Religious polarization and justification of belief in invisible scientific versus religious entities.

Children and adults express greater confidence in the existence of invisible scientific as compared to invisible religious entities. To further examine this differential confidence, 5- to 11-year-old Turkish children and their parents (N = 174, 122 females) from various regions in Türkiye, a country with an ongoing tension between secularism and religion, were tested in 2021 for their belief in invisible entities. Participants expressed more confidence in the existence of scientific than religious entities. For scientific entities, children justified their belief primarily by elaborating on the properties of the entity, rather than referring to the testimonial source of their judgment. This pattern was reversed for religious entities, arguably, highlighting the role of polarization in shaping the testimony children typically hear.

Children's expectations about the stability of others' knowledge and preference states.

It is a crucial ability to predict others' psychological states across time and contexts. Focusing on cultural inventions such as songs and stories, we contrasted children's attributions of stability with others' knowledge and preference states across time and space and whether these attributions change as a function of children's familiarity with the known/liked items. Children (91 4-year-olds and 97 6-year-olds) were introduced to characters who knew or liked a song, a story, a game and a dance that were either novel or familiar. Children were asked whether the characters would still know/like these when they move to another city or when they grow up to be an adult. Both age groups expected these attributes to be more durable in the moving scenario compared with the growing-up scenario, but this trend became more robust with age. Whereas overall children did not judge knowledge as more durable than preferences, children found knowledge to be more enduring with age. The 6-year-olds' stability attributions also increased when known/liked items were familiar. These results suggest that, across the preschool years, children become more nuanced in their predictions about the future forms of knowledge and preference states.

Children use epistemic states flexibly to make diagnostic social inferences.

Children are sensitive to their own and others' epistemic states and use these to guide their learning and communication. Here, we systematically examined children's use of epistemic states to make diagnostic social inferences. Specifically, we investigated children's group membership inferences based on what others do and do not know and what role children's own knowledge states and the type of knowledge play in these inferences. Across two preregistered studies, 7- and 8-year-old children (N = 100) were shown targets who were knowledgeable (Study 1) or ignorant (Study 2) of familiar and unfamiliar knowledge items that were either general or culture-specific and asked to guess whether the targets would be linguistic ingroup or outgroup members. Children inferred that the targets would speak their native language if they shared targets' epistemic states and a foreign language if they did not. Importantly, these patterns were particularly evident when epistemic states involved cultural knowledge. Further, children's inferences became more nuanced with age. These findings suggest that others' knowledge states are socially meaningful in childhood and children use their own and others' epistemic states in flexible ways to guide their diagnostic social judgments. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Children intend to teach conventional but not moral norms selectively to ingroup members.

Several studies have investigated factors guiding children's decisions when learning from others, although less is known about factors that govern children's decisions when they transfer knowledge to others. Here we asked whether children would privilege ingroup members when teaching and, if so, whether this tendency would persist when transferring different kinds of information (conventional norms vs. moral norms). In Experiment 1 (N = 24), we first replicated ingroup preference based on minimal group membership with 5- and 6-year-old Turkish children. In Experiment 2 (N = 64), we examined whether children would consider group membership and the type of knowledge to be transferred in their teaching intentions. Children were introduced to two ignorant targets differing in their group membership and were asked to choose one or both of these targets to teach conventional or moral norms. Children were more likely to choose ingroup members for teaching conventional norms and both members when teaching moral norms. Further, this trend was particularly evident among girls. These results suggest that children make flexible teaching decisions considering the social attributes of the learners and raise interesting questions regarding the mechanisms underlying children's information transfer. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Adult listeners can extract age-related cues from child-directed speech.

This study investigated adult listeners' ability to detect age-related cues in child-directed speech (CDS). Participants (N = 186) listened to two speech recordings directed at children between the ages of 6 and 44 months and guessed which had addressed a younger or an older child. The recordings came from North American English-speaking mothers and listeners were native speakers of Turkish with varying degrees of English knowledge. Participants were randomly assigned to listen either to the original recordings or to the low-pass filtered versions. Accuracy was above chance level across all groups. Participants' English level, age, and the age difference between the addressees significantly predicted accuracy. After controlling for these variables, we found a significant effect of condition. Participants' accuracy tended to be better in the unfiltered condition with the exception of male participants without children. These results suggest that age-related variations in CDS are perceptually available to adult listeners. Furthermore, even though sensitivity to the age-related cues is facilitated by the availability of content-related cues in speech, it does not seem to be solely dependent on these cues, providing further support for the form-function relations in CDS.

