<p>Social norms are pivotal in guiding decision-making. Motives for following social norms are often described as gaining or avoiding (dis)approval and as an adaptive heuristic. We propose that social norms also serve an emotion-regulating function. Across three preregistered experiments (n_total = 2518), we operationalized uncertainty as complexity, risk, and ambiguity. Results first confirmed that descriptive social norms are more influential in uncertain situations than in less uncertain ones. When testing the psychological processes, uncertain situations did not make social norms more salient. For emotion regulation, however, we found a fairly consistent pattern across all three experiments; being exposed to a descriptive social norm mitigated participants' negative emotions. These results advance past research by suggesting that descriptive norms serve an emotion-regulating function.</p>