AbstractIn three samples (Ns = 286, 304, and 273), we found that endorsement of conspiracy theories, paranormal beliefs, and psychological misconceptions were all positively intercorrelated, supporting an individual difference in the tendency to generally endorse unsubstantiated claims. Multiple regression analyses further supported generality, showing that intuitive cognitive style positively predicted all three types of unsubstantiated beliefs in all samples, except conspiracy theory belief in the third sample, while rational‐analytic cognitive style was a less consistent predictor. Unexpectedly, in all samples, a new measure of cynicism was a significant, positive predictor of all three unsubstantiated beliefs (not only conspiracy theory belief as predicted). Although general skeptical attitude did not predict any unsubstantiated belief measure, a new measure of scientific skepticism negatively predicted both paranormal and conspiracy theory belief. Discussion centers on whether cynicism and scientific skepticism should be added to dual‐process accounts of the tendency to generally accept unsubstantiated claims.