Factoids—a word coined by Norman Mailer in his introduction to<jats:italic>Marilyn</jats:italic>—are mere speculations or guesses which have been repeated so often that they are eventually taken for hard facts. There is something decidedly unbiological about such factoids: the tendency to get stronger the longer they live is one of their most insidious qualities. Factoids occur in all branches of scholarship and many are of course still well disguised—their complete discovery would create havoc in the subjects concerned. Archaeology, converted from treasure hunting into an historical discipline, is for obvious reasons prone to create a number of factoids.The process by which mere hypotheses attain the apparent rank of established fact, without ever having been proved, presents a linguistic and a psychological aspect. Linguistically, words or particles indicating the hypothetical character of a statement are dropped one by one in a process of constant repetition. The subjunctive is exchanged for the indicative, and in the end the factoid is formulated as a straightforward factual sentence. Psychologically, the repetition of unproved hypotheses is facilitated by an attitude which is as indispensable in research as it is ambivalent: a certain amount of implicit trust in the results of other scholars' research.