Trench warfare

Fascinating discovery when reading the Wikipedia article on AxThe Evolution of Cooperation, recommended in Dacher Keltner's psychology course:

The book included two chapters comparing Axelrod's findings to surprising findings in seemingly unrelated fields. In one of these, Axelrod examined spontaneous instances of cooperation during trench warfare in World War I, often called Live and Let Live. Troops of one side would shell the other side with mortars, but would often do so on a rigid schedule, and aim for a specific point in the other side's trenches, allowing the other side to minimize casualties. The other side would reciprocate in kind. The generals on both sides were satisfied that shelling was occurring and therefore the war was progressing satisfactorily, while the men in the trenches found a way to cooperatively protect themselves.