Oxytocin attenuates racial categorization in 14-month-old infants.

Intergroup bias - the preferential attitudes one holds towards one's social group - is a ubiquitous socio-cognitive phenomenon. In fact, studies show that already in the first months of life, infants manifest a preference for members of their own social group. This points to the possibility of inborn mechanisms involved in social group cognition. Here we assess the effect of a biological activation of infants' affiliative motivation on their social categorization capacity. In a first visit to the lab, mothers self-administered either Oxytocin (OT) or placebo (PL) via a nasal spray and then engaged in a face-to-face interaction with their 14-month-old infants, a procedure previously shown to increase OT levels in infants. Infants then performed a racial categorization task presented on an eye-tracker. Mothers and infants returned a week later and repeated the procedure while self-administering the complementary substance (i.e., PL or OT, respectively). In total, 24 infants completed the two visits. We found that whereas infants in the PL condition on the first visit exhibited racial categorization, infants in the OT condition in their first visit did not. Moreover, these patterns remained a week later despite the change in substance. Thus, OT inhibited racial categorization when infants first encountered the to-be-categorized faces. These findings highlight the role of affiliative motivation in social categorization, and suggest that the neurobiology of affiliation may provide insights on mechanisms that may be involved in the downstream prejudicial consequences of intergroup bias.

Comparing the broad socio-cognitive profile of youth with Williams syndrome and 22q11.2 deletion syndrome.

BACKGROUND: Numerous studies have assessed the socio-cognitive profile in Williams syndrome (WS) and, independently, in 22q11.2 deletion syndrome (22q11.2DS). Yet, a cross-syndrome comparison of these abilities between individuals with these two syndromes with known social deficits has not been conducted. METHODS: Eighty-two children participated in four study groups: WS (n = 18), 22q112.DS (n = 24), age-matched individuals with idiopathic developmental disability (IDD; n = 20) and typically developing (TD) controls (n = 20). Participants completed four socio-cognitive tests: facial emotion recognition, mental state attribution, differentiating real from apparent emotions and trait inference based on motives and actions-outcomes. RESULTS: The current findings demonstrate that children with WS were better in labelling happy faces compared with children with 22q11.2DS, partially reflecting their exaggerated social drive. In the false belief task, however, the WS and IDD groups performed poorly compared with the 22q11.2DS group, possibly due to their difficulty to interpret subtle social cues. When asked to identify the gap between real-negative vs. apparent-positive emotions, the 22q11.2DS group performed similarly to TD children but better than the WS group, possibly due to their anxious personality and their innate bias towards negatively valence cues. Finally, individuals with WS were more willing to become friends with a story character even when the character's motives were negative, reflecting their difficulty to avoid potentially harmful real-life situations. CONCLUSIONS: Overall, our multi-facet socio-cognitive battery uncovered strengths and weaknesses in social cognition that are syndrome-specific, shared among the genetic syndromes, or common to the three clinical groups compared with healthy controls. Our findings underscore the need to devise age-specific and condition-specific assessment tools and intervention programs towards improving these children's socio-cognitive deficits.

Children's avoidance of lexical overlap: a pragmatic account.

Children tend to choose an unfamiliar object rather than a familiar one when asked to find the referent of a novel name. This response has been taken as evidence for the operation of certain lexical constraints in children's inferences of word meanings. The present studies test an alternative--pragmatic--explanation of this phenomenon among 3-year-olds. In Study 1 children responded to a request for the referent of a novel label in the same way that they responded to a request for the referent of a novel fact. Study 2 intimated that children assume that labels are common knowledge among members of the same language community. Study 3 demonstrated that shared knowledge between a speaker and listener plays a decisive role in how children interpret a speaker's request. The findings suggest that 3-year-olds' avoidance of lexical overlap is not unique to naming and may derive from children's sensitivity to speakers' communicative intentions.

Essentialism in Brazilian children's extensions of animal names.

The present study investigates whether Brazilian children have essentialist beliefs about animal categories. Two groups of Brazilian 4-year-olds (middle class and from shantytowns) were told that 2 animals share either internal or superficial properties. They were then taught labels for the animals. Across conditions, children from both groups were equally likely to interpret the labels as referring to mutually exclusive categories of animals, but they differed on how likely they were to maintain an inclusion relation between the labels. More important, children from both groups were more likely to accept a common label for animals sharing internal than superficial properties, indicating that internal property information convinced children that the animals were of the same kind. These findings were comparable to the results of a recent study by G. Diesendruck, S. A. Gelman, and K. Lebowitz (1998) with North American 4-year-olds.

Domain differences in absolute judgments of category membership: evidence for an essentialist account of categorization.

There has been some debate about the correspondence between typicality gradients and category membership. The present study investigates the relationship between these two measures in the domains of animals and artifacts. Forty-two adults judged the degree of typicality or category membership of 293 animals and artifacts. The subjects' tendency for animals, but not for artifacts, was to make more absolute ratings on category membership (i.e., judging exemplars as definitely members or definitely not members of their respective category) than on typicality. More importantly, at almost every level of typicality, subjects were more likely to make absolute judgments of category membership for animals than for artifacts. These results indicate that people treat category membership of animals as relatively absolute (which best fits an essentialist model of categorization) and treat category membership of artifacts as relatively graded (which best fits a prototype model of categorization). These domain differences add crucial supporting evidence for claims about the domain-specificity of essentialism.

Conceptual and linguistic biases in children's word learning.

Four studies examined the influence of essentialist information and perceptual similarity on preschoolers' interpretations of labels. In Study 1, 3-, 4-, and 5-year-olds were less likely to interpret 2 labels for animals as referring to mutually exclusive categories: when the animals were said to share internal, rather than superficial, properties and when the animals were perceptually similar rather than dissimilar. In Study 2, neither internal nor functional property information influenced 4-year-olds' interpretations of labels for artifacts. Studies 3 and 4 provide baseline data, demonstrating that the domain differences were not due to prior differences in children's lexical knowledge in the 2 domains. These results suggest that children have essentialist beliefs about animals, but not about artifacts, and that these beliefs interact with children's assumptions about word meaning in determining their interpretations of labels.

The effect of perceptual similarity and linguistic input on children's acquisition of object labels.

This study investigated whether and when children establish various semantic relations between old and new words. Fifty two-year-olds were taught labels for objects previously referred to by an overextended term. We found that children were more likely to learn a new label when (a) it referred to a new object that was perceptually dissimilar, rather than similar, to a known one, and (b) when linguistic information indicated it had an inclusion, rather than a mutually exclusive, relation to a known label. Children were more likely to interpret a new label as mutually exclusive to a known one when their referents were perceptually dissimilar. These findings are discussed in light of theories of lexical development, particularly with regard to conceptualizations of constraints on the acquisition of word meaning.