How do violations of Gricean maxims affect reading?

•We examined how readers process violations of the Gricean maxim of quantity.•Redundant size modifiers delay first-pass times for the noun phrase.•Ambiguous nouns and redundant color modifiers do not immediately delay processing.•Initial referential processing is led by the meaning of the referring expression.•Violations of the Gricean maxim affect late reading measures.

Four eye-tracking experiments examined how violations of the Gricean maxim of quantity affect reading. Experiments 1 and 2 showed that first-pass reading times for size-modified definite nouns (the small towel) were longer when the modifier was redundant, as the context contained one rather than two possible referents, whereas first-pass times for bare nouns (the towel) were unaffected by whether the context contained multiple referents that resulted in ambiguity. Experiment 3 showed that unlike redundant size modifiers, redundant color modifiers did not increase first-pass times. Experiment 4 confirmed this finding, demonstrating that the effect of redundancy was dependent on the meaning of the modifier. We propose that initial referential processing is led by the lexico-semantic representation of the referring expression rather than Gricean expectations about optimal informativeness: Redundancy of a size-modifier immediately disrupts comprehension because the processor fails to activate the referential contrast implied by the meaning of the modifier, whereas referential ambiguity has no immediate effect, as it allows the activation of at least one semantically-compatible referent.