Child-directed teaching and social learning at 18 months of age: evidence from Yucatec Mayan and US infants.

In several previous studies, 18-month-old infants who were directly addressed demonstrated more robust imitative behaviors than infants who simply observed another's actions, leading theorists to suggest that child-directed interactions carried unique informational value. However, these data came exclusively from cultural communities where direct teaching is commonplace, raising the possibility that the findings reflect regularities in infants' social experiences rather than responses to innate or a priori learning mechanisms. The current studies consider infants' imitative learning from child-directed teaching and observed interaction in two cultural communities, a Yucatec Mayan village where infants have been described as experiencing relatively limited direct instruction (Study 1) and a US city where infants are regularly directly engaged (Study 2). Eighteen-month-old infants from each community participated in a within-subjects study design where they were directly taught to use novel objects on one day and observed actors using different objects on another day. Mayan infants showed relative increases in imitative behaviors on their second visit to the lab as compared to their first visit, but there was no effect of condition. US infants showed no difference in imitative behavior in the child-directed vs. observed conditions; however, infants who were directly addressed on their first visit showed significantly higher overall imitation rates than infants who observed on their first visit. Together, these findings call into question the idea that child-directed teaching holds automatic or universal informational value.

Learning From Others and Spontaneous Exploration: A Cross-Cultural Investigation.

How does early social experience affect children's inferences and exploration? Following prior work on children's reasoning in pedagogical contexts, this study examined U.S. children with less experience in formal schooling and Yucatec Mayan children whose early social input is predominantly observational. In Experiment 1, U.S. 2-year-olds (n = 77) showed more restricted exploration of a toy following a pedagogical demonstration than an interrupted, accidental, or no demonstration (baseline). In Experiment 2, Yucatec Mayan and U.S. 2-year-olds (n = 66) showed more restricted exploration following a pedagogical than an observational demonstration, while only Mayan children showed more restriction with age. These results suggest that although schooling is not a necessary precursor for sensitivity to pedagogy, early social experience may influence children's inferences and exploration in pedagogical contexts.

The development and diversity of religious cognition and behavior: Protocol for Wave 1 data collection with children and parents by the Developing Belief Network.

The Developing Belief Network is a consortium of researchers studying human development in diverse social-cultural settings, with a focus on the interplay between general cognitive development and culturally specific processes of socialization and cultural transmission in early and middle childhood. The current manuscript describes the study protocol for the network's first wave of data collection, which aims to explore the development and diversity of religious cognition and behavior. This work is guided by three key research questions: (1) How do children represent and reason about religious and supernatural agents? (2) How do children represent and reason about religion as an aspect of social identity? (3) How are religious and supernatural beliefs transmitted within and between generations? The protocol is designed to address these questions via a set of nine tasks for children between the ages of 4 and 10 years, a comprehensive survey completed by their parents/caregivers, and a task designed to elicit conversations between children and caregivers. This study is being conducted in 39 distinct cultural-religious groups (to date), spanning 17 countries and 13 languages. In this manuscript, we provide detailed descriptions of all elements of this study protocol, give a brief overview of the ways in which this protocol has been adapted for use in diverse religious communities, and present the final, English-language study materials for 6 of the 39 cultural-religious groups who are currently being recruited for this study: Protestant Americans, Catholic Americans, American members of the Church of Jesus Christ of Latter-day Saints, Jewish Americans, Muslim Americans, and religiously unaffiliated Americans.

What counts as effective input for word learning?

The talk children hear from their primary caregivers predicts the size of their vocabularies. But children who spend time with multiple individuals also hear talk that others direct to them, as well as talk not directed to them at all. We investigated the effect of linguistic input on vocabulary acquisition in children who routinely spent time with one vs. multiple individuals. For all children, the number of words primary caregivers directed to them at age 2 ; 6 predicted vocabulary size at age 3 ; 6. For children who spent time with multiple individuals, child-directed words from all household members also predicted later vocabulary and accounted for more variance in vocabulary than words from primary caregivers alone. Interestingly, overheard words added no predictive value to the model. These findings suggest that speech directed to children is important for early word learning, even in households where a sizable proportion of input comes from overheard speech.

