A Developmental Investigation of Processing Costs in Implicature Production

Much developmental work has been devoted to scalar implicatures. These are implicitly communicated propositions linked to relatively weak terms (consider how Some pragmatically implies Not all) that are more likely to be carried out by adults than by children. Children tend to retain the linguistically encoded meaning of these terms (wherein Some is compatible with All). In three experiments, we gauge children's performance with scalars while investigating four factors that can have an effect on implicature production: (i) the role of (the presence or absence of) distractor items; (ii) the nature of the task (verbal judgments versus action-based judgments); (iii) the choice of scalar expression (the French quantifier quelques versus certains); and (iv) the type of scale that contextualizes the weak utterance (the affirmative All versus the negative None). Experiment 1 replicated earlier findings showing that 9-year-olds are more likely than adults to consider as true statements such as Some turtles are in the boxes (uttered when all turtles are in the boxes) while employing the quantifier certains in a truth evaluation task containing multiple distractor items. The task in Experiment 2 increased implicature production across all ages (4-, 5-, and 7-year-olds as well as adults) but maintained the developmental effect while using quelques in an action-based task containing no distractor items. Experiment 3 showed that 9-year-olds are more likely to produce implicatures with quelques than they are with certains in the action task while adults are not affected by the choice of term. Overall, these results identify seemingly harmless task features that can prevent even older children (9-year-olds) from carrying out implicatures (e.g., through the inclusion of distractors) while also showing how implicature production among even young children (4- to 5-year-olds) can be facilitated by task features (e.g., the use of an action task) and without the introduction of special training.