Predicting verbal skills and what verbal skills predict in early childhood

This thesis investigated individual differences in verbal skills of children and how variation in verbal skills is related to mathematics skills as a developmental outcome, by focusing largely on early childhood. In Chapter 2, we investigated differences in verb-based (linguistic) prediction skills of Dutch- and Turkish-speaking adults and 4- and 5-year-old children. Adults in both language groups and Dutch-speaking children showed a significant prediction effect, while Turkish-speaking children did not. Furthermore, we found a stronger prediction effect for Dutch-speaking adults than for Dutch-speaking children. We reasoned that the cross-linguistic differences in verb-based prediction skills of children were related to how Dutch and Turkish denoted sentence meaning (i.e., via word order in Dutch and via a case marker system in Turkish). The age-related differences in prediction skills were explained through a usage-based perspective. In Chapter 3, we investigated the roles of a broad set of verbal skills (an earlier measure of productive vocabulary, receptive grammar, receptive and productive vocabulary, and language production) and three components of working memory (phonological short-term memory, central executive, episodic buffer) that could explain individual differences in Turkish-speaking 4- to 8-year-old children's linguistic prediction based on case markers. We found that children's prediction skills were significantly related to (i) their earlier productive vocabulary skills, (ii) a mastery of using the case markers manipulated in the experiment (i.e., accusative and nominative) in their own productions, and (iii) episodic buffer component of working memory. In Chapter 4, we investigated the roles of mothers' stimulating parenting at ages 3-5 and children's verbal skills at ages 3-7 in early elementary mathematics skills in a nationally representative cohort of children living in Turkey. Stimulating parenting construct included a set of parenting behaviors that were verbally and academically beneficial, provided a variety of experiences and learning materials supporting school readiness, and were responsive to the child. Children's verbal skills involved age-appropriate measures of receptive vocabulary, phonological skills, and reading skills at school ages. By estimating structural models and systematically testing them to achieve a parsimonious final model, we found that verbal skills at age 6 longitudinally mediated the association between stimulating parenting practices at ages 3-5 and mathematics skills at age 7. We discussed the contributions of individual parenting behaviors and verbal skills to mathematics skills in early elementary years.