A cognitive bias refers to the systematic pattern of deviation from norm or rationality in judgment, whereby inferences about other people and situations may be drawn in an illogical fashion. Individuals create their own "subjective social reality" from their perception of the input. An individual's construction of social reality, not the objective input, may dictate their behaviour in the social world. Thus, cognitive biases may sometimes lead to perceptual distortion, inaccurate judgment, illogical interpretation, or what is broadly called irrationality.
Some cognitive biases are presumably adaptive. Cognitive biases may lead to more effective actions in a given context. Furthermore, cognitive biases enable faster decisions when timeliness is more valuable than accuracy, as illustrated in heuristics. Other cognitive biases are a "by-product" of human processing limitations, resulting from a lack of appropriate mental mechanisms (bounded rationality), or simply from a limited capacity for information processing.
A continually evolving list of cognitive biases has been identified over the last six decades of research on human judgment and decision-making in cognitive science, social psychology, and behavioral economics. Kahneman and Tversky (1996) argue that cognitive biases have efficient practical implications for areas including clinical judgment, entrepreneurship, finance, and management.
Bias arises from various processes that are sometimes difficult to distinguish. These include
The notion of cognitive biases was introduced by Amos Tversky and Daniel Kahneman in 1972 and grew out of their experience of people's innumeracy, or inability to reason intuitively with the greater orders of magnitude. Tversky, Kahneman and colleagues demonstrated several replicable ways in which human judgments and decisions differ from rational choice theory. Tversky and Kahneman explained human differences in judgement and decision making in terms of heuristics. Heuristics involve mental shortcuts which provide swift estimates about the possibility of uncertain occurrences (Baumeister & Bushman, 2010, p. 141). Heuristics are simple for the brain to compute but sometimes introduce "severe and systematic errors" (Tversky & Kahneman, 1974, p. 1125).
For example, the representativeness heuristic is defined as the tendency to "judge the frequency or likelihood" of an occurrence by the extent of which the event "resembles the typical case" (Baumeister & Bushman, 2010, p. 141). The "Linda Problem" illustrates the representativeness heuristic (Tversky & Kahneman, 1983). Participants were given a description of "Linda" that suggests Linda might well be a feminist (e.g., she is said to be concerned about discrimination and social justice issues). They were then asked whether they thought Linda was more likely to be a "(a) bank teller" or a "(b) bank teller and active in the feminist movement". A majority chose answer (b). This error (mathematically, answer (b) cannot be more likely than answer (a)) is an example of the "conjunction fallacy"; Tversky and Kahneman argued that respondents chose (b) because it seemed more "representative" or typical of persons who might fit the description of Linda. The representativeness heuristic may lead to errors such as activating stereotypes and inaccurate judgements of others (Haselton et al., 2005, p. 726).
Alternatively, critics of Kahneman and Tversky such as Gerd Gigerenzer argue that heuristics should not lead us to conceive of human thinking as riddled with irrational cognitive biases, but rather to conceive rationality as an adaptive tool that is not identical to the rules of formal logic or the probability calculus. Nevertheless, experiments such as the "Linda problem" grew into the heuristics and biases research program which spread beyond academic psychology into other disciplines including medicine and political science.
Biases can be distinguished on a number of dimensions. For example,
Some biases reflect a subject's motivation, for example, the desire for a positive self-image leading to egocentric bias and the avoidance of unpleasant cognitive dissonance. Other biases are due to the particular way the brain perceives, forms memories and makes judgments. This distinction is sometimes described as "hot cognition" versus "cold cognition", as motivated reasoning can involve a state of arousal.
Among the "cold" biases,
The fact that some biases reflect motivation, and in particular the motivation to have positive attitudes to oneself accounts for the fact that many biases are self-serving or self-directed (e.g. illusion of asymmetric insight, self-serving bias). There are also biases in how subjects evaluate in-groups or out-groups; evaluating in-groups as more diverse and "better" in many respects, even when those groups are arbitrarily-defined (ingroup bias, outgroup homogeneity bias).
Some cognitive biases belong to the subgroup of attentional biases which refer to the paying of increased attention to certain stimuli. It has been shown, for example, that people addicted to alcohol and other drugs pay more attention to drug-related stimuli. Common psychological tests to measure those biases are the Stroop task and the dot probe task.
The following is a list of the more commonly studied cognitive biases:
A 2012 Psychological Bulletin article suggests that at least 8 seemingly unrelated biases can be produced by the same information-theoretic generative mechanism. It is shown that noisy deviations in the memory-based information processes that convert objective evidence (observations) into subjective estimates (decisions) can produce regressive conservatism, the belief revision (Bayesian conservatism), illusory correlations, illusory superiority (better-than-average effect) and worse-than-average effect, subadditivity effect, exaggerated expectation, overconfidence, and the hard–easy effect.
Many social institutions rely on individuals to make rational judgments.
The securities regulation regime largely assumes that all investors act as perfectly rational persons. In truth, actual investors face cognitive limitations from biases, heuristics, and framing effects.
A fair jury trial, for example, requires that the jury ignore irrelevant features of the case, weigh the relevant features appropriately, consider different possibilities open-mindedly and resist fallacies such as appeal to emotion. The various biases demonstrated in these psychological experiments suggest that people will frequently fail to do all these things. However, they fail to do so in systematic, directional ways that are predictable.
Cognitive biases are also related to the persistence of superstition, to large social issues such as prejudice, and they also work as a hindrance in the acceptance of scientific non-intuitive knowledge by the public.
However, in some academic disciplines, the study of bias is very popular. For instance, bias is a wide spread phenomenon and well studied, because most decisions that concern the minds and hearts of entrepreneurs are computationally intractable
Similar to Gigerenzer (1996), Haselton et al. (2005) state the content and direction of cognitive biases are not "arbitrary" (p. 730). Moreover, cognitive biases can be controlled. Debiasing is a technique which aims to decrease biases by encouraging individuals to use controlled processing compared to automatic processing (Baumeister & Bushman, 2010, p. 155). In relation to reducing the FAE, monetary incentives and informing participants they will be held accountable for their attributions have been linked to the increase of accurate attributions. Training has also shown to reduce cognitive bias. Morewedge and colleagues (2015) found that research participants exposed to one-shot training interventions, such as educational videos and debiasing games that taught mitigating strategies, exhibited significant reductions in their commission of six cognitive biases immediately and up to 3 months later.
Cognitive bias modification refers to the process of modifying cognitive biases in healthy people and also refers to a growing area of psychological (non-pharmaceutical) therapies for anxiety, depression and addiction called cognitive bias modification therapy (CBMT). CBMT is sub-group of therapies within a growing area of psychological therapies based on modifying cognitive processes with or without accompanying medication and talk therapy, sometimes referred to as applied cognitive processing therapies (ACPT). Although cognitive bias modification can refer to modifying cognitive processes in healthy individuals, CBMT is a growing area of evidence-based psychological therapy, in which cognitive processes are modified to relieve suffering from serious depression, anxiety, and addiction. CBMT techniques are technology assisted therapies that are delivered via a computer with or without clinician support. CBM combines evidence and theory from the cognitive model of anxiety, cognitive neuroscience, and attentional models.
There are criticisms against theories of cognitive biases based on the fact that both sides in a debate often claim each other's thoughts to be in human nature and the result of cognitive bias, while claiming their own viewpoint as being the correct way to "overcome" cognitive bias. This is not due simply to debate misconduct but is a more fundamental problem that stems from psychology's making up of multiple opposed cognitive bias theories that can be non-falsifiably used to explain away any viewpoint.