Within the cognitive science of religion, some scholars hypothesize (1) that minimally counterintuitive (MCI) concepts enjoy a transmission advantage over both intuitive and highly counterintuitive concepts, (2) that religions concern counterintuitive agents, objects, or events, and (3) that the transmission advantage of MCI concepts makes them more likely to be found in the world’s religions than other kinds of concepts. We hypothesized that the memorability of many MCI supernatural concepts was due in large part to other characteristics they possess, such (...) as their frequent and salient association with moral concerns and the alleviation of existential anxieties, and that without such characteristics they would fail to be memorable. We report the results of three experiments designed to test the relative contributions of minimal counterintuitiveness, moral valence, and existential anxiety to the memorability of supernatural ideas. We observed no main effects for minimal counterintuitiveness but did observe main effects for both moral valence and existential anxiety. We also found that these effects did not seem to stem from the greater visualizability of morally valenced concepts or concepts that concerned existential anxieties. These findings challenge important claims made by leading researchers regarding MCI concepts within the cognitive science of religion. (shrink)