The scientist-practitioner gap refers to the phenomenon of individuals with a scientific background exhibiting non-scientific beliefs. Informed by the social-cognitive process model, this study aimed to develop a more coherent understanding of how such non-scientific beliefs can be predicted by individuals' cognitive flexibility mediated by their epistemic curiosity. A questionnaire was administered to 332 undergraduate students majoring in science at 2 universities in Taiwan. It included items on cognitive flexibility, 2 types of epistemic curiosity, and non-scientific beliefs. After the reliability and validity of the items and constructs were validated, structural equation modeling was applied to verify the research model. Results indicated that the 2 types of epistemic curiosity, interest-type and deprivation-type, were positively predicted by cognitive flexibility but were negatively reflected in the students' non-scientific beliefs. The study also tested the gender difference for each factor and found that female students majoring in science tended to have stronger non-scientific beliefs than their male counterparts. The results imply that if a higher level of cognitive flexibility is attained, the scientist-practitioner gap may be reduced.