Scalar diversity and negative strengthening

Abstract

In recent years, experimental research has demontrated great variability in the rates
of scalar inferences across different triggering expressions (Doran et al. 2009, 2012, van Tiel
et al. 2016). These studies have been taken as evidence against the so-called uniformity assumption,
which posits that scalar implicature is triggered by a single mechanism and that the
behaviour of one scale should generalize to the whole family of scales. In the following, we
present an experimental study that tests negative strengthening for a variety of strong scalar
terms, following up on van Tiel et al. (2016). For example, we tested whether the statement
John is not brilliant is strengthened to mean that John is not intelligent (see especially Horn
1989). We show that endorsement rates of the scalar implicature (e.g., John is intelligent but
not brilliant) are anti-correlated with endorsements of negative strengthening. Further, we
demonstrate that a modified version of the uniformity hypothesis taking into account negative
strengthening is consistent with van Tiel et al.’s data. Therefore, variation across scales may be
more systematic than suggested by the van Tiel et al. study.
Keywords: Scalar diversity, scalar implicature, manner implicature, negative strengthening,
inferencing task.