A total of 68 second- and fourth-graders participated in a study of children's expressiveness and encoding and decoding skills. They were chosen on the basis of their parents' self-reports of low or high expressiveness on the Family Expressiveness Questionnaire. In hour-long, videotaped interviews with their mothers, subjects sorted 25 cards depicting a variety of activities into piles according to the likeability of the activities. Subjects discussed the activities in two different ways. For a measure of baseline affect, they described the two most liked, two most neutral, and two most disliked activities, and why they felt the way they did about the activities. For a measure of encoding skill, they attempted to describe those activities in ways that did not reflect their real feelings about the activities. After being given the example of a child showing joy at receiving an unwanted gift from grandparents, children were asked to discuss both the liked and disliked items as if they were neutral (inhibition); the liked items as if they were disliked and vice versa (masking); and the neutral items as if they were liked and disliked (simulation). Findings revealed that children from both grades were fairly accurate in their attempts to inhibit, mask, and simulate both positive and negative affect. No main effects were found for sex, grade, or family expressiveness. (RH)