James Hampton

The principle of compositionality is a statement about the semantics of expressions. It can also be framed slightly differently so that it becomes a principle about the content of complex concepts. This article explains this principle, and the reasons for deviating from it. It will review the psychological research on typicality effects and non-logical reasoning which suggest that explanations can be given for significant phenomena if concepts are understood as prototypes. The evidence suggests that the combination of prototypes follows a principle corresponding to something like PC' rather than PC. PC' states that the content of a complex concept is completely determined by the contents of its parts and their mode of combination, together with general knowledge. A prototype representation of the conjunctive concept is formed by aggregating one feature with another. Any instance is then judged to belong in the conjunction on the basis of its overall similarity to this composite representation.

By highlighting relations between experimental and theoretical work, this volume explores new ways of addressing one of the central challenges in the study of language and cognition. The articles bring together work by leading scholars and younger researchers in psychology, linguistics and philosophy. An introductory chapter lays out the background on concept composition, a problem that is stimulating much new research in cognitive science. Researchers in this interdisciplinary domain aim to explain how meanings of complex expressions are derived from simple lexical concepts and to show how these meanings connect to concept representations. Traditionally, much of the work on concept composition has been carried out within separate disciplines, where cognitive psychologists have concentrated on concept representations, and linguists and philosophers have focused on the meaning and use of logical operators. This volume demonstrates an important change in this situation, where convergence points between these three disciplines in cognitive science are emerging and are leading to new findings and theoretical insights. This book is open access under a CC BY license.

ABSTRACTRecent research on moral dynamics shows that an individual's ethical mind-set moderates the impact of an initial ethical or unethical act on the likelihood of behaving ethically on a subsequent occasion. More specifically, an outcome-based mind-set facilitates Moral Balancing, whereas a rule-based mind-set facilitates Moral Consistency. The objective was to look at the evolution of moral choice across a series of scenarios, that is, to explore if these moral patterns are maintained over time. The results of three studies showed that Moral Balancing is not..

A recent study has established that thinkers reliably engage in epistemic appraisals of concepts of natural categories. Here, five studies are reported which investigated the effects of different manipulations of category learning context on appraisal of the concepts learnt. It was predicted that dimensions of concept appraisal could be affected by manipulating either procedural factors or declarative factors. While known effects of these manipulations on metacognitive judgements such as category learning judgements and confidence at test were replicated, procedural factors had no reliable effects on the dimensions of concept appraisal. Effects of declarative manipulations on some forms of concept appraisal were observed.

This paper reports the first empirical investigation of the hypothesis that epistemic appraisals form part of the structure of concepts. To date, studies of concepts have focused on the way concepts encode properties of objects and the way those features are used in categorization and in other cognitive tasks. Philosophical considerations show the importance of also considering how a thinker assesses the epistemic value of beliefs and other cognitive resources and, in particular, concepts. We demonstrate that there are multiple, reliably judged, dimensions of epistemic appraisal of concepts. Four of these dimensions are accounted for by a common underlying factor capturing how well people believe they understand a concept. Further studies show how dimensions of concept appraisal relate to other aspects of concepts. First, they relate directly to the hierarchical organization of concepts, reflecting the increase in specificity from superordinate to basic and subordinate levels. Second, they predict inductive choices in category-based induction. Our results suggest that epistemic appraisals of concepts form a psychologically important yet previously overlooked aspect of the structure of concepts. These findings will be important in understanding why individuals sometimes abandon and replace certain concepts; why social groups do so, for example, during a “scientific revolution”; and how we can facilitate such changes when we engage in deliberate “conceptual engineering” for epistemic, social, and political purposes.

If people believe that some property is true of all members of a class such as sofas, then they should also believe that the same property is true of all members of a conjunctively defined subset of that class such as uncomfortable handmade sofas. A series of experiments demonstrated a failure to observe this constraint, leading to what is termed the inverse conjunction fallacy. Not only did people often express a belief in the more general statement but not in the more specific, but also when they accepted both beliefs, they were inclined to give greater confidence to the more general. It is argued that this effect underlies a number of other demonstrations of fallacious reasoning, particularly in category-based induction. Alternative accounts of the phenomenon are evaluated, and it is concluded that the effect is best interpreted in terms of intensional reasoning [Tversky, A., & Kahneman, D.. Extensional versus intuitive reasoning: the conjunction fallacy in probability judgment. Psychological Review, 90, 293-315.]

Within-category induction is the projection of a generic property from a class to a subtype of that class. The modifier effect refers to the discovery reported by Connolly et al., that the subtype statement tends to be judged less likely to be true than the original unmodified sentence. The effect was replicated and shown to be moderated by the typicality of the modifier. Likelihood judgements were also found to correlate between modified and unmodified versions of sentences. Experiment 2 elicited justifications, which suggested three types of reason for the effect-pragmatics, knowledge-based reasoning, and uncertainty about attribute inheritance. It is argued that the results provide clear evidence for the default inheritance of prototypical attributes in modified concepts, although a full account of the effect remains to be given

The modifier effect is the reduction in perceived likelihood of a generic property sentence, when the head noun is modified. We investigated the prediction that the modifier effect would be stronger for mutable than for central properties, without finding evidence for this predicted interaction over the course of five experiments. However Experiment 6, which provided a brief context for the modified concepts to lend them greater credibility, did reveal the predicted interaction. It is argued that the modifier effect arises primarily from a general lack of confidence in generic statements about the typical properties of unfamiliar concepts. Neither prototype nor classical models of concept combination receive support from the phenomenon. 2010 Elsevier Inc. All rights reserved

This paper addresses theoretical problems arising from the vagueness of language terms, and intuitions of the vagueness of the concepts to which they refer. It is argued that the central intuitions of prototype theory are sufficient to account for both typicality phenomena and psychological intuitions about degrees of membership in vaguely defined classes. The first section explains the importance of the relation between degrees of membership and typicality (or goodness of example) in conceptual categorization. The second and third section address arguments advanced by Osherson and Smith (1997), and Kamp and Partee (1995), that the two notions of degree of membership and typicality must relate to fundamentally different aspects of conceptual representations. A version of prototype theory—the Threshold Model—is proposed to counter these arguments and three possible solutions to the problems of logical selfcontradiction and tautology for vague categorizations are outlined. In the final section graded membership is related to the social construction of conceptual boundaries maintained through language use.