Why Do Bilingual Children Use Code-Switching?

The purpose of this digest is to help pediatricians, speech language pathologists, classroom teachers, and other professionals who work with bilingual children and their parents understand common parental concerns related to bilingual childrearing and become familiar with the current science on bilingual child development. Greater insight into both issues will allow these professionals to provide more effective and scientifically sound advice to parents.
A growing number of U.S. parents view bilingualism as a laudable family goal. The reasons for this trend include a desire to maintain ties to the parents' heritage language and culture, to provide children with academic and cognitive advantages, and to promote cross-cultural understanding
Some believed that language delay was the result of this confusion. Several advice publications (e.g., Eisenberg, Murkoff, & Hathaway, 1989; Honig, n.d.) suggest that confusion could be avoided by using the one-parent, one-language approach to bilingual childrearing, in which each caregiver uses only one language with the child and parents refrain from using two languages in the same conversation.
However, research indicates that the ability to switch back and forth between languages, sometimes called code-switching, is a sign of mastery of two linguistic systems, not a sign of language confusion, and that children as young as 2 are able to code-switch in socially appropriate ways (Lanza, 1992). Research also shows that many normally developing bilingual children mix their two languages, with the type and amount of code-switching depending on environmental factors, such as how much the parents or wider community engage in
In particular, we know a growing amount about the limits of television and video as instructional aides with young children. For instance, recent studies have examined the process of perceptual narrowing in infants, that is, infants' gradual loss of the ability to perceive sounds unlike those in the language(s) to which they are regularly exposed. Researchers have found that live interaction (e.g., reading or talking to a child) is more effective than exposure to recorded sounds (e.g., television) in reversing the narrowing process (Kuhl, Feng-Ming, & Huei-Mei, 2003). Other studies have found that, for older children, being read aloud to in the second language increases second language vocabulary much more than watching television in that language (Patterson, 2002). In short, while audio and video materials can serve as a positive and entertaining source of support for language learning, human interaction is the best method for fostering both first and second language