Earlier studies found a discrepancy between the display and feeling of surprise. Therefore, we assessed what factors influence the display of surprise in children of two age groups: 8- and 11-year-olds. We manipulated the social setting (children either competed or collaborated), and the cause of surprise (a surprisingly positive or negative event). We found that children used more features to express negatively caused surprise, compared to positively caused surprise and that 11-year-olds used more facial features than 8-year-olds. In a subsequent perception study, adults judged video clips with surprised and neutral reactions, for the degree of surprise that was displayed. We found higher ratings of surprise for negatively vs. positively surprised children, competing vs. collaborating children, and 11-year-olds vs. 8-year-olds. These results confirm that in addition to the feeling of surprise, its cause, the social setting, and age also affect the display of surprise.