Search

Children in the United States (N = 488, 4-11 years, 239 females, 248 males, one other, 53% White; data collected 2021-2022) participated in three studies investigating their expectations about immigrants. Participants recognized that immigration impacts characters' national identity and behaviors. Although previous research reported that children may essentialize nationality, participants instead reasoned flexibly about immigrant characters. Children expected immigrant characters to share behaviors and preferences with people from both their heritage and host countries, suggesting they may think immigrants hold dual national identities. Even the youngest children tested (ages 4-6) reasoned flexibly about behaviors based on immigration status. Thus, children appear to view national identity as constructed through social and cultural experiences, rather than something innate., (© 2024 The Author(s). Child Development © 2024 Society for Research in Child Development.)

Evaluating whether someone's behavior is praiseworthy or blameworthy is a fundamental human trait. A seminal study by Hamlin and colleagues in 2007 suggested that the ability to form social evaluations based on third-party interactions emerges within the first year of life: infants preferred a character who helped, over hindered, another who tried but failed to climb a hill. This sparked a new line of inquiry into the origins of social evaluations; however, replication attempts have yielded mixed results. We present a preregistered, multi-laboratory, standardized study aimed at replicating infants' preference for Helpers over Hinderers. We intended to (1) provide a precise estimate of the effect size of infants' preference for Helpers over Hinderers, and (2) determine the degree to which preferences are based on social information. Using the ManyBabies framework for big team-based science, we tested 1018 infants (567 included, 5.5-10.5 months) from 37 labs across five continents. Overall, 49.34% of infants preferred Helpers over Hinderers in the social condition, and 55.85% preferred characters who pushed up, versus down, an inanimate object in the nonsocial condition; neither proportion differed from chance or from each other. This study provides evidence against infants' prosocial preferences in the hill paradigm, suggesting the effect size is weaker, absent, and/or develops later than previously estimated. As the first of its kind, this study serves as a proof-of-concept for using active behavioral measures (e.g., manual choice) in large-scale, multi-lab projects studying infants., (© 2024 John Wiley & Sons Ltd.)

Humans learn about the world through inductive reasoning, generalizing information about an individual to others in the category. Indeed, by infancy, monolingual children expect people who speak the same language (but not people who speak different languages) to be similar in their food preferences (Liberman et al., 2016). Here, we ask whether infants who are exposed to linguistic diversity are more willing to generalize information even across language-group lines. To test this, we ran an inductive inference task and collected data on exposure to linguistic diversity at the interpersonal and neighborhood levels. Infants with more linguistically diverse social networks were more likely to generalize a food preference across speakers of different languages. However, this relationship was not seen for neighborhood diversity. We discuss implications of this work on understanding the development of bias and its malleability based on early social experiences. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Across two preregistered studies with children (3-12-year-olds; N = 356) and adults ( N = 262) from the United States, we find robust expectations for intergroup empathic biases. Participants predicted that people would feel better about ingroup fortunes than outgroup fortunes and worse about ingroup misfortunes than outgroup misfortunes. Expectations of empathic bias were stronger when there was animosity and weaker when there was fondness between groups. The largest developmental differences emerged in participants' expectations about how others feel about outgroup misfortunes, particularly when there was intergroup animosity. Whereas young children (3-5-year-olds) generally expected people to feel empathy for the outgroup (regardless of the relationship between the groups), older children (9-12-year-olds) and adults expected Schadenfreude (feeling good when an outgroup experiences a misfortune) when the groups disliked one another. Overall, expectations of empathic biases emerge early but may be weaker when there are positive intergroup relationships. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Although the ability to consider others' visual perspectives to interpret ambiguous communication emerges during childhood, people sometimes fail to attend to their partner's perspective. Two studies investigated whether 4- to 6-year-olds show a "closeness-communication bias" in their consideration of a partner's perspective in a communication task. Participants played a game that required them to take their partner's visual perspective in order to interpret an ambiguous instruction. If children, like adults, perform worse when they overestimate the extent to which their perspective is aligned with that of a partner, then they should make more perspective-taking errors when interacting with a socially close partner compared with a more socially distant partner. In Study 1, social closeness was based on belonging to the same social group. In Study 2, social closeness was based on caregiving, a long-standing social relationship with a close kinship bond. Although social group membership did not affect children's consideration of their partner's perspective, children did make more perspective-taking errors when interacting with a close caregiver compared with a novel experimenter. These findings suggest that close personal relationships may be more likely to lead children to overestimate perspective alignment and hinder children's perspective-taking than shared social group membership, and they highlight important questions about the mechanisms underlying the effects of partner characteristics in perspective-taking tasks., (Copyright © 2023 Elsevier Inc. All rights reserved.)

