  All the topics covered in §3 deserve books of their own. My aim here has been to sketch the ways in which modern understanding of the mind reveals the inadequacy and implausibility of the claim that humans have innate representations of UG that are responsible for their acquisition of language. There are likely many, many processes implicated in the attainment of linguistic competence, that many of them are likely specialized by natural selection for linguistic tasks, but that many of them also retain their other, and older, functions. The linguistic nativist's theory views our acquisition of grammatical competence as a simple matter — one that can be described at one level of explanation, and in terms of a single kind of process. This is very unlikely to be the case. Multiple systems and multiple processes are at work in the acquisition of linguistic knowledge, and our understanding of language acquisition, when it comes, is likely to involve theories of many kinds and at many different levels, and to resemble the theory of the Chomskyan nativist in few or no  respects.[29] 