Scalar implicatures—inferences from a weak description (“Iate some of the cookies”) that a stronger alternative is true(“I didn’t eat all”)—are paradigm cases of pragmatic infer-ence. Children’s trouble with scalar implicatures is thus animportant puzzle for theories of pragmatic development, giventheir communicative competence in other domains. Previousresearch has suggested that access to alternatives might be key.Here, we explore children’s reaction times in a new paradigmfor measuring scalar implicature processing. Alongside fail-ures on scalar implicatures with “some,” we replicate previ-ous reports of failures with “none,” and find evidence of aspeed-accuracy trade-off for both quantifiers. Motivated bythese findings, we explore the relationship between accuracyand reaction time with a Drift Diffusion Model. We find evi-dence consistent with the hypothesis that preschoolers lack ac-cess to the alternatives for scalar implicature computation, al-though this set of alternatives may be broader than previouslyassumed
