Integrating a decade-long program of empirical research with current cognitive theory, this book demonstrates that psychological research has profound implications for current debates about what it means to be rational. The author brings new evidence to bear on these issues by demonstrating that patterns of individual differences--largely ignored in disputes about human rationality--have strong implications for explanations of the gap between normative and descriptive models of human behavior. Separate chapters show how patterns of individual differences have implications for all of the major critiques of purported demonstrations of human irrationality in the heuristics and biases literature. In these critiques, it has been posited that experimenters have observed performance errors rather than systematically irrational responses; the tasks have required computational operations that exceed human cognitive capacity; experimenters have applied the wrong normative model to the task; and participants have misinterpreted the tasks. In a comprehensive set of studies, Stanovich demonstrates that gaps between normative and descriptive models of performance on some tasks can be accounted for by positing these alternative explanations, but that not all discrepancies from normative models can be so explained. Individual differences in rational thought can in part be predicted by psychological dispositions that are interpreted as characteristic biases in people's intentional-level psychologies. Presenting the most comprehensive examination of individual differences in the heuristics and biases literature that has yet been published, experiments and theoretical insights in this volume contextualize the heuristics and biases literature exemplified in the work of various investigators.

How to assess critical aspects of cognitive functioning that are not measured by IQ tests: rational thinking skills. Why are we surprised when smart people act foolishly? Smart people do foolish things all the time. Misjudgments and bad decisions by highly educated bankers and money managers, for example, brought us the financial crisis of 2008. Smart people do foolish things because intelligence is not the same as the capacity for rational thinking. The Rationality Quotient explains that these two traits, often (and incorrectly) thought of as one, refer to different cognitive functions. The standard IQ test, the authors argue, doesn't measure any of the broad components of rationality—adaptive responding, good judgment, and good decision making. The authors show that rational thinking, like intelligence, is a measurable cognitive competence. Drawing on theoretical work and empirical research from the last two decades, they present the first prototype for an assessment of rational thinking analogous to the IQ test: the CART (Comprehensive Assessment of Rational Thinking). The authors describe the theoretical underpinnings of the CART, distinguishing the algorithmic mind from the reflective mind. They discuss the logic of the tasks used to measure cognitive biases, and they develop a unique typology of thinking errors. The Rationality Quotient explains the components of rational thought assessed by the CART, including probabilistic and scientific reasoning; the avoidance of “miserly” information processing; and the knowledge structures needed for rational thinking. Finally, the authors discuss studies of the CART and the social and practical implications of such a test. An appendix offers sample items from the test.

Integrating a decade-long program of empirical research with current cognitive theory, this book demonstrates that psychological research has profound implications for current debates about what it means to be rational. The author brings new evidence to bear on these issues by demonstrating that patterns of individual differences--largely ignored in disputes about human rationality--have strong implications for explanations of the gap between normative and descriptive models of human behavior. Separate chapters show how patterns of individual differences have implications for all of the major critiques of purported demonstrations of human irrationality in the heuristics and biases literature. In these critiques, it has been posited that experimenters have observed performance errors rather than systematically irrational responses; the tasks have required computational operations that exceed human cognitive capacity; experimenters have applied the wrong normative model to the task; and participants have misinterpreted the tasks. In a comprehensive set of studies, Stanovich demonstrates that gaps between normative and descriptive models of performance on some tasks can be accounted for by positing these alternative explanations, but that not all discrepancies from normative models can be so explained. Individual differences in rational thought can in part be predicted by psychological dispositions that are interpreted as characteristic biases in people's intentional-level psychologies. Presenting the most comprehensive examination of individual differences in the heuristics and biases literature that has yet been published, experiments and theoretical insights in this volume contextualize the heuristics and biases literature exemplified in the work of various investigators.

