Beyond belief: The probability-based notion of surprise in children.

Improbable events are surprising. However, it is unknown whether children consider probability when attributing surprise to other people. We conducted four experiments that investigate this issue. In the first three experiments, children saw stories in which two characters received a red gumball from two gumball machines with different distributions, and children then judged which character was more surprised. Experiment 1 (N = 120) shows development in children's use of probability to infer surprise. Children aged 7 correctly inferred that the character with a lower chance of getting a red gumball would be more surprised, but 4- to 6-year-olds did not. Experiment 2 (N = 120) shows that children's performance does not improve when the probability of getting a red gumball is zero and should be maximally surprising. Experiment 3 (N = 120) demonstrates that 6-year-olds' performance improves when they are prompted to consider probabilities, but not when they are prompted to consider the characters' beliefs. Experiment 4 (N = 60) replicates this finding, but using a new design in which children attributed emotions to just a single character. Together these findings suggest that by age 6, a conceptual shift occurs, in which children begin to integrate their understanding of probability with their understanding of surprise. (PsycINFO Database Record (c) 2018 APA, all rights reserved).