Familiarity with past patterns reduces perceived world complexity and harm. [causal]
In familiar worlds, the past prevails over the present and the future. The past does not contain any 'other possibilities'; complexity is reduced at the outset. Thus an orientation to things past can simplify the world and render it less harmful. One can assume that the familiar will remain, that the established will be repeated and that the familiar world will continue into the future.
Niklas Luhmann, Trust and Power, loc. 137