Fundamental questions

All humans achieve competence in whatever language is used around them when growing up, with little apparent need for explicit conscious instruction (setting aside extremely pathological cases). Linguists assume that the ability to acquire and use language is an innate, biologically based potential of modern human beings, similar to the ability to walk, because nonhumans do not acquire human language in this way (although many nonhuman animals can learn to respond to language, or can even be trained to use it to a degree).^[11]
There is no consensus, however, as to the extent of humans' innate potential for language, or the degree to which such innate abilities are specific to language. Some theorists claim that there is a very large set of highly abstract and specific binary settings coded into the human brain; the combinations of these settings would give rise to every language on the planet. Other linguists claim that the ability to learn language is a product of general human cognition. It is, however, generally agreed that there are no strong genetic differences underlying the differences between languages: An individual will acquire whatever language(s) he or she is exposed to as a child, regardless of parentage or ethnic origin. Nevertheless, recent research suggests that even weak genetic biases in speakers may, over a number of generations, influence the evolution of particular languages, leading to a nonrandom distribution of certain linguistic features across the world. ^[12]