How do infants learn to associate a new word to the correct object?

One way monolingual children do this is by using the disambiguation principle: if they are confronted with two objects, one new and one familiar, and they hear a new word, they will tend to associate it to the new object (because they already know the name for the familiar object).

This study compared 17- and 18-month-old infants from monolingual, bilingual, and trilingual family backgrounds. Infants’ use of the disambiguation principle was inferred from their tendency to look more at the new object after hearing a new word than after hearing a familiar word. The results showed that trilingual infants did not follow the disambiguation principle, probably because they know that the same object can take different names in their different languages. Bilingual children behaved more like monolinguals, although they followed the disambiguation principle less consistently.

This is a summary of the following published article: “Monolingual, bilingual, trilingual: infants’ language experience influences the development of a word-learning heuristic” by Krista Byers-Heinlein and Janet F. Werker (2009). Developmental Science, 12(5), 815-823.