Joint action is central to countless aspects of human life. Here I examine the roots of joint action in infancy. First, I provide evidence that—contrary to popular belief—1‐year‐old infants do have the social‐cognitive prerequisites needed to participate in joint action, even in a relatively strict sense: they can read others’ goals and intentions, they have some basic understanding of common knowledge, and they have the ability and motivation to help others achieve their goals. Then I review some evidence of infants’ (...) and young children’s active participation in different types of joint action, from prelinguistic communication to more instrumental collaborations with others, with a particular focus on whether young children show evidence of an understanding of the commitments and obligations entailed in joint action. I conclude that the uniquely human ability and motivation to participate in joint action is already seen in infants by 1 year of age. (shrink)

The paper describes a system for dealing with nestings of belief in terms of the mechanism of computational environment. A method is offered for computing the beliefs of A about B (and so on) in terms of the systems existing knowledge structures about A and B separately. A proposal for belief percolation is put forward: percolation being a side effect of the process of the computation of nested beliefs, but one which could explain the acquisition of unsupported beliefs. It is (...) argued that the mechanism proposed is compatible with a general least effort hypothesis concerning human mental functioning. (shrink)

Traditional definitions of common ground in terms of iterative de re attitudes do not apply to conversations where at least one conversational participant is not acquainted with the other(s). I propose and compare two potential refinements of traditional definitions based on Abelard’s distinction between generality in sensu composito and in sensu diviso.

Inspired by early proposals in philosophy, dominant accounts of language posit a central role for mutual knowledge, either encoded directly in common ground, or approximated through other cognitive mechanisms. Using existing empirical evidence from language and memory, we challenge this tradition, arguing that mutual knowledge captures only a subset of the mental states needed to support communication. In a novel theoretical proposal, we argue for a cognitive architecture that includes separate, distinct representations of the self and other, and a cognitive (...) process that compares these representations continuously during conversation, outputting both similarities and differences in perspective. Our theory accounts for existing data, interfaces with findings from other cognitive domains, and makes novel predictions about the role of perspective in language use. We term this new account the Multiple Perspectives Theory of mental states in communication. (shrink)

I argue that semantics is the study of the proprietary database of a centrally inaccessible and informationally encapsulated input–output system. This system’s role is to encode and decode partial and defeasible evidence of what speakers are saying. Since information about nonlinguistic context is therefore outside the purview of semantic processing, a sentence’s semantic value is not its content but a partial and defeasible constraint on what it can be used to say. I show how to translate this thesis into a (...) detailed compositional-semantic theory based on the influential framework of Heim and Kratzer. This approach situates semantics within an independently motivated account of human cognitive architecture and reveals the semantics–pragmatics interface to be grounded in the underlying interface between modular and central systems. (shrink)

Clark highlights a neglected issue in research on language use: the process by which speakers and addressees anchor utterances with respect to individual entities in their common ground. In his review, he identifies the challenges linked to investigations of anchoring, but also displays the pitfalls of evading it.

Perspective taking is a critical yet tangled construct that is used to describe a range of psychological processes and that is applied interchangeably with related constructs. The resulting ambiguity is particularly vexing in science education, where although perspective taking is recognized as critical to informed citizens’ ability to negotiate scientifically related societal issues, or socioscientific issues via socioscientific reasoning, the precise nature of perspective taking remains elusive. To operationalize perspective taking, a theoretical conceptual analysis was employed and used to position (...) perspective taking within the context of SSR. The resulting, more precise construct identified as socioscientific perspective taking requires engagement with others or their circumstances, an etic/emic shift in one’s viewpoint, and a moral context guided by conscience. (shrink)

The coordinated attack scenario and the electronic mail game are two paradoxes of common knowledge. In simple mathematical models of these scenarios, the agents represented by the models can coordinate only if they have common knowledge that they will. As a result, the models predict that the agents will not coordinate in situations where it would be rational to coordinate. I argue that we should resolve this conflict between the models and facts about what it would be rational to do (...) by rejecting common knowledge assumptions implicit in the models. I focus on the assumption that the agents have common knowledge that they are rational, and provide models to show that denying this assumption suffices for a resolution of the paradoxes. I describe how my resolution of the paradoxes fits into a general story about the relationship between rationality in situations involving a single agent and rationality in situations involving many agents. (shrink)

