To explain the evolutionary emergence of uniquely human skills and motivations for cooperation, Tomasello et al. (2012, in Current Anthropology 53(6):673–92) proposed the interdependence hypothesis. The key adaptive context in this account was the obligate collaborative foraging of early human adults. Hawkes (2014, in Human Nature 25(1):28–48), following Hrdy (Mothers and Others, Harvard University Press, 2009), provided an alternative account for the emergence of uniquely human cooperative skills in which the key was early human infants’ attempts to solicit care and (...) attention from adults in a cooperative breeding context. Here we attempt to reconcile these two accounts. Our composite account accepts Hrdy’s and Hawkes’s contention that the extremely early emergence of human infants’ cooperative skills suggests an important role for cooperative breeding as adaptive context, perhaps in early Homo. But our account also insists that human cooperation goes well beyond these nascent skills to include such things as the communicative and cultural conventions, norms, and institutions created by later Homo and early modern humans to deal with adult problems of social coordination. As part of this account we hypothesize how each of the main stages of human ontogeny (infancy, childhood, adolescence) was transformed during evolution both by infants’ cooperative skills “migrating up” in age and by adults’ cooperative skills “migrating down” in age. (shrink)

Research on theory of mind has primarily focused on demonstrating and understanding the ability to represent others' non‐factive mental states, for example, others' beliefs in the false‐belief task. This requirement confuses the ability to represent a particular kind of non‐factive content (e.g., a false belief) with the more general capacity to represent others' understanding of the world even when it differs from one's own. We provide a way of correcting this. We first offer a simple and theoretically motivated account on (...) which tracking another agent's understanding of the world and keeping that representation separate from one's own are the essential features of a capacity for theory of mind. We then show how these criteria can be operationalized in a new experimental paradigm: the “diverse‐knowledge task.”. (shrink)

Could interacting mindreaders be in a position to know things which they would be unable to know if they were manifestly passive observers? This paper argues that they could. Mindreading is sometimes reciprocal: the mindreader’s target reciprocates by taking the mindreader as a target for mindreading. The paper explains how such reciprocity can significantly narrow the range of possible interpretations of behaviour where mindreaders are, or appear to be, in a position to interact. A consequence is that revisions and extensions (...) are needed to standard theories of the evidential basis of mindreading. The view also has consequences for understanding how abilities to interact combined with comparatively simple forms of mindreading may explain the emergence, in evolution or development, of sophisticated forms of social cognition. (shrink)

Henry Wellman and colleagues have provided evidence of a robust developmental progression in theory-of-mind (or as we will say, “mindreading”) abilities, using verbal tasks. Understanding diverse desires is said to be easier than understanding diverse beliefs, which is easier than understanding that lack of perceptual access issues in ignorance, which is easier than understanding false belief, which is easier than understanding that people can hide their true emotions. These findings present a challenge to nativists about mindreading, and are said to (...) support a social-constructivist account of mindreading development instead. This article takes up the challenge on behalf of nativism. Our goal is to show that the mindreading-scale findings fail to support constructivism because well-motivated alternative hypotheses have not yet been controlled for and ruled out. These have to do with the pragmatic demands of verbal tasks. (shrink)

False belief tasks have enjoyed a monopoly in the research on children’s development of a theory of mind. They have been granted this status because they promise to deliver an unambiguous assessment of children’s understanding of the representational nature of mental states. Their poor cousins, true belief tasks, have been relegated to occasional service as control tasks. That this is their only role has been due to the universal assumption that correct answers on true belief tasks are inherently ambiguous regarding (...) the level of the child’s understanding of mental states. It has also been due to the universal assumption that nothing in the child’s developing theory of mind would lead to systematically incorrect answers on true belief tasks. We review new findings that 4- and 5-year-olds do err, systematically and profoundly, on the true belief versions of all the extant belief tasks. This reveals an intermediate level of understanding in the development of children’s theory of mind. Researchers have been unaware of this intermediate level because it produces correct answers in false belief tasks. A simple two-task battery—one true belief task and one false belief task—is sufficient to remove the ambiguity from each task. The new findings show that children do not acquire an understanding of beliefs, and hence a representational theory of mind, until after 6 years of age, or 2 years later than most developmental psychologists have concluded. This raises the question of how to interpret other new findings that infants are able to pass false belief tasks. We review these new infant studies, as well as recent studies on chimpanzees, in light of older children’s failure on true belief tasks, and end with some speculation about how all of these new findings might be reconciled. (shrink)

