Variability and patterns in children's media use and links with language development.

AIM: Media use is widespread and rising, but how often and for what purpose young children use media varies, which has differential impacts on development. Yet little work has measured how and why children under 36 months use digital media or media's consequences for language. METHODS: The current study measures how and why 17- to 30-month-old children use digital media and associations with their language abilities. The amount of use, type of activity and caregiver reasons for children's media use were then compared to the child's vocabulary and mean length of utterance. RESULTS: About 17- to 30-month-old children are primarily exposed to TV/videos over other media forms, which are often used to occupy children. Video time (but not other activities) negatively predicts children's language. The negative impact of videos on vocabulary persists regardless of the reason for use, however, the effect of videos on expressive language may be tempered when videos are used for education or connecting. CONCLUSION: Children under 36 months are using digital media at high rates. What they are doing and why they use media is critical to predict the effect it might have on language development. Further research and anticipatory guidance on the consequences of videos are needed.

Late bloomer or language disorder? Differences in toddler vocabulary composition associated with long-term language outcomes.

Children with delays in expressive language (late talkers) have heterogeneous developmental trajectories. Some are late bloomers who eventually "catch-up," but others have persisting delays or are later diagnosed with developmental language disorder (DLD). Early in development it is unclear which children will belong to which group. We compare the toddler vocabulary composition of late talkers with different long-term outcomes. The literature suggests most children with typical development (TD) have vocabularies dominated by names for categories organized by similarity in shape (e.g., cup), which supports a bias to attend to shape when generalizing names of novel nouns-a bias associated with accelerated vocabulary development. Previous work has shown that as a group, late talkers tend to say fewer names for categories organized by shape and are less likely to show a "shape bias" than TD children. Here, in a retrospective analysis of 850 children, we compared the vocabulary composition of groups of toddlers who were late bloomers or persisting late talkers. At Time 1 (13-27 months), the persisting late talkers said a smaller proportion of shape-based nouns than both TD children and late bloomers who "caught up" to typically sized vocabularies months later (18-38-months). Additionally, children who received a DLD diagnosis between 4 and 7 years said a significantly smaller proportion of shape-based nouns in year two than TD children and children with other diagnoses (e.g., dyslexia). These findings bring new insight into sources of heterogeneity amongst late talkers and offer a new metric for assessing risk. RESEARCH HIGHLIGHTS: Toddler vocabulary composition, including the proportion of names for categories organized by shape, like spoon, was used to retrospectively compare outcomes of late talking children Persisting Late Talkers said a smaller proportion of shape-based nouns during toddlerhood relative to Late Bloomers (late talkers who later caught up to have typically-sized vocabularies) Children with later DLD diagnoses said a smaller proportion of shape-based nouns during toddlerhood relative to children without a DLD diagnosis The data illustrate the cascading effects of vocabulary composition on subsequent language development and suggest vocabulary composition may be one important marker of persisting delays.

Margarita glasses and high heels: How attention to shape, age, and vocabulary impacts children's recognition of typical and atypical exemplars.

Children's ability to recognize object shape is foundational for successful early word learning. However, the prototypical shape of objects may not be easily accessible-take margarita glasses, for instance. The current study examined 304 U.S. children 17- to 42-month-old (152 females) from 2017 to 2020, asking how shape, age, and vocabulary abilities predict recognition of everyday objects. Children's ability to recognize objects increases with age and vocabulary, replicating prior work. Moreover, performance was partially moderated by object's typicality and shape features, and children's own attention to shape (shape bias) may mediate the effect, especially with prototypically shaped objects. The current study highlights how both child-specific variables and context features interact to shape language abilities, underscoring the emergent and multi-causal nature of word learning.

The timescales of word learning in children with language delays: In-the-moment mapping, retention, and generalization.

Learning new words and, subsequently, a lexicon, is a time-extended process requiring encoding of word-referent pairs, retention of that information, and generalization to other exemplars of the category. Some children, however, fail in one or more of these processes resulting in language delays. The present study examines the abilities of children who vary in vocabulary size (including both children with normal language (NL) and late talking (LT) children) across multiple timescales/processes - known and novel word mapping, novel word retention, and novel noun generalization. Results indicate that children with lower language skills suffer from deficits in quick in-the-moment mapping of known words compared to their NL peers, but age and vocabulary size rather than normative vocabulary ranking or NL/LT status better predicts performance on retention and generalization processes. Implications for understanding language development as a holistic process with multiple interacting variables are discussed.

Coding social interactions in naturalistic settings: The taxonomy of dyadic conversation.

