Four studies investigated whether and when infants connect information about an actor's affect and perception to their action. Arguably, this may be a crucial way in which infants come to recognize the intentional behaviors of others. In Study 1 an actor grasped one of two objects in a situation where cues from the actor's gaze and expression could serve to determine which object would be grasped, specifically the actor first looked at and emoted positively about one object but not the other. Twelve-month-olds, but not 8-month-olds, recognized that the actor was likely to grasp the object which she had visually regarded with positive affect. Studies 2, 3, and 4 replicated the main finding from Study 1 with 12- and 14-month-olds and included several contrasting conditions and controls. These studies provide evidence that the ability to use information about an adult's direction of gaze and emotional expression to predict action is both present, and developing at the end of the first year of life. q 2002 Elsevier Science B.V. All rights reserved.

The current article proposes a new theory of infant pointing involving multiple layers of intentionality and shared intentionality. In the context of this theory, evidence is presented for a rich interpretation of prelinguistic communication, that is, one that posits that when 12-month-old infants point for an adult they are in some sense trying to influence her mental states. Moreover, evidence is also presented for a deeply social view in which infant pointing is best understoodFon many levels and in many waysFas depending on uniquely human skills and motivations for cooperation and shared intentionality (e.g., joint intentions and attention with others). Children’s early linguistic skills are built on this already existing platform of prelinguistic communication. Human beings communicate with one another in unique ways. Most obviously, humans communicate with one another linguistically, that is, with socially learned, intersubjectively shared symbols of a type not used by other animal species in their natural forms of communication. But humans also communicate with one another in unique ways gesturally. Many of the most important gestures humans useFfor example,

Two experiments investigated the proclivity of 14-month-old infants (a) to altruistically help others toward individual goals, and (b) to cooperate toward a shared goal. The infants helped another person by handing over objects the other person was unsuccessfully reaching for, but did not help reliably in situations involving more complex goals. When a programmed adult partner interrupted a joint cooperative activity at specific moments, infants sometimes tried to reengage the adult, perhaps indicating that they understood the interdependency of actions toward a shared goal. However, as compared to 18- and 24-month-olds, their skills in behaviorally coordinating their actions with a social partner remained rudimentary. Results are integrated into a model of cooperative activities as they develop over the 2nd year of life. Prosocial behaviors such as helping and cooperation are interesting both cognitively and motivationally: To help someone with a problem, the helper must understand the other’s unachieved goal and possess the altruistic motivation to act on behalf of the other. Whereas in the case of helping, understanding another’s individual goal of action might be sufficient, cooperative activities are based on the formation of a shared goal. That is, two or more persons have to perform interdependent roles directed at a shared goal and possess the motivation to mutually support each other’s action to reach that goal. These kinds of prosocial behaviors are at the core of the human condition. Indeed, humans might act altruistically and cooperate in ways not found in other primates (e.g., Alexander, 1987; Richerson & Boyd, 2005), giving rise to social-cognitive skills such as complex mind reading

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this paper should be addressed to S. L. Williams, Language Research Center, 3401 Panthersville Road, GA 30034, U.S.A. 301 S. WILLIAMS et al. on the object and with the object as though the object was an animate being. The ape is also expected to know that it must imitate the actions of the caretaker actions that during the demonstration are directed toward the caretaker herself. The ape needs both to imitate what it sees and also to understand the intent of the speaker. A dog cannot achieve such an understanding, but apes often can (Hayes, as can young children (Bates et al., making it difficult to determine whether correct responses with such contexts are based upon language comprehension per se or upon extralinguistic cues. Of course, it is often impractical, with apes and children alike, to demand that language comprehension be context-free before one recognizes that it is occurring. To ensure the very process of language acquisition, the parent or caregiver must have some understanding of a young child's or ape's level of comprehension even as they start to comprehend. The beginning of language comprehension in children can be observed between months of age (Bates, 1993). Throughout this time, an adult may not always be aware of the degree to which he or she is monitoring a child's development of comprehension, but nonetheless the caregiver has a relatively good understanding of what the child can comprehend; and she or he will direct communications to the child accordingly (e.g. Bates, 1993). Given that context does influence this process, we looked at the comprehension of spoken English sentences in a pair of bonobos (Pan paniscus). To date, three bonobos and one common chimpanzee (Pan troglodytes) have demonstrated a capacity to understand speech and graphic sy...