The social meaning of common knowledge across development.

Common knowledge can be a potent sign of shared social attributes among people, but not all knowledge is socially meaningful to the same extent. For instance, compared to shared knowledge of cultural practices, knowledge of self-evident facts might be a poorer indicator of shared group membership among individuals. Two studies explored adults' and 6-to-9 years old children's social inferences based on what others know as well as their sensitivity to the distinctions in the diagnostic potential of different kinds of knowledge. Participants were presented with targets who were knowledgeable about familiar things that are either culture-specific (e.g., a traditional dance) or general (e.g., a self-evident fact), and asked to make inferences about their language and where they live. Adults and 8-year-olds privileged culture-specific knowledge over general knowledge when making both kinds of inferences about the targets, whereas 6-year-olds did not distinguish between the two knowledge types. Thus, what others know is socially meaningful from early in life, and across development, children become increasingly aware of the diagnostic potential of culture-specific knowledge when making social inferences about others. These findings suggest novel social implications of knowledge assessment.

Infants' expectations about the recipients of infant-directed and adult-directed speech.

Across cultures, adults produce infant-directed speech (IDS) when addressing infants. We explored whether infants expect IDS to be directed at infants and adult-directed speech (ADS) to adults. Infants from Spain and Turkey (12-15 months) watched animated videos with geometric figures, where one adult figure talked to an infant or another adult figure, while they were gazing at each other (Experiments 1 and 2). In some events, the adult figure addressed the infant figure with IDS, or the other adult figure with ADS (congruent); and in others, the same adult figure addressed the other adult figure with IDS or the infant figure with ADS (incongruent). Both groups of infants showed greater looking at incongruent than congruent events. This preference disappeared when the two figures gazed away from each other (Experiment 3). Thus, by 12 months of age, infants have nuanced expectations that different speech registers such as IDS and ADS are appropriate for addressing different recipients in third-party communicative contexts.

Children and Adults Selectively Attribute Shared Cultural Knowledge to Speakers of the Same Language.

Children's and adults' attributions of shared knowledge of and shared preference for songs were investigated across two prominent social categories: language and gender. Both attributions indicate similarity among individuals but shared cultural knowledge can be more informative about common social history than shared preference, as it is mainly transferred through social interactions within cultures, while preferences can have various sources. Both 5- to 6-year-old children (N = 60) and adults (N = 160) generalized knowledge of songs across individuals who speak the same-language rather than same-gender individuals. In contrast, preference for songs was not systematically generalized across either category. Thus, individuals selectively infer shared cultural knowledge among same-language speakers, suggesting an early emerging link between shared knowledge and cultural boundaries.

Essentialization of Social Categories Across Development in Two Cultures.

Children display an "essentialist" bias in their everyday thinking about social categories. However, the degree and form of this bias varies with age and with the nature of the categories, as well as across cultures. This project investigated the development of the essentialist bias across five social categories (i.e., gender, nationality, religious affiliation, socioeconomic status (rich/poor), and sports-team supporter) in two countries. Children between 5 and 10 years of age in Turkey (Study 1, N = 74) and the United States (Study 2, N = 73), as well as adults in both countries (Study 3, N = 223), participated. Results indicate surprising cross-cultural parallels with respect to both the rank ordering of essentialist thinking across these five categories and increasing differentiation among them over development.

The role of intergroup biases in children's endorsement of information about novel individuals.

A great body of evidence suggests that children are remarkably selective in accepting information from different sources. Yet, very few studies have focused on children's learning about the attributes of others. In three experiments, we examined how 6- and 7-year-olds' ingroup and outgroup biases about novel target individuals and their biases to follow ingroup informants interact in social learning contexts. Overall, children exhibited a positivity bias, accepting positive testimony about ingroup and outgroup targets, but this bias was significantly higher for ingroup targets. Furthermore, whereas children accepted the positive testimony about ingroup targets regardless of the informant's group membership, children selectively relied on ingroup informants when endorsing information about outgroup targets. These results suggest that children's existing biases interact with their acquisition of knowledge in complex ways and shape their social evaluations. These findings may have important implications for developing strategies to prevent negative biases against outgroup individuals among children.

