Dan Sperber

Henrich and Boyd (2002) were the first to propose a formal model of the role of attraction in cultural evolution. They came to the surprising conclusion that, when both attraction and selection are at work, final outcomes are determined by selection alone. This result is based on a deterministic view of cultural attraction, different from the probabilistic view introduced in Sperber (1996). We defend this probabilistic view, show how to model it, and argue that, when both attraction and selection are at work, both affect final outcomes.

Someone asked ‘What time is it?’ when her watch reads 3:08 is likely to answer ‘It is 3:10.’ We argue that a fundamental factor that explains such rounding is a psychological disposition to give an answer that, while not necessarily strictly truthful or accurate, is an optimally relevant one (in the sense of relevance theory) i.e. an answer from which hearers can derive the consequences they care about with minimal effort. A rounded answer is easier to process and may carry the same consequences as one that is accurate to the minute. Hence rounding is often a way of optimising relevance. Three simple experiments give support and greater precision to the view that relevance is more important than strict truthfulness in verbal communication.

Social learning mechanisms are usually assumed to explain both the spread and the persistence of cultural behaviour. In a recent article, we showed that the fidelity of social learning commonly found in transmission chain experiments is not high enough to explain cultural stability. Here we want to both enrich and qualify this conclusion by looking at the case of song transmission in song birds, which can be faithful to the point of being true replication. We argue that this high fidelity results from natural selection pressure on cognitive mechanisms. This observation strengthens our main argument. Social learning mechanisms are unlikely to be faithful enough to explain cultural stability because they are generally selected not for high fidelity but for generalisation and adjustment to the individual’s needs, capacities and situation

In two experiments, we investigated whether 13-month-old infants expect agents to behave in a way consistent with information to which they have been exposed. Infants watched animations in which an animal was either provided information or prevented from gathering information about the actual location of an object. The animal then searched successfully or failed to retrieve it. Infants’ looking times suggest that they expected searches to be effective when—and only when—the agent had had access to the relevant information. This result supports the view that infants’ possess an incipient metarepresentational ability that permits them to attribute beliefs to agents. We discuss the viability of more conservative explanations and the relationship between this early ability and later forms of ‘theory of mind’ that appear only after children have become experienced verbal communicators.

How are non-declarative sentences understood? How do they differ semantically from their declarative counterparts? Answers to these questions once made direct appeal to the notion of illocutionary force. When they proved unsatisfactory, the fault was diagnosed as a failure to distinguish properly between mood and force. For some years now, efforts have been under way to develop a satisfactory account of the semantics of mood. In this paper, we consider the current achievements and future prospects of the mood-based semantic programme.

Experimental evidence on reasoning and decision making has been used to argue both that human rationality is adequate and that it is defective. The idea that reasoning involves not one but two mental systems (see Evans and Over, 1996; Sloman, 1996; Stanovich, 2004 for reasoning, and Kahneman and Frederick, 2005 for decision making) makes better sense of this evidence. ‘System 1’ reasoning is fast, automatic, and mostly unconscious; it relies on ‘fast and frugal’ heuristics (to use Gigerenzer’s expression (Gigerenzer et al., 1999)) offering seemingly effortless conclusions that are generally appropriate in most settings, but may be faulty, for instance in experimental situations devised to test the limits of human reasoning abilities. ‘System 2’ reasoning is slow, consciously controlled and effortful, but makes it possible to follow normative rules and to overcome the shortcomings of system 1 (Evans and Over, 1996). The occurrence of both sound and unsound inferences in reasoning experiments and more generally in everyday human thinking can be explained by the roles played by these two kinds of processes. Depending on the problem, the context, and the person (the ability for system 2 reasoning is usually seen as varying widely between individuals, see Stanovich and West (2000)) either system 1 or system 2 reasoning is more likely to be activated, with different consequences for people’s ability to reach the normatively correct solution (Evans, 2006). The two systems can even compete: system 1 suggests an intuitively appealing response while system 2 tries to inhibit this response and to impose its own norm-guided one. Much evidence has accumulated in favour of such a dual view of reasoning (Evans, 2003, in press; for arguments against, see Osman, 2004). There is, however, some vagueness in the way the two systems are characterized. Instead of a principled distinction, we are presented with a bundle of contrasting features—slow/fast, automatic/controlled, explicit/implicit, associationist/rule based, modular/central— which, depending on the specific dual process theory, are attributed more or less exclusively to one of the two systems..

