Hypothesis: Human nature in large populations is universally the same over time and place. Institutions differ and are what define societies.
Explanation: Whenever humans live together, they form institutions. Institutions define, add, and limit. A society is largely determined by its institutions. Governments are run by the people chosen through the selection process of institutions
Implications: The way to judge an institution is by the type of person it brings forward. Which qualities are encouraged and rewarded, good or bad ones? Integrity or craftiness, compassion or cruelty, modesty or arrogance? Some systems bring forward the intelligent, others the hacks. Those who float to the top, the successful ones, these with qualities the system prizes, who then run the system.
Non-democracies permit anyone to rise to the top, for qualities rewarded by the system are out of sight of the public. A small group may set up a system which is hateful to the bulk of the population which can do nothing to change it. Generations of the wrong persons may achieve power and glory.
Democracies promote better rulers than other systems because public opinion has a vital role in the selection process. Candidates in an election must appeal to the electorate; a candidate who cannot gain popular support will not advance. While the electorate is far from infallible, it has a better record than any other selection process.
Thus the importance of getting the institutions right – or why 1776 and 1787 remain vital dates in American history.