Causes and consequences of variability in early language learning

At every age, individuals vary substantially in language abilities. This chapter focuses on individual differences in language proficiency that are already evident in the second year of life. Although studies over a century have documented links between parent-child verbal interactions and later language outcomes, the emphasis in research since the 1970s has been on commonalities across children, rather than on individual differences, where they come from, and how they matter. Recent studies show that differences in early processing efficiency predict language growth, and that variability in early language experience contributes to these differences in processing skill. These findings suggest that it is time to reframe the debate about the causes and consequences of variability in language learning. Keywords: Early experience; language processing; individual differences