Yucatec Maya Children's Responding to Emotional Challenge.

While the field of affective science has seen increased interest in and representation of the role of culture in emotion, prior research has disproportionately centered on Western, English-speaking, industrialized, and/or economically developed nations. We investigated the extent to which emotional experiences and responding may be shaped by cultural display rule understanding among Yucatec Maya children, an indigenous population residing in small-scale communities in remote areas of Mexico's Yucatan peninsula. Data were collected from forty-two 6- and 10-year-old Yucatec children who completed a resting baseline and a structured disappointing gift task. Children were asked about whether specific emotions are better to show or to hide from others and self-reported the intensity of their discrete positive and negative emotional experiences. We observed and coded expressive positive and negative affective behavior during and after the disappointing gift task, and continuously acquired physiological measures of autonomic nervous system function. These multi-method indices of emotional responding enable us to provide a nuanced description of children's observable and unobservable affective experiences. Results generally indicated that children's understanding of and adherence to cultural display rules (i.e., to suppress negative emotions but openly show positive ones) was evidenced across indices of emotion, as predicted. The current study is a step toward the future of affective science, which lies in the pursuit of more diverse and equitable representation in study samples, increased use of concurrent multimethod approaches to studying emotion, and increased exploration of how emotional processes develop.

Language input and acquisition in a Mayan village: how important is directed speech?

Theories of language acquisition have highlighted the importance of adult speakers as active participants in children's language learning. However, in many communities children are reported to be directly engaged by their caregivers only rarely (Lieven, 1994). This observation raises the possibility that these children learn language from observing, rather than participating in, communicative exchanges. In this paper, we quantify naturally occurring language input in one community where directed interaction with children has been reported to be rare (Yucatec Mayan). We compare this input to the input heard by children growing up in large families in the United States, and we consider how directed and overheard input relate to Mayan children's later vocabulary. In Study 1, we demonstrate that 1-year-old Mayan children do indeed hear a smaller proportion of total input in directed speech than children from the US. In Study 2, we show that for Mayan (but not US) children, there are great increases in the proportion of directed input that children receive between 13 and 35 months. In Study 3, we explore the validity of using videotaped data in a Mayan village. In Study 4, we demonstrate that word types directed to Mayan children from adults at 24 months (but not word types overheard by children or word types directed from other children) predict later vocabulary. These findings suggest that adult talk directed to children is important for early word learning, even in communities where much of children's early language input comes from overheard speech.

Changing language input following market integration in a Yucatec Mayan community.

Like many indigenous populations worldwide, Yucatec Maya communities are rapidly undergoing change as they become more connected with urban centers and access to formal education, wage labour, and market goods became more accessible to their inhabitants. However, little is known about how these changes affect children's language input. Here, we provide the first systematic assessment of the quantity, type, source, and language of the input received by 29 Yucatec Maya infants born six years apart in communities where increased contact with urban centres has resulted in a greater exposure to the dominant surrounding language, Spanish. Results show that infants from the second cohort received less directed input than infants in the first and, when directly addressed, most of their input was in Spanish. To investigate the mechanisms driving the observed patterns, we interviewed 126 adults from the communities. Against common assumptions, we showed that reductions in Mayan input did not simply result from speakers devaluing the Maya language. Instead, changes in input could be attributed to changes in childcare practices, as well as caregiver ethnotheories regarding the relative acquisition difficulty of each of the languages. Our study highlights the need for understanding the drivers of individual behaviour in the face of socio-demographic and economic changes as it is key for determining the fate of linguistic diversity.

Language as a marker of ethnic identity among the Yucatec Maya.

