The role of vocabulary versus knowledge in children's language learning: a fifty-year perspective

Much public attention has been drawn to the "30 million-word gap' between children growing up in more vs. less privileged families. I argue in this paper that conceptualizing the gap in quantity of words, which is useful in emphasizing the size of the challenge, misconceptualizes the real differences, which are in knowledge of the world rather than just vocabulary size, and risks luring early childhood educators and parents into overly simple solutions. If we recognize the challenge as one of knowledge rather than just vocabulary size, we also are in a better position to support second language learners whose knowledge base across both languages is a better predictor of academic success than vocabulary in the second language.