La. Petitto et al., Bilingual signed and spoken language acquisition from birth: implications for the mechanisms underlying early bilingual language acquisition, J CHILD LAN, 28(2), 2001, pp. 453-496
Divergent hypotheses exist concerning the types of knowledge underlying ear
ly bilingualism, with some portraying a troubled course marred by language
delays and confusion, and others portraying one that is largely unremarkabl
e. We studied the extraordinary case of bilingual acquisition across two mo
dalities to examine these hypotheses. Three children acquiring Langues des
Signes Quebecoise and French, and three children acquiring French and Engli
sh (ages at onset approximately 1;0, 2;6 and 3;6 per group) were videotaped
regularly over one year while we empirically manipulated novel and familia
r speakers of each child's two languages. The results revealed that both gr
oups achieved their early linguistic milestones in each of their languages
at the same time land similarly to monolinguals), produced a substantial nu
mber of semantically corresponding words in each of their two languages fro
m their very first words or signs (translation equivalents), and demonstrat
ed sensitivity to the interlocutor's language by altering their language ch
oices. Children did mix their languages to varying degrees, and some persis
ted in using a language that was not the primary language of the addressee,
but the propensity to do both was directly related to their parents' mixin
g rates, in combination with their own developing language preference. The
signing-speaking bilinguals did exploit the modality possibilities, and the
y did simultaneously mix their signs and speech, but in semantically princi
pled and highly constrained ways. It is concluded that the capacity to diff
erentiate between two languages is well in place PRIOR to first words, and
it is hypothesized that this capacity may result from biological mechanisms
that permit the discovery of early phonological representations. Reasons w
hy paradoxical views of bilingual acquisition have persisted are also offer
ed.