Delusions are a common symptom of schizophrenia and dementia. Though most English dictionaries define a delusion as a false opinion or belief, there is currently a lively debate about whether delusions are really beliefs and indeed, whether they are even irrational. The book is an interdisciplinary exploration of the nature of delusions. It brings together the psychological literature on the aetiology and the behavioural manifestations of delusions, and the philosophical literature on belief ascription and rationality. The thesis of the book (...) is that delusions are continuous with ordinary beliefs, a thesis that could have important theoretical and practical implications for psychiatric classification and the clinical treatment of subjects with delusions. By bringing together recent work in philosophy of mind, cognitive psychology and psychiatry, the book offers a comprehensive review of the philosophical issues raised by the psychology of normal and abnormal cognition, defends the doxastic conception of delusions, and develops a theory about the role of judgements of rationality and of attributions of self-knowledge in belief ascription. Presenting a highly original analysis of the debate on the nature of delusions, this book will interest philosophers of mind, epistemologists, philosophers of science, cognitive scientists, psychiatrists, and mental health professionals. (shrink)

Three challenges to a unified understanding of delusions emerge from Radden's On Delusion (2011). Here, I propose that in order to respond to these challenges, and to work towards a unifying framework for delusions, we should see delusions as arising in inference under uncertainty. This proposal is based on the observation that delusions in key respects are surprisingly like perceptual illusions, and it is developed further by focusing particularly on individual differences in uncertainty expectations.

My central question in this paper is how delusional beliefs are related to self-deception. In section 1, I summarize my position on what self-deception is and how representative instances of it are to be explained. I turn to delusions in section 2, where I focus on the Capgras delusion, delusional jealousy (or the Othello syndrome), and the reverse Othello syndrome.

Does the formation of delusions involve abnormal reasoning? According to the prominent ‘two-factor’ theory of delusions (e.g. Coltheart, 2007), the answer is yes. The second factor in this theory is supposed to affect a deluded individual's ability to evaluate candidates for belief. However, most published accounts of the two-factor theory have not said much about the nature of this second factor. In an effort to remedy this shortcoming, Coltheart, Menzies and Sutton (2010) recently put forward a Bayesian account of inference (...) in delusions. I outline some criticisms of this important account, and sketch an alternative account of delusional inference that, I argue, avoids these criticisms. Specifically, I argue that the second factor in delusion formation involves a systematic deviation from Bayesian updating, a deviation that may be characterized as a bias towards ‘explanatory adequacy’. I present a numerical model of this idea and show that my alternative account is broadly consistent with prominent prediction error models of delusion formation (e.g. Corlett, Murray et al., 2007). (shrink)

This collection of essays focuses on the interface between delusions and self-deception.

Bortolotti’s Delusions and Other Irrational Beliefs defends the view that delusions are beliefs on a continuum with other beliefs. A different view is that delusions are more like illusions, that is, they arise from faulty perception. This view, which is not targeted by the book, makes it easier to explain why delusions are so alien and disabling but needs to appeal to forensic aspects of functioning.

“Mad belief” (in analogy with Lewisian “mad pain”) would be a belief state with none of the causal role characteristic of belief—a state not caused or apt to have been caused by any of the sorts of events that usually cause belief and involving no disposition toward the usual behavioral or other manifestations of belief. On token-functionalist views of belief, mad belief in this sense is conceptually impossible. Cases of delusion—or at least some cases of delusion—might be cases of belief (...) gone half-mad, cases in which enough of the functional role characteristic of belief is absent that the subject is in an “in-between” state regarding the delusive content, such that it is neither quite right to say the subject determinately believes the delusive content nor quite right to say that she determinately fails to believe that content. Although Bortolotti (2010) briefly mentions such “sliding scale” approaches to the relationship of delusion and belief, she dismisses such approaches on rather thin grounds and then later makes some remarks that seem consonant with sliding scale approaches. (shrink)

