No negative evidence revisited: Beyond learnability or who has to prove what to whom.

P. Gordon (see record 1990-14375-001) in his commentary on N. J. Bohannon and L. Stanowicz (see record 1989-00984-001) argued that (a) the original M. E. Gold (1967) learnability proof bears little relevance for innateness of language, (b) the Bohannon and Stanowicz results do not justify abandoning innate restraints on language learning, and (c) there may be cases in which such feedback is unavailable. In this reply, the relevant and irrelevant aspects of both the original Gold proof and more modern attempts at learnability are discussed. Uniqueness, a concept central to all modern formal models, is also adaptable to account for the negative evidence available in the child's input language. Rates of feedback found in Bohannon and Stanowicz are shown to be sufficient to spur learning in many species, including concept formation tasks in humans, and anecdotal counterevidence against the universality of negative evidence is discounted. It is suggested that using innate factors as a "default" explanation is a dangerous and counterproductive scientific endeavor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)