Recent research into cultural transmission suggests that humans are disposed to learn, remember, and transmit certain types of information more easily than others, and that any information that is passed between people will be subjected to cognitive selective pressures that alter the content and structure so as to make it maximally transmittable. This paper presents a review of emerging research on content biases in cultural evolution with relevance to the transmission of popular narratives. This is illustrated with content analysis of (...) urban legends, which found that most exploited at least one known content bias, with emotional information and social information being the most frequent. We argue that the narratives do not succeed because of the transmission of adaptively relevant information but because of their exploitation of content biases in human cognition. (shrink)