I don’t know that we can assume that Americans are necessarily more resistant to change than other groups of human beings. Humans in general both fear and embrace change–we want things to get better, but we fear making things worse.
As to the seeingly most salient issue, universal health care, it can be easy to think that someplace, like, say Canada, probably just went and implemented single-payer, eh? All very polite and efficient and sensible, eh?
But actually, when single-payer was first introduced in Canada–initially at the provincial level, in Saskatchewan–it was by all accounts pretty controversial; and we’re not just talking about polite disagreements either, we’re talking about burning the provincial premier in effigy, occupations of legislative buildings, and a strike–oh, and all that was done by doctors!
One point made in that article (which is about exactly 20 years old; it was written in response to the attempt at health care reform made during the Clinton Administration) is that there is a structural difference in the government of the United States as opposed to the governments of other advanced nations. The U.S. Constitution is designed on the “checks and balances” model; “gridlock” or at least resistance to change wasn’t considered a bug, but a feature, by the framers of the U.S. Constitution. Elsewhere, parliamentary systems are much more common, allowing the party or coalition of parties that wins the election–and it’s often a single national election, not 536 separate national elections–to implement whatever program they ran on and received a mandate from the people to do in spite of assorted effigy-burnings, strikes, and protests. (That this is a difference between the U.S. and other First World countries–and maybe a significant flaw of the American system–is something that’s been talked about in relation to this decade’s round of huge fights over health care reform, government shutdowns, and general gridlock.)
So, Americans as a people aren’t necessarily any more innately resistant to change than Canadians or Swedes or whoever, but our system was set up in a way that magnifies resistance to change and makes implementing change more difficult. (This probably also explains the problems with implementing less consequential changes, like updating our currency or implementing the Metric System, as well as the big stuff like health care reform.) Our Constitution’s innate conservatism probably does interact with the political temperament of the American people in a sort of feedback loop–we grow up learning about “checks and balances” and sort of taking in from an early age that our Constitution’s resistance to quick or radical change is a good thing–which, for some kinds of change, I suppose it is. Hard for a dictator or radical totalitarian movement to seize power. Unfortunately, also hard to implement universal health care. (Or get rid of the freaking penny.)