Supplemental Material for (Mobile) Self-Enhancement in Selective Exposure: The Complex Relationship Between Negative Self-Threat and Downward Comparison

People often select different media content through different channels. Explanations of these differences in selective exposure typically rely on technical features of these channels. Beyond technical explanations, the present study argues that channel perceptions can shape selective exposure within these channels. We draw from the Selective Exposure Self- and Affect-Management model to argue that people who feel bad about themselves are motivated to enhance themselves by engaging in downward comparison. Critically, we test whether self-enhancement can be fulfilled for individuals who perceive their smartphones as extensions of themselves, obviating the need for downward comparison. Hypotheses are investigated in a preregistered experiment using a custom-designed, mobile-compatible social media platform. Negative self-threat (i.e., self-threat and negative affect) did not prompt downward comparison overall. At the beginning of the browsing period, negative self-threat decreased downward comparison, while at the end of the browsing period, negative self-threat increased downward comparison. Results were independent of browsing device and identity self-extension. We discuss the complex relationship between negative self-threat and downward comparison and its implications for how channel perceptions can shape selective exposure.