The triple-filter bubble: Using agent-based modelling to test a meta-theoretical framework for the emergence of filter bubbles and echo chambers.

Filter bubbles and echo chambers have both been linked recently by commentators to rapid societal changes such as Brexit and the polarization of the US American society in the course of Donald Trump's election campaign. We hypothesize that information filtering processes take place on the individual, the social, and the technological levels (triple-filter-bubble framework). We constructed an agent-based modelling (ABM) and analysed twelve different information filtering scenarios to answer the question under which circumstances social media and recommender algorithms contribute to fragmentation of modern society into distinct echo chambers. Simulations show that, even without any social or technological filters, echo chambers emerge as a consequence of cognitive mechanisms, such as confirmation bias, under conditions of central information propagation through channels reaching a large part of the population. When social and technological filtering mechanisms are added to the model, polarization of society into even more distinct and less interconnected echo chambers is observed. Merits and limits of the theoretical framework, and more generally of studying complex social phenomena using ABM, are discussed. Directions for future research such as ways of comparing our simulations with actual empirical data and possible measures against societal fragmentation on the three different levels are suggested.

Majority members' acculturation goals as predictors and effects of attitudes and behaviours towards migrants.

Migration causes permanent processes of acculturation involving migrants but also members of mainstream society. A longitudinal field study with 70 German majority members investigated how their acculturation goals causally related to their attitudes and behaviours towards migrants. We distinguished acculturation goals concerning the migrants' culture(s) (what migrants should do) and acculturation goals concerning the usually neglected own changing mainstream culture. Both were conceived along the two dimensions of 'culture maintenance' and 'culture adoption'. Cross-sectionally we found many strong links between acculturation goals and attitudes and behaviours towards migrants, only some of which held longitudinally. As hypothesized there was no clear one-sided causal direction. As many causal links lead from acculturation goals to attitudes and behaviours, as in the opposite direction. Majority members' German culture acculturation goals proved especially valuable, because they determined attitudes and behaviour towards migrants most strongly.