Monolingual toddlers reportedly rely more heavily on the Mutual Exclusivity Principle (MEP) than their age-matched bilingual counterparts when learning new words. Here, we re- visit this issue by testing monolingual and bilingual 24-month- olds’ reliance on the MEP to learn novel colour labels across multiple labelling instances, where cross-situational statistics link a particular label to a particular colour – but not a particular object. In addition, we ask whether the presentation of atypically-coloured objects (e.g., turquoise dogs) may have influenced how readily toddlers attached novel labels to colour terms rather than objects. Thus far, our results demonstrate that monolingual and bilingual toddlers are equally successful in learning colour labels when taught with atypically-coloured objects. However, only bilingual children are able to learn colour labels taught with typically-coloured objects. We conclude that researchers need to carefully consider the richness and statistical input in children’s learning environments to better understand development in diverse language settings.

Past studies have shown that adult listeners can classify gender from children’s speech – long before anatomical differences between the sexes emerge. This suggests that gender differences in speaking style are learned early in life through socialization. Yet, no study to date has asked whether children also perceive gender cues in child speech. In Study 1, we found that 3.5- to 6-year-olds were able to detect gender from their age-matched peers’ speech, and that their performance was moderated by parents’ gender attitudes. In Study 2, we examine whether the effect of parental socialization is mirrored in children's production. We predicted that how easy children's gender can be perceived from their speech is moderated by parents’ gender attitudes. Our findings support our prediction. Taken together, our results demonstrate that sensitivity to gender cues emerges early in life, and that parental socialization contributes to the development of both gendered speech perception and production.

Early vocabulary development is heavily influenced by children’s language environment. For example, higher SES children who have frequent and rich interactions with caregivers tend to have larger vocabulary size than lower SES children who have less stable home environment (e.g., Hoff & Naigles, 2002). Because of the recent pandemic, most Canadian children have experienced dramatic changes to their day-to-day life. In the current study, we ask whether the pandemic environment affects children’s vocabulary growth. We compare the MacArthur-Bates Communicative Development Inventory (CDI) scores of 11- to 34-month-olds collected before (N=1365) and after (N=301) the onset of COVID-19. Preliminary results show that CDI scores collected for toddlers after the pandemic onset are significantly lower than those collected before. We will continue to collect additional CDI data, and examine how factors such as screen time, reading time, SES, and number of people the child has regular interaction with mediate children’s vocabulary size.

Past studies have revealed that language experience impacts children’s vocabulary development. For example, bilingual children tend to have smaller vocabularies than monolingual children in each of their languages. However, it is unclear whether routine exposure to multiple accents also affects children’s vocabulary growth. Here, using standardized vocabulary assessments, we compared the reported vocabulary sizes of 11- to 34-month-old monolingual and bilingual children (N = 2881) who had various degrees of accent exposure. Our results show that routine exposure to multiple accents, regardless of accent type, does not negatively impact vocabulary development. Our findings suggest that children are well-equipped to handle language variation in their input.