Members of a human group are bound with one another by multiple flows of information. (Here we use “information” in a broad sense that includes not only the content of people’s knowledge, but also that of their beliefs, assumptions, fictions, rules, norms, skills, maps, images, and so on.) This information is materially realized in the mental representations of the people, and in their public productions, that is, their cognitively guided behaviors and the enduring material traces of these behaviors. Mentally represented information is transmitted from individuals to individuals through public productions. Public representations such as speech, gestures, writing, or pictures are a special type of public productions, the function of which is to communicate a content. Public representations play a major role in information transmission. Much information, however, is communicated implicitly, that is, without being publicly represented. Information can also be transmitted without being properly speaking communicated, not even implicitly, as when one individual acquires a skill by observing and imitating the behavior of others. Most information transmitted among humans is about local and transient circumstances, and is not transmitted beyond these. Some information of more general relevance, however, is repeatedly transmitted, and propagates throughout the group. Talk of “culture” (whatever the preferred definition or theory of culture) is about this widely distributed information and about its material realizations inside people’s mind and in their common environment (see Sperber 1996). One can study cultural phenomena in two main ways. One can interpret them, that is, try and make their contents intelligible to people of another culture, or more intelligible to members of the culture in which these phenomena occurs, as do anthropologists and historians. One may also try and explain causally how these cultural phenomena emerge, stabilize and evolve..

In Relevance: Communication and Cognition, we outline a new approach to the study of human communication, one based on a general view of human cognition. Attention and thought processes, we argue, automatically turn toward information that seems relevant: that is, capable of yielding cognitive effects – the more, and the more economically, the greater the relevance. We analyse both the nature ofcognitive effects and the inferential processes by which they are derived. Communication can be achieved by two different means: by encoding and decoding messages or by providing evidence for an intended inference about the communicator's informative intention. Verbal communication, we argue, exploits both types of process. The linguistic meaning of an utterance, recovered by specialised decoding processes, serves as the input to unspecialised central inferential processes by which the speaker's intentions are recognised. Fundamental to our account of inferential communication is the fact that to communicate is to claimsomeone's attention, and hence to imply that the information communicated is relevant. We call this idea, that communicated information comes with a guarantee of relevance, the principle of relevance. We show that every utterance has at most a single interpretation consistent with the principle of relevance, which is thus enough on its own to account for the interaction of linguistic meaning with contextual factors in disambiguation, reference assignment, the recovery of implicatures, the interpretation ofmetaphor and irony, the recovery of illocutionary force, and other linguistically underdetermined aspects of utterance interpretation.

There is a conventional discourse in favor of interdisciplinary research. At the same time there is much indifference or even disregard for such research and there are important institutional obstacles to its development. This first contribution to a virtual seminar aims at feeding reflexion on the conditions in which this research is either truly beneficial, even necessary, or is of little value. Favorable conditions for interdisciplinary research have a history, linked to that of scientific disciplines and their institutions. Is this history in the process of taking a new turn with the development of new forms of scientific communication through the Internet? I draw on my experience in the social and the cognitive sciences to reflect on the strength and weaknesses of interdisciplinary research and on its future.

Although a few pioneers in psycholinguistics had, for more than twenty years, approached various pragmatic issues experimentally, it is only in the past few years that investigators have begun employing the experimental method in testing pragmatic hypotheses. We see this emergence of a proper experimental pragmatics as an important advance with a great potential for further development. In this chapter we want to illustrate what can be done with experimental approaches to pragmatic issues by presenting one case, that of so-called ‘scalar inferences’, where the experimental method has helped sharpen a theoretical debate and has provided uniquely relevant evidence. We will focus on work done by the first author and his collaborators or work closely related to theirs, but other authors have also made important contributions to the topic

We argue that there is a continuum of cases without any demarcation between more individual and more cultural information, and that therefore “culture” should be viewed as a property that human mental representations and practices exhibit to a varying degree rather than as a type or a subclass of these representations and practices (or of “information”). We discuss the relative role of preservative and constructive processes in transmission. We suggest a revision of Richerson and Boyd’s classification of the forces of cultural evloution.

This chapter determines a major empirical hurdle for any future discipline of memetics. It mainly shows that one can find very similar copies of some cultural item, link these copies through a causal chain of events which faithfully reproduced those items, and nevertheless not have an example of memetic inheritance. In addition, the stability of cultural patterns is proof that fidelity in copying is high despite individual variations. It is also believed that what is offered as an explanation is precisely what needs to be explained; what is offered as a solution is in fact the very problem to be solved. Moreover, the issue is whether the relative stability observed in cultural transmission is proof of replication. The example of the acquisition of language is briefly addressed. The Darwinian model of selection is informative, and in various ways, for thinking about culture. Imitation is of course well worth investigating. On the other hand, the grand project of memetics is misled.