People who are in close relationships tend to do and like the same things, a phenomenon termed the "homophily principle." The present research probed for evidence of the homophily principle in 4- to 6-year-old children. Across two experiments, participants ( N = 327; 166 girls, 161 boys; located in the Midwestern United States) were asked to predict the closeness of two people based on their preferences. Participants in Experiment 1 indicated that people with a shared preference or a shared dispreference were more closely affiliated than people whose preferences diverged, suggesting inferences of homophily. Furthermore, children were not only relying on the emotional valences expressed: They expected people with a shared preference to be closer than people who expressed positive emotions about different items and expected people with a shared dispreference to be closer than people who expressed negative emotions about different items. Experiment 2 replicated and extended the main findings of Experiment 1 with more naturalistic stimuli. The present studies provide strong evidence that young children apply the homophily principle to their reasoning about social relationships. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Here we investigated infants' developing ability to use emotional expressions as signals that guide their learning about objects. To do so, we presented 16- to 21-month-old infants ( N = 99) with actors who conveyed anger, fear, or pain, and tested infants' generalization of others' emotional expressions (Study 1) and infants' exploration of objects (Study 2). Our findings suggest that infants attend to the information conveyed by emotional expressions: When two expressions provide different information (e.g., one conveys threat, and the other does not), infants treated those emotions differently, even if they were both negative. Specifically, infants were more likely to generalize negative emotional expressions that conveyed threat compared to nonthreatening negative emotions (Study 1) and were more likely avoid interacting with potentially threatening items compared to items that were merely evaluated negatively (Study 2). But, when two emotional expressions provided the same information (e.g., that an item was threatening) infants responded similarly to those two emotions (Study 1). These findings are in line with evolutionary theories, which posit that emotions are critical information signals that can be used to learn about the world. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Children must navigate multifaceted social hierarchies to make sense of the social world. Whereas race and social status covary in many societies, minimal research has examined whether children use race as a status marker. Across three studies, we asked 3- to 11-year-old American children (N = 646) to determine which of two models was "in charge" while varying the models' race and posture cues. When the cue of race was presented individually (Study 1), children used it to derive their status inferences. That is, they expected a White model to more likely be "in charge" than a Black model. However, when the cue of race was presented in conjunction with conflicting posture cues (Study 3), children relied more heavily on posture to determine who was in "in charge." Thus, whereas children have learned the association between White and higher status from their community, they understand that other cues may be more indicative of social status., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

The lion's share of research on secrecy focuses on how deciding to keep or share a secret impacts a secret-keeper's well-being. However, secrets always involve more than one person: the secret-keeper and those from whom the secret is kept or shared with. Although secrets are inherently social, their consequences for people's reputations and social relationships have been relatively ignored. Secrets serve a variety of social functions, including (1) changing or maintaining one's reputation, (2) conveying social utility, and (3) establishing friendship. For example, if Beth has a secret about a past misdemeanor, she might not tell any of her friends in order to maintain her reputation as an outstanding citizen. If Beth does share this secret with her friend Amy, Amy could interpret this as a sign of trust and think that their friendship is special. However, Amy could also choose to share Beth's secret with the rest of the friend group to show that she is a useful member with access to valuable information about others. Attention to these social functions of secrets emerges from a young age, and secrets play a prominent role in human relationships throughout the lifespan. After providing an overview of what is currently known about the relational consequences of secrecy in childhood and adulthood, we discuss how social and developmental psychologists could work together to broaden our understanding of the sociality of secrets. Future steps include incorporating more dyadic and social network analyses into research on secrets and looking at similar questions across ages. This article is categorized under: Psychology > Reasoning and Decision Making., (© 2021 Wiley Periodicals LLC.)

