Language dominance in bilinguals with two sign languages
What is it about?
Bilingual individuals who speak two different spoken languages often have a dominant language in which they are more fluent, making perfectly balanced bilingual speakers a rare occurrence. This phenomenon could also hold true for signers who know two sign languages. However, communication between deaf signers who use different sign languages is typically more successful than conversations between speakers of different spoken languages. This is because distinct sign languages have more similarities between them than distinct spoken languages due to the prevalence of depicting features. For example, in several sign languages, expressing "I drink" involves pointing at oneself and then moving the hand towards the mouth, resembling drinking from a cup. This commonality could make becoming equally fluent, or dominant, in two sign languages relatively easy. This study discovered a method that enables us to measure the fluency levels of bilingual individuals in two sign languages. The results showed that, like speakers, signers also tend to be more fluent in one sign language compared to the other. Balanced bilingualism in the signed modality appears to be a rare occurrence. Signers who aspire to become fluent in a second sign language may need to use it frequently to improve their fluency levels.
Why is it important?
The study confirms that achieving equal fluency in two sign languages may be as difficult as in spoken languages, highlighting the similarities between signed and spoken languages. Fluency levels in sign languages need consideration in domains such as education, public policy, commerce, and clinical settings. For instance, suboptimal interventions for patients and students with two sign languages may be prevented by correctly identifying fluency levels and deploying instructions, treatments, or interventions in appropriate languages.