The purpose of this exploratory study was to examine child and environmental factors known to be associated to language development and how they relate to results in expressive vocabulary, expressive language, and receptive language in language-delayed toddlers. The cross-sectional data on 96 French-speaking children aged 18–36 months were gathered at the point of entry into a longitudinal study of 2-year-old children displaying language delay. Measures of language, child development, and child and environmental factors were administered. When several factors individually associated with language development were considered concurrently, cognitive development was consistently associated with the outcomes. Other child factors, such as male gender and age, were also retained in the regression model explaining expressive vocabulary, whereas only age was added in the model explaining expressive language. Two environmental factors were involved in receptive language; that is, parental education and parental stress accounted for 8% of the variance. Factors linked to development varied across language modalities such that parental education and parental stress were related to comprehension but not to production. The findings suggest a strong biological trajectory for expressive language development and vocabulary production, which are not affected by environmental factors.
Département de réadaptation, Programme de maîtrise en orthophonie, Université Laval, Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale, Québec, Canada (Drs Sylvestre and Desmarais); Département de médecine sociale et préventive, Université Laval, Centre de Recherche L'Hôtel-Dieu-de-Québec, Québec, Canada (Dr Meyer); Département de chirurgie, Université Laval and Direction de Santé publique de la Capitale-Nationale, Québec, Canada (Dr Bairati); École de psychologie (Dr Rouleau) and Département de psychiatrie (Dr Merette), Université Laval, Centre de Recherche Université Laval–-Robert Giffard, Québec, Canada.
Correspondence: Audette Sylvestre, PhD, Département de réadaptation, Programme de maîtrise en orthophonie, Pavillon Ferdinand-Vandry, Université Laval, 1050, avenue de la Médecine, Québec, QC, Canada G1V 0A6 (firstname.lastname@example.org).
This study was supported by Grant 6472 from the Fonds de la recherche en santé du Québec (Quebec Fund for Health Research).
The authors thank Lyne Champoux, Karine Messier, Hélène Crépeau, Olga Gordynska, Isabel Moreau, and numerous research assistants as well as statistics consultants for their assistance. They also thank the SLPs who collaborated in the recruitment of participants and the children and parents who generously gave of their time to participate in this study.
The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.