Presupposition projection from disjunction is symmetric

Abstract

The role of linear order for presupposition projection is a key theoretical question, but the empirical status of (a-)symmetries in projection from various connectives remains controversial. We present experimental evidence that presupposition projection from disjunction is symmetric. 'Bathroom disjunctions', where either disjunct seems able to support a presupposition in the other if its negation entails it, have been argued to be evidence for symmetric projection; but there are alternative theoretical options. Adapting the paradigm of Mandelkern et al. (2020) for projection from conjunction, our experimental data supports the view that we are dealing with genuinely symmetric projection from disjunction. This contrasts with Mandelkern et al.'s findings for asymmetric projection from conjunction, and thus provides evidence for variation in projection (a-)symmetry across connectives, contra accounts proposing general accounts predicting uniform asymmetry effects due to left-to-right processing (e.g. Schlenker 2009).