This book brings together an influential sequence of papers that argue for a radical re-conceptualisation of the psychology of inference, and of cognitive science more generally. The papers demonstrate that the thesis that logic provides the basis of human inference is central to much cognitive science, although the commitment to this view is often implicit. They then note that almost all human inference is uncertain, whereas logic is the calculus of certain inference. This mismatch means that logic is not the appropriate model for human thought. Oaksford and Chater's argument draws on research in computer science, artificial intelligence and philosophy of science, in addition to experimental psychology. The authors propose that probability theory, the calculus of uncertain inference, provides a more appropriate model for human thought. They show how a probabilistic account can provide detailed explanations of experimental data on Wason's selection task, which many have viewed as providing a paradigmatic demonstration of human irrationality. Oaksford and Chater show that people's behaviour appears irrational only from a logical point of view, whereas it is entirely rational from a probabilistic perspective. The shift to a probabilistic framework for human inference has significant implications for the psychology of reasoning, cognitive science more generally, and forour picture of ourselves as rational agents.

Setting forth the state of the art, leading researchers present a survey on the fast-developing field of Connectionist Psycholinguistics: using connectionist or "neural" networks, which are inspired by brain architecture, to model empirical data on human language processing. Connectionist psycholinguistics has already had a substantial impact on the study of a wide range of aspects of language processing, ranging from inflectional morphology, to word recognition, to parsing and language production. Christiansen and Chater begin with an extended tutorial overview of Connectionist Psycholinguistics which is followed by the latest research by leading figures in each area of research. The book also focuses on the implications and prospects for connectionist models of language, not just for psycholinguistics, but also for computational and linguistic perspectives on natural language. The interdisciplinary approach will be relevant for, and accessible to psychologists, cognitive scientists, linguists, philosophers, and researchers in artificial intelligence.

This book brings together an influential sequence of papers that argue for a radical re-conceptualisation of the psychology of inference, and of cognitive science more generally. The papers demonstrate that the thesis that logic provides the basis of human inference is central to much cognitive science, although the commitment to this view is often implicit. They then note that almost all human inference is uncertain, whereas logic is the calculus of certain inference. This mismatch means that logic is not the appropriate model for human thought.
Oaksford and Chater's argument draws on research in computer science, artificial intelligence and philosophy of science, in addition to experimental psychology. The authors propose that probability theory, the calculus of uncertain inference, provides a more appropriate model for human thought. They show how a probabilistic account can provide detailed explanations of experimental data on Wason's selection task, which many have viewed as providing a paradigmatic demonstration of human irrationality.
Oaksford and Chater show that people's behavior appears irrational only from a logical point of view, whereas it is entirely rational from a probabilistic perspective. The shift to a probabilistic framework for human inference has significant implications for the psychology of reasoning, cognitive science more generally, and for our picture of ourselves as rational agents.

The conditional, if...then, is probably the most important term in natural language and forms the core of systems of logic and mental representation. It occurs in all human languages and allows people to express their knowledge of the causal or law-like structure of the world and of others' behaviour, e.g., if you turn the key the car starts, if John walks the dog he stops for a pint of beer; to make promises, e.g., if you cook tonight, I'll wash up all week; to regulate behaviour, e.g., if you are drinking beer, you must be over 18 years of age; to suggest what would have happened had things been different, e.g., if the match had been dry it would have lit, among many other possible uses. The way in which the conditional is modelled also determines the core of most logical systems. Unsurprisingly, it is also the most researched expression in the psychology of human reasoning.
Cognition and Conditionals is the first volume for over 20 years (On Conditionals, 1986, CUP) that brings together recent developments in the cognitive science and psychology of conditional reasoning. Over the last 10 to 15 years, research on conditionals has come to dominate the psychology of reasoning providing a rich seam of results that have created new theoretical possibilities. This book shows how these developments have led researchers to view people's conditional reasoning behaviour more as succesful probabilistic reasoning rather than as errorful logical reasoning. It shows how the multifarious, and apparently competing, theoretical positions developed over the last 50 years in this area - mental logics, mental models, heuristic approaches, dual process theory, and probabilistic approaches-have responded to these insights. Its organisation reflects the view that an integrative approach is emerging that may need to exploit aspects of all these theoretical positions to explain the rich and complex phenomenon of reasoning with conditionals. It includes an introductory chapter relating the development of the psychology of reasoning to developments in the logic and semantics of the conditional. It also includes chapters by many of the leading figures in this field.
Cognition and Conditionals will be a valuable resource for cognitive scientists, psychologists and philosophers interested how people actually reason with conditionals.