During dialog, references are presented, accepted, and potentially reused. Two experiments were conducted to examine reuse in a naturalistic setting. In Experiment 1, where the participants interacted face to face, self-presented references and references accepted through verbatim repetition were reused more. Such biases persisted after the end of the interaction. In Experiment 2, where the participants interacted over the phone, reference reuse mainly depended on whether the participant could see the landmarks being referred to, although this bias seemed to be (...) only transient. Consistent with the memory-based approach to dialog, these results shed light on how differences in accessibility in memory affect the unfolding of the interaction. (shrink)

According to one view of linguistic information, a speaker can convey contextually new information in one of two ways: by asserting the content as new information; or by presupposing the content as given information which would then have to be accommodated. This distinction predicts that it is conversationally more appropriate to assert implausible information rather than presuppose it. A second view rejects the assumption that presuppositions are accommodated; instead, presuppositions are assimilated into asserted content and both are correspondingly open to (...) challenge. Under this view, we should not expect to find a difference in conversational appropriateness between asserting implausible information and presupposing it. To distinguish between these two views of linguistic information, we performed two self-paced reading experiments with an on-line stops-making-sense judgment. The results of the two experiments—using the presupposition triggers the and too—show that accommodation is inappropriate relative to non-presuppositional controls when the presupposed information is implausible but not when it is plausible. These results provide support for the first view of linguistic information: the contrast in implausible contexts can only be explained if there is a presupposition-assertion distinction and accommodation is a mechanism dedicated to reasoning about presuppositions. (shrink)

Anecdotal evidence suggests that participants in conversation can sometimes act as a coalition. This implies a level of conversational organization in which groups of individuals form a coherent unit. This paper investigates the implications of this phenomenon for psycholinguistic and semantic models of shared context in dialog. We present a corpus study of multiparty dialog which shows that, in certain circumstances, people with different levels of overt involvement in a conversation, that is, one responding and one not, can nonetheless access (...) the same shared context. We argue that contemporary models of shared context need to be adapted to capture this situation. To address this, we propose “grounding by proxy,” in which one person can respond on behalf of another, as a simple mechanism by which shared context can accumulate for a coalition as a whole. We explore this hypothesis experimentally by investigating how people in a task-oriented coalition respond when their shared context appears to be weakened. The results provide evidence that, by default, coalition members act on each other's behalf, and when this fails they work to compensate. We conclude that this points to the need for a new concept of collective grounding acts and a corresponding concept of collective contexts in psycholinguistic and semantic models of dialog. (shrink)

Evidence suggests that speakers can take account of the addressee's needs when referring. However, what representations drive the speaker's audience design has been less clear. This study aims to go beyond previous studies by investigating the interplay between the visual and linguistic context during audience design. Speakers repeated subordinate descriptions given in the prior linguistic context less and used basic-level descriptions more when the addressee did not hear the linguistic context than when s/he did. But crucially, this effect happened only (...) when the referent lacked the visual attributes associated with the expressions, so there was no other contextual cue available for the identification of the referent. This suggests that speakers flexibly use different contextual cues to help their addressee map the referring expression onto the intended referent. In addition, speakers used fewer pronouns when the addressee did not hear the linguistic antecedent than when s/he did. This suggests that although speakers may be egocentric during anaphoric reference, they can cooperatively avoid pronouns when the linguistic antecedents were not shared with their addressee during initial reference. (shrink)

For people to contribute to discourse, they must do more than utter the right sentence at the right time. The basic requirement is that they add to their common ground in an orderly way. To do this, we argue, they try to establish for each utterance the mutual belief that the addressees have understood what the speaker meant well enough for current purposes. This is accomplished by the collective actions of the current contributor and his or her partners, and these (...) result in units of conversation called contributions. We present a model of contributions and show how it accounts for a variety of features of everyday conversations. (shrink)