Most human variation is structured around symbolically marked cultural ('ethnic') groups that require common codes of communication. Consequently, many have hypothesised that using others' linguistic competences as markers of their descent is part of an evolved human psychology. However, there is also evidence that the use of language as ethnic markers is not universally applied, but context specific. We explore the tension between these views by studying responses to bilingualism among 121 adults living in Mayan communities undergoing rapid socioeconomic changes involving increased contact with Spanish-speaking towns. We show that, although competences in Mayan were strongly tied to perceiving others as having a Mayan ethnic identity, ethnolinguistic category membership was not seen as stable through life, vertically transmitted, nor regarded as incompatible with competences in Spanish. Moreover, we find variation in how people reasoned about ethnolinguistic identities depending on their own linguistic repertoires. Our work suggests that, while there may be an evolved predisposition to use language as a signal of group identity, our developmental plasticity allows us to respond adaptively to social information around us, leading to psychological and behavioural variation within and across populations. How people reason about others based on their linguistic profiles will affect the payoffs of acquiring different languages and ultimately the long-term sustainability of linguistic diversity.

Cultural and Developmental Influences on Overt Visual Attention to Videos.

Top-down influences on observers' overt attention and how they interact with the features of the visual environment have been extensively investigated, but the cultural and developmental aspects of these modulations have been understudied. In this study we investigated these effects for US and Yucatec Mayan infants, children, and adults. Mayan and US participants viewed videos of two actors performing daily Mayan and US tasks in the foreground and the background while their eyes were tracked. Our region of interest analysis showed that viewers from the US looked significantly less at the foreground activity and spent more time attending to the 'contextual' information (static background) compared to Mayans. To investigate how and what visual features of videos were attended to in a comprehensive manner, we used multivariate methods which showed that visual features are attended to differentially by each culture. Additionally, we found that Mayan and US infants utilize the same eye-movement patterns in which fixation duration and saccade amplitude are altered in response to the visual stimuli independently. However, a bifurcation happens by age 6, at which US participants diverge and engage in eye-movement patterns where fixation durations and saccade amplitudes are altered simultaneously.

Are child-directed interactions the cradle of social learning?

Theorists have proposed that child-directed, ostensive interactions provide a critical point of entry for supporting children's learning from others, either because they render the intentions of a teacher easier to understand (e.g., Barresi & Moore, 1996; Moore, 2010; Tomasello, 1999) or because they mark information as culturally important and generalizable (e.g., Csibra & Gergely, 2009). This article evaluates these proposals in light of data from U.S. and European children, as well as from communities where directed interactions with young children are rare. The evidence reviewed from both bodies of work leave reason to doubt the claim that directed interactions provide automatic and innate informational value for learners. Instead, the value of child-directed teaching contexts likely stems from 2 factors: how these interactions focus children's attention in the moment, and how children learn to reason pragmatically regarding the value child-directed contexts have.

Why do child-directed interactions support imitative learning in young children?

Child-directed cues support imitation of novel actions at 18 months, but not at two years of age. The current studies explore the mechanisms that underlie the propensity that children have to copy others at 18 months, and how the value of child-directed communication changes over development. We ask if attentional allocation accounts for children's failure to imitate observed actions at 18 months, and their success at two years of age, and we explore the informational value child-directed contexts may provide across ontogeny. Eighteen-month-old (Study 1) and two-year-old (Study 2) children viewed causally non-obvious actions performed by child-directed (Study 1 & 2), observed (Study 1 & 2), or non-interactive (Study 2) actors, and their visual attention and imitative behaviors were assessed. Results demonstrated that child-directed contexts supported imitative learning for 18-month-old children, independent of their effects on proximal attention. However, by two years of age, neither directness nor communication between social partners was a necessary condition for supporting social imitation. These findings suggest that developmental changes in children's propensity to extract information from observation cannot be accounted for by changes in children's interpretation of what counts as child-directed information, and are likely not due to changes in how children allocate attention to observed events.