Homophily structures human social networks: people tend to seek out or be attracted to those who share their preferences or values, and to generally expect social connections between similar people. Here, we probe the nature and extent of infants' homophilic thinking by asking whether infants can use information about other people's shared preferences in the absence of other socially relevant behaviors (e.g., their proximity or joint attention) to infer their affiliation. To do so, we present infants with scenarios in which two people either share a preference or have opposing preferences while varying (across studies) the degree to which those people engage in other socially relevant behaviors. We show that by 14 months of age, infants demonstrate clear inferences of homophily: they expect two people with a shared preference to be more likely to affiliate than two people without such similarity, even in the absence of other social behaviors that signal friendship. Although such cognition begins to emerge by 6-months, younger infants' inferences are bolstered by social behaviors that signal friendship. Thus, an abstract understanding that homophily guides third-party affiliation has its roots in the second year of life, and potentially earlier., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Ingesting dangerous substances can lead to illness, or even death, meaning that it is critical for humans to learn how to avoid potentially dangerous foods. However, young children are notoriously bad at choosing foods; they are willing to put nonfoods and disgust elicitors into their mouths. Because food choice is inherently social, we hypothesized that social learning and contamination might separately influence children's decisions about whether to eat or avoid a food. Here, we asked how children reason about foods that are contaminated by someone from within versus outside their culture. We presented 3- to 11-year-olds (N = 534) with videos of native and foreign speakers eating snacks. In Studies 1a and 1b, one speaker contaminated her food and the other did not, and we asked children (a) which food they would prefer to eat, (b) how germy each food was, and (c) which food would make them sick. Although children rated the contaminated food as germier regardless of whether it was contaminated by a foreign speaker (Study 1a) or by a native speaker (Study 1b), children were more likely to report that they would avoid eating foreign contaminated food compared with native contaminated food. In Study 2, we used a non-forced-choice method and found converging evidence that children attend to both culture and contamination when making food choices but that with age they place more weight on contamination status., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Children learn about other people through gossip. Although gossip can be a valuable and efficient way to learn about others, evaluating gossip's credibility requires understanding when people may be biased, and using this information to update the truth-value placed on the gossip. For instance, people may be motivated to improve their and their friends' reputations (or to worsen their enemies' reputations). Therefore, testimony that cuts against these social motivations may be more credible. Here, in four studies with 3- to 13-year-old children (total N = 860), we examined (1) children's expectations about the type of gossip people were likely to spread about friends versus enemies, and (2) children's ability to discount testimony that is in line with a speaker's social biases (e.g., negative testimony about a friend). We found that children expect speakers to say nice things about their friends, and mean things about their enemies. And, children were less likely to endorse potentially biased testimony, though the strength of their ability to avoid endorsing biased testimony varied based on the domain of testimony. Overall, these studies suggest that children expect a speaker's testimony to be systematically biased based on her relationships. Our results underscore the importance of tracking and using relationships when evaluating testimony, because relationships have immense power for helping us effectively make sense of an ambiguous world., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Socially savvy individuals track what they know and what other people likely know, and they use this information to navigate the social world. We examine whether children expect people to have shared knowledge based on their social relationships (e.g., expecting friends to know each other's secrets, expecting members of the same cultural group to share cultural knowledge) and we compare children's reasoning about shared knowledge to their reasoning about common knowledge (e.g., the wrongness of moral violations). In three studies, we told 4- to 9-year-olds (N = 227) about what a child knew and asked who else knew the information: The child's friend (Studies 1-3), the child's schoolmate (Study 1), another child from the same national group (Study 2), or the child's sibling (Study 3). In all three studies, older children reliably used relationships to infer what other people knew. Moreover, with age, children increasingly considered both the type of knowledge and an individual's social relationships when reporting who knew what. The results provide support for a 'Selective Inferences' hypothesis and suggest that children's early attention to social relationships facilitates an understanding of how knowledge transfers - an otherwise challenging cognitive process., (© 2020 John Wiley & Sons Ltd.)

