List of cognitive biases

Cognitive bias is distortion in the way we perceive reality (see also cognitive distortion).

Some of these have been verified empirically in the field of psychology, others are considered general categories of bias.

Decision making and behavioral biases
Many of these biases are studied for how they affect belief formation and business decisions and scientific research
 * anchoring - the tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions.
 * bandwagon effect - the tendency to do (or believe) things because many other people do (or believe) the same.
 * belief bias - the tendency to base assessments on personal beliefs (see also belief perseverance and Experimenter's regress)
 * bias blind spot - the tendency not to compensate for one's own cognitive biases.
 * confirmation bias - the tendency to search for or interpret information in a way that confirms one's preconceptions.
 * congruence bias - the tendency to test hypotheses exclusively through direct testing
 * contrast effect - the enhancement or diminishment of a weight or other measurement when compared with recently observed contrasting object.
 * disconfirmation bias - the tendency for people to extend critical scrutiny to information which contradicts their prior beliefs and accept uncritically information that is congruent with their prior beliefs.
 * endowment effect - the tendency for people to value something more as soon as they own it.
 * hyperbolic discounting - the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs, the closer to the present both payoffs are.
 * illusion of control - the tendency for human beings to believe they can control or at least influence outcomes which they clearly cannot.
 * impact bias - the tendency for people to overestimate the length or the intensity of the impact of future feeling states.
 * just-world phenomenon - the tendency for people to believe the world is "just" and so therefore people "get what they deserve."
 * loss aversion - the tendency for people to strongly prefer avoiding losses than acquiring gains (see also sunk cost effects)
 * mere exposure effect - the tendency to express undue liking for things merely because they are familiar with them.
 * color psychology - the tendency for cultural symbolism of certain colors to affect affective reasoning.
 * planning fallacy - the tendency to underestimate task-completion times.
 * pseudocertainty effect - the tendency to make risk-averse choices if the expected outcome is positive, but risk-seeking choices to avoid negative outcomes.
 * rosy retrospection - the tendency to rate past events more positively than they had actually rated them when the event occurred.
 * selective perception - the tendency for expectations to affect perception.
 * status quo bias - the tendency for people to like things to stay relatively the same.
 * 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.
 * Zeigarnik effect - the tendency for people to remember uncompleted or interrupted tasks better than completed ones.

Probability prediction biases
Many of these biases are often studied for how they affect business and economic decisions and how they affect experimental research.
 * anthropic bias - the tendency for one's evidence to be biased by observation selection effects.
 * availability error - the distortion of one's perceptions of reality due to the tendency to remember one alternative outcome of a situation much more easily than another.
 * clustering illusion - the tendency to see patterns where actually none exist
 * conjunction fallacy - the tendency to assume that specific conditions are more probable than general ones.
 * gambler's fallacy - the tendency to assume that individual random events are influenced by previous random events&mdash;"the coin doesn't have memory"
 * hindsight bias - sometimes called the "I-knew-it-all-along" effect, is the inclination to see past events as being predictable.
 * illusory correlation - beliefs that inaccurately suppose a relationship between a certain type of action and an effect.
 * Observer-expectancy effect - when a researcher expects a given result and therefore unconsciously manipulates an experiment or misinterprets data in order to find it. (see also subject-expectancy effect)
 * Positive outcome bias (prediction) - a bias in prediction in which people overestimate the probability of good things happening to them. (see also wishful thinking and valence effect)
 * recency effect - the tendency to weigh recent events more than earlier events (see also peak-end rule)
 * primacy effect - the tendency to weigh initial events more than subsequent events

Social biases
Most of these biases are labeled as attributional biases.
 * Barnum effect (or Forer Effect) - the 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.
 * egocentric bias - occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would.
 * false consensus effect - the tendency for people to overestimate the degree to which others agree with them.
 * fundamental attribution error - the tendency for people to over-emphasize personality-based explanations for behaviors observed in others while under-emphasizing the role and power of situational influences on the same behavior. (see also group attribution error, positivity effect, and negativity effect)
 * halo effect - the 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. (see also physical attractiveness stereotype)
 * illusion of asymmetic insight - people perceive their knowledge of their peers to surpass their peers' knowledge of them.
 * ingroup bias - preferential treatment people give to whom they perceive to be members of their own groups.
 * Lake Wobegon effect - the human tendency to report flattering beliefs about oneself and believe that one is above average (see also worse-than-average effect, and overconfidence effect).
 * notational bias - a form of cultural bias in which a notation induces the appearance of a nonexistent natural law.
 * outgroup homogeneity bias - individuals see members of their own group as being relatively more varied than members of other groups.
 * projection bias - the tendency to unconsciously assume that others share the same or similar thoughts, beliefs, values, or positions.
 * self-serving bias - the tendency to claim more responsibility for successes than failures. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way beneficial to their interests. (see also group-serving bias)
 * trait ascription bias - the tendency for people to view themselves as relatively variable in terms of personality, behavior and mood while viewing others as much more predictable.
 * self-fulfilling prophecy - the tendency to engage in behaviors that elicit results which will (consciously or subconsciously) confirm our beliefs.

Memory errors
See Memory bias.

Common theoretical causes of some cognitive biases

 * Attribution theory, especially:
 * Salience
 * Cognitive dissonance, and related:
 * Impression management
 * Self-perception theory
 * Heuristics, including:
 * Availability heuristic
 * Representativeness heuristic
 * Adaptive Bias