  Radicalized beliefs, such as those tied to QAnon, Russiagate, and other
political conspiracy theories, can lead some individuals and groups to engage
in violent behavior, as evidenced in recent months. Understanding the
mechanisms by which such beliefs are accepted, spread, and intensified is
critical for any attempt to mitigate radicalization and avoid increased
political polarization. This article presents and agent-based model of a social
media network that enables investigation of the effects of censorship on the
amount of dissenting information to which agents become exposed and the
certainty of their radicalized views. The model explores two forms of
censorship: 1) decentralized censorship-in which individuals can choose to
break an online social network tie (unfriend or unfollow) with another
individual who transmits conflicting beliefs and 2) centralized censorship-in
which a single authority can ban an individual from the social media network
for spreading a certain type of belief. This model suggests that both forms of
censorship increase certainty in radicalized views by decreasing the amount of
dissent to which an agent is exposed, but centralized "banning" of individuals
has the strongest effect on radicalization.
