The base rate fallacy is directly dependent on a particular judgment paradigm in which information may be unambiguously designated as either “base rate” or “individuating,” and in which subjects make two-stage sequential judgments. The paradigm may be a poor match for real world settings, and the fallacy may thus be undefined for natural ecologies of judgment.

Abstract(1) There is enough contradictory evidence regarding the role of base rates in category learning to confirm the nonexistence of biases in such learning. (2) It is not always possible to activate statistical reasoning through frequentist representation. (3) It is necessary to use the concept of systematic processing in reconsidering the published work on biases.

The fallacy beneath the base rate fallacy is that we know what a base rate is. We talk as if base rates and individuating information were two different kinds of information. From a Bayesian perspective, however, the only difference between base rate and individuating information is – which comes first.

Consistent with Koehler's position, we propose a generalization of the base rate fallacy and earlier conservatism literatures. In studies using both traditional tasks and new tasks based on ecologically valid base rates, our subjects typically underweight individuating information at least as much as they underweight base rates. The implications of cue consistency for averaging heuristics are discussed.

: This article describes a psychological test of Hull's (1988) theory of science as an evolutionary process by seeing if it can account for how scientists sometimes remember and cite the scientific literature. The conceptual adequacy of Hull's theory was evaluated by comparing it to Bartlett's (1932) seminal theory of human remembering. Bartlett found that remembering is an active, reconstructive process driven by a schema that biases recall in the direction of proto- typicality and personal involvement. This account supports Hull's (...) theory of science because it shows that the characteristics of reconstructive remembering are consistent with the generic properties of an evolutionary process. The empirical adequacy of Hull's theory was evaluated by comparing the predictions made from this evolutionary viewpoint against evidence from the history of science. Six cases studies of well-known psychological experiments that had been subject to repeated miscitation errors were collected and reviewed. All six case studies revealed a systematic pattern of distortions that is consistent with the schema-induced biases of reconstructive remembering. These findings support Hull's claim that science is an evolutionary process with scientists as interactors, scientific beliefs as replicators, and schemata as means for that replication. (shrink)

Ayn Rand’s Objectivist epistemology is the foundation of an impressive, comprehensive, and integrated system of political philosophy, psychology, art, and literature. Friedrich Hayek’s operational system of epistemology and his analysis of the psychology of perception (presented primarily in The Sensory Order) is not as clearly integrated with his economics and political philosophy—and many have debated their consistency with one another. This paper engages in a comparative analysis of Rand’s and Hayek’s epistemology.

This paper focuses on how experiences of trauma can lead to generalized fear of people, objects and places that are similar or contextually or conceptually related to those that produced the initial fear, causing epistemic, affective, and practical harms to those who are unduly feared and those who are intimates of the victim of trauma. We argue that cases of fear generalization that bring harm to other people constitute examples of injustice closely akin to testimonial injustice, specifically, mnemonic injustice. Mnemonic (...) injustice is a label that has been introduced to capture how injustice can occur via the operation of human memory systems when stereotypes shape what is remembered. Here we argue that injustices can also occur via memory systems when trauma leads to a generalized fear. We also argue that this calls for a reformulation of the notion of mnemonic injustice. (shrink)

Fear generalisation is a psychological phenomenon that occurs when fear that is elicited in response to a frightening stimulus spreads to similar or related stimuli. The practical harms of pathological fear generalisation related to trauma are well-documented, but little or no attention has been given so far to its epistemic harms. This paper fills this gap in the literature. It shows how the psychological phenomenon, when it becomes pathological, substantially curbs the epistemic agency of those who experience the fear that (...) generalizes, limiting their ability to respond to evidence, and substantially limiting their epistemic horizons. It is argued that when these epistemic harms are caused by wrongful actions and decisions of individuals or institutions, because the fear is elicited in response to a traumatic experience inflicted by them, the harms should be considered epistemic wrongs. The epistemic wrongs are closely akin to agential epistemic injustice, a variety of distributive epistemic injustice, and sometimes also involve epistemic exclusion. The paper thereby identifies a previously underexplored psychological mechanism that can be a vehicle through which both individuals and institutions can epistemically wrong others. The argument has implications for how both epistemic wrongs and epistemic injustice should be conceived, suggesting that both can occur without being caused by primarily epistemic flaws or errors, or a bad epistemic character. Finally, it highlights the advantage of taking a victim-centred approach to understanding epistemic harm. (shrink)

According to the Argument for Autonomous Mental Disorder, mental disorder can occur in the absence of brain disorder, just as software problems can occur in the absence of hardware problems in a computer. This article argues that the AAMD is unsound. I begin by introducing the “natural dysfunction analysis” of disorder, before outlining the AAMD. I then analyze the necessary conditions for realizer autonomous dysfunction. Building on this, I show that software functions disassociate from hardware functions in a way that (...) mental functions do not disassociate from brain functions. It follows that mental disorders are brain disorders necessarily. (shrink)

Any instance (i.e., event, behavior, trait) belongs to infinitely many reference classes, hence there are infinitely many base rates from which to choose. People clearly do not entertain all possible reference classes, however, so something must be limiting the search space. We suggest some possible mechanisms that determine which reference class is evoked for the purpose of judgment and decision.

