Today David Barner (UCSD) will be giving a talk in the linguistics department. (He will also be giving a different talk tomorrow.)
Time/Date: Monday, 22 October, 2018, 15:30 – 17:00
Place: McGill Campus, 1085 Dr. Penfield, Room 117
Title: Access to alternatives and the acquisition of logical language
Though children begin to use logical connectives and quantifiers earlier in acquisition, studies in both linguistics and psychology have documented surprising failures in children’s interpretation of expressions. Early accounts, beginning with Piaget, ascribed these failures to children’s still burgeoning semantic and conceptual representations, arguing that children acquire ever more powerful logical resources as they development and acquire language. But more recent accounts, drawing on a Gricean divide between semantics and pragmatics, have argued that certain of these failures might not reflect semantic incompetence, but instead changes in children’s pragmatic reasoning abilities. In particular, early studies argued that children might be more “logical” than adults, perhaps because of difficulties with Gricean reasoning, or theory of mind. In this talk, I investigate this question, and argue that neither pragmatic incompetence nor conceptual/semantic change can explain children’s behaviors, and that instead children’s judgments stem from difficulties with “access to alternatives”.
I show this in two parts. First, I consider the case study of scalar implicature, and show that children when children hear an utterance like the one in (1) they fail to compute a scalar implicature like in (3) because they are unable to spontaneously generate the stronger alternative scale mate in (2). But when scalar alternatives are provided contextually or are “unique” alternatives, children no longer struggle with implicatures. I show that children easily compute “ad hoc” implicatures and ignorance implicatures (where all relevant alternatives are provided in the original utterances), as well as inferences that exhibit similar computational structure, like mutual exclusivity. Also, I show that children’s problems cannot be ascribed to difficulties with epistemic (theory of mind) reasoning, ruling out the idea that their problems are related to understanding other minds and intentions.
(1) I ate some of the cake
(2) I ate all of the cake
(3) I ate some (but not all) of the cake
In the second part, I discuss one variant of the “access to alternatives” hypothesis, that exploits Roberts’ (1996) notion of the Question Under Discussion. On this hypothesis, there is a symmetrical relation between a speaker’s intended QUD when uttering a statement, and the alternative statements are relevant to evaluating that QUD, such that (1) knowing a speaker’s intended QUD specifies which alternatives are relevant, and (2) knowing which alternatives are relevant specifies the speaker’s intended QUD. On this view, children’s ability to make logical inferences should be affected either by making alternatives available in context, or by narrowing the QUD. To explore this idea, I present data from three studies. First, I review evidence from a recent study by Skordos and Papafragou (2016) in which children’s rate of implicature can be improved by either means (alternatives or direct QUD narrowing). Second, I present data regarding quantifier spreading in (4). Like in past studies, I show that, in a context where three girls are riding 3 out of 4 available elephants (Context A), children judge (4) to be false (as though the intended question is, “Is every elephant is ridden by a girl?). However, when identical utterance is first probed in a context that renders it false (Context B), children subsequently judge (4) to be true in Context A (now understanding the question to be “Is every girl riding an elephant?). I argue that Context B provides a state of affairs providing what Crain calls “plausible dissent”, by making clear the speaker’s intended meaning (i.e., here, the QUD), which in absence of Context B children must infer from other contextual cues – e.g., “What is question is the speaker most likely to ask in this context?”
(4) Every girl is riding an elephant.
Context A: <g, e> <g, e> <g, e> <e>
Context B: <g, e> <g, e> <g> <e>
Also, I show that providing relevant states of affairs can likewise affect scalar implicature, and that when children are not provided with a context that makes the denial of a statement plausible (a la Crain), they fail to converge on the intended QUD, fail to generate relevant linguistic alternatives, and derive non-adult-like inferences – e.g., interpreting disjunction as conjunction. I show that, contrary to several recent reports, children do not interpret disjunction as conjunction if the context properly narrows the speaker’s intended QUD by providing states of affairs that render test statements deniable.