Pre-existing beliefs and expectations influence judgments of novel health information

The present study examined whether health information is judged differently depending on pre-existing beliefs and expectations. People's initial beliefs and expectations were assessed by a questionnaire about acupuncture and a trustworthiness and preference rating task of doctors' faces. Then, newspaper headlines about novel acupuncture treatment were shown and rated for their feasibility in a normal and framed condition. The judged feasibility of the newspaper headlines correlated strongly with initial beliefs about acupuncture in the normal condition, and with initial expectations towards a doctor's face in the framed condition. Thus, as suggested by Bayes Theorem, pre-existing beliefs and expectations influence judgments of novel health information.