Dual Processes, Development, and Scalar Implicature

Dual process theories suggest that our thinking is determined by separate, but interacting, heuristic and analytic processes. We describe an experiment designed to investigate the development of these processes. We examined the extent to which groups of 6, 9, 12, and 15 year-old participants and a group of adults were sensitive to scalar implicature in pragmatically enriched and pragmatically impoverished contexts. For younger participants we find high rates of pragmatic responding in enriched contexts and high rates of logical responding in impoverished contexts. Early adolescents displayed universally pragmatic responding whilst logical responding re-emerged in older adolescents and adults. These results suggest that heuristic processes develop earlier than analytic processes but that they are not well developed until early adolescence.