Learning, Hygiene, and Traditional Medicine

To be effective, informational interventions must be convincing. Messages related to infectious disease prevention invoke the germ theory of disease, which may conflict with disease models from traditional medicine. A novel program in rural Pakistan attempts to make hygiene messages more convincing by using microscopes to demonstrate that microbes exist. In a randomized evaluation, we find that the microscope demonstrationstrengthens the impact of hygiene instruction on learning, hygiene, and health. The microscope demonstration weakens traditional medical beliefs, suggesting that traditional and modern beliefs are substitutes. Likewise, the intervention is more effective for nonbelievers in traditional medicine, which is consistent with Bayesian learning and suggests that traditional beliefs contribute to the burden of infectious disease.