@timorl Also, changes caused by a single event (e.g. any of the changes that happened in US as a direct result of attacks on WTC), changes that happened as a result of technology becoming available (easing of travel and long-distance communications come to mind as the technologies most likely to be implicated), and changes that were caused by some combination of environmental effects (e.g. migration from countryside to cities; or popularization of the concept of factory worker, which as you know caused e.g. the dowry-caused constraints on marriage to become less important).