Effect of Media Environment Diversity and Advertising Tone on Information Search, Selective Exposure, and Affective Polarization

This paper examines the effects of our modern media environment on affective polarization. We conducted an experiment during the last month of the 2012 presidential election varying both the choice of media sources available about the major presidential candidates, and the tone of political advertisements presented to subjects. We posit that voters in a high-choice, ideologically-diverse media environment will exhibit greater affective polarization than those in a "mainstream'' ideologically neutral environment. We also hypothesize that subjects who are exposed to negative rather than positive political advertisements will show increased affective polarization. We provide causal evidence that the combination of a high-choice ideologically diverse media environment and exposure to negative political ads, significantly increases affective polarization. We also find that both overall information search and selective exposure to information are influenced by our experimental manipulations, with the greatest amount of search, and the most biased search, conducted by Romney supporters in the Negative Ads, Diverse Media condition.