Infants' and toddlers' language development during the pandemic: Socioeconomic status mattered.

The disruption caused by the COVID-19 pandemic has raised concerns about children's development. Here, we examined the impact of the pandemic on Canadian infants' and toddlers' (N = 539) language development. Specifically, we assessed changes in 11- to 34-month-olds' activities that are known to affect vocabulary development (i.e., screen and reading times). We also compared these children's vocabulary sizes with those of 1365 children collected before the pandemic using standardized vocabulary assessments. Our results show that screen and reading times were most negatively affected in lower-income children. For vocabulary growth, no measurable change was detected in middle- and high-income children, but lower-income 19- to 29-month-olds fared worse during the pandemic than during pre-pandemic times. Moving forward, these data indicate that educators and policymakers should pay particular attention to children from families with lower socioeconomic status during times of crisis and stress.

The Icing on the Cake. Or Is it Frosting? The Influence of Group Membership on Children's Lexical Choices.

Adults are skilled at using language to construct/negotiate identity and to signal affiliation with others, but little is known about how these abilities develop in children. Clearly, children mirror statistical patterns in their local environment (e.g., Canadian children using zed instead of zee), but do they flexibly adapt their linguistic choices on the fly in response to the choices of different peers? To address this question, we examined the effect of group membership on 7- to 9-year-olds' labeling of objects in a trivia game, exploring whether they were more likely to use a particular label (e.g., sofa vs. couch) if members of their "team" also used that label. In a preregistered study, children (N = 72) were assigned to a team (red or green) and were asked during experimental trials to answer questions-which had multiple possible answers (e.g., blackboard or chalkboard)-after hearing two teammates and two opponents respond to the same question. Results showed that children were significantly more likely to produce labels less commonly used by the community (i.e., dispreferred labels) when their teammates had produced those labels. Crucially, this effect was tied to group membership, and could not be explained by children simply repeating the most recently used label. These findings demonstrate how social processes (i.e., group membership) can guide linguistic variation in children.

Looking for Wugs in all the Right Places: Children's Use of Prepositions in Word Learning.

To help infer the meanings of novel words, children frequently capitalize on their current linguistic knowledge to constrain the hypothesis space. Children's syntactic knowledge of function words has been shown to be especially useful in helping to infer the meanings of novel words, with most previous research focusing on how children use preceding determiners and pronouns/auxiliary to infer whether a novel word refers to an entity or an action, respectively. In the current visual world experiment, we examined whether 28- to 32-month-olds could exploit their lexical semantic knowledge of an additional class of function words-prepositions-to learn novel nouns. During the experiment, children were tested on their ability to use the prepositions in, on, under, and next to to identify novel creatures displayed on a screen (e.g., The wug is on the table), as well as their ability to later identify the creature without accompanying prepositions (e.g., Look at the wug). Children overall demonstrated understanding of all the prepositions but next to and were able to use their knowledge of prepositions to learn the associations between novel words and their intended referents, as shown by greater-than chance looks to the target referent when no prepositional phrase was provided.