Older Sibling Influences on the Language Environment and Language Development of Toddlers in Bilingual Homes.

Two separate studies examined older siblings' influence on the language exposure and language development of U.S.-born toddlers who were being raised in bilingual homes. The participants in Study 1 were 60 children between 16 and 30 months who had heard English and another language at home from birth; 26 had older siblings and 34 did not. The participants in Study 2 were 27 children, assessed at 22 and 30 months, who had heard English and Spanish from birth; 14 had school aged older siblings and 13 did not. Both studies found that older siblings used English more in talking to the toddlers than did other household members and that toddlers with older siblings were more advanced in English language development. Study 2 also found that the presence of a school aged older sibling increased mothers' use of English with their toddlers and that toddlers without a school aged older sibling were more advanced in Spanish than the toddlers with a school aged older sibling. These findings contribute to a picture of the complex processes that shape language use in bilingual homes and cause variability in young children's bilingual development.