Genetic Evidence for Bidirectional Effects of Early Lexical and Grammatical Development

• DOI: 10.1111/1467-8624.7402005
• Publication Date: 2004-01-12T13:48:36Z
• Authors: Ginette Dionne; Philip S. Dale; Michel Boivin; Robert Plomin
• Keywords: Bootstrapping (finance); Lexical functional grammar

This article addresses the autonomy hypothesis of vocabulary and grammar bootstrapping mechanisms in early language development. Two birth cohorts 1,505 1,049 same‐sex twin pairs from UK were assessed at 2 3 years on vocabulary, using adapted versions MacArthur Communicative Development Inventory. Vocabulary correlate strongly both cohorts. Multivariate genetic modeling reveals a consistently high correlation between years. finding suggests same influences operate for grammar, incompatible with traditional hypothesis, least acquisition. Cross‐lagged longitudinal models indicate lexical syntactical to