Why Don Americans Take So Few Pride In European Heritage & Distance Itself?

I think Americans are just rather insular and feel they are the "best" in the world. Us Europeans obviously contributed huge amounts to America, so the traits are still there (especially British, French, Spanish and German heritage), but nowadays people there seem to be a bit less knowlegable on world affairs. There's a video of some American girl who gives a garbled answer during a beauty contest, and I think that sums up how we imagine the majority of American people to be: sweet, but rather clueless.