Brain and Cognitive Sciences, MIT Psychological and Brain Sciences, University of Louisville

Children are sensitive to whether informants provide sufficient information for accurate learning (Gweon et al., 2011). Do children think that informants should always provide as much information as possible? Here we show that children consider other’s prior knowledge and the cost of information to decide how much information is appropriate. We showed children toys that had 20 identical buttons, three of which played music. Given a choice between an informant who demonstrated all 20 buttons (exhaustive informant) or just the three that played music (selective informant), children preferred the exhaustive informant only when the learner was naïve about how many buttons worked and could be mislead by a selective demonstration (Experiment 1). Given an opportunity to teach themselves, children were more likely to provide exhaustive information when the learner did not know how many buttons worked on the toy (Experiment 2). These results suggest that young children consider others’ prior knowledge to balance the cost and the benefit of information in learning from others and in teaching others.