Recent experimental findings of subtle forms of prejudice prompted this search for a similar phenomenon outside the laboratory. In Study 1, with a sample of more than 12 000 citations by North American social scientists, names of both citing and cited authors were classified as Jewish, non Jewish, or other Author's name category was associated with 41 per cent greater odds of citing an author from the same name category Study 2 included over 17 000 citations from a much narrower research domain (prejudice research), and found a similar (40 per cent) surplus in odds of citing an author of the author's own ethnic name category. Further analyses failed to support two hypotheses — differential assortment of researchers by ethnicity to research topics, and selective citation of acquaintances' works — that were plausible alternatives to the hypothesis that the observed citation discrimination revealed implicit (unconsciously operating) prejudicial attitudes. Given the sociopolitically liberal reputation of social scientists (and of prejudice researchers especially), it seems unlikely that the observed bias in citations reflected conscious prejudicial attitudes.