Does incidental exposure on Social Media equalize or reinforce participatory gaps? Evidence from a panel study

Existing research indicates that incidental exposure to political information on social media may function as an equalizer, stimulating political engagement among the politically detached. In this article, we challenge this notion and propose that there are good reasons to assume that incidental exposure may reinforce existing gaps. We test the equalizing against the reinforcing hypothesis using data from a two-wave panel study (N = 559). We find a positive main effect of incidental exposure on low-effort digital participation. However, this effect was not conditional on political interest, as the equalizing assumption would have suggested. More interestingly, we found that the effect of incidental exposure on high-effort digital participation was conditional on political interest. However, against the assumption of equalization, individuals with low levels of political interest were negatively affected by incidental exposure, thus lending support for the reinforcement hypothesis. Possible reasons for these findings are discussed.