I think part of the problem is that things like this come from international research, with constant refinements. Now where does the first of something come from if bits were taken from others research with successive builds...
Aye, many on that list that flat out aren't American (such as the motorbike*...) are at best part American based on existing ideas (incremental improvements), or an American idea but the practical work done by (or with) others.
CD's are another one that IIRC is an odd one.
From memory the original idea came from an American, but the actual working CD format came directly from research done by Sony and Phillips, which in turn was based on work from other parties.
Yet the basic principle which it works by can be traced back to a system developed in France for looms/weaving (with the punch card, the first digital data storage system
)...
Back on topic.
I don't think that Reagan was "stupid", but I don't think he was hugely smart, rather he was average with a good team of advisers and handlers who knew how to take a reasonably smart, popular, known face and turn him into a politician.
I personally don't think that Americans are any more dumb than any other nationality.
However they are often very proud, and many have very little interest in things outside their borders which tends to make a some of them extremely ignorant of the outside world - not because they are stupid, but because America is big enough to let it's residents be fairly isolated from the rest of the world.
Whilst Europeans for example are often only a few tens/hundreds of miles at most from neighbouring countries, and will commonly travel to another country for a holiday for reasons such as different scenery/beaches/skiing, Americans can have almost any sort of holiday conditions without leaving the USA.
Add to that an education system that varies wildly (as do education levels), and a TV/Radio culture that is much more highly based on "local" affairs and entertainment, with very little regulation in some ways, and it's not surprising that they can get some very strange ideas that can make them sound extemely stupid to the outside world.
When some "news" channels are little more than propaganda that reinforces certain ideas without any requirement to try and be balanced, that just makes it worse**, it's quite easy to fall into believing something that is stupid/not real.
Ultimately, it all comes down to Education levels, access to information, and the habit of learning to think for yourself, in those regards some Americans ironically are probably closer to the likes of people in Pakistan/India/Afghanistan in regards to how polarized their views can be by their lack of exposure to the outside world/other view points.
In Pakistan etc it's often in remote areas the case that the primary news/education comes from religious sources, in America it's all to easy to fall into only listening/reading the often highly polarized news and opinions that fit the political affiliation, and it's then that you get the large numbers of people who can believe (and be very vocal) in a manner that makes them look "dumb", but be extremely smart/capable in their day to day jobs or other areas where they do have to think for themselve.
Add to that the American dominance of many parts of the media, and the "dumb" ones get a LOT of exposure.
Basically, in one sentence.
Smart people can seem very dumb depending on circumstances.
Sorry for the long rambling post, i've not been able to sleep
*IIRC they are either French or German depending on which definition you use (German for the first internal combustion, French for a steam powered one, or was it the other way round?).
**And one of the reasons having one person controlling too much of the media is a bad thing.
