ABSTRACT
in this chapter, we consider and critically evaluate the collective heuristic/bias model, the view that epistemically adequate group polarization is explained in terms of collective heuristics and epistemically inadequate group polarization in terms of collective biases. According to this picture, group polarization, understood as a collective belief-forming process, is a feature of the group itself, and it is to be identified as a cognitive heuristic of the collective agent (in the good cases) or as a cognitive bias (in the bad cases) rather than as an irreducibly collective virtue or vice. This view is shown to have two problems: the empirical adequacy problem and the type-1/type-2 problem.
