This article described three heuristics that are employed in making judgements under uncertainty: representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and adjustment from an anchor, which is usually employed in numerical prediction when a relevant value (...) is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgements and decisions in situations of uncertainty. (shrink)

Past work has demonstrated that people’s moral judgments can influence their judgments in a number of domains that might seem to involve straightforward matters of fact, including judgments about freedom, causation, the doing/allowing distinction, and intentional action. The present studies explore whether the effect of morality in these four domains can be explained by changes in the relevance of alternative possibilities. More precisely, we propose that moral judgment influences the degree to which people regard certain alternative possibilities as relevant, which (...) in turn impacts intuitions about freedom, causation, doing/allowing, and intentional action. Employing the stimuli used in previous research, Studies 1a, 2a, 3a, and 4a show that the relevance of alternatives is influenced by moral judgments and mediates the impact of morality on non-moral judgments. Studies 1b, 2b, 3b, and 4b then provide direct empirical evidence for the link between the relevance of alternatives and judgments in these four domains by manipulating (rather than measuring) the relevance of alternative possibilities. Lastly, Study 5 demonstrates that the critical mechanism is not whether alternative possibilities are considered, but whether they are regarded as relevant. These studies support a unified framework for understanding the impact of morality across these very different kinds of judgments. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:TOWARD A GENERAL THEORY OF FICTION by James D. Parsons When nelson Goodman writes, "All fiction is literal, literary falsehood," he seems to be disregarding at least one noteworthy tradition.1 The tradition I have in mind includes works by Jeremy Bendiam, Hans Vaihinger, Tobias Dantzig, Wallace Stevens, and a host ofother writers in many fields who have been laboring for more man two centuries to clear the ground for (...) a general theory of fiction. Such a general dieory would, if its exponents are right about its relevemce, be situated at the very heart of die law, literature, religion, science, mathematics — in fact, of humem life itself. Fiction dien would be no neirrow litereiry falsehood, but a kind of pressure, eis Wedlace Stevens said, which die imagination exerts "against die pressure of reality," and which "helps us to live our lives,"2 or, in Hans Vaihingens metaphor, "a scaffolding afterwards to be demolished" 3 — that is, elfter it heis served its constructive purpose. A fiction is a vitally useful creation of die mind corresponding to nothing in the real world. Most people eire aware of some of these fictions, from the perfect geometric figures of Euclid to the black box of contemporary axiomatics. There are many odiers. The notion diat all human beings are equal before die law is a fiction that can serve opposing purposes: it can work as an instrument for securing greater justice in the courts and in society, or it can function as ceimouflage, helping to perpetuate em unjust legal system and em oppressive social order — emd probably in any actual situation it serves both purposes at once. In die science of mechanics the idea of a pure vacuum, in which moving objects meet with no resistance, was for some centuries a useful fiction diat made possible the exact mathematiced analysis of motion in memy forms — another useful fiction. The notion of normality in psychology — mat diere is a universal standard of reference for human behavior — is stdl utilized by clinical and laboratory workers in the field, in spite of the metssive sociological emd ethnographic criticisms that have been leveled against it. In science generally, the idea that 92 James D. Parsons93 diere is a community of experts who by dieir combined influence decide what the trudi is in every field is a fiction diat seems to have come to the end of its usefulness, diough some philosophers have written about it as if it were a reality and not a fiction at edl. The fictions I have cited so far are none of them literary, nor être diey fedse in the ordinetry meaning of the word. They are simply not true; they describe nothing mat exists, except in die mind, emd cem be considered false only if one forgets what they eire emd tries, illegitimately, to apply tests of trudi to them in a direct way. Among the fictions mat might be called literary are the fictions derived from mydis. Now, a myth is a story told in answer to a question or a series of questions that has never been asked, eidier about the real world or (most likely) about the perennial performance of a ritual. The mydi is designed to forestall the questioning, because the questions that might be raised would be too embarrassing or because questions about some aspects of reality ceuinot be formulated without distorting our relation to them. These are the aspects of reedity that can be viewed only out of die corner of the eye, that disappear when we focus our gaze upon diem, and mat can be identified only indirectly.4 The more explicitly fictional devices, too, of poetry, drama, and the novel develop out of the attempt to achieve some sort of cognizeuice of the seune aspects of reality that are related in mydis. I do not meetn to imply that literature, of which mydi is a part, is concerned only with such disconcerting or evanescent aspects of reality. Literature, like all the great realms of culture, is concerned with the whole of reality. It has to be, omerwise its more passionate, its more ediereed concerns would have no lodging place, no environment in which to maintain... (shrink)

The mesostriatal dopamine system is prominently implicated in model-free reinforcement learning, with fMRI BOLD signals in ventral striatum notably covarying with model-free prediction errors. However, latent learning and devaluation studies show that behavior also shows hallmarks of model-based planning, and the interaction between model-based and model-free values, prediction errors, and preferences is underexplored. We designed a multistep decision task in which model-based and model-free influences on human choice behavior could be distinguished. By showing that choices reflected both influences we could (...) then test the purity of the ventral striatal BOLD signal as a model-free report. Contrary to expectations, the signal reflected both model-free and model-based predictions in proportions matching those that best explained choice behavior. These results challenge the notion of a separate model-free learner and suggest a more integrated computational architecture for high-level human decision-making. (shrink)