Homogeneity or implicature: An experimental investigation of free choice

Abstract

A sentence containing disjunction in the scope of a possibility modal, such as Angie is allowed to buy the boat or the car, gives rise to the FREE CHOICE inference that Angie can freely choose between the two. This inference poses a well-known puzzle, in that it is not predicted by a standard treatment of modals and disjunction (e.g., Kamp 1974). To complicate things further, FREE CHOICE tends to disappear under negation: Angie is not allowed to buy the boat or the car doesn’t merely convey the negation of free choice, but rather the stronger DUAL PROHIBITION reading that Angie cannot buy either one. There are two main approaches to the FREE CHOICE-DUAL PROHIBITION pattern in the literature. While they both capture the relevant data points, they make a testable, divergent prediction regarding the status of positive and negative sentences in a context in which Angie can only buy one of the two objects, e.g., the boat. In particular, the implicature-based approach (e.g., Fox 2007; Klinedinst 2007; Bar-Lev & Fox 2017) predicts that the positive sentence is true in such a context, but associated with a false implicature, while it predicts the negative sentence to be straightforwardly false. The alternative approach (e.g., Aloni 2018; Goldstein 2018; Willer 2017) predicts both the positive and negative sentences to be equally undefined. Investigating the contrast between these sentences in such a context therefore provides a clear way to address the debate between implicature and non-implicature accounts of FREE CHOICE. We present an experiment aiming to do just this, the results of which present a challenge for the implicature approach. We further discuss how the implicature approach could in theory be developed to account for our results, based on a recent proposal by Enguehard & Chemla (2018) on the distribution of implicatures.

Choice and prohibition in non-monotonic contexts

“…There are also a variety of challenges for this approach stemming from certain differences between implicatures and free choice in their processing and acquisition profiles (Chemla and Bott 2014;Tieu et al 2016). Other challenges stem from the interaction between free choice and presuppositions (Romoli and Santorio 2019;Marty and Romoli 2019) and the status of positive versus negative sentences in certain contexts (Tieu et al 2018). 7 See Chierchia (2004Chierchia ( , 2013, Chierchia et al (2012), Magri (2009), Meyer (2013, among others.…”

Free choice and homogeneity

“…This has at least two upshots. First, in the case of Free Choice Tieu et al 2019 found exactly the pattern of responses predicted by a homogeneity account. Second, Free Choice patterned quite differently than the early access Simon Goldstein kind of exclusivity implicature on display in (21-a).…”

“…The pragmatic accounts in Chemla 2008 andFox 2007 differ from the accounts here in at least the treatment of Free Choice when disjunction takes wide scope to possibility modals and the treatment of duals to ♦ and ∨. In addition, we'll review recent experimental work in Santorio 2019 andTieu et al 2019 that seems to favor the present account. The semantic accounts in Aher 2012 and Aloni 2018 differ from our own by departing further from classical logic, giving up instances of the Law of Excluded Middle, Law of Non-Contradiction, and Explosion.…”

“…The first observation here (paralleling Lobner 2000, Fodor 1970 on plural definites), is simply that free choice constructions generate truth value gaps. Tieu et al 2019 ran an experiment in which they gave participants a scenario in which Sue is only allowed to buy a boat, and asked them to consider: (20) Sue is allowed to buy the boat or the car. (20)…”

“…Second, Free Choice patterned quite differently than the early access Simon Goldstein kind of exclusivity implicature on display in (21-a). In this way, Tieu et al 2019 offers both evidence of a homogeneity effect in the case of Free Choice, and a way of distinguishing the homogeneity and implicature based accounts of Free Choice (of which more in §10). Križ 2015a argues that homogeneity in plural predication involves a distinctive pattern of projection, involving a special kind of supervaluation over undefined individuals which treats them alike.…”