Shake it baby, but only when needed: Preschoolers adapt their exploratory strategies to the information structure of the task.

Previous research has suggested that active engagement with the world drives children's remarkable learning capabilities. We investigated whether preschoolers are "ecological learners," that is, whether they are able to select those active learning strategies that are most informative in a given task. Children had to choose which of two exploratory actions (open vs. shake) to perform to find an egg shaker hidden in one of four small boxes, contained in two larger boxes. Prior to this game, children either learnt that the egg was equally likely to be found in any of the four small boxes (Uniform condition), or that it was most likely to be found in one particular small box (Skewed condition). Results of Study 1 show that 3- and 4-year-olds successfully tailored their exploratory actions to the different likelihood-distributions: They were more likely to shake first in the Uniform compared to the Skewed condition. Five-year-olds were equally likely to shake first, irrespective of condition, even when incentivized to shake only when needed (Study 2a). However, when the relevance of the frequency training for the hiding game was highlighted (Study 2b and Study 2c), the 5-year-olds showed the same behavioural pattern as the younger preschoolers in Study 1. We suggest that ecological learning may be a key mechanism underlying children's effectiveness in active learning.