We have been oversold on the base rate fallacy in probabilistic judgment from an empirical, normative, and methodological standpoint. At the empirical level, a thorough examination of the base rate literature (including the famous lawyer–engineer problem) does not support the conventional wisdom that people routinely ignore base rates. Quite the contrary, the literature shows that base rates are almost always used and that their degree of use depends on task structure and representation. Specifically, base rates play a relatively larger role (...) in tasks where base rates are implicitly learned or can be represented in frequentist terms. Base rates are also used more when they are reliable and relatively more diagnostic than available individuating information. At the normative level, the base rate fallacy should be rejected because few tasks map unambiguously into the narrow framework that is held up as the standard of good decision making. Mechanical applications of Bayes's theorem to identify performance errors are inappropriate when (1) key assumptions of the model are either unchecked or grossly violated, and (2) no attempt is made to identify the decision maker's goals, values, and task assumptions. Methodologically, the current approach is criticized for its failure to consider how the ambiguous, unreliable, and unstable base rates of the real world are and should be used. Where decision makers' assumptions and goals vary, and where performance criteria are complex, the traditional Bayesian standard is insufficient. Even where predictive accuracy is the goal in commonly defined problems, there may be situations (e.g., informationally redundant environments) in which base rates can be ignored with impunity. A more ecologically valid research program is called for. This program should emphasize the development of prescriptive theory in rich, realistic decision environments. (shrink)

Koehler is right that base rate information is used, to various degrees, both in laboratory tasks and in everyday life. However, it is not time to turn our backs on laboratory tasks and focus solely on ecologically valid decision making. Tightly controlled experimental data are still needed to understandhowbase rate information is used, and how this varies among groups.

Since James defined emotion as consciousness of bodily reactions and Cannon and others detailed the nature of these reactions, there has been an increasing tendency among behaviorists to equate emotions with visceral reactions and to neglect some of the genetic and adaptive aspects of emotion which had been discussed by Darwin.

Koehler is right to argue for more nuanced interpretation of base rate anomalies. These anomalies are best understood in relation to a broader class of cognitive anomalies, which are important for theory and practice. Recognizing a need for more nuanced analysis should not be taken as a license for treating the effects as “explained away.”.

Koehler's target article attempts a balanced view of the relevance of knowledge of base rates to judgments of subjective or credal probability, but he is not sensitive enough to the difference between requiring and permitting the equation of probability judgments with base rates, the interaction between precision of base rate and reference class information, and the possibility of indeterminate probability judgment.

Two distinct issues are sometimes confused in the base rate literature: Why do people make logical mistakes in the assessment of probabilities? and why do subjects not use base rates the way experimenters do? The latter problem may often reflect differences in an implicit reference class rather than a disinclination to update a base rate by Bayes' theorem. Also important are considerations concerning the interaction of several potentially relevant base rates.

The underutilization of base rates is a consistent finding. The strong claim that base rates are ignored has been rejected and this needs no further emphasis. Following the path of “normal science,” research examines the conditions predicting changes in the degree of underutilization. A scientific revolution that might dethrone the heuristics and biases paradigm is not in sight.

Koehler's call for a reanalysis of the base rate fallacy is particularly important in the applied domain of accounting, since base rate data appear to be an important input for many accounting tasks. In this commentary I discuss the use of base rates in accounting and explain why more flexible standards of performance are important when judging the use of base rates.

Commentators agree that simple conclusions about a general base rate fallacy are not appropriate. It is more constructive to identify conditions under which base rates are differentially weighted. Commentators also agree that improving the ecological validity of the research is desirable, although this is less important to those interested exclusively in psychological processes. The philosophers and ecologists among the commentators offer a kinder perspective on base rate reasoning than the psychologists. My own perspective is that the interesting questions (both psychological (...) and normative/prescriptive) are best answered through empirical studies that use real-world performance standards. (shrink)

ArgumentThe article retraces the shifting conceptualizations of psychological trauma in experimental psychopathological research in the middle decades of the twentieth century in the United States. Among researchers studying so-called experimental neuroses in animal laboratories, trauma was an often-invoked category used to denote the clash of conflicting forces believed to lead to neurotic suffering. Experimental psychologists, however, soon grew skeptical of the traumatogenic model and ultimately came to reject neurosis as a disease entity. Both theoretical differences and practical circumstances, such as (...) the technical challenge of stabilizing neurotic symptoms in rats, led to this demise. Yet, despite their reservations, experimental psychologists continued to employ traumatic stimuli to produce psychopathological syndromes. In the 1960s, a new understanding of trauma evolved, which emphasized the loss of control experienced by traumatized animal subjects. These shifting ideas about trauma, I argue, reflect both varying experimental cultures, epistemic norms as well as changing societal concerns. (shrink)

This commentary discusses three points: (1) The implications of the fact that it is rational to ignore base rates if probabilities are estimated by frequencies from samples without missing data (natural sampling); (2) second order probabilities distributions are a plausible way to model imprecise probabilities; and (3) Bayesian networks represent a normative reference for multi-cue models of probabilistic inference.

Failure to consider base rate is regarded as potentially hazardous, mainly because its consideration is assumed to be determined solely by P(H/D), the probability of the individuating data if the hypothesis is true, and not at all by P(D/˜H), the probability if the hypothesis is false. However, when P(D/˜H) is unconfounded from P(D/H), it turns out to be the stronger determinant of base rate consideration.