I think you're underestimating Neanderthals there - evidence is growing that they were in fact, pretty smart. (they just had cultural habits which lead to their demise)
Goppers though - are a very different kettle of fish. If there was a blood test for chronic stupidity ---------- the test machine would be flashing red from Gopper blood and the report would have stars all over it - with - ''extremely dangerous stupidity levels well in excess''
Whilst not particularly smart Americans began to revive the idea that they were 'exceptional' in about the 1980 to 1990 mark - the concept goes back to about 1630 with a bloke called John Winthrop, who thought that it must be god's idea to have his colony -
a little later - the American revolution - they got a real boost because they thought that they were so great at this liberty, democracy and individualism gig
The French were of no help - because French political thinker Alexis de Tocqueville was among the first to explicitly describe America as "exceptional" in his 1835 Democracy in America
what a pillock
Fast forward to now - and look what they've got ---------------
Not particularly a lot of exceptionalism going on right there