Secrets play a powerful role in human social relationships. Here, we examine the developmental trajectory of 3- to 10-year-old children's (N = 630) expectations about (a) how relationships impact whether people will keep secrets, and (b) how relationships are impacted when a confidee keeps versus tells a confider's secret. Sophisticated expectations about the role of secrets in relationship maintenance develop across childhood. In particular, school-age children (6- to 10-year-olds) expect friends to be more likely to keep each other's secrets than nonfriends (Study 1), and expect that if a friend breaks this norm and shares his friend's secret with a third-party, it will harm the friendship (Studies 2 and 3). These expectations were specific to inferences about secrets: school-age children did not expect that sharing (or keeping) a friend's fact or surprise would impact the friendship strength (Studies 2 and 3). These findings did not hold for preschoolers (3- to 5-year-olds), who did not have clear expectations linking secret sharing to friendship strength. Taken together, our results indicate that by 6 years of age, children understand that social relationships can increase people's obligations to keep each other's secrets, and that failing to do so can harm the relationship. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Tomasello provides compelling evidence that children understand that people are morally obligated toward members of their social group. We call for expanding the scope of inquiry to encompass the full developmental trajectory of humans' understanding of the relation between moral obligation, sociality, and stancetaking in interaction. We suggest that humans display a lifelong preoccupation with the sociality of moral obligation.

Friendship fundamentally shapes interactions, and predicting other people's affiliations is crucial for effectively navigating the social world. We investigated how 3- to 11-year-old children use three cues to reason about friendship: propinquity, similarity, and loyalty. In past work, researchers asked children to report on their own friendships and found a shift from an early focus on propinquity to a much later understanding of the importance of loyalty. Indeed, attention to loyalty was not standard until adolescence. Across four studies (total N = 900), we used a simpler method in which we asked children to make a forced-choice decision about which of two people a main character was better friends with. Although we replicated the finding that understanding the importance of loyalty increases with age, we also found evidence that even the youngest children tested (3- to 5-year-olds) can use loyalty to predict friendship. Thus, a sophisticated understanding of how social interactions unfold differently between friends and nonfriends may be evident by the preschool years. We also discuss interesting developmental differences in how children weigh the importance of each of these friendship cues., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Secrets carry valuable social information. Because the content of secrets can be damaging to the secret-keeper's reputation, people should only disclose their secrets to people whom they trust. Therefore, tracking which people know each other's secrets can be used as cue of social relationships: If one person tells another person a secret, those people are likely friends. Here, in 5 studies with 3- to 12-year-old children (total N = 452), we examined the developmental trajectory of reasoning about secret sharing as an indication of third-party friendship. By age 6, but not before, children expected that a person would be friends with someone that she told a secret. We replicated this main finding across four studies by comparing secret sharing to other cues of affiliation. Children treated sharing a secret as a stronger cue to friendship than sharing a physical object (Study 1), sharing a fact (Studies 2-4), or sharing membership on the same sports team (Study 3). Although younger children did not understand that secret sharing indicated friendship, they did expect people to be more likely to disclose their secrets to friends than to nonfriends (Study 5). Taken together, our results indicate that children understand the social significance of sharing secrets and use secret sharing to make important predictions about the social world. Specifically, children infer social relationships based on which people know each other's secrets and expect others to share secrets selectivity with friends. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Recent research has shown that infants selectively approach prosocial versus antisocial characters, suggesting that foundations of sociomoral development may be present early in life. Despite this, to date, the mental processes involved in infants' prosocial preferences are poorly understood. To explore a possible role of emotions in early social evaluations, the current studies examined whether four samples of infants and toddlers express different emotional reactions after observing prosocial (giving) versus antisocial (taking) events. Experimentally blind coders rated infants' and toddlers' emotional reactions to prosocial and antisocial interactions from video using a 1- to 7-point Likert scale of negative to positive emotion; reactions were rated as more positive after viewing prosocial compared to antisocial interactions in three of four samples. While the observed effects were small, a single-paper meta-analysis suggests that the findings are robust and stable across age. These results support the possibility that emotional reactions play some role in infants' sociomoral evaluations. Statement of contribution What is already known Infants prefer prosocial to antisocial individuals from the first year of life. Emotion plays some role in the sociomoral judgments of children and adults. What this study adds Infants and toddlers express more positive reactions after observing prosocial giving versus antisocial taking acts, though observed effect sizes are small. Naïve coders can predict at a better than chance rate what type of act an infant or toddler just viewed based on their facial expressions. Provides the first evidence that emotion plays some to-be-specified role in infants' and toddlers' sociomoral evaluations., (© 2017 The British Psychological Society.)