Here I reply to the main points raised by the commentators on the arguments put forward in my Delusions and Other Irrational Beliefs (OUP, 2009). My response is aimed at defending a modest doxastic account of clinical delusions, and is articulated in three sections. First, I consider the view that delusions are inbetween perceptual and doxastic states, defended by Jacob Hohwy and Vivek Rajan, and the view that delusions are failed attempts at believing or not-quitebeliefs, proposed by Eric Schwitzgebel and (...) Maura Tumulty. Then, I address the relationship between the doxastic account of delusions and the role, nature, and prospects of folk psychology, which is discussed by Dominic Murphy, Keith Frankish, and Maura Tumulty in their contributions. In the final remarks, I turn to the continuity thesis and suggest that, although there are important differences between clinical delusions and non-pathological beliefs, these differences cannot be characterised satisfactorily in epistemic terms. (shrink)

Delusional beliefs have sometimes been considered as rational inferences from abnormal experiences. We explore this idea in more detail, making the following points. Firstly, the abnormalities of cognition which initially prompt the entertaining of a delusional belief are not always conscious and since we prefer to restrict the term “experience” to consciousness we refer to “abnormal data” rather than “abnormal experience”. Secondly, we argue that in relation to many delusions (we consider eight) one can clearly identify what the abnormal cognitive (...) data are which prompted the delusion and what the neuropsychological impairment is which is responsible for the occurrence of these data; but one can equally clearly point to cases where this impairments is present but delusion is not. So the impairment is not sufficient for delusion to occur. A second cognitive impairment, one which impairs the ability to evaluate beliefs, must also be present. Thirdly (and this is the main thrust of our chapter) we consider in detail what the nature of the inference is that leads from the abnormal data to the belief. This is not deductive inference and it is not inference by enumerative induction; it is abductive inference. We offer a Bayesian account of abductive inference and apply it to the explanation of delusional belief. (shrink)

The effects of mental disorder are apparent and pervasive, in suffering, loss of freedom and life opportunities, negative impacts on education, work satisfaction and productivity, complications in law, institutions of healthcare, and more. With a new edition of the 'bible' of psychiatric diagnosis - the DSM - under developmental, it is timely to take a step back and re-evalutate exactly how we diagnose and define mental disorder. This new book by Derek Bolton tackles the problems involved in the definition and (...) boundaries of mental disorder. It addresses two main questions regarding mental illness. Firstly, what is the basis of the standards or norms by which we judge that a person has a mental disorder - that the person's mind is not working as it should, that their mental functioning is abnormal? Controversies about these questions have been dominated by the contrast between norms that are medical, scientific or natural, on the one hand, and social norms on the other. The norms that define mental disorder seem to belong to psychiatry, to be medical and scientific, but are they really social norms, hijacked and disguised by the medical profession? Secondly, what is the validity of the distinction between mental disorder and order, between abnormal and normal mental functioning? To what extent, notwithstanding appearances, does mental disorder involve meaningful reactions and problem-solving? These responses may be to normal problems of living, or to not so normal problems - to severe psycho-social challenges. Is there after all order in mental disorder? With the closing of asylums and the appearance of care in the community, mental disorder is now in our midst. While attempts have been made to define clearly a concept of mental disorder that is truly medical as opposed to social, there is increasing evidence that such a distinction is unviable - there is no clear line between what is normal in the population and what is abnormal. 'What is Mental Disorder?' reviews these various crucial developments and their profound impact for the concept and its boundaries in a provocative and timely book. (shrink)

This is a comprehensive resource of original essays by leading thinkers exploring the newly emerging inter-disciplinary field of the philosophy of psychiatry. The contributors aim to define this exciting field and to highlight the philosophical assumptions and issues that underlie psychiatric theory and practice, the category of mental disorder, and rationales for its social, clinical and legal treatment. As a branch of medicine and a healing practice, psychiatry relies on presuppositions that are deeply and unavoidably philosophical. Conceptions of rationality, personhood (...) and autonomy frame our understanding and treatment of mental disorder. Philosophical questions of evidence, reality, truth, science, and values give meaning to each of the social institutions and practices concerned with mental health care. The psyche, the mind and its relation to the body, subjectivity and consciousness, personal identity and character, thought, will, memory, and emotions are equally the stuff of traditional philosophical inquiry and of the psychiatric enterprise. A new research field--the philosophy of psychiatry--began to form during the last two decades of the twentieth century. Prompted by a growing recognition that philosophical ideas underlie many aspects of clinical practice, psychiatric theorizing and research, mental health policy, and the economics and politics of mental health care, academic philosophers, practitioners, and philosophically trained psychiatrists have begun a series of vital, cross-disciplinary exchanges. This volume provides a sampling of the research yield of those exchanges. Leading thinkers in this area, including clinicians, philosophers, psychologists, and interdisciplinary teams, provide original discussions that are not only expository and critical, but also a reflection of their authors' distinctive and often powerful and imaginative viewpoints and theories. All the discussions break new theoretical ground. As befits such an interdisciplinary effort, they are methodologically eclectic, and varied and divergent in their assumptions and conclusions; together, they comprise a significant new exploration, definition, and mapping of the philosophical aspects of psychiatric theory and practice. (shrink)