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)

Several cognitive accounts of human communication argue for a language-independent, prelinguistic basis of human communication and language. The current study provides evidence for the universality of a prelinguistic gestural basis for human communication. We used a standardized, semi-natural elicitation procedure in seven very different cultures around the world to test for the existence of preverbal pointing in infants and their caregivers. Results were that by 10–14 months of age, infants and their caregivers pointed in all cultures in the same basic (...) situation with similar frequencies and the same proto-typical morphology of the extended index finger. Infants’ pointing was best predicted by age and caregiver pointing, but not by cultural group. Further analyses revealed a strong relation between the temporal unfolding of caregivers’ and infants’ pointing events, uncovering a structure of early prelinguistic gestural conversation. Findings support the existence of a gestural, language-independent universal of human communication that forms a culturally shared, prelinguistic basis for diversified linguistic communication. (shrink)

Against the prior view that primate communication is based only on signal decoding, comparative evidence suggests that primates are able, no less than humans, to intentionally perform or understand impulsive or habitual communicational actions with a structured evaluative nonconceptual content. These signals convey an affordance-sensing that immediately motivates conspecifics to act. Although humans have access to a strategic form of propositional communication adapted to teaching and persuasion, they share with nonhuman primates the capacity to communicate in impulsive or habitual ways. (...) They are also similarly able to monitor fluency, informativeness and relevance of messages or signals through nonconceptual cues. (shrink)

The fact that humans cooperate with nonkin is something we take for granted, but this is an anomaly in the animal kingdom. Our species’ ability to behave prosocially may be based on human-unique psychological mechanisms. We argue here that these mechanisms include the ability to care about the welfare of others (other-regarding concerns), to “feel into” others (empathy), and to understand, adhere to, and enforce social norms (normativity). We consider how these motivational, emotional, and normative substrates of prosociality develop in (...) childhood and emerged in our evolutionary history. Moreover, we suggest that these three mechanisms all serve the critical function of aligning individuals with others: Empathy and other-regarding concerns align individuals with one another, and norms align individuals with their group. Such alignment allows us to engage in the kind of large-scale cooperation seen uniquely in humans. (shrink)

Children learn about the world from the testimony of other people, often coming to accept what they are told about a variety of unobservable and indeed counter-intuitive phenomena. However, research on children’s learning from testimony has paid limited attention to the foundations of that capacity. We ask whether those foundations can be observed in infancy. We review evidence from two areas of research: infants’ sensitivity to the emotional expressions of other people; and their capacity to understand the exchange of information (...) through non-verbal gestures and vocalization. We conclude that a grasp of the bi-directional exchange of information is present early in the second year. We discuss the implications for future research, especially across different cultural settings. (shrink)

In this article, I defend Neo-Gricean accounts of language and communication from an objection about linguistic development. According to this objection, children are incapable of understanding the minds of others in the way that Neo-Gricean accounts require until long after they learn the meanings of words, are able to produce meaningful utterances, and understand the meaningful utterances of others. In answering this challenge, I outline exactly what sorts of psychological states are required by Neo-Gricean accounts and conclude that there is (...) sufficient evidence that these types of psychological states are present in and capable of being understood by the children in question. (shrink)

The study of human-human communication and the development of computational models for human-agent communication have diverged significantly throughout the last decade. Yet, despite frequently made claims of “super-human performance” in, e.g., speech recognition or image processing, so far, no system is able to lead a half-decent coherent conversation with a human. In this paper, we argue that we must start to re-consider the hallmarks of cooperative communication and the core capabilities that we have developed for it, and which conversational agents (...) need to be equipped with: incremental joint co-construction and mentalizing. We base our argument on a vast body of work on human-human communication and its psychological processes that we reason to be relevant and necessary to take into account when modeling human-agent communication. We contrast those with current conceptualizations of human-agent interaction and formulate suggestions for the development of future systems. (shrink)