In a collaborative work situation at a distance, the use of avatars to represent collaborators reduces collaborative effort. Also, animated avatars can help distant users to ground their relationship and facilitate their interaction because they materialise visual clues for the distant collaborators and their current activity. To check the validity of these hypotheses we set up an experiment based on the use of a collaborative virtual environment (CVE) synchronised for collective medical decision-making. Several teams of practitioners from different disciplines will (...) be required to deal with liver tumours displayed in Argonaute 3D. In this paper, we provide some evidence from existing studies for the hypotheses and select several measures to estimate the grounding process in CVEs. Next, we briefly describe the setup used to collect observable data with Argonaute 3D and we summarise first observations acquired with practitioners. (shrink)

Over the last three decades, joint action has received various definitions, which for all their differences share many features. However, they cannot fit some perplexing cases of weak joint action, such as demonstrations, where agents rely on distinct epistemic sources, and as a result, have no first-hand knowledge about each other. I argue that one major reason why the definition of such collective actions is akin to the classical ones is that it crucially relies on the concept of common knowledge. (...) To this end, I first argue for the necessity of common knowledge for joint action in general due to the increased reliability of success it entails. I then defend the relevance of common knowledge against several criticisms, point at an adequate weakening, and discuss alternative approaches. Although structurally weaker, the common knowledge has a richer content in weak joint actions. As a result, even if the links between individuals are seriously stretched, much is still shared among them. Weak joint actions still require considerable cognitive abilities indeed. (shrink)

We report two experiments that investigated the widely held assumption that speakers use the addressee’s discourse model when choosing referring expressions (e.g., Ariel, 1990; Chafe, 1994; Givón, 1983; Prince, 1985), by manipulating whether the addressee could hear the immediately preceding linguistic context. Experiment 1 showed that speakers increased pronoun use (and decreased noun phrase use) when the referent was mentioned in the immediately preceding sentence compared to when it was not, even though the addressee did not hear the preceding sentence, (...) indicating that speakers used their own, privileged discourse model when choosing referring expressions. The same pattern of results was found in Experiment 2. Speakers produced more pronouns when the immediately preceding sentence mentioned the referent than when it mentioned a referential competitor, regardless of whether the sentence was shared with their addressee. Thus, we conclude that choice of referring expression is determined by the referent’s accessibility in the speaker’s own discourse model rather than the addressee’s. (shrink)

The notion of common ground is important for the production of referring expressions: In order for a referring expression to be felicitous, it has to be based on shared information. But determining what information is shared and what information is privileged may require gathering information from multiple sources, and constantly coordinating and updating them, which might be computationally too intensive to affect the earliest moments of production. Previous work has found that speakers produce overinformative referring expressions, which include privileged names, (...) violating Grice’s Maxims, and concluded that this is because they do not mark the distinction between shared and privileged information. We demonstrate that speakers are in fact quite effective in marking this distinction in the form of their utterances. Nonetheless, under certain circumstances, speakers choose to overspecify privileged names. (shrink)

This essay presents a philosophical and computational theory of the representation of de re, de dicto, nested, and quasi-indexical belief reports expressed in natural language. The propositional Semantic Network Processing System (SNePS) is used for representing and reasoning about these reports. In particular, quasi-indicators (indexical expressions occurring in intentional contexts and representing uses of indicators by another speaker) pose problems for natural-language representation and reasoning systems, because--unlike pure indicators--they cannot be replaced by coreferential NPs without changing the meaning of the (...) embedding sentence. Therefore, the referent of the quasi-indicator must be represented in such a way that no invalid coreferential claims are entailed. The importance of quasi-indicators is discussed, and it is shown that all four of the above categories of belief reports can be handled by a single representational technique using belief spaces containing intensional entities. Inference rules and belief-revision techniques for the system are also examined. (shrink)

What role do speakers'/authors’ communicative intentions play in language interpretation? Cognitive scientists generally assume that listeners'/readers’ recognitions of speakers'/authors’ intentions is a crucial aspect of utterance interpretation. Various philosophers, literary theorists and anthropologists criticize this intentional view and assert that speakers'/authors’ intentions do not provide either the starting point for linguistic interpretation or constrain how texts should be understood. Until now, cognitive scientists have not seriously responded to the current challenges regarding intentions in communication. My purpose in this article is (...) to provide just such a response. I briefly describe some of the empirical evidence in cognitive science on the importance of intentions in communication. I then discuss some of the criticisms of the intentional view that have arisen in the humanities and social sciences. Following this, I offer a partial resolution to the intentionalist controversy that recognizes the differing views on the idea of linguistic interpretation. I specifically suggest a way of thinking about linguistic interpretation in terms of the time‐course of understanding that provides a metric for evaluating the role of intentions in communication. This time‐course perspective on linguistic understanding provides for the plurality of ideas that now exist both in cognitive science and in postmodern philosophical thought. (shrink)

