@LibrarianofHate @MPCtxt well, there's nyborg's study of religious groups in the u.s. (adolescents): https://www.researchgate.net/profile/Helmuth_Nyborg/publication/223637492_The_intelligencereligiosity_nexus_A_representative_study_of_white_adolescent_Americans/links/553215a20cf27acb0deab383.pdf …
@LibrarianofHate @MPCtxt can't think of others off the top of my head just now. @JayMan471? diffs in iq/life outcomes for Xtian/rel groups?