Identifying specific language impairment in deaf children acquiring British Sign Language: Implications for theory and practice

TLDR

This study is the first group investigation of specific language impairment in deaf users of British Sign Language, aiming to explore its implications for theory and clinical practice. The authors recruited 50 deaf children, identified 13 with SLI, and evaluated them on BSL sentence comprehension, nonsense sign repetition, expressive grammar, narrative skills, and non‑verbal intelligence and fine‑motor control. The SLI group showed marked language delays relative to matched peers, unrelated to BSL exposure or general cognition, with heterogeneous patterns of impairment across language domains.

Abstract

This paper presents the first ever group study of specific language impairment (SLI) in users of sign language. A group of 50 children were referred to the study by teachers and speech and language therapists. Individuals who fitted pre‐determined criteria for SLI were then systematically assessed. Here, we describe in detail the performance of 13 signing deaf children aged 5–14 years on normed tests of British Sign Language (BSL) sentence comprehension, repetition of nonsense signs, expressive grammar and narrative skills, alongside tests of non‐verbal intelligence and fine motor control. Results show these children to have a significant language delay compared to their peers matched for age and language experience. This impaired development cannot be explained by poor exposure to BSL, or by lower general cognitive, social, or motor abilities. As is the case for SLI in spoken languages, we find heterogeneity within the group in terms of which aspects of language are affected and the severity of the impairment. We discuss the implications of the existence of language impairments in a sign language for theories of SLI and clinical practice.