Ilana Frank, Diane Poulin-Dubois
The mutual exclusivity principle, which states that an object category can have only one name, has been shown to be used by toddlers and preschoolaged children(Markman, 1991). Studies of the mutual exclusivity principle in bilingual children aged over 3.5 years have generally found a tendency to honor the principle within languages, but not across languages. To date, younger bilinguals'adherence to this principle has not been investigated. In the present cross-sectional study, monolingual and bilingual children aged 27 and 35 months were tested. Both monolingual and bilingual children were presented with two novel labels for the same object, a violation of the mutual exclusivity principle within a language. They were then tested on their comprehension of the two labels. Bilingual children participated in an additional task in which mutual exclusivity was violated across languages Results indicated that across both language groups, the older children honored mutual exclusivity more than the younger children. No differences were found between monolinguals and bilinguals in adherence to mutual exclusivity. In addition, bilingual children performed similarly when mutual exclusivity was violated within a language and across languages The proportion of translation equivalents in the bilingual children's vocabulary did not predict their performance on the mutual exclusivity task. These results suggest that bilingual language experience does not significantly alter adherence to the mutual exclusivity principle before the age of three years.