Defined and formalized several decades ago, widely used in philosophy and game theory, the concept of common knowledge is still considered as problematic, although not always for the right reasons. I suggest that the epistemic status of a group of human agents in a state of common knowledge has not been thoroughly analyzed. In particular, every existing account of common knowledge, whether formal or not, is either too strong to fit cognitively limited individuals, or too weak to adequately describe their (...) state. I provide a realistic definition of common knowledge, based on a formalization of David Lewis’ seminal account and show that it is formally equivalent to probabilistic common belief. This leads to a philosophical analysis of common knowledge which answers several common criticisms and sheds light on its nature. (shrink)

Thirty years ago, grounded cognition had roots in philosophy, perception, cognitive linguistics, psycholinguistics, cognitive psychology, and cognitive neuropsychology. During the next 20 years, grounded cognition continued developing in these areas, and it also took new forms in robotics, cognitive ecology, cognitive neuroscience, and developmental psychology. In the past 10 years, research on grounded cognition has grown rapidly, especially in cognitive neuroscience, social neuroscience, cognitive psychology, social psychology, and developmental psychology. Currently, grounded cognition appears to be achieving increased acceptance throughout cognitive (...) science, shifting from relatively minor status to increasing importance. Nevertheless, researchers wonder whether grounded mechanisms lie at the heart of the cognitive system or are peripheral to classic symbolic mechanisms. Although grounded cognition is currently dominated by demonstration experiments in the absence of well-developed theories, the area is likely to become increasingly theory driven over the next 30 years. Another likely development is the increased incorporation of grounding mechanisms into cognitive architectures and into accounts of classic cognitive phenomena. As this incorporation occurs, much functionality of these architectures and phenomena is likely to remain, along with many original mechanisms. Future theories of grounded cognition are likely to be heavily influenced by both cognitive neuroscience and social neuroscience, and also by developmental science and robotics. Aspects from the three major perspectives in cognitive science—classic symbolic architectures, statistical/dynamical systems, and grounded cognition—will probably be integrated increasingly in future theories, each capturing indispensable aspects of intelligence. (shrink)

David Lewis is widely regarded as the philosopher who introduced the concept of common knowledge. His account of common knowledge differs greatly from most later accounts in philosophy and economy, with the central notion of his theory being ‘having reason to believe’ rather than ‘knowledge’. Unfortunately, Lewis’s account is rather informal, and the argument has a few gaps. This paper assesses two major attempts to formalise Lewis’s account and argues that these formalisations are missing a crucial aspect of this account. (...) Therefore, a new reconstruction is proposed, which explicitly discusses ‘reasons’ and uses a logic inspired by justification logic. (shrink)

The prequel to this paper introduced the topic of iteration principles in epistemology and surveyed some arguments in support of them. In this sequel, I'll consider two influential families of objection to iteration principles. The first turns on the idea that they lead to some variety of skepticism, and the second turns on ‘margin for error’ considerations adduced by Timothy Williamson.

Epistemic iteration principles are principles according to which some or another epistemic operator automatically iterates---e.g., if it is known that P, then it is known that P, or there is evidence that P, then there is evidence that there is evidence that P. This article provides a survey of various arguments for and against epistemic iteration principles, with a focus on arguments relevant to a wide range of such principles.

Language use can be viewed as a form of joint activity that requires the coordination of meaning between individuals. Because the linguistic signal is notoriously ambiguous, interlocutors need to draw upon additional sources of information to resolve ambiguity and achieve shared understanding. One way individuals can achieve coordination is by using inferences about the interlocutor’s intentions and mental states to adapt their behavior. However, such an inferential process can be demanding in terms of both time and cognitive resources. Here, we (...) suggest that interaction provides interlocutors with many cues that can support coordination of meaning, even when they are neither produced intentionally for that purpose nor interpreted as signaling speakers’ intention. In many circumstances, interlocutors can take advantage of these cues to adapt their behavior in ways that promote coordination, bypassing the need to resort to deliberative inferential processes. (shrink)

