Children were more likely correctly to specify possibilities when uncertainty resided in the physical world, and more likely to guess the outcome when objectively identical uncertainty arose from their own perspective of ignorance (epistemic uncertainty). In Experiment 1, 4-to 6-year-olds more frequently marked both doors from which a block might emerge when the outcome was undetermined, than when the block was hidden behind one door. In Experiment 2 (5-to 6-year-olds) and 3 (5-to 8-yearolds), children more frequently placed food in both possible locations when an imaginary pet was yet to be placed in a box, than when it was hidden in one. Results have implications for interpretive theory of mind and 'curse of knowledge'.
Epistemic and physical uncertainty 3Children's Sensitivity to Their Own Relative Ignorance:
Handling of Possibilities Under Conditions of Epistemic and Physical UncertaintyAdults' and children's handling or mishandling of uncertainty have long been the focus of research attention. In the adult literature, a number of researchers have made a distinction between uncertainty which arises in the external world (for example about the fall of a die not yet thrown), and uncertainty which resides internally due to ignorance on the part of the observer (for example about the fall of a die which has been thrown but out of the observer's view). The latter is commonly labeled epistemic uncertainty; the former has been given various labels and here we shall use the term physical uncertainty. In the experiments reported here we compare children's handling of these two types of uncertainty and show that, as for adults, the variable is of psychological importance:Exactly the same probability is treated differently when uncertainty is epistemic rather than physical. In our tasks with children, however, the effect operates in the opposite direction from that found in the adult studies, and we speculate why.In what follows we begin by summarizing the published research on children's handling of uncertainty, most of which involves procedures giving rise to epistemic rather than physical uncertainty. Then we show how adults respond differently to the two types of uncertainty in tasks unlike those used with children. Finally we set up our predictions for children's handling of the two types of uncertainty in tasks which derive from the existing developmental literature.
Epistemic and physical uncertainty 4Children have a well documented tendency to under-estimate the uncertainty arising from limited information in a wide range of circumstances, to a much greater extent than adults. The literature on children's understanding of ambiguity highlights changes between around 5 and 8 years in children's acceptance of the possibility of alternative interpretations of limited input (e.g. Beal, 1988;Flavell, Speer, Green & August, 1981;Robinson & Robinson, 1982;Robinson, Goelman & Olson, 1983;Taylor, 1988), and this has been supplemented by more recent studies (Apperly & Robinson, 1998;Beck & Robinson, 2001;Carpendale & Chan...