Person:

Carey, Susan

Determining which dimensions of social classification are culturally significant is a developmental challenge. Some suggest this is accomplished by differentially privileging intrinsic visual cues over nonintrinsic cues (Atran, 1990; Gil-White, 2001), whereas others point to the role of noun labels as more general promoters of kind-based reasoning (Bigler & Liben, 2007; Gelman, 2003). A novel groups procedure was employed to examine the independent effects of noun labels and visual cues on social categorization. Experiment 1 demonstrated that in the absence of a visual cue, a noun label supported social categorization among 4-year-olds and 7-year-olds. Experiments 2 and 3 demonstrated that children and adults fail to differentiate between intrinsic and nonintrinsic visual cues to category membership, suggesting that this distinction is not central to the acquisition of social category concepts. Experiments 2 and 3 also showed that in the absence of a shared noun label, visual cues were not sufficient for younger children to form social categories. Experiment 4 ruled out a potential demand characteristic in the previous experiments. Together, these results reveal the primacy of verbal labels over visual cues for social categorization in young children and suggest a developmental change between ages 4 and 7 in the ability to construct new representations of social category concepts.

Do infants learn to interpret others’ actions through their own experience producing goal-directed action, or does some knowledge of others’ actions precede first-person experience? Several studies report that motor experience enhances action understanding, but the nature of this effect is not well understood. The present research investigates what is learned during early motoric production, and it tests whether knowledge of goal-directed actions, including an assumption that actors maximize efficiency given environmental constraints, exists before experience producing such actions. Three-month-old infants (who cannot yet effectively reach for and grasp objects) were given novel experience retrieving objects that rested on a surface with no barriers. They were then shown an actor reaching for an object over a barrier and tested for sensitivity to the efficiency of the action. These infants showed heightened attention when the agent reached inefficiently for a goal object; in contrast, infants who lacked successful reaching experience did not differentiate between direct and indirect reaches. Given that the infants could reach directly for objects during training and were given no opportunity to update their actions based on environmental constraints, the training experience itself is unlikely to have provided a basis for learning about action efficiency. We suggest that infants apply a general assumption of efficient action as soon as they have sufficient information (possibly derived from their own action experience) to identify an agent’s goal in a given instance.

Infants and adults are thought to infer the goals of observed actions by calculating the actions’ efficiency as a means to particular external effects, like teaching an object or location. However, many intentional actions lack an external effect or external goal (e.g. dance). We show that for these actions, adults infer that the agents’ goal is to produce the movements themselves: Movements are seen as the intended outcome, not just a means to an end. We test what drives observers to infer such movement-based goals, hypothesizing that observers infer movement-based goals to explain actions that are clearly intentional, but are not an efficient means to any plausible external goal. In three experiments, we separately manipulate intentionality and efficiency, equating for movement trajectory, perceptual features, and external effects. We find that participants only infer movement based goals when the actions are intentional and are not an efficient means to external goals. Thus, participants appear to infer that movements are the goal in order to explain otherwise mysterious intentional actions. These findings expand models of goal inference to account for intentional yet ‘irrational’ actions, and suggest a novel explanation for over imitation as emulation of movement-based goals.

Four experiments investigated whether infants and adults infer that a novel entity that interacts in a contingent, communicative fashion with an experimenter is itself an intentional agent. The experiments contrasted the hypothesis that such an inference follows from amodal representations of the contingent interaction alone with the hypothesis that features of the experimenter’s behavior might also influence intentional attribution. Twelve- to 13-month-old infants and adults observed a novel entity respond contingently to a confederate experimenter, the form of whose actions varied across conditions. For infants, intentionality attribution was assessed by the extent to which they subsequently followed the faceless entity’s implied attentional focus. For adults, intentionality attribution was assessed from their use of psychological terms when later describing the entity’s behavior. In both groups, construal of the entity as an intentional agent was limited to a subset of contingent interaction conditions. At both ages, the pattern of responses across conditions suggests that whether an observed contingent interaction can be seen as a social interaction influences the attribution of intentional agency. These results further indicate that the agent detection mechanism responding to third-party contingent interactions, as a context-sensitive process, is distinct from the mechanism responding to directly experienced contingent interactions, suggested by prior developmental work to be based solely on amodal representations of an entity’s contingent reaction to behaviors of an infant. (PsycINFO Database Record (c) 2013 APA, all rights reserved)

