Nevertheless, It Persists

Abstract: Social media have become important environments for people to express and explore their political views. Yet, relatively little is known about how affordances provided by social media platforms affect whether and how users express political opinions. This work argues that message persistence (i.e., the temporal extent to which messages can be accessed by users) is a central affordance of many social media, which affects not only users’ likelihood of political expression, but also so-called self-effects in terms of users feeling socially committed to their expressed views. In a pre-registered experiment ( N = 994), we varied the level of message persistence in a social media platform and used behavioral measures of opinion expression. Contrary to expectations, high-persistence social media provoked more opinion expressions than low-persistence social media. Only minimal evidence was found of self-effects and the persistence of the social media environment did not influence self-related outcomes. Results are discussed in light of political expression literature and the role of self-effects in social media.