Evolution, selection and cognition: from "learning" to parameter setting in biology and in the study of language.

Most biologists and some cognitive scientists have independently reached the conclusion that there is no such thing as learning in the traditional "instructive" sense. This is, admittedly, a somewhat extreme thesis, but I defend it here in the light of data and theories jointly extracted from biology, especially from evolutionary theory and immunology, and from modern generative grammar. I also point out that the general demise of learning is uncontroversial in the biological sciences, while a similar consensus has not yet been reached in psychology and in linguistics at large. Since many arguments presently offered in defense of learning and in defense of "general intelligence" are often based on a distorted picture of human biological evolution, I devote some sections of this paper to a critique of "adaptationism," providing also a sketch of a better evolutionary theory (one based on "exaptation"). Moreover, since certain standard arguments presented today as "knock-down" in psychology, in linguistics and in artificial intelligence are a perfect replica of those once voiced by biologists in favor of instruction and against selection, I capitalize on these errors of the past to draw some lessons for the present and for the future.