The better part of not knowing: Virtuous ignorance.

Suppose you are presented with 2 informants who have provided answers to the same question. One provides a precise and confident answer, and the other says that they do not know. If you were asked which of these 2 informants was more of an expert, intuitively you would select the informant who provided the certain answer over the ignorant informant. However, for cases in which precise information is practically or actually unknowable (e.g., the number of leaves on all the trees in the world), certainty and confidence indicate a lack of competence, while expressions of ignorance may indicate greater expertise. In 3 experiments, we investigated whether children and adults are able to use this "virtuous ignorance" as a cue to expertise. Experiment 1 found that adults and children older than 9 years selected confident informants for knowable information and ignorant informants for unknowable information. However, 5-6-year-olds overwhelmingly favored the confident informant, even when such certainty was completely implausible. In Experiment 2 we replicated the results of Experiment 1 with a new set of items focused on predictions about the future, rather than numerical information. In Experiment 3, we demonstrated that 5-8-year-olds and adults are both able to distinguish between knowable and unknowable items when asked how difficult the information would be to acquire, but those same children failed to reject the precise and confident informant for unknowable items. We suggest that children have difficulty integrating information about the knowability of particular facts into their evaluations of expertise. (PsycINFO Database Record