Many rituals are socially stipulated such that engaging in a group's rituals can fundamentally signal membership in that group. Here, we asked whether infants infer information about people's social affiliation based on whether those people perform the same ritualistic action versus different actions. We presented 16-month-old infants with two people who used the same object to achieve the same goal: turning on a light. In a first study, the actions that the actors used to turn on the light had key properties of ritual: they were not causally necessary to reach the overall goal, and there were no features of the situation that required doing the particular actions. We varied whether the two actors performed the same action or performed different actions to turn on the light. Infants expected people who used the same ritualistic action to be more likely to affiliate than people who used different actions. A second study indicated that these results were not due to perceptual similarity: when the differences in the actors' actions were not marked by properties of ritual, but were instead due to situational constraints, infants expected the actors to affiliate. Thus, infants understand the social significance of people engaging in common, potentially ritualistic actions, and expect these actions to provide information about third-party social relationships., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Developmental psychology can shed light on (1) the intuitive systems that underlie folk-economic beliefs (FEBs), and (2) how FEBs are created and revised. Boyer & Petersen (B&P) acknowledge the first, but we argue that they do not seriously consider the second. FEBs vary across people (and within a person), and much of this variation may be explained by socialization, social context, and social learning.

Although children demonstrate robust social preferences for ingroup members early in ontogeny, it is not yet clear whether these preferences are based on children generally liking people who are more familiar or on children holding specific biased beliefs about people in their ingroup as compared with people in their outgroup. Here, we investigated the origins of humans' propensity to link ingroup members with positive behaviors and outgroup members with negative behaviors by asking whether linguistic group membership influences children's expectations of how people will act. Our findings indicate that the effect of group membership on children's expectations about other people's actions varies across both domain (moral and conventional) and age. Whereas all children in our study (3- to 11-year-olds) expected ingroup members to be more likely to conform to social conventions and expected outgroup members to be more likely to break conventional rules, only older children (7- to 11-year-olds) used social group membership to form expectations about which people would be more likely to act morally versus immorally. Thus, younger children do not automatically form biased character judgments based on group membership, although they do understand that social group membership is particularly relevant for reasoning about which people will be more likely to act in line with social norms., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Resource sharing is an important aspect of human society, and how resources are distributed can provide people with crucial information about social structure. Indeed, a recent partiality account of resource distribution suggested that people may use unequal partial resource distributions to make inferences about a distributor's social affiliations. To empirically test this suggestion derived from the theoretical argument of the partiality account, we presented 4- to 9-year-old children with distributors who gave out resources unequally using either a partial procedure (intentionally choosing which recipient would get more) or an impartial procedure (rolling a die to determine which recipient would get more) and asked children to make judgments about whom the distributor was better friends with. At each age tested, children expected a distributor who gave partially to be better friends with the favored recipient (Studies 1-3). Interestingly, younger children (4- to 6-year-olds) inferred friendship between the distributor and the favored recipient even in cases where the distributor used an impartial procedure, whereas older children (7- to 9-year-olds) did not infer friendship based on impartial distributions (Study 1). These studies demonstrate that children use third-party resource distributions to make important predictions about the social world and add to our knowledge about the developmental trajectory of understanding the importance of partiality in addition to inequity when making social inferences., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Forming conceptually-rich social categories helps people to navigate the complex social world by allowing them to reason about the likely thoughts, beliefs, actions, and interactions of others, as guided by group membership. Nevertheless, social categorization often has nefarious consequences. We suggest that the foundation of the human ability to form useful social categories is in place in infancy: social categories guide the inferences infants make about the shared characteristics and social relationships of other people. We also suggest that the ability to form abstract social categories may be separable from the eventual negative downstream consequences of social categorization, including prejudice, discrimination, and stereotyping. Although a tendency to form inductively-rich social categories appears early in ontogeny, prejudice based on each particular category dimension may not be inevitable., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Language provides rich social information about its speakers. For instance, adults and children make inferences about a speaker's social identity, geographic origins, and group membership based on her language and accent. Although infants prefer speakers of familiar languages (Kinzler, Dupoux, & Spelke, 2007), little is known about the developmental origins of humans' sensitivity to language as marker of social identity. We investigated whether 9-month-olds use the language a person speaks as an indicator of that person's likely social relationships. Infants were familiarized with videos of two people who spoke the same or different languages, and then viewed test videos of those two individuals affiliating or disengaging. Results suggest that infants expected two people who spoke the same language to be more likely to affiliate than two people who spoke different languages. Thus, infants view language as a meaningful social marker and use language to make inferences about third-party social relationships., (Copyright © 2016 Cognitive Science Society, Inc.)