[This download contains the Table of Contents and Chapter 1.] This first book-length study of confabulation breaks ground in both philosophy and cognitive science.

Ordinarily, if you say something like “I see a comet,” you might make a mistake about whether it is a comet that you see, but you could not be right about whether it is a comet but wrong about who is seeing it. There cannot be an “error of identification” in this case. In making a judgement like, “I see a comet,” there are not two steps, finding out who is seeing the thing and finding out what it is that (...) is being seen, so that you could go wrong at either step. The only place to go wrong is in your description of what is being seen. We usually take it that the same point applies to present-tense ascriptions to oneself of psychological states in general. You can get it wrong about which psychological state you are in, but you cannot get it right about the psychological state but wrong about whose psychological state it is. In contrast, in a room full of people, I might hear a noise and conclude, “Bill sneezed,” and in this case I could be wrong either about who it was that sneezed or about whether it was a sneeze, rather than say a death-rattle. (shrink)

The theory of rationality has traditionally been concerned with the investigation of the norms of rational thought and behaviour, and with the reasoning pro‐cedures that satisfy them. As a consequence, the investigation of irrationality has largely been restricted to the behaviour or thought that violates these norms. There are, how‐ever, other forms of irrationality. Here we propose that the delusions that occur in schizophrenia constitute a paradigm of irrationality. We examine a leading theory of schizophrenic delusion and propose that some (...) delusions can be traced to a violation of a condition on thought we call egocentricity. We argue that the violation of egocen‐tricity leads to irrational states that cannot be explained by the traditional categories of irrationality and conclude, therefore, that these states belong in a new branch of the theory of irrationality, that of experiential irrationality. (shrink)

In this paper we defend the doxastic conception of delusions against the metacognitive account developed by Greg Currie and collaborators. According to the metacognitive model, delusions are imaginings that are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief. We argue that the metacognitive account is untenable, and that the traditional conception of (...) delusions as beliefs should be retained. (shrink)

Psychiatric treatment and diagnosis rests upon a richer conception of normativity than, for example, cognitive neuropsychology. This paper explores the role that considerations of rationality can play in defining this richer conception of normativity. It distinguishes two types of rationality and considers how each type can break down in different ways in delusional psychiatric disorders.

I argue that some cases of delusions show the inadequacy of those theories of interpretation that rely on a necessary rationality constraint on belief ascription. In particular I challenge the view that irrational beliefs can be ascribed only against a general background of rationality. Subjects affected by delusions seem to be genuine believers and their behaviour can be successfully explained in intentional terms, but they do not meet those criteria that according to Davidson (1985a) need to be met for the (...) background of rationality to be in place. (shrink)

* [Irrationality]: ___ Irrationality, like rationality, is a normative concept. Someone who acts or reasons irrationally, or whose beliefs or emotions are irrational, has departed from a standard.