Social interaction and conversation is an essential aspect of human behavior, yet existing methods for coding conversations are outdated, and often can only be used in contrived research settings. The Taxonomy of Dyadic Conversation (TDC) is a coding system designed to code dyadic interactions in natural settings by labeling the utterances and turns taken within an interaction using speech categories. The TDC was used to code child-caregiver and adult-adult conversations in a children's museum and during a public forum, respectively. Results supported hypotheses that predicted adult-adult interactions would contain more Declarative Statement and Acknowledgment utterances than child-caregiver interactions, while child-caregiver interactions contained fewer Conversational Turns, as well as more Command and Encouragement utterances. Results also indicated high levels of inter-rater reliability. The potential for additions and modifications to be applied to the standard TDC is discussed.

Yes, but We need reliability to advance infant work, but there's more to consider too: Important nuances of reliability and the need to include validity.

The field of development needs more reliable infant work - improving our measures and methods is at the heart of accurately understanding why children do what they do! However, as scientists, we cannot stop with reliability but must also include measures of validity in our studies. In this commentary, we clarify and expand upon discussions of reliability and measurement error. We also argue for the importance of assessing the validity of our measures and tasks. Indeed, careful considerations of both reliability and validity are necessary for improving infant research.

Patterns of mutual exclusivity and retention: A study of monolingual and bilingual 2-year-olds.

When children learn their native language, they tend to treat objects as if they only have one label-a principle known as mutual exclusivity. However, bilingual children are faced with a different cognitive challenge-they need to learn to associate two labels with one object. In the present study, we compared bilingual and monolingual 24-month-olds' performance on a challenging and semi-naturalistic forced-choice referent selection task and retention test. Overall, both language groups performed similarly on referent selection but differed on retention. Specifically, while monolingual infants showed some retention, bilingual infants performed at chance and significantly worse than their monolingual peers.

Sometimes it is better to know less: How known words influence referent selection and retention in 18- to 24-month-old children.

Young children are surprisingly good word learners. Despite their relative lack of world knowledge and limited vocabularies, they consistently map novel words to novel referents and, at later ages, show retention of these new word-referent pairs. Prior work has implicated the use of mutual exclusivity constraints and novelty biases, which require that children use knowledge of well-known words to disambiguate uncertain naming situations. The current study, however, presents evidence that weaker vocabulary knowledge during the initial exposure to a new word may be better for retention of new mappings. Children aged 18-24 months selected referents for novel words in the context of foil stimuli that varied in their lexical strength and novelty: well-known items (e.g., shoe), just-learned weakly known items (e.g., wif), and completely novel items. Referent selection performance was significantly reduced on trials with weakly known foil items. Surprisingly, however, children subsequently showed above-chance retention for novel words mapped in the context of weakly known competitors compared with those mapped with strongly known competitors or with completely novel competitors. We discuss implications for our understanding of word learning constraints and how children use known words and novelty during word learning.

Developing language in a digital world.

Young children's screen time is increasing, raising concerns about its negative impact on language development, particularly vocabulary. However, digital media is used in a variety of ways, which likely differentially impact language development. Instead of asking 'how much' screen time, the focus should be on how digital media is used.

Social interactions offset the detrimental effects of digital media use on children's vocabulary.

Young children's rapid vocabulary growth during the first few years is supported by input during social interactions with caregivers and, increasingly, from digital media. However, the amount of exposure to both sources can vary substantially across socioeconomic classes, and little is known about how social interactions and digital media use together predict vocabulary in the first few years of life. The current study takes a first step toward examining whether increased social interactions with other individuals may buffer the potentially detrimental effects of digital media use on language among a socioeconomically diverse sample. 305 caregivers of children between 17 and 30-months completed questionnaires about their family demographics, their child's technology use, and the child's daily routines and social interactions. Findings suggest children who experience fewer human interactions and greater technology exposure have smaller vocabularies than their peers who socialize more and use less technology, and this disparity becomes greater as children get older. Moreover, the number of social interactions moderates the link between SES, digital media, and vocabulary such that the negative impact of digital media on vocabulary for children from low SES households can be offset with increased social interactions. Together, this suggests that increasing the amount of human interactions may serve as a protective factor for vocabulary outcomes in a world where digital media use is prominent.

Capturing the Heterogeneity of Word Learners by Analyzing Persons.

Accurately capturing children's word learning abilities is critical for advancing our understanding of language development. Researchers have demonstrated that utilizing more complex statistical methods, such as mixed-effects regression and hierarchical linear modeling, can lead to a more complete understanding of the variability observed within children's word learning abilities. In the current paper, we demonstrate how a person-centered approach to data analysis can provide additional insights into the heterogeneity of word learning ability among children while also aiding researchers' efforts to draw individual-level conclusions. Using previously published data with 32 typically developing and 32 late-talking infants who completed a novel noun generalization (NNG) task to assess word learning biases (i.e., shape and material biases), we compare this person-centered method to three traditional statistical approaches: (1) a t-test against chance, (2) an analysis of variance (ANOVA), and (3) a mixed-effects regression. With each comparison, we present a novel question raised by the person-centered approach and show how results from the corresponding analyses can lead to greater nuance in our understanding of children's word learning capabilities. Person-centered methods, then, are shown to be valuable tools that should be added to the growing body of sophisticated statistical procedures used by modern researchers.

