Do speakers and listeners observe the Gricean Maxim of Quantity?

The Gricean Maxim of Quantity is believed to govern linguistic performance. Speakers are assumed to provide as much information as required for referent identification and no more, and listeners are believed to expect unambiguous but concise descriptions. In three experiments we examined the extent to which naïve participants are sensitive to the Maxim of Quantity. The first was a production experiment which demonstrated that speakers over-describe almost one-third of the time. The second experiment showed that listeners do not judge over-descriptions to be any worse than concise expressions. The third experiment used the Visual World Paradigm to assess listeners’ moment-by-moment interpretations of over-described utterances. This last experiment revealed that over-descriptions trigger eye movements that can be interpreted as indicating confusion. The results provide support for the use of a simple heuristic such as Minimal Attachment or Argument Saturation to create an initial parse. We conclude that people are only moderately Gricean.