The aim of this paper is to investigate how predispositions (i.e. stable individual traits that regulate the acceptance or non-acceptance of the political communications that a person receives’), shape opinion change in citizen deliberation. Research suggests that the role of predispositions in deliberation varies depending on the topic (Smets & Isernia 2014) and that political awareness increases the likelihood for opinion consistency between predisposition and opinion (Hansen 2007). The importance of political awareness during opinion formation suggests a cleavage between politically sophisticated and less sophisticated people. Concerning group composition, research on group polarization suggests that predispositions might be strengthened in like-minded groups since the argument pool and the information provided will be biased. This paper (based on two experiments in citizen deliberation dealing with immigration and language policy) seeks to examine the relationship between predispositions and deliberation more fully by including three intervening variables: topic, political sophistication and group composition.