Early phonology revealed by international adoptees' birth language retention

Dutch adults who, as international adoptees, had heard Korean early in life but had forgotten it learned to identify an unfamiliar three-way Korean consonant distinction significantly faster than controls without such experience. Even adoptees who had been adopted at 3-5 mo of age showed the learning advantage. Thus, early exposure to spoken language, even in the first half-year of life, leaves traces that can facilitate later relearning. Before 6 mo, infants often discriminate foreign-language phonological contrasts better than adults can. This has been widely held to mean that infants younger than 6 mo have no native-language phonological knowledge to capture spoken input. Our findings are significant because they indicate that phonological knowledge is indeed in place before age 6 mo.