Early exposure to multiple languages can enhance children's communication skills, even when children are effectively monolingual (Fan, Liberman, Keysar & Kinzler, ). Here we report evidence that the social benefits of multilingual exposure emerge in infancy. Sixteen-month-old infants participated in a communication task that required taking a speaker's perspective to understand her intended meaning. Infants were presented with two identical toys, such as two cars. One toy was mutually visible to both the infant and the speaker, but the other was visible only to the infant and was blocked from the speaker's view by an opaque barrier. The speaker requested the mutually visible toy and we evaluated whether infants understood the speaker's request. Whereas monolingual infants were at chance in choosing between the two toys, infants with multilingual exposure reliably chose the toy the speaker requested. Successful performance was not related to the degree of exposure to other languages, suggesting that even minimal multilingual exposure may enhance communication skills., (© 2016 John Wiley & Sons Ltd.)

Selecting appropriate foods is a complex and evolutionarily ancient problem, yet past studies have revealed little evidence of adaptations present in infancy that support sophisticated reasoning about perceptual properties of food. We propose that humans have an early-emerging system for reasoning about the social nature of food selection. Specifically, infants' reasoning about food choice is tied to their thinking about agents' intentions and social relationships. Whereas infants do not expect people to like the same objects, infants view food preferences as meaningfully shared across individuals. Infants' reasoning about food preferences is fundamentally social: They generalize food preferences across individuals who affiliate, or who speak a common language, but not across individuals who socially disengage or who speak different languages. Importantly, infants' reasoning about food preferences is flexibly calibrated to their own experiences: Tests of bilingual babies reveal that an infant's sociolinguistic background influences whether she will constrain her generalization of food preferences to people who speak the same language. Additionally, infants' systems for reasoning about food is differentially responsive to positive and negative information. Infants generalize information about food disgust across all people, regardless of those people's social identities. Thus, whereas food preferences are seen as embedded within social groups, disgust is interpreted as socially universal, which could help infants avoid potentially dangerous foods. These studies reveal an early-emerging system for thinking about food that incorporates social reasoning about agents and their relationships, and allows infants to make abstract, flexible, adaptive inferences to interpret others' food choices., Competing Interests: The authors declare no conflict of interest.

Skilled social interactions require knowledge about others' intentions and the ability to implement this knowledge in real-time to generate appropriate responses to one's partner. Young infants demonstrate an understanding of other people's intentions (e.g. Woodward, Sommerville, Gerson, Henderson & Buresh, 2009), yet it is not until the second year that infants seem to master the real-time implementation of their knowledge during social interactions (e.g. Warneken & Tomasello, 2007). The current study investigates the possibility that developments in social competence during the second year are related to increases in the speed with which infants can employ their understanding of others' intentions. Twenty- to 22-month-old infants (N = 23) viewed videos of goal-directed actions on a Tobii eye-tracker and then engaged in an interactive perspective-taking task. Infants who quickly and accurately anticipated another person's future behavior in the eye-tracking task were more successful at taking their partner's perspective in the social interaction. Success on the perspective-taking task was specifically related to the ability to correctly predict another person's intentions. These findings highlight the importance of not only being a 'smart' social partner but also a 'fast' social thinker., (© 2015 John Wiley & Sons Ltd.)

