Can a funny story about tooth brushing decrease plaque scores in children? A longitudinal field experiment

Dental caries is the most common chronic condition among children, it is thus a necessity to develop health communication tools to increase children’s dental hygiene. Prior research among adults indicates that entertaining narrative communication can promote health behaviors, but knowledge on narrative effects on children’s health outcomes is limited. In a repeated measures field experiment (N = 94, 4-10 years) we examined the long-term effects of repeated exposure to a humorous tooth brushing narrative about an orange monkey, versus an expository text on dental care, on children’s self-reported and biomedical dental hygiene (plaque scores). We also explored narrative, affective and cognitive processes. Findings showed that the humorous narrative increased character engagement, enjoyment, and moral judgment compared with the expository condition. Enjoyment and moral judgment, in turn, predicted increases and decreases in plaque scores, respectively. We conclude that effectiveness of humorous narrative approach crucially depends on whether the child understands it when a story character is violating the rule.