This paper is concerned with the problem of selfidentification in the domain of action. We claim that this problem can arise not just for the self as object, but also for the self as subject in the ascription of agency. We discuss and evaluate some proposals concerning the mechanisms involved in selfidentification and in agencyascription, and their possible impairments in pathological cases. We argue in favor of a simulation hypothesis that claims that actions, whether overt or covert, are centrally simulated (...) by the neural network, and that this simulation provides the basis for action recognition and attribution. (shrink)

Theories of self-deception divide into those that hold that the state is characterized by some kind of synchronic tension or conflict between propositional attitudes and those that deny this. Proponents of the latter like Al Mele claim that their theories are more parsimonious, because they do not require us to postulate any psychological mechanisms beyond those which have been independently verified. But if we can show that there are real cases of motivated believing which are characterized by conflicting propositional attitudes, (...) however, the parsimony argument against incongruent mental state accounts is undermined. I argue that anosognosia presents us with a real-life example of motivated belief together with (sub)-doxastic conflict. (shrink)

Self-deception raises complex questions about the nature of belief and the structure of the human mind. In this book, Alfred Mele addresses four of the most critical of these questions: What is it to deceive oneself? How do we deceive ourselves? Why do we deceive ourselves? Is self-deception really possible? -/- Drawing on cutting-edge empirical research on everyday reasoning and biases, Mele takes issue with commonplace attempts to equate the processes of self-deception with those of stereotypical interpersonal deception. Such attempts, (...) he demonstrates, are fundamentally misguided, particularly in the assumption that self-deception is intentional. In their place, Mele proposes a compelling, empirically informed account of the motivational causes of biased beliefs. At the heart of this theory is an appreciation of how emotion and motivation may, without our knowing it, bias our assessment of evidence for beliefs. Highlighting motivation and emotion, Mele develops a pair of approaches for explaining the two forms of self-deception: the "straight" form, in which we believe what we want to be true, and the "twisted" form, in which we believe what we wish to be false. -/- Underlying Mele's work is an abiding interest in understanding and explaining the behavior of real human beings. The result is a comprehensive, elegant, empirically grounded theory of everyday self-deception that should engage philosophers and social scientists alike. (shrink)

Recreative Minds develops a philosophical theory of imagination that draws upon the latest work in psychology. This theory illuminates the use of imagination in coming to terms with art, its role in enabling us to live as social beings, and the psychological consequences of disordered imagination. The authors offer a lucid exploration of a fascinating subject.

The condition known as Multiple Personality Disorder (MPD) or Dissociative Identity Disorder (DID) is metaphysically strange. Can there really be several distinct persons operating in a single body? Our view is that DID sufferers are single persons with a severe mental disorder. In this paper we compare the phenomenology of dissociation between personality states in DID with certain delusional disorders. We argue both that the burden of proof must lie with those who defend the metaphysically extravagant Multiple Persons view and (...) that there is little theoretical motivation to yield to that view in light of the fact that the core symptoms of DID bear remarkable similarity to the symptoms of these other disorders where no such extravagance is ever seriously entertained. (shrink)

An examination of verbal hallucinations and thought insertion as examples of "alienated self-consciousness.".

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we (...) draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice. (shrink)

Cognitive approaches contribute to our understanding of delusions by providing an explanatory framework that extends beyond the personal level to the sub personal level of information-processing systems. According to one influential cognitive approach, two factors are required to account for the content of a delusion, its initial adoption as a belief, and its persistence. This chapter reviews Bayesian developments of the two-factor framework.

Delusions are deeply evidence-resistant. Patients with delusions are unmoved by evidence that is in direct conflict with the delusion, often responding to such evidence by offering obvious, and strange, confabulations. As a consequence, the standard view is that delusions are not evidence-responsive. This claim has been used as a key argumentative wedge in debates on the nature of delusions. Some have taken delusions to be beliefs and argued that this implies that belief is not constitutively evidence-responsive. Others hold fixed the (...) evidenceresponsiveness of belief and take this to show that delusions cannot be beliefs. Against this common assumption, I appeal to a large range of empirical evidence to argue that delusions are evidence-responsive in the sense that subjects have the capacity to respond to evidence on their delusion in rationally permissible ways. The extreme evidence-resistance of delusions is a consequence of powerful masking factors on these capacities, such as strange perceptual experiences, motivational factors, and cognitive biases. This view makes room for holding both that belief is constitutively evidence-responsive and that delusions are beliefs, and it has important implications for the study and treatment of delusions. (shrink)