Are people rational? This question was central to Greek thought; and has been at the heart of psychology and philosophy for millennia. This book provides a radical and controversial reappraisal of conventional wisdom in the psychology of reasoning, proposing that the Western conception of the mind as a logical system is flawed at the very outset. It argues that cognition should be understood in terms of probability theory, the calculus of uncertain reasoning, rather than in terms of logic, the calculus of certain reasoning.

A work that reveals the profound links between the evolution, acquisition, and processing of language, and proposes a new integrative framework for the language sciences. Language is a hallmark of the human species; the flexibility and unbounded expressivity of our linguistic abilities is unique in the biological world. In this book, Morten Christiansen and Nick Chater argue that to understand this astonishing phenomenon, we must consider how language is created: moment by moment, in the generation and understanding of individual utterances; year by year, as new language learners acquire language skills; and generation by generation, as languages change, split, and fuse through the processes of cultural evolution. Christiansen and Chater propose a revolutionary new framework for understanding the evolution, acquisition, and processing of language, offering an integrated theory of how language creation is intertwined across these multiple timescales. Christiansen and Chater argue that mainstream generative approaches to language do not provide compelling accounts of language evolution, acquisition, and processing. Their own account draws on important developments from across the language sciences, including statistical natural language processing, learnability theory, computational modeling, and psycholinguistic experiments with children and adults. Christiansen and Chater also consider some of the major implications of their theoretical approach for our understanding of how language works, offering alternative accounts of specific aspects of language, including the structure of the vocabulary, the importance of experience in language processing, and the nature of recursive linguistic structure.

Are people rational? This question was central to Greek thought; and has been at the heart of psychology, philosophy, rational choice in social sciences, and probabilistic approaches to artificial intelligence. This book provides a radical re-appraisal of conventional wisdom in the psychology of reasoning.
For almost two and a half thousand years, the Western conception of what it is to be a human being has been dominated by the idea that the mind is the seat of reason - humans are, almost by definition, the rational animal. From Aristotle to the present day, rationality has been explained by comparison to systems of logic, which distinguish valid (i.e., rationally justified) from invalid arguments. Within psychology and cognitive science, such a logicist conception of the mind was adopted wholeheartedly from Piaget onwards. Simultaneous with the construction of the logicist program in cognition, other researchers found that people appeared surprisingly and systematically illogical in some experiments. Proposals within the logicist paradigm suggested that these were mere performance errors, although in some reasoning tasks only as few as 5% of people's reasoning was logically correct.
In this book a more radical suggestion for explaining these puzzling aspects of human reasoning is put forward: the Western conception of the mind as a logical system is flawed at the very outset. The human mind is primarily concerned with practical action in the face of a profoundly complex and uncertain world. Oaksford and Chater argue that cognition should be understood in terms of probability theory, the calculus of uncertain reasoning, rather than in terms of logic, the calculus of certainreasoning. Thus, the logical mind should be replaced by the probabilistic mind - people may possess not logical rationality, but Bayesian rationality.

A radical reinterpretation of how your mind works - and why it could change your life 'An astonishing achievement. Nick Chater has blown my mind' Tim Harford 'A total assault on all lingering psychiatric and psychoanalytic notions of mental depths ... Light the touchpaper and stand well back' New Scientist We all like to think we have a hidden inner life. Most of us assume that our beliefs and desires arise from the murky depths of our minds, and, if only we could work out how to access this mysterious world, we could truly understand ourselves. For more than a century, psychologists and psychiatrists have struggled to discover what lies below our mental surface. In The Mind Is Flat, pre-eminent behavioural scientist Nick Chater reveals that this entire enterprise is utterly misguided. Drawing on startling new research in neuroscience, behavioural psychology and perception, he shows that we have no hidden depths to plumb, and unconscious thought is a myth. Instead, we generate our ideas, motives and thoughts in the moment. This revelation explains many of the quirks of human behaviour - for example why our supposedly firm political beliefs, personal preferences and even our romantic attractions are routinely proven to be inconsistent and changeable. As the reader discovers, through mind-bending visual examples and counterintuitive experiments, we are all characters of our own creation, constantly improvising our behaviour based on our past experiences. And, as Chater shows us, recognising this can be liberating.

