In the 14th century, processions of penitent sinners traveled from town to town after the plague, which had broken out in Central Asia in 1346, spread throughout Europe. God's judgment was to be mitigated through self-flagellation, and the impending apocalypse was to be averted. However, the phenomenon of the flagellant processions is not homogeneous, particularly regarding their attitude towards the clergy. A radical, anti-clerical stance in the Thuringian region contrasts with a moderate-cooperative approach in the Upper Rhine and Dutch areas. What factors contributed to these differences and facilitated the radicalization of the groups? Maximilian Koskull applies the Modes of Religiosity theory of the English ethnologist Harvey Whitehouse to the late medieval flagellant processions. The uniqueness of the theory lies in the incorporation of cognitive psychological insights into the complex mechanisms of human behavior.