The content and spread of conspiracy theories

Belief in conspiracy theories (CTs) is associated with numerous societal harms, including violence, vaccine refusal, and political extremism. Given the speed and intensity with which information spread through the internet, there is a pressing need to understand what CTs are and how they circulate. Across four studies, This PhD thesis works towards this goal: understanding the content and spread of CTs. In Study 1, we developed the largest corpus of CTs available today, LOCO, that allows to explore the content and spread of CTs. An analysis of linguistic content showed that conspiracy texts are focused on deception, power, and dominance. Conspiracy webpages that rely on prototypical conspiratorial language are more shared on Facebook. In Study 2, we found that conspiracy texts are more interconnected, more topically heterogeneous, and more similar to one another. These results provided strong empirical support for an overarching conspiracy worldview in conspiracy narratives. In Study 3, we developed measures to assess elements of divergent and convergent thinking in texts. We show that conspiracy texts were more original, semantically divergent, and sophisticated, but less appropriate to their context and less variable compared to those in non-conspiracy texts. Results point to an imbalance between divergent and convergent thinking and may explain the accumulation of CTs within people’s belief systems. In Study 4, we devised a field study to compare the impact of social media and individual cognitive biases on online browsing behavior towards websites classified on ideological types and strength. We found that as the websites’ conspiratorial ideology increases, the contribution from individual cognitive biases increases at the expense of traffic from social media. In sum, results obtained from this thesis have practical implications. As for the content of CTs, the presence of conspiracy mentality that emerges from texts represents a foreseeable possibility to develop algorithms for the automatic detection of CTs online. In regard to the spread of CTs, knowing that individual cognitive biases drive access to conspiracy websites suggests that individual-level interventions, such as improving critical thinking, should be prioritized in the fight against the spread of CTs.