Children from age 6 to 16 judged which of two photographs of unfamiliar faces showed the same person as an inspection photograph. Recognition accuracy improved markedly between ages 6 and 10 with little change thereafter. Six- and eight-year-old children were especially susceptible to error when certain disguises were provided, in both memory and simultaneous presentation conditions. In contrast, when the stimuli depicted familiar faces, six-year-old children made few errors and showed no susceptibility to confounding paraphernalia. We concluded that young children encode new faces in terms of striking, relatively isolated, features. By age 10 or 12 the adult capacity has emerged, enabling configurational representation of a face from very little exposure to it.

Unlike older children and adults, children of less than about 10 years of age remember photographs of faces presented upside down almost as well as those shown upright and are easily fooled by simple disguises. The development at age 10 of the ability to encode orientation-specific configurational aspects of a face may reflect completion of certain maturational changes in the right cerebral hemisphere.

Assessed the development in approximately 160 6–16 yr old Ss of the ability to encode unfamiliar faces. Performance improved markedly between ages 6 and 10 and then remained at a fixed level or actually declined for several years, finally improving again by age 16. Evidence is provided that this distinctive developmental course reflects, in part, acquisition of processes specific to the encoding of faces rather than general pattern encoding or metamemorial skills. The possibility that maturational factors contribute to the developmental course of face recognition is raised, and 2 sources of data relevant to assessing this possibility are discussed.

Studies of agrammatic Broca's aphasics' comprehension of sentences containing articles have demonstrated profound deficits. It has not been clear whether the impairments are due to an inability to isolate the article in the stream of speech, or to difficulty in the construction and/or interpretation of various syntactic, semantic, or pragmatic levels of representation. This paper reports three experiments on Broca's aphasics' ability to distinguish between common nouns (e.g., “a rose”) and proper nouns (e.g., “Rose”). This grammatical form class decision is signaled by the presence or absence of an article, and is represented at the lexical node level of linguistic analysis. The three experiments demonstrated that Broca's aphasics point to pictures representing classes of objects when asked to point to “the X” and point to pictures representing unique individuals when asked to point to “X”. Thus, they were shown to be able to use the presence or absence of an article to determine lexical category. Their performance was especially accurate in an oral language context which was highly redundant and in a written language context where patients themselves could control the rate of information flow. They were quantitatively impaired, relative to controls, in a third study, which made higher information processing demands. Moreover, in this third study nonsense syllables preceding the noun which are phonologically similar to a known article were much more likely to evoke the misclassification of its noun as common than were phonologically distinct nonsense syllables. These data indicate that Broca's aphasics indeed have some difficulty isolating the article in the stream of speech. Nevertheless, detailed analyses of aphasics' performance revealed their ability to distinguish between common nouns and proper nouns even under these demanding conditions. Taken together, the three studies show that insofar as agrammatic patients are able to keep track of the presence or absence of articles, they can make a grammatical decision at the lexical node level of linguistic analysis. We conclude, then, that agrammatic Broca's aphasics are particularly impaired in the use of articles to construct and/or interpret phrasal constituents.

Recent studies have documented an evolutionarily primitive, early emerging cognitive system for the mental representation of numerical quantity (the analog magnitude system). Studies with non-human primates, human infants, and preschoolers have shown this system to support computations of numerical ordering, addition, and subtraction involving whole number concepts prior to arithmetic training. Here we report evidence that this system supports children’s predictions about the outcomes of halving and perhaps also doubling transformations. A total of one hundred and thirty-eight kindergarten and first grade children were asked to reason about the quantity resulting from the doubling or halving of an initial numerosity (of a set of dots) or an initial length (of a bar). Controls for dot size, total dot area, and dot density ensured that children were responding to the number of dots in the arrays. Prior to formal instruction in symbolic multiplication, division, or rational number, halving (and perhaps doubling) computations appear to be deployed over discrete and possibly continuous quantities. The ability to apply simple multiplicative transformations to analog magnitude representations of quantity may form a part of the toolkit that children use to construct later concepts of rational number.

No abstract provided.