Each of these revolutions was instigated by a monarchy mismanaging or over-extending its power in the face of public disapproval. While the exact details differed considerably, these governments demanded certain religious beliefs, economic restrictions, taxes or military obligations, to which their citizens made numerous and very vocal objections. When the monarchy overruled this objection, or bungled an attempted concession, it only antagonized the public, and made it easier for opponents of the government to frame its leaders as totalitarian despots.
These revolutions served to further cement the prominence of democratic government in the modern world, and to diminish both the real and perceived power of monarchs. However the similarities are not numerous; for example, the standard of living in daily post-revolutionary American life was very different from the French or Chinese standpoint, and the ideology informing these revolutions differed as well; while Americans and French were, in some sense, inspired by a new and different philosophy of what life, government and citizenship meant, the English were largely concerned with religion, and the Chinese with at least partially inspired by long-term ethnic strife. These differences suggest that the root of these revolutions was something intrinsic to human nature, i.e. the desire not to be dominated, especially by someone you perceive to be different from yourself and uninterested in your happiness.