Klaus Alfønso, Ubiquity of ambiguity.
Ambiguity is a striking property of natural language distinguishing it from arti-ficial languages. The mathematically well defined case of syntactic ambiguity ispresent in sentences that can be structurally analysed in more than one way:(1) The officer watched the spy with the telescope.(2) The word of the Lord came to Zechariah, son of Berekiah, the prophet.(3) The passengers who left the boat first were old men and women.In an optimal communication system, a feature like syntactic ambiguity wouldseem to be dysfunctional. Effective coding implies that one signal corresponds toone meaning and can therefore be interpreted deterministically. Syntactic ambiguity, one would assume, should not be found in a successful communicationsystem like human language.

Its ubiquity thus poses an evolutionary puzzle: why has such an apparent imperfection emerged in language? One view of language imperfections is that they are artifacts arising from internal constraints of the innate language faculty (Chomsky, 2002). Nativists conclude from the poverty of stimulus argument that language acquisition is not primarily a matter of learning but rather of setting predefined, genetically determined parameters of the innate language faculty.This view is contrasted by an approach taken in studies of language evolutionwhich explain hallmarks of language by the fact that language undergoes culturaltransmission (Hurford, 2002; Brighton, Kirby, & Smith, 2005). This idea is basedon the observation that language acquisition represents a special class of learningproblem as the output of the language learning of one generation is the input tothe learning of the next generation. Properties of language are exhibited becauselanguage itself, as opposed to its users, adapts to be learnable. Brighton (2003)points out that in such an iterated learning framework, language imperfectionsreflect residues of linguistic evolution through cultural transmission.