Corpses, maggots, poodles and rats: emotional selection operating in three phases of cultural transmission of urban legends

In one conception of cultural evolution, the evolutionary success of cultural units that are transmitted from individual to individual is determined by forces of cultural selection. Here we argue that it is helpful to distinguish between several distinct phases of the transmission process in which cultural selection can operate. As a simple model we distinguish between a choose-to-receive phase, an encode-and-retrieve phase, and a choose-to-transmit phase. Proposed forces of cultural selection, such as various content biases, have typically been experimentally investigated only with respect to a single of these phases. Here we focus on emotional selection in cultural transmission of urban legends, which has previously been shown to operate in the choose-to-transmit phase. In a series of experiments we studied serial transmission of stories based on urban legends manipulated to be either high or low on disgusting content. One experiment used the classic serial reproduction methodology where only the encode-and-retrieve phase is involved. Another experiment instead involved choices of what material to read and what material to pass along. In both experiments, stories high on disgust were retained to a greater extent further down the chain. Thus, the prevalence of disgusting urban legends in America may be explained by emotional selection through a multitude of pathways.