An examination of alien abduction belief can inform how we ought to approach constructing explanations of monothematic delusion formation. I argue that the formation and maintenance of alien abduction beliefs can be explained by a one-factor account, and that this explanatory power generalizes to (other) cases of monothematic delusions. There are no differences between alien abduction beliefs and monothematic delusions which indicate the need for additional explanatory factors in cases of the latter. I make the additional point that whilst alien (...) abduction beliefs can be readily explained using a one-factor framework, the two-factor framework requires adjustment to accommodate them. I conclude that theorists interested in delusion formation have much to learn from the case of alien abduction belief. (shrink)

After briefly reviewing some of the empirical and philosophical literature suggesting that there may be an adaptive role for delusion formation, we discuss the results of a recent study consisting of in-depth interviews with people experiencing delusions. We analyse three such cases in terms of the circumstances preceding the development of the delusion; the effects of the development of the delusion on the person’s situation; and the potential protective nature of the delusional belief as seen from the first-person perspective. We (...) argue that the development of the delusional belief can play a short-term protective function and we reflect on the implications that this might have for our understanding of psychotic symptoms, for the stigma associated with mental health issues, and for treatment options. (shrink)

Drawing on the latest work in cognitive neuroscience, a philosopher proposes that delusions are narrative models that accommodate anomalous experiences.

Introduction. There is substantial evidence that patients with delusions exhibit a reasoning bias—known as the “jumping to conclusions” bias—which leads them to accept hypotheses as correct on the basis of less evidence than controls. We address three questions concerning the JTC bias that require clarification. Firstly, what is the best measure of the JTC bias? Second, is the JTC bias correlated specifically with delusions, or only with the symptomatology of schizophrenia? And third, is the bias enhanced by emotionally salient material? (...) Methods. To address these questions, we conducted a series of meta-analyses of studies that used the Beads task to compare the probabilistic reasoning styles of individuals with and without delusions. Results. We found that only one of four measures of the JTC bias—“draws to decision”—reached significance. The JTC bias exhibited by delusional subjects—as measured by draws to decision—did not appear to be solely an epiphenomenal effect of schizophrenic symptomatology, and was not amplified by emotionally salient material. Conclusions. A tendency to gather less evidence in the Beads task is reliably associated with the presence of delusional symptomatology. In contrast, certainty on the task, and responses to contradictory evidence, do not discriminate well between those with and without delusions. The implications for the underlying basis of the JTC bias, and its role in the formation and maintenance of delusions, are discussed. (shrink)

What sort of mental state is a delusion? What causes delusions? Why are delusions pathological? This book examines these questions, which are normally considered separately, in a much-needed exploration of an important and fascinating topic, Kengo Miyazono assesses the philosophical, psychological and psychiatric literature on delusions to argue that delusions are malfunctioning beliefs. Delusions belong to the same category as beliefs but - unlike healthy irrational beliefs - fail to play the function of beliefs. Delusions and Beliefs: A Philosophical Inquiry (...) will be of great interest to students of philosophy of mind and psychology and philosophy of mental disorder, as well as those in related fields such as mental health and psychiatry. (shrink)

Elisabeth Pacherie is a research fellow in philosophy at Institut Jean Nicod, Paris. Her main research and publications are in the areas of philosophy of mind, psychopathology and action theory. Her publications include a book on intentionality (_Naturaliser_ _l'intentionnalité_, Paris, PUF, 1993) and she is currently preparing a book on action and agency.

In this article I ask whether elaborated and systematized delusions emerging in the context of schizophrenia have the potential for epistemic innocence. Cognitions are epistemically innocent if they have significant epistemic benefits that could not be attained otherwise. In particular, I propose that a cognition is epistemically innocent if it delivers some significant epistemic benefit to a given agent at a given time, and if alternative cognitions delivering the same epistemic benefit are unavailable to that agent at that time. Elaborated (...) and systematized delusions in schizophrenia are typically false and exemplify failures of rationality and self-knowledge. Empirical studies suggest that they may have psychological benefits by relieving anxiety and enhancing meaningfulness. Moreover, these delusions have been considered as adaptive in virtue of the fact that they enable automated learning to resume after a significant disruption caused by incorrect prediction-error signalling. I argue that such psychological benefits and adaptive features also have positive epistemic consequences. More precisely, delusions can be a means to restoring epistemic functionality in agents who are overwhelmed by hypersalient experiences in the prodromal stage of psychosis. The analysis leads to a more complex view of the epistemic status of delusions than is found in the contemporary philosophical literature and has some implications for clinical practice. 1 Introduction2 Types of Delusions3 What Is Wrong with Elaborated and Systematized Delusions?4 Finding Life Meaningful5 Learning Resumed6 Epistemic Innocence7 Epistemic Benefit8 No Alternatives9 Conclusions and Implications. (shrink)

