The Relationship between Alternate Language Exposure and English Comprehension in Infants

Abstract

Most language acquisition research to date focuses on monolingual infants. In American society there is a burgeoning population of bilingual families where infants must learn the nuances of two languages simultaneously. To extend understanding of language development to this population, research specific to bilingual infants is needed. This study investigates 19-20 month old infants’ abilities to understand English when exposed to varying levels of alternate languages, including Hebrew, Hindi, Italian, Japanese, Korean, Portuguese, Punjabi, Serbo-Croatian, Spanish, and Urdu. Participants included 26 babies whose language exposure consisted of at least 99% English, and 22 babies exposed to English and at least 15% of an alternate language. Infants’ English noun comprehension was measured using the Intermodal Preferential Looking Paradigm. During a four minute session, infants’ gazes were tracked while they looked at simultaneous images, one of which corresponded to a spoken English noun. Before or afterwards, parents identified which of the 16 trial words they believed their infants were able to understand and say. Comparisons were made through two-tailed t-tests that assumed unequal variances. Results showed that infants whose daily language exposure consists of 15-39% of an alternate language understood more English nouns than infants exposed to 40-90% of an alternate language and more than monolinguals. Comparisons of parental reports of infants’ speech similarly showed that infants exposed to higher levels of alternate language said fewer English nouns than infants exposed to lower levels of alternate language and fewer than monolingual infants. Validity of parental reports was evaluated through comparisons of parental estimations and experimental results. Monolingual parents reported higher levels of English comprehension than infants showed in the experimental task, while parents of bilinguals did not demonstrate this effect. Possible explanations for these results are discussed in light of past research and implications for English acquisition of bilingual children are considered.