Lexical Trajectories in Italian of Toddlers from Low-income Bilingual Immigrant and Monolingual Families

Introduction. Children from low-income families show a gap in vocabulary development due to early socio-cultural and economic (SES) inequities. Even within low SES strata, there is wide variability in children’s vocabulary development. This variability is related to multiple interacting environmental factors, one of the most relevant ones being exposure to only the societal language or also to a minority language. In Italy, the growth in the incidence of absolute poverty is mainly detected in families with minors and immigrant families. However, evidence concerning the vocabulary developmental trajectories of young children from disadvantaged families in Italy and their association with environmental factors is limited. The present longitudinal study extends previous research to toddlers from low-income families in Italy by (1) comparing expressive vocabulary trajectories in Italian (the societal language) to normative data and (2) investigating environmental factors related to expressive vocabulary development from 18 to 36 months. Method. Participants were 83 toddlers (41 girls) from low-income monolingual (n = 28) and bilingual immigrant (n = 55) families. Using the Italian CDI, nursery teachers assessed vocabulary at 18-, 24-, 30-, and 36-months. Parents reported information about environmental factors: being raised in monolingual or bilingual environments, maternal education, frequency of home language activities in Italian (HLA), and daily hours at nursery school. Results. (1) At each assessment time, the median vocabulary scores of toddlers from low-income families were lower than normative data from the CDI; (2) mixed models showed that children’s vocabulary increased from 18- to 36- months. Bilinguals showed lower vocabulary than monolinguals from 18 to 30 months, but not at 36 months because bilinguals’ rate of development was higher than that of monolinguals. Maternal education and HLA predicted vocabulary from 18- to 36- months over and above being raised in monolingual or bilingual environments. Discussion. Poverty affects early vocabulary development in Italian. A bilingual immigrant environment contributes to variability in vocabulary within a homogeneous low-income group, but it is not an additional risk factor at 36 months. Maternal education and HLA are protective factors of early vocabulary acquisition in disadvantaged contexts.