Predicting Vocabulary Development in Bilingual Children Using Early Measures of Word Comprehension

Objectives: Although prior research has found that vocabulary and speed of lexical access in toddlerhood predict language development later in childhood, whether relations are significant appears to depend on differences across studies in task and participant characteristics. The current study expands on these findings by comparing the relative predictive utility of vocabulary and two measures of speed of lexical access to later vocabulary development in simultaneous bilingual children. Methodology: Participants included 32 French-English bilingual children in a longitudinal cohort study tested at 23 months, age three, and age four. At 23 months, children completed a two-alternative forced choice measure of vocabulary from which we coded decontextualized receptive vocabulary, and speed of lexical access operationalized as visual response latency and haptic response latency. At ages three and four, children completed a standardized receptive vocabulary assessment.Data and Analysis: We examined the relation between 23-month predictors and outcomes using correlational and regression analyses.Findings/Conclusions: Decontextualized vocabulary at 23 months predicted vocabulary outcomes at ages three and four. Visual response latency predicted vocabulary at age three, but not age four. Haptic response latency predicted vocabulary at age four, but not age three. Neither vocabulary nor latency was significant when controlling for the effects of the other predictors.Originality: This is the first study to investigate the relation between multiple direct measures of vocabulary and lexical access and language outcomes in bilingual children.Significance/Implications: This study contributes to our understanding of toddler language measures and how demand characteristics interact with participant characteristics to influence the roles of these measures in predicting later outcomes. Limitations: Given the small sample size and limited outcome measures, results should be interpreted with some caution and used to guide future research on early predictors of long-term vocabulary development in bilingual children.