Trick or treat: Children's understanding of surprise

This study examines the hypothesis that an understanding of false belief would lead to a radical change in young children's understanding of surprise. In Experiment 1, children aged 3 to 8 years were asked to assess the knowledge state of another person and to then choose an object that would surprise that person. The results showed that whereas the 3-year-olds' choice of surprising object varied with the object, the 5-year-olds' choice of object varied with their assessment of the other's knowledge state. Hence, understanding surprise depends on an understanding of false belief. In Experiment 2, the number of questions was reduced and children were required to match a schematized facial expression to the object judged to be surprising. Again, older children, unlike their younger counterparts, pointed out that surprised faces are made when another's expectations are violated. Once children begin to ascribe belief states to others they begin to understand that surprise depends upon the unexpected. The results help resolve the differences in the findings of Wellman and Banerjee (1991) and Hadwin and Perner (1991) on children's understanding of surprise. In natural judgements, young children employ a principle of desirability; older children employ principles of belief violation.