Humans have attained an unparalleled level of sophistication when engaging in collaborative and cooperative activities. Remarkably, the skills and motivation to engage in complex forms of collaboration and cooperation seem to emerge early on during infancy and childhood. In this paper, I extensively review the literature on the evolution and development of human cooperation, emphasizing important aspects of inter-cultural variation in collaborative and cooperative behaviour. This will not only allow us to confront the different evolutionary scenarios in which cooperation may (...) have emerged, but will especially provide the reader with a first orientation in the abundant literature on human cooperation. (shrink)

The poor performances of typically developing children younger than 4 in the first-order false-belief task “Maxi and the chocolate” is analyzed from the perspective of conversational pragmatics. An ambiguous question asked by an adult experimenter (perceived as a teacher) can receive different interpretations based on a search for relevance, by which children according to their age attribute different intentions to the questioner, within the limits of their own meta-cognitive knowledge. The adult experimenter tells the child the following story of object-transfer: (...) “Maxi puts his chocolate into the green cupboard before going out to play. In his absence, his mother moves the chocolate from the green cupboard to the blue one.” The child must then predict where Maxi will pick up the chocolate when he returns. To the child, the question from an adult (a knowledgeable person) may seem surprising and can be understood as a question of his own knowledge of the world, rather than on Maxi's mental representations. In our study, without any modification of the initial task, we disambiguate the context of the question by (1) replacing the adult experimenter with a humanoid robot presented as “ignorant” and “slow” but trying to learn and (2) placing the child in the role of a “mentor” (the knowledgeable person). Sixty-two typical children of 3 years-old completed the first-order false belief task “Maxi and the chocolate,” either with a human or with a robot. Results revealed a significantly higher success rate in the robot condition than in the human condition. Thus, young children seem to fail because of the pragmatic difficulty of the first-order task, which causes a difference of interpretation between the young child and the experimenter. (shrink)

Children often refer to things ambiguously but learn not to from responding to clarification requests. We review and explore this learning process here. In Study 1, eighty-four 2- and 4-year-olds were tested for their ability to request stickers from either (a) a small array with one dissimilar distracter or (b) a large array containing similar distracters. When children made ambiguous requests, they received either general feedback or specific questions about which of two options they wanted. With training, children learned to (...) produce more complex object descriptions and did so faster in the specific feedback condition. They also tended to provide more information when requesting stickers from large arrays. In Study 2, we varied only distracter similarity during training and then varied array size in a generalization test. Children found it harder to learn in this case. In the generalization test, 4-year-olds were more likely to provide information (a) when it was needed because distracters were similar to the target and (b) when the array size was greater (regardless of need for information). We discuss how clear cues to potential ambiguity are needed for children to learn to tailor their referring expression to context and how several cues of heuristic value (e.g., more distracters > say more) can promote the efficiency of communication while language is developing. Finally, we consider whether it would be worthwhile drawing on the human learning process when developing algorithms for the production of referring expressions. (shrink)

Humans have attained an unparalleled level of sophistication when engaging in collaborative and cooperative activities. Remarkably, the skills and motivation to engage in complex forms of collaboration and cooperation seem to emerge early on during infancy and childhood. In this paper, I extensively review the literature on the evolution and development of human cooperation, emphasizing important aspects of inter-cultural variation in collaborative and cooperative behaviour. This will not only allow us to confront the different evolutionary scenarios in which cooperation may (...) have emerged, but will especially provide the reader with a first orientation in the abundant literature on human cooperation. (shrink)

Teaching allows human culture to exist and to develop. Despite its significance, it has not been studied in depth by the cognitive neurosciences. Here we propose two hypotheses to boost the claim that teaching is a human instinct, and to expand our understanding of how teaching occurs as a dynamic bi-directional relation within the teacher-learner dyad. First, we explore how children naturally use ostensive communication when teaching; allowing them to be set in the emitter side of natural pedagogy. Then, we (...) hypothesize that the capacity to teach may precede to even have a mature metacognition and, we argue that a teacher will benefit from the interaction with her student, improving her understanding on both contents of knowledge: her own and her student’s. Thus, we propose that teaching may be the driving force of metacognitive development and may be occurring as an instinct from very early ages. (shrink)