How do communities establish shared communication systems? The Common Knowledge view assumes that symbolic conventions develop through the accumulation of common knowledge regarding communication practices among the members of a community. In contrast with this view, it is proposed that coordinated communication emerges a by‐product of local interactions among dyads. A set of multi‐agent computer simulations show that a population of “egocentric” agents can establish and maintain symbolic conventions without common knowledge. In the simulations, convergence to a single conventional system (...) was most likely and most efficient when agents updated their behavior on the basis of local rather than global, system‐level information. The massive feedback and parallelism present in the simulations gave rise to phenomena that are often assumed to result from complex strategic processing on the part of individual agents. The implications of these findings for the development of theories of language use are discussed. (shrink)

According to decision theory, the rational initial action in a sequential decision-problem may be found by backward induction or folding back. But the reasoning which underwrites this claim appeals to the agent's beliefs about what she will later believe, about what she will later believe she will still later believe, and so forth. There are limits to the depth of people's beliefs. Do these limits pose a threat to the standard theory of rational sequential choice? It is argued, first, that (...) the traditional solutions of certain games depend on knowledge which exceeds depth limits, and that these solutions therefore cannot be shown rational in the usual sense. Then, for that related reason even folding back solutions of one-person problems cannot be! A revision of our notion of rational choice is proposed, analogous to the reliabilist account of knowledge of Goldman and others, by which this paradox is resolved. (shrink)

Language and Theory of Mind come together in communication, but their relationship has been intensely contested. I hypothesize that pragmatic markers connect language and Theory of Mind and enable their co-development and co-evolution through a positive feedback loop, whereby the development of one skill boosts the development of the other. I propose to test this hypothesis by investigating two types of pragmatic markers: demonstratives and articles. Pragmatic markers are closed-class words that encode non-representational information that is unavailable to consciousness, but (...) accessed automatically in processing. These markers have been associated with implicit Theory of Mind because they are used to establish joint attention and mark shared knowledge. Here I develop a theoretical account of how joint attention is the basis for children’s later tracking of common ground. The developmental path from joint attention to common ground parallels language change, with demonstrative forms giving rise to definite articles. This parallel opens the possibility of modelling the emergence of Theory of Mind in human development in tandem with its routinization across language communities and generations of speakers. I therefore propose that, in order to understand the relationship between language and Theory of Mind, we should study pragmatics at three parallel timescales: during language acquisition, language use, and language change. (shrink)

The effect of upper bounds on message delivery times in a computer network upon the dynamics of knowledge gain is investigated. Recent work has identified centipedes and brooms—causal structures that combine message chains with time bound information—as necessary conditions for knowledge gain and common knowledge gain, respectively. This paper shows that, under the full-information protocol, these structures are both necessary and sufficient for such epistemic gain. We then apply this analysis to gain insights into the relation between “everyone knows” and (...) common knowledge. We prove a tight threshold on the depth k, beyond which Ek G (everyone in G knows nested to depth k) collapses into CG (common knowledge), when this knowledge concerns the occurrence of a spontaneous event. The threshold depends on the size of the group G of agents, as well as the time that has elapsed since the event of interest occurred. The existence of such a threshold is not guaranteed for all protocols, which is demonstrated here by presenting a counterexample in which no such threshold exists. (shrink)

This article proposes that Goffman's "Frame Analysis" can be interpreted as a step toward unpacking the idea of context. His analysis implies a recursive model involving frames within frames. The key problem is that neither Goffman nor anyone else has clearly defined what is meant by a frame. I propose that it can be represented by a word, phrase, or proposition. A subjective context can be represented as an assembly of these items, joined together by operators such as and, since, (...) if, not, and then. Furthermore, this model can be combined with the recursive levels of mutual awareness in earlier approaches to consensus. The combination would represent the inter subjective context: it can be used to find the minimum amount of background that would allow consensual interpretations of discourse. It could also construct a chain that links discourse to the institutional level, the micro-macro pathway from word and gesture to social structure. Goffman hinted that mathematical notation might be used to represent a frame assembly. By adding levels of awareness to such notation, it could represent social facts. Because the use of vernacular words rather than concepts is a problem in social science, Goffman's approach has a general as well as a particular significance. (shrink)

