Above, the reader finds a heading consisting of two questions. This is to stress that they are intimately related and deserve to be approached together. At the same time, however, they are separable, both as such and because the second question has developed into a large research domain in its own right over the years. So, the two questions will be treated in juxtaposition, one after the other. Moreover, the second question will be discussed in some detail whereas the first one will be only briefly touched upon, simply due to the fact that I have familiarised myself more with the second question.

Why do social norms change, despite the fact that their mission is to be sustained?

Generally, human interaction is regulated – if not from the very outset in the development of all societies, at some early stage. Such regulation is enacted both by means of physical power and with the aid of norms. But to a substantial degree, physical power also relies on something other than itself since it would not function without loyalty from strategic groups and ultimately from the subjects or citizens in general. Norms serve to stabilise social interaction, be it peaceful or characterised by more or less violent conflicts. If such stabilising measures are successful, they will strengthen the norms through a series of feedback loops. Norms are introduced in order to be preserved through vertical and horizontal transmission, and thus, they promote human action in accordance with the norms. But they change, nevertheless, some more than others and more so in certain situations and under certain circumstances – even those that appear especially stable, sometimes even timeless. Some become stricter vis-à-vis human needs and desires whereas others get more relaxed. According to a new study of meta norms in 57 countries, in modern, basically liberal countries, what is called spreading of information is the most typical informal sanction applied, whereas verbal confrontation and avoidance of norm breakers are more frequent in more hierarchical and less liberal countries. Since modernisation is a historical process, this clearly indicates that norms do change.

On the micro level, change of attitudes towards lethal violence as well as non-lethal violence are paradigmatic examples of such long-term normative shifts.