Is the US average intelligence level lower than other developed countries?

American integrity is the same as all others.

However, a resent study that compared the European education system with that of the USA. Came to the conclusion that if the educational system of the USA improved 2 fold, in comparison to that of mainland European,then it could be regarded as having been slightly improved.

Both the USA and the UK have the developed world's lowest standard of general education.

Both are extremely conservative societies and both are weighed down by nationalistic-dogmas.

Honestly,

From what I've observed, Americans are more oblivious than the rest of the world. 

Example: In school we're only required to learn the 50 states.

It's pretty standard to learn all of the countries, states, and territories of the world in South America and East Asia.

The intelligence level of US citizens varies. Actually in my medical transcription career, I have seen many indian doctors settled abroad. So you can see that there is a mixture of races in USA and the average intelligence might vary significantly. People from different parts of the world come to USA for jobs and they settle there on the basis of their merit. 

Educational standards have been lowered. Watch the political assumptions. Republicans tend to be smarter than Democrats. Google it. Actually, use DuckDuckGo. 

Yes, they almost always score lower on standard testing than all Asian countries and most European countries. Better than most central and South American countries, and better than most African countries.

Voting for Clinton would've been even dumber.

It’s probably unfair to the many intelligent Americans who must be out there somewhere, but by the evidence here and on every other comments section everywhere, it would seem that your assertion is spot on.

That's sounds like this place everyday, aren't you use to it yet?

America has always seemed to have a more vocal or rather free fringe than most other countries, but god knows we all have them. 

EDIT: Let’s look At the USA historically, back in the 18th century it looked like a colony or colonies full of * dangerous * radicals, fringe people who talked about republicanism, secularism, a right for all citizens to carry arms and a written constitution! Crazy illuminati folk at the time. People who needed stamping out. 

Or look at the 20th century, where a myriad of hippie communities, strange religious cults and semi separatist militias sprang up and even if they didn’t originate from the USA like Scientology ( we Brits are the proud founders of that religion) they followed the age old tradition and set roots not in Europe, but in the * free world * America 

I personally think America’s fringe groups have become less radical as time has gone by, not more so 

It isn’t.

There are plenty of people world wide spouting drivel.

Most innovations originate from US, and the non white westerners ride on their coat tails.