Chapter 1 The Invention of Language by Children: Environmental and Biological Influences on the Acquisition of Language

Human children grow up in cultural settings of enormous diversity. This differentiation sometimes leads us to overlook those aspects of development that are highly similar, even universal to our species. For example, under widely varying environmental circumstances, while learning different languages within different cultures and under different conditions of child rearing, with different motivations and talents, all normal children acquire their native tongue to a high level of proficiency within a narrow developmental time frame. Evidence from the study of the language learning process suggests that this constancy of outcome, despite variation in environment, has its explanation in biology. Language is universal in the species just because the capacity to learn it is innately given. In Descartes's (1662/1911) words: "It is a very remarkable fact that there are none … without even excepting idiots, that they cannot arrange different words together, forming of them a statement by which they make known their thoughts; while on the other hand, there is no other animal, however perfect and fortunately circumstanced it may be, which can do the same."In other words, some part of the capacity to learn languages must be "innate." At the same time, it is equally clear that language is "learned." There are about five thousand different languages now in use on the earth, and the speakers of one cannot understand the speakers of the next. Moreover, specific exposure conditions strikingly influence how each of these is acquired: there is a massive correlation between being born in England and coming to speak English and being born in France and speaking French. This immediately shows that the language function is heavily affected by specific environmental stimulation.