Article copyright 2002. We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second (...) factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor. (shrink)

Cognitive neuropsychiatry (CN) is the explanation of psychiatric disorder by the methods of cognitive neuropsychology. Within CN there are, broadly speaking, two approaches to delusion. The first uses a one-stage model, in which delusions are explained as rationalizations of anomalous experiences via reasoning strategies that are not, in themselves, abnormal. Two-stage models invoke additional hypotheses about abnormalities of reasoning. In this paper, I examine what appears to be a very strong argument, developed within CN, in favor of a two-stage explanation (...) of the difference in content between the Capgras and Cotard delusions. That explanation treats them as alternative rationalizations of essentially the same phenomenology. I show, however, that once we distinguish the phenomenology (and the neuroetiology), a one-stage model is adequate. In the final section I make some more general remarks on the one- and two-stage models. (shrink)

"Psychiatry and Philosophy of Science" explores conceptual issues in psychiatry from the perspective of analytic philosophy of science. Through an examination of those features of psychiatry that distinguish it from other sciences - for example, its contested subject matter, its particular modes of explanation, its multiple different theoretical frameworks, and its research links with big business - Rachel Cooper explores some of the many conceptual, metaphysical and epistemological issues that arise in psychiatry. She shows how these pose interesting challenges for (...) the philosopher of science while also showing how ideas from the philosophy of science can help to solve conceptual problems within psychiatry. Cooper's discussion ranges over such topics as the nature of mental illnesses, the treatment decisions and diagnostic categories of psychiatry, the case-history as a form of explanation, how psychiatry might be value-laden, the claim that psychiatry is a multi-paradigm science, the distortion of psychiatric research by pharmaceutical industries, as well as engaging with the fundamental question whether the mind is reducible to something at the physical level. "Psychiatry and Philosophy of Science" demonstrates that cross-disciplinary contact between philosophy of science and psychiatry can be immensely productive for both subjects and it will be required reading for mental health professionals and philosophers alike. (shrink)

A new theory is taking hold in neuroscience. It is the theory that the brain is essentially a hypothesis-testing mechanism, one that attempts to minimise the error of its predictions about the sensory input it receives from the world. It is an attractive theory because powerful theoretical arguments support it, and yet it is at heart stunningly simple. Jakob Hohwy explains and explores this theory from the perspective of cognitive science and philosophy. The key argument throughout The Predictive Mind is (...) that the mechanism explains the rich, deep, and multifaceted character of our conscious perception. It also gives a unified account of how perception is sculpted by attention, and how it depends on action. The mind is revealed as having a fragile and indirect relation to the world. Though we are deeply in tune with the world we are also strangely distanced from it. (shrink)

An aberrant belief is extreme or unusual in nature. In the most serious cases these beliefs cause emotional distress in those who hold them, and typify the core symptoms of psychological disorders. Each of the chapters in this volume seeks to examine the role that biases in reasoning can play in the formation of aberrant beliefs. The chapters consider several conjectures about the role of reasoning in aberrant belief, including the role of the jumping to conclusion bias in delusional beliefs, (...) the probabilistic bias in paranormal beliefs, the role of danger confirming reasoning in phobias, and the controversial notion that people with schizophrenia do not succumb to specific forms of reasoning bias. There are also chapters evaluating different theoretical perspectives, and suggestions for future research. Aberrant Beliefs and Reasoning is the first volume presenting an overview of contemporary research in this growing subject area. It will be essential reading for academics and students in the fields of human reasoning, cognitive psychology and philosophy, and will also be of great interest to clinicians and psychiatrists. (shrink)