Deaf children of elementary and secondary school age participated in a study designed to examine their understanding of display rules, the principles governing the expression and concealment of emotion in social situations. The results showed that deaf children's knowledge of display rules, as measured by their reported concealment of emotion, was comparable to that of hearing children of the same age. However, deaf children were less likely to report that they would conceal happiness and anger. They were also less likely to produce reasons for concealing emotion and a smaller proportion of their reasons were prosocial, that is, relating to the feelings of others. The results suggest that the understanding of display rules (which function to protect the feelings of other people) may develop more gradually in deaf children raised in a spoken language environment than it does in hearing children.