people to overestimate the degree to which others agree with them.
  • Illusion of transparency, the tendency for people to overestimate the degree to which their personal mental state is known by others, and to overestimate how well they understand others' personal mental states.
  • Naïve cynicism, expecting more egocentric bias in others than in oneself.
  • Optimism bias: The tendency to be over-optimistic, underestimating greatly the probability of undesirable outcomes and overestimating favorable and pleasing outcomes.
  • Outgroup homogeneity bias, where individuals see members of other groups as being relatively less varied than members of their own group.
  • Pessimism bias: The tendency to overestimate the likelihood that bad things will happen..
  • Spotlight effect: The tendency to overestimate the amount that other people notice one's appearance or behavior.
  • Worse-than-average effect: A tendency to believe ourselves to be worse than others at tasks which are difficult.

    Decision

In decision or choice tasks, people select one option out of several.

Association

  • Ambiguity effect, the tendency to avoid options for which the probability of a favorable outcome is unknown.
  • Authority bias, the tendency to attribute greater accuracy to the opinion of an authority figure and be more influenced by that opinion.
  • Automation bias, the tendency to depend excessively on automated systems which can lead to erroneous automated information overriding correct decisions.
  • Default effect, the tendency to favor the default option when given a choice between several options.
  • Dread aversion, just as losses yield double the emotional impact of gains, dread yields double the emotional impact of savouring.
  • The framing effect is the tendency to draw different conclusions from the same information, depending on how that information is presented.
  • Hyperbolic discounting, where discounting is the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs. Hyperbolic discounting leads to choices that are inconsistent over time—people make choices today that their future selves would prefer not to have made, despite using the same reasoning. Also known as current moment bias or present bias, and related to Dynamic inconsistency. A good example of this is a study showed that when making food choices for the coming week, 74% of participants chose fruit, whereas when the food choice was for the current day, 70% chose chocolate.
  • Compassion fade, the tendency to behave more compassionately towards a small number of identifiable victims than to a large number of anonymous ones.
  • Loss aversion, where the perceived disutility of giving up an object is greater than the utility associated with acquiring it.
  • Neglect of probability, the tendency to completely disregard probability when making a decision under uncertainty.
  • Non-adaptive choice switching: After experiencing a bad outcome with a decision problem, the tendency to avoid the choice previously made when faced with the same decision problem again, even though the choice was optimal. Also known as "once bitten, twice shy" or "hot stove effect".
  • Prevention bias: When investing money to protect against risks, decision makers perceive that a dollar spent on prevention buys more security than a dollar spent on timely detection and response, even when investing in either option is equally effective.
  • Pseudocertainty effect, the tendency to make risk-averse choices if the expected outcome is good but risk-seeking choices if it is bad.
  • Risk compensation or Peltzman effect: The tendency to take greater risks when perceived safety increases.
  • Zero-risk bias, the preference for reducing a small risk to zero over a greater reduction in a larger risk.