Previous research has shown that children and adults express more confidence in the existence of unobservable scientific (e.g., germs), as compared to religious, phenomena (e.g., the soul). We asked if the same pattern would emerge among parents ( N = 77) and children ( N = 85) in Iran, a country with widespread commitment to religious values and beliefs. Parents expressed confidence in the existence of various scientific and religious phenomena but were more confident that scientific phenomena exist. Moreover, even though Iranian parents expressed a high valuation of both science and religion, their valuation of science was higher than that of religion. Like their parents, older children also expressed greater confidence in the existence of scientific, as compared to religious, phenomena. We conclude that with age, the kind of discourse children are exposed to elicits more confidence in the existence of scientific phenomena even in a religious society.

The study was approved by the IRB of the relevant institutions. Parents of all child participants were provided an information sheet and verbally assented to the study. Children verbally assented. For reasons of confidentiality, no signatures or identifiable information were collected. We consent to this paper being published by the publisher upon acceptance. All data, analysis codes, and materials are available and open on OSF [https://osf.io/fbt73/]