In this research, we investigate how a negative (or hostile) norm regarding minorities at the societal level can fuel polarization between majority subgroups at the local level. We hypothesize that rapid social change in the form of polarization results from the interplay between small group processes and perceptions of society at large. By employing a novel analytic approach that uses variances to capture non‐linear societal change, we were able to study polarization processes. In three studies among high school and university students (N = 347), we manipulated the majority norm about a minority category (positive vs. negative). Subsequently, participants read about a minority member's ambiguous behaviour and evaluated this target. All studies used a similar paradigm, but they varied in whether or not participants discussed the ambiguous behaviour within local groups. Results showed that the majority norm at the societal level affected perceptions of the minority member's behaviour when people discussed this behaviour in a local majority group but not when they reflected on it individually. Specifically, group discussions led to polarization between local groups within a broader social category, but only in the context of a negative majority norm. This effect was predicted by the a priori perception of the local group norm. Results are discussed in terms of the integration of society‐ and group‐level processes when studying the development of intergroup attitudes and practical implications for the coarsening climate of the societal debate about current societal issues.