"Contagion'' appears frequently in peer-reviewed articles and in popular media to explain the spread of ideas, feelings, and behaviors. In the context of social science, however, we argue that this metaphor leads to magical thinking and should be described as a simile, rather than a metaphor. We review literature on "social contagion'' using the dialogical paradigm and conclude that peer-reviewed claims tend to correspond with imagined realities from epidemiology rather than social science, including assumptions of passive and linear microbial spread, as well as pathology. We explore case studies on the spread of laughter, riot behavior, and "mass psychogenic illness,'' and find that social contagion involves social meanings negotiated at the level of persons and groups that are uncharacteristic to the spread of diseases. Dialogism is presented as a correction to the epidemiological paradigm.