The rational analysis method, first proposed by John R. Anderson, has been enormously influential in helping us understand high-level cognitive processes.
The Probabilistic Mind is a follow-up to the influential and highly cited 'Rational Models of Cognition' (OUP, 1998). It brings together developments in understanding how, and how far, high-level cognitive processes can be understood in rational terms, and particularly using probabilistic Bayesian methods. It synthesizes and evaluates the progress in the past decade, taking into account developments in Bayesian statistics, statistical analysis of the cognitive 'environment' and a variety of theoretical and experimental lines of research. The scope of the book is broad, covering important recent work in reasoning, decision making, categorization, and memory. Including chapters from many of the leading figures in this field,
The Probabilistic Mind will be valuable for psychologists and philosophers interested in cognition.

This interdisciplinary new work explores one of the central theoretical problems in linguistics: learnability. The authors, from different backgrounds--linguistics, philosophy, computer science, psychology and cognitive science-explore the idea that language acquisition proceeds through general purpose learning mechanisms, an approach that is broadly empiricist both methodologically and psychologically. For many years, the empiricist approach has been taken to be unfeasible on practical and theoretical grounds. In the book, the authors present a variety of precisely specified mathematical and computational results that show that empiricist approaches can form a viable solution to the problem of language acquisition. It assumes limited technical background and explains the fundamental principles of probability, grammatical description and learning theory in an accessible and non-technical way. Different chapters address the problem of language acquisition using different assumptions: looking at the methodology of linguistic analysis using simplicity based criteria, using computational experiments on real corpora, using theoretical analysis using probabilistic learning theory, and looking at the computational problems involved in learning richly structured grammars. Written by four researchers in the full range of relevant fields: linguistics (John Goldsmith), psychology (Nick Chater), computer science (Alex Clark), and cognitive science (Amy Perfors), the book sheds light on the central problems of learnability and language, and traces their implications for key questions of theoretical linguistics and the study of language acquisition.

Imitation is not the low-level, cognitively undemanding behavior it is often assumed to be, but rather--along with language and the ability to understand other minds--one of a trio of related capacities that are fundamental to human mentality. In these landmark volumes, leading researchers across a range of disciplines provide a state-of-the-art view of imitation, integrating the latest findings and theories with reviews of seminal work, and revealing why imitation is a topic of such intense current scientific interest. Perspectives are drawn from neuroscience and brain imaging, animal and developmental psychology, primatology, ethology, philosophy, anthropology, media studies, economics, sociology, education, and law. These volumes provide a resource that makes this research accessible across disciplines and clarifies its importance for the social sciences and philosophy as well as for the cognitive sciences. As a further aid to cross-fertilization, each volume includes extensive interdisciplinary commentary and discussion. The first volume considers possible mechanisms of imitation, including discussion of mirror systems, ideomotor and common coding theories, and the possibility of "shared circuits" for control, imitation, and simulation, and then takes up imitation in animals, with illuminating comparisons to human imitation. The second volume focuses first on the roles of imitation in human development and in learning to understand the minds of others, and then on the broader social and cultural roles and functions of imitation, including discussions of meme theory and cultural evolution, and of the pervasive imitative tendencies of normal adults and their relevance forunderstanding the effects of the media on human behavior.

Setting forth the state of the art, leading researchers present a survey on the fast-developing field of Connectionist Psycholinguistics: using connectionist or neural networks, which are inspired by brain architecture, to model empirical data on human language processing. Connectionist psycholinguistics has already had a substantial impact on the study of a wide range of aspects of language processing, ranging from inflectional morphology, to word recognition, to parsing and language production.

Christiansen and Chater begin with an extended tutorial overview of Connectionist Psycholinguistics which is followed by the latest research by leading figures in each area of research. The book also focuses on the implications and prospects for connectionist models of language, not just for psycholinguistics, but also for computational and linguistic perspectives on natural language. The interdisciplinary approach will be relevant for, and accessible to psychologists, cognitive scientists, linguists, philosophers, and researchers in artificial intelligence.