Children's sensitivity to their own relative ignorance: handling of possibilities under epistemic and physical uncertainty.

Children more frequently specified possibilities correctly when uncertainty resided in the physical world (physical uncertainty) than in their own perspective of ignorance (epistemic uncertainty). In Experiment 1 (N=61), 4- to 6-year-olds marked both doors from which a block might emerge when the outcome was undetermined, but a single door when they knew the block was hidden behind one door. In Experiments 2 (N=30; 5- to 6-year-olds) and 3 (N=80; 5- to 8-year-olds), children placed food in both possible locations when an imaginary pet was yet to occupy one, but in a single location when the pet was already hidden in one.