Maturational Constraints on Language Learning

TLDR

The study proposes that maturational constraints limit language acquisition and examines two hypotheses: decay of language‑specific constraints and the impact of expanding nonlinguistic cognitive abilities. The authors review empirical evidence and propose two mechanisms: maturational decay of language‑specific constraints and the influence of expanding nonlinguistic cognitive abilities. Studies show that language learning is successful only with early exposure, with performance declining linearly through childhood and flattening in adulthood, indicating that maturational constraints weaken over time.

Abstract

This paper suggests that there are constraints on learning required to explain the acquisition of language, in particular, maturational constraints. First, empirical evidence for this claim is reviewed. The evidence from several studies of both first and second language acquisition suggests that normal language learning occurs only when exposure to the language begins early in life. With exposure beginning later in life, asymptotic performance in the language declines: the effects over age of first exposure are approximately linear through childhood, with a flattening of the function in adulthood. These outcomes argue that some type of constraints ensuring successful language learning exist early in life, and weaken with increasing maturation. Second, two hypotheses are considered as to the nature of these maturational changes. One hypothesis is that constraints on learning particular to language acquisition undergo maturational decay. A second hypothesis, which is considered in more detail, suggests that language learning abilities decline because of the expansion of nonlinguistic cognitive abilities.