“Zivilcourage” is highly socially desirable in democratic societies, yet a lack thereof is often deplored. Systematic investigations paint strikingly different pictures on the prevalence of courageous interventions against others’ norm violations – depending on the methodological approach. The Research Group “Moral Courage” investigates psychological antecedents and barriers of this kind of behaviour. Our studies have shown that the ambiguity of a norm violation can be a strong inhibiting factor. However, some people incur costs to reduce ambiguity, and take informed decisions to intervene.