Early language exposure is essential to developing a formal language system, but may not be sufficient for communicating effectively. To understand a speaker's intention, one must take the speaker's perspective. Multilingual exposure may promote effective communication by enhancing perspective taking. We tested children on a task that required perspective taking to interpret a speaker's intended meaning. Monolingual children failed to interpret the speaker's meaning dramatically more often than both bilingual children and children who were exposed to a multilingual environment but were not bilingual themselves. Children who were merely exposed to a second language performed as well as bilingual children, despite having lower executive-function scores. Thus, the communicative advantages demonstrated by the bilinguals may be social in origin, and not due to enhanced executive control. For millennia, multilingual exposure has been the norm. Our study shows that such an environment may facilitate the development of perspective-taking tools that are critical for effective communication., (© The Author(s) 2015.)

Predicting others' affiliative relationships is critical to social cognition, but there is little evidence of how this ability develops. We examined 9-month-old infants' inferences about 3rd-party affiliation based on shared and opposing evaluations. Infants expected 2 people who expressed shared evaluations to interact positively, whereas they expected 2 people who expressed opposing evaluations to interact negatively. A control condition revealed that infants' expectations could not be due to mere perceptual repetition. Thus, an abstract understanding that 3rd-party affiliation can be based on shared intentions has roots in the 1st year of life. These findings have implications for understanding humans' earliest representations of the social world., (PsycINFO Database Record (c) 2014 APA, all rights reserved.)

Adults tend to like individuals who are similar to themselves, and a growing body of recent research suggests that even infants and young children prefer individuals who share their attributes or personal tastes over those who do not. In this study, we examined the nature and development of attitudes toward similar and dissimilar others in human infancy. Across two experiments with combined samples of more than 200 infant participants, we found that 9- and 14-month-old infants prefer individuals who treat similar others well and treat dissimilar others poorly. A developmental trend was observed, such that 14-month-olds' responses were more robust than were 9-month-olds'. These findings suggest that the identification of common and contrasting personal attributes influences social attitudes and judgments in powerful ways, even very early in life.

High glucose (HG) has been shown to induce insulin resistance in both type 1 and type 2 diabetes. However, the molecular mechanism behind this phenomenon is unknown. Insulin receptor substrate (IRS) proteins are the key signaling molecules that mediate insulin's intracellular actions. Genetic and biological studies have shown that reductions in IRS1 and/or IRS2 protein levels are associated with insulin resistance. In this study we have shown that proteasome degradation of IRS1, but not of IRS2, is involved in HG-induced insulin resistance in Chinese hamster ovary (CHO) cells as well as in primary hepatocytes. To further investigate the molecular mechanism by which HG induces insulin resistance, we examined various molecular candidates with respect to their involvement in the reduction in IRS1 protein levels. In contrast to the insulin-induced degradation of IRS1, HG-induced degradation of IRS1 did not require IR signaling or phosphatidylinositol 3-kinase/Akt activity. We have identified glycogen synthase kinase 3beta (GSK3 beta or GSK3B as listed in the MGI Database) as a kinase required for HG-induced serine(332) phosphorylation, ubiquitination, and degradation of IRS1. Overexpression of IRS1 with mutation of serine(332) to alanine partially prevents HG-induced IRS1 degradation. Furthermore, overexpression of constitutively active GSK3 beta was sufficient to induce IRS1 degradation. Our data reveal the molecular mechanism of HG-induced insulin resistance, and support the notion that activation of GSK3 beta contributes to the induction of insulin resistance via phosphorylation of IRS1, triggering the ubiquitination and degradation of IRS1.

