Investigations that focus on children's hand gestures often conclude that gesture production arises as a result of having multiple representations. To date, the predictive validity of this notion has not been tested. In this study, we compared the gestures of 82 five-year-old children holding either a single or a dual representation. The children retold a story narrated to them, with pictures, by the experimenter. In one condition the children heard a false belief story and hence, when retelling, held two beliefs--or representations--concurrently. In the other conditions, the children retold a version of the story without the false belief component and therefore held single representations. Children were four times more likely to gesture in the false belief condition than in two comparable true belief conditions, supporting the notion that gestures may function to externalise some of the child's cognitive process, particularly when they hold multiple representations.