Pragmatic deficits of persons with autism spectrum disorders [ASDs] are often traced back to a dysfunction in Theory of Mind. However, the exact nature of the link between pragmatics and mindreading in autism is unclear. Pragmatic deficits in ASDs are not homogenous: in particular, while inter-subjective dimensions are affected, some other pragmatic capacities seem to be relatively preserved. Moreover, failure on classical false-belief tasks stems from executive problems that go beyond belief attribution; false-belief tasks require taking an alternative perspective on (...) the reality. While this capacity is functional in typically developing young children, it is impaired in ASDs. Typically developing children are capable of taking their interlocutor's perspective into account when communicating, whereas poor cognitive flexibility makes it difficult for persons with ASDs to grasp the inter-subjective character of communicative stimuli. This analysis predicts that those pragmatic processes that amount to merely taking into account salient contextual facts during utterance interpretation, without necessarily adopting the interlocutor's perspective, may be preserved in ASDs. (shrink)

Young children help others in a range of situations, relatively indiscriminate of the characteristics of those they help. Recent results have suggested that young children’s helping behaviour extends even to humanoid robots. However, it has been unclear how characteristics of robots would influence children’s helping behaviour. Considering previous findings suggesting that certain robot features influence adults’ perception of and their behaviour towards robots, the question arises of whether young children’s behaviour and perception would follow the same principles. The current study (...) investigated whether two key characteristics of a humanoid robot (animate autonomy and friendly expressiveness) would affect children’s instrumental helping behaviour and their perception of the robot as an animate being. Eighty-two 3-year-old children participated in one of four experimental conditions manipulating a robot’s ostensible animate autonomy (high/low) and friendly expressiveness (friendly/neutral). Helping was assessed in an out-of-reach task and animacy ratings were assessed in a post-test interview. Results suggested that both children’s helping behaviour, as well as their perception of the robot as animate, were unaffected by the robot’s characteristics. The findings indicate that young children’s helping behaviour extends largely indiscriminately across two important characteristics. These results increase our understanding of the development of children’s altruistic behaviour and animate-inanimate distinctions. Our findings also raise important ethical questions for the field of child-robot interaction. (shrink)

This paper proposes an intermediate account of personhood, based on the capacity to participate in intersubjective interactions. We articulate our proposal as a reply to liberal and restrictive accounts, taking Mark Rowlands’ and Stephen Darwall’s proposals as contemporary representatives of each view, respectively. We argue that both accounts fall short of dealing with borderline cases and defend our intermediate view: The criteria of personhood based on the second-person perspective of mental state attribution. According to it, a person should be able (...) to participate in intersubjective interactions. We apply our proposal to the borderline cases of non-human primates and human infants. (shrink)

Recent findings have shown that children’s teaching is guided by their evaluation of what a pupil does versus does not know. While children certainly teach to remedy a knowledge gap between themselves and a learner, we argue that children’s appraisal of the nature of the knowledge that they are seeking to convey and not just whether a knowledge gap exists plays an important role in children’s decision to transmit information. Specifically, we argue that children are more likely to transmit information (...) a pupil does not know in at least three cases: if that information is difficult for the learner to acquire on her own, generic rather than specific, and normative rather than descriptive. (shrink)

The aim of this paper is to explore the minimal representational requirements for pointing. One year old children are capable of pointing – what does this tell us about their representational capacities? We analyse three options: (1) pointing presupposes non-perceptual representations, (2) pointing does not presuppose any representation at all, (3) pointing presupposes perceptual representations. Rather than fully endorsing any of these three options, the aim of the paper is to explore the advantages and disadvantages of each.

