Dan Sperber

Groups do better at reasoning tasks than individuals, and, in some cases, do even better than any of their individual members. Here is an illustration. In the standard version of Wason selection task (Wason, 1966), the most commonly studied problem in the psychology of reasoning, only about 10% of participants give the correct solution, even though it can be arrived at by elementary deductive reasoning.1 Such poor performance begs for an explanation, and a great many have been offered. What makes the selection task relevant here is that the difference between individual and group performance is striking. Moshman & Geil for instance (1998, see also Maciejovsky & Budescu, 2007) had participants try and resolve the task either individually or in groups of five or six participants. While, unsurprisingly, only 9% of the participants working on their own found the correct solution, an astonishing 70% of the groups did. Moreover, when groups were formed with participants who had first tried to solve the task individually, 80% of the groups succeeded, including 30% of the groups in which none of the members had succeeded on his or her own. How are such differences between individual and group performance to be explained?

When is a conclusion worth deriving? We claim that a conclusion is worth deriving to the extent that it is relevant in the sense of relevance theory (Sperber & Wilson, 1995). To support this hypothesis, we experiment with ''indeterminate relational problems'' where we ask participants what, if anything, follows from premises such as A is taller than B, A is taller than C . With such problems, the indeterminate response that nothing follows is common, and we explain why. We distinguish several types of determinate conclusions and show that their rate is a function of their relevance. We argue that by appropriately changing the formulation of the premises, the relevance of determinate conclusions can be increased, and the rate of indeterminate responses thereby reduced. We contrast these relevance-based predictions with predictions based on linguistic congruence.

When people speak, their words never fully encode what they mean, and the context is always compatible with a variety of interpretations. How can comprehension ever be achieved? Wilson and Sperber argue that comprehension is an inference process guided by precise expectations of relevance. What are the relations between the linguistically encoded meanings studied in semantics and the thoughts that humans are capable of entertaining and conveying? How should we analyse literal meaning, approximations, metaphors and ironies? Is the ability to understand speakers' meanings rooted in a more general human ability to understand other minds? How do these abilities interact in evolution and in cognitive development? MEANING AND RELEVANCE sets out to answer these and other questions, enriching and updating relevance theory and exploring its implications for linguistics, philosophy, cognitive science and literary studies

This work examines how people interpret the sentential connective “or”, which can be viewed either inclusively (A or B or both) or exclusively (A or B but not both). Following up on prior work concerning quantifiers (Noveck, 2001; Noveck & Posada, 2003; Bott & Noveck, 2004) which shows that the common pragmatic interpretation of “some,” some but not all, is conveyed as part of an effortful step, we investigate how extra effort applied to disjunctive statements leads to a pragmatic interpretation of “or”, or but not both. Experiment 1 compelled participants to wait for three seconds before answering, hence giving them the opportunity to process the utterance more deeply. Experiments 2 and 3 emphasized “or”, either by visual means (“OR”) or by prosodic means (contrastive stress) as another way to encourage participants to apply more effort. Following a relevance-theoretic line of argument, we hypothesized that conditions encouraging more processing effort would give rise to more pragmatic inferences and hence to more exclusive interpretations of the disjunction. This prediction was confirmed in the three experiments.

Our main aim in this paper is to show that constructing an adequate theory of communication involves going beyond Grice’s notion of speaker’s meaning. After considering some of the difficulties raised by Grice’s three-clause definition of speaker’s meaning, we argue that the characterisation of ostensive communication introduced in relevance theory can provide a conceptually unified explanation of a much wider range of communicative acts than Grice was concerned with, including cases of both ‘showing that’ and ‘telling that’, and with both determinate and indeterminate import.

The idea that cultural evolution exhibits variation, competition, and inheritance and therefore can be studied by adjusting the Darwinian theory of evolution by natural selection is an attractive one. It has been argued by a number of authors (e.g., Campbell 1960; Monod 1970; Dawkins 1976; Cavalli-Sforza and Feldman 1981; Boyd and Richerson 1985; Durham 1991; Aunger 2002; Mesoudi et al. 2004) and pursued in a variety of ways, some (Dawkins and memeticists) staying close to the Darwinian model, others (e.g., Boyd, Richerson, and their collaborators) being more innovative. We agree that there are relevant analogies between biological and cultural evolution and, in particular, that cultural items do exhibit variation, competition, and cumulative modification. On the other hand, we believe that a proper understanding of the mechanisms of cultural propagation drawing on the work of cognitive and social scientists (see Sperber and Hirschfeld 1999 for a review) contradicts the idea that culture exhibits inheritance in the strict sense needed for the theory of evolution by natural selection to apply straightforwardly to it. If so, it will take more than adjusting the Darwinian model to be faithful to the Darwinian inspiration.

This the tenth volume in the Vancouver Studies in Cogntive Science series. It concerns metarepresentation: the construction and use of representations that represent other representations. Metarepresentations are ubiquitous among human beings, whenever we think or talk about mental states or linguistic acts, or theorize about the mind or language. It is crucial to the unconscious process we use to divine the mental states of others, and ultimately to any workable theory of the mind. This volume collects previously unpublished studies on the subject by an interdisciplinary group of contributors, including: Daniel Dennett, Alvin Goldman, Keith Lehrer, Leda Cosmides and John Tooby

Short abstract (98 words). Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given humans’ exceptional dependence on communication and vulnerability to misinformation. A wide range of evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis.