This study addresses reality TV as popular science. Proposing that we might better understand this popular media form by locating it within a wider context, the project locates key traditions and practices that were drawn upon to help formulate reality TV in the United States in the history of social experiments.During the emergence of commercial forms of popular science in the nineteenth century, P.T. Barnum was an influential creator of a form of entertainment in which the object was to discern what was real in a manufactured amusement. By the 1950s and 1960s, both Candid Camera creator Allen Funt and behavioral psychologist Stanley Milgram formulated their projects as social experiments that placed unsuspecting people into carefully designed situations. Psychologist Phillip Zimbardo reconfigured social experiments in his Stanford prison experiment, paralleling similar uses in the public-television series An American Family, by studying social roles and types. All of these previous practices offered methods and rationales for what is known currently as reality TV, a genre that Mark Burnett helped develop by claiming to test and examine types of human behavior, and inform the ongoing making of a genre well-suited for the post-network era.Adding to more recent work of critical genre analysis, one of the contributions of this study is to explore social experiments as a genre. This study also documents the many characteristics shared by the scientific and commercial versions of social experiments, arguing that they have informed each other and have been responses to and products of the same social imperatives. The study concludes by reflecting on the value of critical genre analysis, as well as on how this example supports efforts to retheorize media participation from a matter of quantity to one of mode.