Procedural metacognition is the set of affect-based mechanisms allowing agents to regulate cognitive actions like perceptual discrimination, memory retrieval or problem solving. This article proposes that procedural metacognition has had a major role in the evolution of communication. A plausible hypothesis is that, under pressure for maximizing signalling efficiency, the metacognitive abilities used by nonhumans to regulate their perception and their memory have been re-used to regulate their communication. On this view, detecting one’s production errors in signalling, or solving species-specific (...) trade-offs between informativeness, processing effort, clarity, or urgency depend on a form of procedural metacognition, called “metacommunication”. How does this view relate to Gricean theories of human communication? A parallel between procedural trade-offs and conversational maxims is discussed for its evolutionary implications. Rather than accepting radically discontinuist interpretations, in which mindreading operates a full reorganization of pragmatics, it is proposed that procedural forms of regulation are entrenched in all forms of human communication. According to contextual demands, humans adopt and monitor more or less demanding informational goals, such as factual updating, clarifying, explaining, proving, and reaching consensus in collective matters. Under time pressure, only part of these goals require adopting others’ viewpoint. Efficiency in collective decision-making, in particular, might have been considerably raised by an ability to interpret others’ intentions and motivations. (shrink)

Humans share with other mammals and primates many social motivations and emotions, but they are also much more cooperative than even their closest primate relatives. Here I review recent comparative experiments and analyses that illustrate humans’ species-typical social motivations and emotions for cooperation in comparison with those of other great apes. These may be classified most generally as (i) ‘you > me’ (e.g., prosocial sympathy, informative and pedagogical motives in communication); (ii) ‘you = me’ (e.g., feelings of mutual respect, fairness, (...) resentment); (iii) ‘we > me’ (e.g., feelings of obligation and guilt); and (iv) ‘WE (in the group) > me’ (e.g., in-group loyalty and conformity to norms, shame, and many in-group biases). The existence of these species-typical and species-universal motivations and emotions provides compelling evidence for the importance of cooperative activities in the human species. (shrink)

Procedural metacognition is the set of affect-based mechanisms allowing agents to regulate cognitive actions like perceptual discrimination, memory retrieval or problem solving. This article proposes that procedural metacognition has had a major role in the evolution of communication. A plausible hypothesis is that, under pressure for maximizing signalling efficiency, the metacognitive abilities used by nonhumans to regulate their perception and their memory have been re-used to regulate their communication. On this view, detecting one’s production errors in signalling, or solving species-specific (...) trade-offs between informativeness, processing effort, clarity, or urgency depend on a form of procedural metacognition, called “metacommunication”. How does this view relate to Gricean theories of human communication? A parallel between procedural trade-offs and conversational maxims is discussed for its evolutionary implications. Rather than accepting radically discontinuist interpretations, in which mindreading operates a full reorganization of pragmatics, it is proposed that procedural forms of regulation are entrenched in all forms of human communication. According to contextual demands, humans adopt and monitor more or less demanding informational goals, such as factual updating, clarifying, explaining, proving, and reaching consensus in collective matters. Under time pressure, only part of these goals require adopting others’ viewpoint. Efficiency in collective decision-making, in particular, might have been considerably raised by an ability to interpret others’ intentions and motivations. (shrink)

Discovering the meaning of novel communicative cues is challenging and amounts to navigating an unbounded hypothesis space. Several theories posit that this problem can be simplified by relying on positive expectations about the cognitive utility of communicated information. These theories imply that learners should assume that novel communicative cues tend to have low processing costs and high cognitive benefits. We tested this hypothesis in three studies in which toddlers (N = 90) searched for a reward hidden in one of several (...) containers. In all studies, an adult communicated the reward's location with an unfamiliar and ambiguous cue. We manipulated the processing costs (operationalized as inferential chain length) and cognitive benefits (operationalized as informativeness) of the possible interpretations of the cues. Toddlers processing of novel communicative cues were guided by expectations of low processing costs (Study 1) and high cognitive benefits (Studies 2 and 3). More specifically, toddlers treated novel cues as if they were easy to process, informative, and accurate, even when provided with repeated evidence to the contrary. These results indicate that, from toddlerhood onward, expectations of cognitive utility shape the processing of novel communicative cues. These data also reveal that toddlers, who are in the process of learning the language and communicative conventions of people around them, exert a pressure favoring cognitive efficiency in communicative systems. (shrink)