The Influence of Shyness on Language Assessment.

PURPOSE: The goal of this study is to examine how shyness affects a child's performance on language assessments that vary in sociability. We hypothesized that accuracy on language tasks would be driven by shyness such that shyer children would perform better on nonsociable tasks compared to sociable tasks. METHOD: The procedures followed a quasi-experimental design. One hundred twenty-two participants, ages 17-42 months and varying in their temperament, each underwent a series of three language tasks. The order of tasks was randomized, and each task varied in the social interaction required: a looking task, a pointing task, and a production task. Data were collected via Zoom, and parents reported their child's shyness level via the Early Child Behavior Questionnaire. RESULTS: Shyness was compared with participants' accuracy across the three tests while controlling for age and vocabulary percentile. There were significant differences in children's performance across the tasks, with respect to shyness. Shyer children performed worse on the production task compared to less shy children. All children did well on the pointing task regardless of shyness level, but performance was more nuanced on the looking task such that shyer children were at times more accurate but also less likely to respond in general. CONCLUSIONS: As shown by these results, shyer and less shy children respond differentially to methods of language assessment that vary in sociability. It is important for clinicians to acknowledge shyness when choosing an appropriate assessment of children's language. Future direction includes assessing performance on standardized assessments. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23845521.

Processes and pathways in development via digital media: Examples from word learning.

Word learning unfolds over multiple, cascading pathways which support in-the-moment processing and learning. The process is refined with each exposure to a word, and exposures to new words occur across a variety of forms and contexts. However, as children are exposed to more and more digital media, the ways in which children encounter, learn, and build on their vocabulary is also shifting. These shifts represent changes in context, content, and at the level of the child that can lead to negative outcomes. Less work, however, has discussed what these differences mean for how things change in the underlying developmental cascade and learning processes. Here, we suggest that the increasing presence of digital media may shift the developmental pathways for learning (the chain of events that support future learning) but not necessarily the developmental processes (the mechanisms underlying learning). Moreover, the interaction of the two may lead to different behavior and outcomes for learning in a digital era. We argue it is imperative for researchers to not only study how digital media differs from everyday learning, but directly measure if the well-worn pathways, processes, and variables found with decades of research with real items translate to a digital media era.

Taking parent personality and child temperament into account in child language development.

Individual differences have become increasingly important in the study of child development and language. However, despite the important role parents play in children's language, no work has examined how parent personality impacts language development. The current study examines the impact of parent personality as well as child temperament on language development in 460 16- to 30-month-old children and 328 31- to 42-month-old children. Findings from both groups suggest multiple aspects of children's language abilities are correlated with their parent's personality. Specifically, parent consciousness, openness, and agreeableness positively correlate with child vocabulary size and other language abilities. Results also replicate and expand research on child temperament and language - child effortful control and surgency were positively correlated, and negative affect negatively correlated with most language abilities even after controlling for parent personality. Critically, parent and child traits appear to impact a child's language abilities above and beyond well-known predictors of language, such as age.

Vocabulary Development and the Shape Bias in Children With Hearing Loss.

Purpose Although children with hearing loss (HL) can benefit from cochlear implants (CIs) and hearing aids (HAs), they often show language delays. Moreover, little is known about the mechanisms by which children with HL learn words. One mechanism by which typically hearing (TH) children learn words is by acquiring word learning biases such as the "shape bias," that is, generalizing the names of novel solid objects by similarity in shape. In TH children, the shape bias emerges out of regularities in the early vocabulary and, once acquired, has consequences for subsequent vocabulary development. Method Here, we ask whether children with HL exhibit similar word learning biases as TH children. In the current study, nineteen 2- to 3.5-year-old children with HL generalized the names of novel objects by similarity in shape or material. We compared their performance to that of 20 TH children matched on age and 20 TH children matched on vocabulary size. Results Children with HL were significantly less likely than age-matched TH children and vocabulary-matched TH children to generalize novel names to objects of the same shape. However, there was also an interaction such that vocabulary has a stronger effect on novel noun generalization for those with HL than for those who are TH. Exploratory analyses of children with HL reveal similar novel noun generalization and vocabulary sizes in children who use CIs and those who use HAs, regardless of hearing age or degree of HL. Conclusion Together, the results suggest that, although vocabulary knowledge drives development of the shape bias in general for all children, it may be especially important for children with HL, who are at risk for language delays.

