I read the book "The theory of social revolution" by Brooks Adams 1913.
He studied the history of social revolutions. He said that about every three generations, the ruling class losses the ability to effectively manage society and revolution results.
when he said "manage society" it is devoid of a moral judgement whether that management is either good or bad for the people.
A generation is usually considered to be 20-30 years, so 60-90 years ago was there some large social upheaval?
WWI, WWII, Russian revolution, Maoist China, Korean War, Vietnam.
What are we in for in the coming years?
Brooks Adams, The Thoery of Social Revolution
https://archive.org/stream/theoryofsoci ... 5/mode/2up