Research on children's theory of mind often restricts conceptually meaningful talk about knowledge to instances where know references a corresponding mental state. This article offers a reappraisal of that view. From a social-pragmatic perspective, even nonreferential talk is meaningful when appropriately embedded in social routines. A synthesis of corpus data suggests children's early talk about knowledge routinely occurs in question–answer contexts. It is argued that the influence of interrogative contexts is evident in children's over-attributions of knowledge when someone is only (...) guessing. This influence is taken as evidence for the role of linguistic practices in shaping the concept of knowledge. (shrink)

To shed light on the key premise of the bifocal stance theory (BST) that social learners flexibly take instrumental and ritual stances, we focus on developmental origins of child-led information transmission, or teaching, as a core social learning strategy. We highlight children's emerging selectivity in information transmission influenced by epistemic and social factors and call for systematic investigation of proposed stance-taking.

Prosocial behaviour benefits another individual and occurs voluntarily. It may have a cognitive and a motivational component. The actor who benefits a recipient – for example by solving her/his problem must recognize the recipient’s goal and understand how to fulfil it and has to be motivated to support the recipient. In the current paper I will review recent studies on prosocial behavior in dogs and I will compare them to studies with primates. I will address the cognitive and motivational skills (...) required for the actor in order to support the recipient. I conclude that dogs and also chimpanzees display a number of prosocial behaviours, but there are remarkable differences. In contrast to humans, which have an outstanding biological predisposition to benefit others, dogs and chimpanzees only do so under certain conditions. (shrink)

In ambiguous situations, infants have the tendency to gather information from a social interaction partner to regulate their behavior [social referencing ]. There are two main competing theories concerning SR’s function. According to social-cognitive information-seeking accounts, infants look at social interaction partners to gain information about the ambiguous situation. According to co-regulation accounts, infants look at social interaction partners to receive emotional support. This review provides an overview of the central developments in SR literature in the past years. We focus (...) on the role of situational aspects such as familiarity of SR partners and situational threat, not only for SR, but also for subsequent behavioral regulation. As the competing accounts make different predictions concerning both contextual factors, this approach may reveal novel insights into the function of SR. Findings showed that a higher familiarity of SR partners consistently resulted in decreased looking and that higher threat remains largely understudied, but seemed to increase looking in the first few studies. Concerning behavioral regulation findings are mixed. We point out that moving toward a more complex situatedness may help to disentangle the heterogeneous results by considering the interaction between familiarity and threat rather than investigating the factors in isolation. From a general perspective, this review underlines the importance of situational factors and their interaction in eliciting a phenomenon, such as SR, but also in determining the nature of the phenomenon itself. (shrink)