Adults design utterances to match listeners' informational needs by making both “generic” adjustments (e.g., mentioning atypical more often than typical information) and “particular” adjustments tailored to their specific interlocutor (e.g., including things that their addressee cannot see). For children, however, relevant evidence is mixed. Three experiments investigated how generic and particular factors affect children's production. In Experiment 1, 4‐ to 5‐year‐old children and adults described typical and atypical instrument events to a silent listener who could either see or not see (...) the events. In later extensions, participants described the same events to either a silent (Experiment 2) or an interactive (Experiment 3) addressee with a specific goal. Both adults and 4‐ to 5‐year‐olds performed generic adjustments but, unlike adults, children made listener‐particular adjustments inconsistently. These and prior findings can be explained by assuming that particular adjustments can be costlier for children to implement compared to generic adjustments. (shrink)

A pragmatic account of referential communication is developed which presents an alternative to traditional Gricean accounts by focusing on cooperativeness and efficiency, rather than informativity. The results of four language‐production experiments support the view that speakers can be cooperative when producing redundant adjectives, doing so more often when color modification could facilitate the listener's search for the referent in the visual display (Experiment 1a). By contrast, when the listener knew which shape was the target, speakers did not produce redundant color (...) adjectives (Experiment 1b). English speakers used redundant color adjectives more often than Spanish speakers, suggesting that speakers are sensitive to the differential efficiency of prenominal and postnominal modification (Experiment 2). Speakers were also cooperative when using redundant size adjectives (Experiment 3). Overall, these results show how discriminability affects a speaker's choice of referential expression above and beyond considerations of informativity, supporting the view that redundant speakers can be cooperative. (shrink)

I show how a conversational process that takes simple, intuitively meaningful steps may be understood as a sophisticated computation that derives the richly detailed, complex representations implicit in our knowledge of language. To develop the account, I argue that natural language is structured in a way that lets us formalize grammatical knowledge precisely in terms of rich primitives of interpretation. Primitives of interpretation can be correctly viewed intentionally, as explanations of our choices of linguistic actions; the model therefore fits our (...) intuitions about meaning in conversation. Nevertheless, interpretations for complex utterances can be built from these primitives by simple operations of grammatical derivation. In bridging analyses of meaning at semantic and symbol‐processing levels, this account underscores the fundamental place for computation in the cognitive science of language use. (shrink)

Albert and De Ruiter provide an introduction to the Conversation Analytic approach to ‘repair’: the ways in which people detect and deal with troubles in speaking, hearing and understanding in conversation. They explain the basic turn‐taking structures involved, provide examples, explain recent developments in the field and highlight some important points of contact and contrast with work in the Cognitive Sciences.

While speakers have been shown to adapt to the knowledge state of their addressee in choosing referring expressions, they often also show some egocentric tendencies. The current paper aims to provide an explanation for this “mixed” behavior by presenting a model that derives such patterns from the probabilistic combination of both the speaker's and the addressee's perspectives. To test our model, we conducted a language production experiment, in which participants had to refer to objects in a context that also included (...) a visually misleading object whose function was either known to both partners, or known just to the speaker but not the addressee. Modeling results indicate that the experimental findings cannot be explained by assuming that speakers tailor a referring expression solely to their own perspective or to the perspective of their addressee. Instead, accounting for the behavioral pattern requires an approach where both perspectives influence the choice of referring expressions. Nevertheless, in our situation, speakers consider their partner's perspective more than their own. (shrink)

This paper presents a framework for the generation of coherent elementary conversational sequences at the speech act level. We will embrace the notion of a cooperative dialogue game in which two players produce speech acts to transfer relevant information with respect to their commitments. Central to the approach is that participants try to achieve some sort of balanced cognitive state as a result of speech act generation and interpretation. Cognitive states of the participants change as a result of the interpretation (...) of speech acts and these changes provoke the production of a subsequent speech act. Describing the properties and the dynamics of the mental constructs that constitute the participants’ cognitive states, such as beliefs and commitments, in relation to the various dialogue contributions is an essential aspect of the game. Although simple in its basic form, the framework enables us to produce abstract conversations with some properties that agree strikingly with coherence structures found in, for instance, Conversation Analysis. (shrink)