Individual differences in early language: Causes, consequences, and implications for research design

Professor Philip S. Dale, University of New Mexico

There is an increasing focus on individual differences in early language development (below age 3) in many basic science and applied fields. This is due in part to improved methods for assessment, and in part to a degree of prediction to later outcomes from these measures, which suggests the potential value of early intervention. I will present an overview of several research literatures on early individual differences. The first is the illumination provided by twin studies on the interplay of genes and environment in causing individual differences. Second is literature on predictions from early measures to later language and literacy, with emphasis on the variability in outcome among late talkers. In the third, I will examine the multidimensional nature of these differences, and the challenge that provides for matching designs in research studies, and also for exploring individual differences in response to intervention.

Friend or Foe? Peer effects in early childhood classrooms

Professor Laura Justice, Ohio State University

Numerous studies have shown peer effects to operate in the primary and upper grades, but few studies have focused on early-childhood settings serving very young children. Our team has conducted a series of studies to explore peer effects (do they operate? How size are the effects?) specific to language skills in early childhood settings, including those that serve a general population of children as well as those that serve specialized populations (i.e., children who are poor, children with disabilities). We have found that peer effects do operate and that effects are consistent across samples of children. In addition, we have explored the benefits of having highly skilled peers for children with disabilities, finding that being educated alongside typically developing highly-skilled children is particularly advantageous for young children with disabilities. Finally, in our recent work we have investigated whether peer effects operate as direct effects (peer-to-peer) or via the teacher as an indirect effect; recent analyses suggest that peer effects operate along their own pathway within the early childhood setting.