Presupposition and accommodation in child language
The proper characterization of presupposition has been at the center of long-standing debate. On an influential view (Stalnaker 1970, 1974, Karttunen 1974), presuppositions reflect formal admittance conditions on utterances: an utterance of a sentence which presupposes p is admitted by a conversational context c only if p is already common ground in c. The theory distinguishes two modes of satisfying the formal requirement: (i) presuppositions may have common ground status prior to utterance, or (ii) they may acheive common ground status post-hoc, via accommodation, an adjustment of the common ground by cooperative listeners so as to meet the requirements of the uttered sentence. While intuitive and general, this two-pronged approach has been criticized on methodological grounds. There have been a number of alternative theories that reject the notion that presuppositions impose admittance conditions and take some form of accommodation as the basic way in which presuppositions relate to the context.
This talk compares these two perspectives on presupposition in terms of their implications for language acquisition. In a series of behavioral experiments, we show that young children generate a default expectation that the presuppositions of an asserted sentence have common ground status prior to utterance, even in situations where accommodation is licensed. More tellingly, even when accommodation is the preferred option for adults, children adopt a different conversational stance. The observed two-step developmental trajectory, we argue, lends support to key tenets of the admittance theory, whose empirical validity may otherwise be masked due to the pragmatic sophistication of adult language users.