A TIMES BOOK OF THE YEAR 2021 'Punchy, funny and invigorating ... Pinker is the high priest of rationalism' Sunday Times 'If you've ever considered taking drugs to make yourself smarter, read Rationality instead. It's cheaper, more entertaining, and more effective' Jonathan Haidt, author of The Righteous Mind In the twenty-first century, humanity is reaching new heights of scientific understanding - and at the same time appears to be losing its mind. How can a species that discovered vaccines for Covid-19 in less than a year produce so much fake news, quack cures and conspiracy theorizing? In Rationality, Pinker rejects the cynical cliché that humans are simply an irrational species - cavemen out of time fatally cursed with biases, fallacies and illusions. After all, we discovered the laws of nature, lengthened and enriched our lives and set the benchmarks for rationality itself. Instead, he explains, we think in ways that suit the low-tech contexts in which we spend most of our lives, but fail to take advantage of the powerful tools of reasoning we have built up over millennia: logic, critical thinking, probability, causal inference, and decision-making under uncertainty. These tools are not a standard part of our educational curricula, and have never been presented clearly and entertainingly in a single book - until now. Rationality matters. It leads to better choices in our lives and in the public sphere, and is the ultimate driver of social justice and moral progress. Brimming with insight and humour, Rationality will enlighten, inspire and empower. 'A terrific book, much-needed for our time' Peter Singer

The Importance of Being Rational systematically defends a novel reasons-based account of rationality. The book's central thesis is that what it is for one to be rational is to correctly respond to the normative reasons one possesses. Errol Lord defends novel views about what it is to possess reasons and what it is to correctly respond to reasons. He shows that these views not only help to support the book's main thesis, they also help to resolve several important problems that are independent of rationality. The account of possession provides novel contributions to debates about what determines what we ought to do, and the account of correctly responding to reasons provides novel contributions to debates about causal theories of reacting for reasons. After defending views about possession and correctly responding, Lord shows that the account of rationality can solve two difficult problems about rationality. The first is the New Evil Demon problem. The book argues that the account has the resources to show that internal duplicates necessarily have the same rational status. The second problem concerns the deontic significance of rationality. Recently it has been doubted whether we ought to be rational. The ultimate conclusion of the book is that the requirements of rationality are the requirements that we ultimately ought to comply with. If this is right, then rationality is of fundamental importance to our deliberative lives.

Existing only in manuscript since the 1940s but enjoying an underground reputation among friends and advocates, this primary document by one of the most original and influential of American poets and thinkers is now being published as Rational Meaning, Laura (Riding) Jackson's testament of the necessity of living for truth. Begun as a dictionary and thesaurus in the 1930s, the work developed into a fundamental reevaluation of language itself. Riding, in close collaboration with her husband, continued this monumental project over the succeeding decades, completing it after his death in 1968. At the core of Rational Meaning, which aims to restore the truth of language by arguing that meaning inheres in words, stands the idea that a total renovation of the knowledge of language is needed, not to develop mere verbal sophistication and respectability but fundamentally to reinvigorate the intellectual processes of consciousness. The book reveals the disastrous extent to which language has been "unlearned" and shows how it may be learned again. Rational Meaning will be essential reading, not only for students of literature but for radical-minded linguists and lexicographers unhappy with the orthodoxies current in their disciplines.

Moral systems, like normative systems more broadly, involve complex mental representations. Rational Rules proposes that moral learning can be understood in terms of general-purpose rational learning procedures. Nichols argues that statistical learning can help answer a wide range of questions about moral thought: Why do people think that rules apply to actions rather than consequences? Why do people expect new rules to be focused on actions rather than consequences? How do people come to believe a principle of liberty, according to which whatever is not expressly prohibited is permitted? How do people decide that some normative claims hold universally while others hold only relative to some group? The resulting account has both empiricist and rationalist features: since the learning procedures are domain-general, the result is an empiricist theory of a key part of moral development, and since the learning procedures are forms of rational inference, the account entails that crucial parts of our moral system enjoy rational credentials. Moral rules can also be rational in the sense that they can be effective for achieving our ends, given our ecological settings. Rational Rules argues that at least some central components of our moral systems are indeed ecologically rational: they are good at helping us attain common goals. Nichols argues that the account might be extended to capture moral motivation as a special case of a much more general phenomenon of normative motivation. On this view, a basic form of rule representation brings motivation along automatically, and so part of the explanation for why we follow moral rules is that we are built to follow rules quite generally.