Acceptance of lexical overlap by monolingual and bilingual toddlers

Abstract

Aims and Objectives: Mutual exclusivity refers to children’s assumption that there are one-to-one correspondences between words and their referents. It is proposed to guide the process of fast-mapping when children encounter novel words in referentially ambiguous situations. However, children are often required to suspend this default assumption and accept lexically overlapping labels, which is particularly common for bilingual children who learn multiple labels for most referents in their environment. Previous research has shown that school-aged bilinguals are more successful at learning overlapping labels than monolinguals, but the mechanisms underlying the development of this word-learning ability remain unknown. Methodology: This study investigated the ability to accept lexical overlap in monolingual and bilingual two-and-a-half-year-old children and its relation to children’s lexical competence. Children’s ability to retain two novel labels assigned to a novel referent was assessed in an interactive lexical overlap paradigm. In addition, parental inventories were used to measure children’s receptive vocabulary size and patterns of language exposure and use. Data and analysis: Data were collected from 68 (34 monolingual and 34 bilingual) children between 26 and 34 months of age. Binomial logistic regressions were used to assess the effects of children’s language background and their individual lexical competence (receptive vocabulary for monolinguals and bilinguals, and conceptual vocabulary size and degree of bilingualism for bilinguals). Findings: Results showed that vocabulary size was a significant predictor of lexical overlap performance for monolingual children, but this was not the case for bilinguals. Originality: These findings are the first to indicate that the individual linguistic experience of growing up monolingual or bilingual shapes the mechanisms that underlie the development and usage patterns of early word-learning strategies. Limitations: This study leaves open the question of what aspect of growing up bilingual leads children to develop word-learning strategies that are shaped by their linguistic experience.