Harnessing atypical developmental profiles to disentangle the link between social functioning, language production, and input

Background. By including individuals with atypical developmental profiles, this study adds to ongoing research that addresses the link between world and mind in (pre)adolescents’ acquisition of socially meaningful language variation (Nardy, Chevrot & Barbu 2013; Smith, Durham & Richards 2013; Van De Mieroop, Zenner & Marzo 2016). In particular, it harnesses the developmental profile of (pre)adolescents with Down Syndrome (DS) for a case study on Belgian Dutch pronouns of address. With strengths in social functioning on the one hand (Fidler et al. 2008; Næss et al. 2017) and challenges with language production on the other (see Abbeduto et al. 2020), these (pre)adolescents and their language use can provide unique insights into how social functioning and language production relate to the development of socially meaningful language variation. We attempt this here through a case study on Belgian Dutch pronouns of address; their two dimensions of socially meaningful variation (formal/informal and standard/colloquial) with patterned yet fuzzy distinctions require a speaker’s highly sophisticated sensitivity (Plevoets, Speelman & Geeraerts 2008). Research question. Against this background, the main question addressed in this study is to what extent (pre)adolescents with DS show variation in the production of Belgian Dutch pronouns of address, with special attention to the social context in question (i.e., the degree of formality and familiarity in the composition of speaker, hearer, and situation) and the degree of prior conceptual activation by priming. The attested variation is interpreted drawing from (pre)adolescents’ social functioning, language production, and their caregiver’s input. Method. As a proof of concept, four dyads consisting of (pre)adolescents with DS and their main caregiver take part in a discourse completion task in which stimuli depicting varied social contexts are aimed at eliciting Belgian Dutch pronouns of address. To assess the full linguistic repertoire, three phases with increasing degrees of priming are integrated. To illustrate, a phase 1 stimulus includes Wat zegt de man tegen de dokter? [‘What does the man say to the doctor?’]. In phase 2, this query is preceded by the sentence De man zegt: ‘ge moet me helpen’ [‘The man says: ‘you have to help me’]. Finally, phase 3 additionally introduces forced choice via predefined answer options, e.g., Kun(t) (u/je/gij) iets aan mijn buikpijn doen? [‘Can you do something about my stomachache?’]. The (pre)adolescents with DS’ social functioning and general language production are measured via well-established diagnostic assessments, and the role of the input is evaluated through a direct comparison of the caregiver’s responses with their child’s on the same task. Results are analyzed and compared per dyad using multifactorial statistics. Findings and implications. Through the innovations of including (pre)adolescents with DS as an understudied community and directly comparing their pronoun use to their caregivers’, this study overall contributes to disentangling how the link between social functioning, language production, and input is reflected in the development of socially meaningful language variation.