Don't look at my answer: subjective uncertainty underlies preschoolers' exclusion of their least accurate memories.

Preschoolers' ability to introspect and make decisions on the basis of these introspections has traditionally been questioned. The present research introduces a novel paradigm to examine the development of the connection between subjective uncertainty about memory and decision making in preschoolers. Three-, 4-, and 5-year-olds (N = 81) encoded items presented once or twice. They then completed a forced-choice test, provided confidence judgments for each response, and decided whether to select or exclude answers to be evaluated for the possibility of reward. Four- and 5-year-olds, but not 3-year-olds, reported lower certainty for incorrect and weaker memories than for correct and stronger memories, and they judiciously excluded their least confident memories, which resulted in accuracy gains for selected memories; these findings highlight age-related improvements in introspection on memory accuracy. Among accurate responses only, even 3-year-olds excluded their least confident answers, which suggests that the connection between uncertainty and decision making precedes the ability to monitor memory accuracy.