Shared cultural knowledge: Effects of music on young children's social preferences.

Adults use cultural markers to discern the structure of the social landscape. Such markers may also influence the social preferences of young children, who tend to conform to their own group and prefer others who do so. However, the forces that propel these preferences are unknown. Here, we use social preferences based on music to investigate these forces in four- and five-year-old children. First, we establish that children prefer other children whose favorite songs are familiar to them. Then we show that this effect depends on shared knowledge: children both prefer others who know songs they themselves know, and avoid others who know songs they do not know, irrespective of the target children's liking of the songs. These results suggest that young children have a remarkably selective sensitivity to shared cultural knowledge. Shared knowledge may be a powerful determinant of children's social preferences, both because it underpins effective communication and because it is conveyed by others through social interactions and therefore can serve as a marker of social group identity.

Infants Prefer Tunes Previously Introduced by Speakers of Their Native Language.

Infants show attentional biases for certain individuals over others based on various cues. However, the role of these biases in shaping infants' preferences and learning is not clear. This study asked whether infants' preference for native speakers (Kinzler, Dupoux, & Spelke, 2007) would modulate their preferences for tunes. After getting equal exposure to two different tunes introduced by two speakers, 7-month-olds (N = 32) listened longer to the tune that was introduced by a native speaker compared to the tune that was introduced by a foreign speaker. This suggests that the social-emotional context in which exposure to stimuli occurs influences auditory preferences, and that the early emerging attentional biases might have important ramifications regarding social learning in early infancy.

Familiarity overrides complexity in rhythm perception: a cross-cultural comparison of American and Turkish listeners.

Despite the ubiquity of dancing and synchronized movement to music, relatively few studies have examined cognitive representations of musical rhythm and meter among listeners from contrasting cultures. We aimed to disentangle the contributions of culture-general and culture-specific influences by examining American and Turkish listeners' detection of temporal disruptions (varying in size from 50-250 ms in duration) to three types of stimuli: simple rhythms found in both American and Turkish music, complex rhythms found only in Turkish music, and highly complex rhythms that are rare in all cultures. Americans were most accurate when detecting disruptions to the simple rhythm. However, they performed less accurately but comparably in both the complex and highly complex conditions. By contrast, Turkish participants performed accurately and indistinguishably in both simple and complex conditions. However, they performed less accurately in the unfamiliar, highly complex condition. Together, these experiments implicate a crucial role of culture-specific listening experience and acquired musical knowledge in rhythmic pattern perception.

Constraints on infants' musical rhythm perception: effects of interval ratio complexity and enculturation.

Effects of culture-specific experience on musical rhythm perception are evident by 12 months of age, but the role of culture-general rhythm processing constraints during early infancy has not been explored. Using a habituation procedure with 5- and 7-month-old infants, we investigated effects of temporal interval ratio complexity on discrimination of standard from novel musical patterns containing 200-ms disruptions. Infants were tested in three ratio conditions: simple (2:1), which is typical in Western music, complex (3:2), which is typical in other musical cultures, and highly complex (7:4), which is relatively rare in music throughout the world. Unlike adults and older infants, whose accuracy was predicted by familiarity, younger infants were influenced by ratio complexity, as shown by their successful discrimination in the simple and complex conditions but not in the highly complex condition. The findings suggest that ratio complexity constrains rhythm perception even prior to the acquisition of culture-specific biases.

Infants prefer the musical meter of their own culture: a cross-cultural comparison.

Infants prefer native structures such as familiar faces and languages. Music is a universal human activity containing structures that vary cross-culturally. For example, Western music has temporally regular metric structures, whereas music of the Balkans (e.g., Bulgaria, Macedonia, Turkey) can have both regular and irregular structures. We presented 4- to 8-month-old American and Turkish infants with contrasting melodies to determine whether cultural background would influence their preferences for musical meter. In Experiment 1, American infants preferred Western over Balkan meter, whereas Turkish infants, who were familiar with both Western and Balkan meters, exhibited no preference. Experiments 2 and 3 presented infants with either a Western or Balkan meter paired with an arbitrary rhythm with complex ratios not common to any musical culture. Both Turkish and American infants preferred Western and Balkan meter to an arbitrary meter. Infants' musical preferences appear to be driven by culture-specific experience and a culture-general preference for simplicity.