  The problem to which Chomsky refers, which is the problem of behavioral competence and thus performance outstripping individual learning histories, goes beyond merely the issue of linguistic behavior in young children.  It appears to be a fundamental fact about human beings that our behavior and behavioral capacities often surpass the limitations of individual reinforcement histories. Our history of reinforcement is often too impoverished to determine uniquely what we do or how we do it. Much learning, therefore, seems to require pre-existing or innate representational structures or principled constraints within which learning occurs. (See also Brewer 1974, but compare with Bates et al. 1998 and Cowie 1998).