Serine/threonine phosphorylation of insulin receptor substrate-1 (IRS-1) is an important negative modulator of insulin signaling. Previously, we showed that glycogen synthase kinase-3 (GSK-3) phosphorylates IRS-1 at Ser(332). However, the fact that GSK-3 requires prephosphorylation of its substrates suggested that Ser(336) on IRS-1 was the "priming" site phosphorylated by an as yet unknown protein kinase. Here, we sought to identify this "priming kinase" and to examine the phosphorylation of IRS-1 at Ser(336) and Ser(332) in physiologically relevant animal models. Of several stimulators, only the PKC activator phorbol ester PMA enhanced IRS-1 phosphorylation at Ser(336). Treatment with selective PKC inhibitors prevented this PMA effect and suggested that a conventional PKC was the priming kinase. Overexpression of PKCalpha or PKCbetaII isoforms in cells enhanced IRS-1 phosphorylation at Ser(336) and Ser(332), and in vitro kinase assays verified that these two kinases directly phosphorylated IRS-1 at Ser(336). The expression level and activation state of PKCbetaII, but not PKCalpha, were remarkably elevated in the fat tissues of diabetic ob/ob mice and in high-fat diet-fed mice compared with that from lean animals. Elevated levels of PKCbetaII were also associated with enhanced phosphorylation of IRS-1 at Ser(336/332) and elevated activity of GSK-3beta. Finally, adenoviral mediated expression of PKCbetaII in adipocytes enhancedphosphorylation of IRS-1 at Ser(336). Taken together, our results suggest that IRS-1 is sequentially phosphorylated by PKCbetaII and GSK-3 at Ser(336) and Ser(332). Furthermore, these data provide evidence for the physiological relevance of these phosphorylation events in the pathogenesis of insulin resistance in fat tissue.

Correct patterning of cells within an epithelium is key to establishing their normal function. However, the precise mechanisms by which individual cells arrive at their final developmental niche remains poorly understood. We developed an optimized system for imaging the developing Drosophila retina, an ideal tissue for the study of cell positioning. Using this technique, we characterized the cellular dynamics of developing wild-type pupal retinas. We also analyzed two mutants affecting eye patterning and demonstrate that cells mutant for Notch or Roughest signaling were aberrantly dynamic in their cell movements. Finally, we establish a role for the adherens junction regulator P120-Catenin in retinal patterning through its regulation of normal adherens junction integrity. Our results indicate a requirement for P120-Catenin in the developing retina, the first reported developmental function of this protein in the epithelia of lower metazoa. Based upon our live visualization of the P120-Catenin mutant as well as genetic data, we conclude that P120-Catenin is acting to stabilize E-cadherin and adherens junction integrity during eye development.

The ability of glycogen synthase kinase-3 (GSK-3) to phosphorylate insulin receptor substrate-1 (IRS-1) is a potential inhibitory mechanism for insulin resistance in type 2 diabetes. However, the serine site(s) phosphorylated by GSK-3 within IRS-1 had not been yet identified. Using an N-terminal deleted IRS-1 mutant and two IRS-1 fragments, PTB-1 1-320 and PTB-2 1-350, we localized GSK-3 phosphorylation site(s) within amino acid sequence 320-350. Mutations of serine 332 or 336, which lie in the GSK-3 consensus motif (SXXXS) within PTB-2 or IRS-1, to alanine abolished their phosphorylation by GSK-3. This suggested that Ser332 is a GSK-3 phosphorylation site and that Ser336 serves as the "priming" site typically required for GSK-3 action. Indeed, dephosphorylation of IRS-1 prevented GSK-3 phosphorylation. Furthermore, the phosphorylated peptide derived from the IRS-1 sequence was readily phosphorylated by GSK-3, in contrast to the nonphosphorylated peptide, which was not phosphorylated by the enzyme. When IRS-1 mutants S332A(IRS-1), S336A(IRS-1), or S332A/336A(IRS-1) were expressed in Chinese hamster ovary cells overexpressing insulin receptors, their insulin-induced tyrosine phosphorylation levels increased compared with that of wild-type (WT) IRS-1. This effect was stronger in the double mutant S332A/336A(IRS-1) and led to enhanced insulin-mediated activation of protein kinase B. Finally, immunoblot analysis with polyclonal antibody directed against IRS-1 phosphorylated at Ser332 confirmed IRS-1 phosphorylation in cultured cells. Moreover, treatment with the GSK-3 inhibitor lithium reduced Ser332 phosphorylation, whereas overexpression of GSK-3 enhanced this phosphorylation. In summary, our studies identify Ser332 as the GSK-3 phosphorylation target in IRS-1, indicating its physiological relevance and demonstrating its novel inhibitory role in insulin signaling.