The Heterogeneity of Word Learning Biases in Late-Talking Children.

Purpose The particular statistical approach researchers choose is intimately connected to the way they conceptualize their questions, which, in turn, can influence the conclusions they draw. One particularly salient area in which statistics influence our conclusions is in the context of atypical development. Traditional statistical approaches such as t tests or analysis of variance lend themselves to a focus on group differences, downplaying the heterogeneity that exists within so many atypically developing populations. Understanding such variability is important-classification of what a disorder is, an individual's diagnosis, and whether or not a child receives intervention all directly relate to an accurate classification of the disorder and individual's abilities compared to their typically developing peers. Method Here, we use word learning biases (i.e., shape and material biases) in late-talking children as a sample case and employ a variety of statistical approaches to compare the conclusions those approaches might warrant. Results We argue that advanced statistical approaches, such as mixed-effects regression, can help us make sense of heterogeneity and are more consistent with a modern dimensional view of language disorders. Conclusions Accurate characterization of late-talking children (and others at risk for delays) and their prognoses is necessary for accurate diagnosis and implementation of appropriate target interventions. It therefore requires rigorous statistical analyses that can capture and allow for interpretation of the heterogeneity inherent in populations with language delays and disorders.

Reproducibility and a unifying explanation: Lessons from the shape bias.

The goal of science is to advance our understanding of particular phenomena. However, in the field of development, the phenomena of interest are complex, multifaceted, and change over time. Here, we use three decades of research on the shape bias to argue that while replication is clearly an important part of the scientific process, integration across the findings of many studies that include variations in procedure is also critical to create a coherent understanding of the thoughts and behaviors of young children. The "shape bias," or the tendency to generalize a novel label to novel objects of the same shape, is a reliable and robust behavioral finding and has been shown to predict future vocabulary growth and possible language disorders. Despite the robustness of the phenomenon, the way in which the shape bias is defined and tested has varied across studies and laboratories. The current review argues that differences in performance that come from even seemingly minor changes to the participants or task can offer critical insight to underlying mechanisms, and that working to incorporate data from multiple labs is an important way to reveal how task variation and a child's individual pathway creates behavior-a key issue for understanding developmental phenomena.

Too Much of a Good Thing: How Novelty Biases and Vocabulary Influence Known and Novel Referent Selection in 18-Month-Old Children and Associative Learning Models.

Identifying the referent of novel words is a complex process that young children do with relative ease. When given multiple objects along with a novel word, children select the most novel item, sometimes retaining the word-referent link. Prior work is inconsistent, however, on the role of object novelty. Two experiments examine 18-month-old children's performance on referent selection and retention with novel and known words. The results reveal a pervasive novelty bias on referent selection with both known and novel names and, across individual children, a negative correlation between attention to novelty and retention of new word-referent links. A computational model examines possible sources of the bias, suggesting novelty supports in-the-moment behavior but not retention. Together, results suggest that when lexical knowledge is weak, attention to novelty drives behavior, but alone does not sustain learning. Importantly, the results demonstrate that word learning may be driven, in part, by low-level perceptual processes.

Moving Word Learning to a Novel Space: A Dynamic Systems View of Referent Selection and Retention.

Theories of cognitive development must address both the issue of how children bring their knowledge to bear on behavior in-the-moment, and how knowledge changes over time. We argue that seeking answers to these questions requires an appreciation of the dynamic nature of the developing system in its full, reciprocal complexity. We illustrate this dynamic complexity with results from two lines of research on early word learning. The first demonstrates how the child's active engagement with objects and people supports referent selection via memories for what objects were previously seen in a cued location. The second set of results highlights changes in the role of novelty and attentional processes in referent selection and retention as children's knowledge of words and objects grows. Together this work suggests that understanding systems for perception, action, attention, and memory, and their complex interaction, is critical to understand word learning. We review recent literature that highlights the complex interactions between these processes in cognitive development and point to critical issues for future work.

Slowing Down Fast Mapping: Redefining the Dynamics of Word Learning.

In this article, we review literature on word learning and propose a theoretical account of how lexical knowledge and word use emerge and develop over time. We contend that the developing lexical system is built on processes that support children's in-the-moment word usage interacting with processes that create long-term learning. We argue for a new characterization of word learning in which simple mechanisms like association and competition, and the interaction between the two, guide children's selection of referents and word use in the moment. This in turn strengthens and refines the network of relationships in the lexicon, improving referent selection and use in future encounters with words. By integrating in-the-moment word use with long-term learning through simple domain-general mechanisms, this account highlights the dynamic nature of word learning and creates a broader framework for understanding language and cognitive development more generally.