gesture and object location

Young infants are sensitive to self-directed social actions, but do they appreciate the intentional, target-directed nature of such behaviors? We addressed this question by investigating infants ’ understanding of social gaze in third-party interactions. Tenmonth-old infants discriminated between two people in mutual versus averted gaze, and expected a person to look at her social partner during conversation. In contrast, 9-monthold infants showed neither ability, even when provided with information that highlighted the gazer’s social goals. These results indicate considerable improvement in infants’ abilities to analyze the social gaze of others towards the end of their first year, which may relate to their appreciation of gaze as both a social and goal-directed action. Running head: INFANTS ’ DEVELOPING UNDERSTANDING OF SOCIAL GAZE 3 Infants ’ Developing Understanding of Social Gaze Eye gaze is a central element of human social interaction that can reflect a person's feelings, her attitudes towards a social partner, and her goals for their interaction (Kleinke, 1986). Within an interaction, social partners attend to each other’s gaze and use gaze to regulate both the immediate sequence of their exchange (Kendon, 1967) and

Young infants are sensitive to self-directed social actions, but do they appreciate the intentional, target-directed nature of such behaviors? The authors addressed this question by investigating infants ’ understanding of social gaze in third-party interactions (N = 104). Ten-month-old infants discriminated between 2 people in mutual versus averted gaze, and expected a person to look at her social partner during conversation. In contrast, 9-month-old infants showed neither ability, even when provided with information that highlighted the gazer’s social goals. These results indicate considerable improvement in infants ’ abilities to analyze the social gaze of others toward the end of their 1st year, which may relate to their appreciation of gaze as both a social and goal-directed action. We are grateful to the infants and families who participated. This research was funded by NSF GRF DGE-0644491 to J.S.B.

We argue for the importance of processes of shared intentionality in children’s early cognitive development. We look briefly at four important social-cognitive skills and how they are transformed by shared intentionality. In each case, we look first at a kind of individualistic version of the skill – as exemplified most clearly in the behavior of chimpanzees – and then at a version based on shared intentionality – as exemplified most clearly in the behavior of human 1- and 2-year-olds. We thus see the following transformations: gaze following into joint attention, social manipulation into cooperative communication, group activity into collaboration, and social learning into instructed learning. We conclude by highlighting the role that shared intentionality may play in integrating more biologically based and more culturally based theories of human development.

Williams syndrome (WS) is a genetic disorder which results in an uneven cognitive profile. Despite superior language compared to other syndromes in the phenotypic outcome, toddlers with WS are as delayed in their language onset and early linguistic development as are toddlers with other syndromes. The cause of this delay in WS is as yet unknown. In a series of experiments, we examined whether atypical socio-interactive precursors to language could contribute to the explanation of the late language onset and atypical developmental pathways observed in WS. Experiment 1 showed that despite superficially good social skills, toddlers with WS were only proficient at dyadic interaction. They were impaired in triadic interaction, essential for the referential uses of language, and showed none of the correlations between socio-interactive markers and language seen in the typical controls. Experiment 2 focused on the comprehension and production of referential pointing. Again, the WS group was impaired, despite vocabulary levels higher than those of typically developing controls. Finally, Experiment 3 examined fine motor skills. The WS lack of pointing could not be explained in terms of motor impairments, since the WS toddlers were proficient at fine motor control, such as the pincer grip. Overall, our data indicate that the early stages of WS language follow an atypical pathway. The findings challenge the frequent claims in the literature that individuals with Williams syndrome have preserved linguistic and social skills. Williams syndrome (WS) is a rare genetic disorder occurring