 More generally, it seems that it is only under quite specific conditions that argumentation reliably leads to consensus (as also suggested by formal modeling of argumentative situations (Betz 2013; Olsson 2013; Mäs &amp; Flache 2013)). Consensus-oriented argumentation seems to work well in cooperative contexts, but not so much in situations of conflict (Dutilh Novaes forthcoming). In particular, the discussing parties must already have a significant amount of background agreement—especially agreement on what counts as a legitimate argument or compelling evidence—for argumentation and deliberation to lead to consensus. Especially in situations of deep disagreement (Fogelin 1985), it seems that the potential of argumentation to lead to consensus is quite limited. Instead, in many real-life situations, argumentation often leads to the opposite result; people disagree with each other even more after engaging in argumentation (Sunstein 2002). This is the well-documented phenomenon of group polarization, which occurs when an initial position or tendency of individual members of a group becomes more extreme after group discussion (Isenberg 1986).