Theory of mind, the ability to attribute mental states to ourselves and others, is crucial for human social interaction and has been argued to fully develop around the age of 4. However, recent research suggests that children can perform rudimentary, preverbal ToM inferences at an earlier age, indicating a discrepancy between this early, implicit ToM and a later mastery of explicit ToM tasks. Already in the second year of life children show competence in grasping what an agent knows and does (...) not know in preverbal communication, whereas explicit performance on ToM tasks can only be observed around the age of 4. One possible explanation is that children require an additional representational resource in order to be able to associate their preverbal understanding with explicit terms that can be used to denote it in standard ToM tasks. The purpose of this thesis is to extend research on ToM in the third year of life by investigating one possible representational resource, namely mental state language. Mental state language is considered crucial for ToM development as it is the first explicit means by which children can verbalize mental states and it plays an important role for both precursors and subsequent mastery of explicit ToM tasks. However, how exactly mental state language production reflects children's awareness and comprehension of mental states remains understudied. Harris, Yang, and Cui have argued that children use mental state terms early on and possess basic representations of their own knowledge and ignorance. Since both mental state terms and basic representations appear to be present at the same time, one might assume that children already possess associations between them. However, experimental tasks that investigate mental state verbs like `know' and `think' are only able to find competence to differentiate between them around the age of 5. Thus, the extent to which the appropriate use of mental state terms in conversation reflects comprehension of the denoted mental states remains unclear. Given that mental state language develops around the second and third year of life, one may gain insight into the role it plays for a transition from implicit to explicit competence by investigating abilities which, according to our current understanding, develop around the same time and show both preverbal and verbal aspects. Perspective-taking and implicit false-belief understanding are such abilities. Children show early preverbal perspective-taking competence at the age of 24 months, but only develop verbal perspective-taking competence around the age of 3. Previous work has identified a relationship between mental state language and verbal perspective-taking at the age of 30 months, but no study has investigated this relationship in connection to preverbal perspective-taking. Also in the area of falsebelief understanding studies have mostly investigated the relationship between mental state language and explicit false-belief tasks, but no study has examined how mental state language may relate to an implicit false-belief task. Finally, mental state language has been found to correlate with a number of different competencies, among them inhibitory control and general language, but no study has systematically investigated which of these competencies serve as precursors that predict children's later mental state language production. Determining precursors is relevant for understanding crucial aspects of mental state language development and how it might relate to children's preverbal representations of mental states. The aims of the present thesis were thus to investigate the relationship between children's mental state language production and their comprehension of mental state terms and mental states, to determine the role that mental state language production may play in preverbal and verbal perspective-taking and implicit false-belief understanding and finally, to identify the basic linguistic and cognitive skills that contribute to the development of mental state language. These aims were pursued through 2 studies. In study 1, children were assessed at two time-points. Once they were tested at the age of 24 months with measures of general language, cognitive and motoric development and inhibition skills. An additional time they were tested at 27 months in order to assess children's mental state language production, their preverbal and verbal perspective-taking skills, meta-cognitive awareness of ignorance, implicit false-belief understanding and finally a task that measured their ability to infer a speaker's need for information from a statement about knowing or not knowing the location of an item and a speaker's desire for an object from statements about wanting or not wanting a particular object. The aim was to determine the concurrent relationship of children's mental state language production and their ability to comprehend and use these terms on experimental tasks, to identify the concurrent relationship between mental state language and preverbal and verbal perspective-taking and implicit false-belief understanding and finally to determine which developmental skills at the age of 24 months are significant predictors of children's later mental state language production. Study 1 showed that 27-month-olds were already able to produce mental state terms and showed a basic understanding of their own knowledge and ignorance, but failed to show comprehension of epistemic mental state terms in experimental tasks. Thus, despite their early competence in producing epistemic mental state terms, children's comprehension of these terms appeared to be limited. The results of the first study also identified that mental state language production was related to children's own verbal level-1 visual perspective-taking, in particular to usage of the verb `know/don't know' in several naturalistic contexts, independent of general language. There was also continuity from children's preverbal understanding of perspectives to their ability to report their own perspective in a verbal task. However, there was no relationship between preverbal understanding of perspectives and mental state language production according to a parental questionnaire, suggesting that early preverbal understanding of perspectives is not related to the mere production of mental state terms unless children already produce these terms in appropriate contexts. In relation to implicit false-belief understanding, children's performance suggested that they followed a simple strategy of looking at the last object location instead of demonstrating false-belief understanding. Finally, study 1 also identified sentence production, inhibition and fine motor skills at 24 months as significant predictors of children's later production of mental state language at 27 months. In study 2, children's ability to infer a speaker's need for information was investigated further by administering a pragmatic inference task from study 1 to 2-, 3- and 5-year-olds and determining at which age children showed competence. Study 2 showed that despite being able to draw the right pragmatic inferences for the mental state verb `want' at the age of 2, only at the age of 5 children were able to draw the right pragmatic inferences for the mental state verb `know/don't know'. The overall results of this thesis implied that the crucial aspect of mental state language is not mere production of the verbs, but children's experience with a variety of contexts in which mental state verbs can be used, corresponding with a socioconstructivist approach to cognitive development. The number of naturalistic contexts related to children's metarepresentations of their own ignorance, to their ability of inferring a speaker's desire and their ability to verbalize their own perspective, thus suggesting that the conversational input children receive is one of the main ways in which mental representations become explicit. Furthermore, the theoretical view that children's preverbal competence may be better explained by a production rule approach instead of early conceptual understanding is discussed. (shrink)