Dan Sperber

Humans have two kinds of beliefs, intuitive beliefs and reflective beliefs. Intuitive beliefs are a fundamental category of cognition, defined in the architecture of the mind. They are formulated in an intuitive mental lexicon. Humans are also capable of entertaining an indefinite variety of higher‐order or‘reflective’propositional attitudes, many of which are of a credat sort. Reasons to hold reflective beliefs are provided by other beliefs that describe the source of the reflective belief as reliable, or that provide an explicit argument in favour of the reflective belief. The mental lexicon of reflective beliefs includes not only intuitive, but also reflective concepts.

This is the text of the Radcliffe-Brown Lecture in Social Anthopology 1999 (To appear in the Proceedings of the British Academy). In it, I argue that to approach society and culture in a naturalistic way, the domain of the social sciences must be reconceptualised by recognising only entities and processes of which we have a naturalistic understanding. These are mental representations and public productions, the processes that causally link them, the causal chains that bond these links, and the complex webs of such causal chains that criss-cross human populations over time and space. Such causal chains may distribute and stabilise representations and productions throughout a human population, thereby generating culture. The lecture introduces several conceptual tools useful for such a naturalistic approach, and illustrates their use with the case study of ritual activity in a Southern Ethiopian household.

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 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

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.

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.