Please don't quote such rubbish "studies".
When you truly meet someone with an IQ less than 80 you will see they are highly suggestible, have difficulty maintaining conversations etc.
The author conveniently disregards some countries (particularly the oil countries) from his analysis as outliers, entirely killing his hypothesis.
Education alone drives up IQ - how then can this be a true reflection of "intelligence" when one can improve at it like any other achievement test?!
Furthermore, testing IQ based of English-language derived questions is an exercise in futility. Even medical mental state assessment tests cannot be adequately interpreted unless familiarity in language is given.
Culturally appropriate and FAIR comparisons (i.e. not comparing the average American to a beggar in another country) needs to be done.
edit
Anyway I love America. As long as they keep KFC around the world and I can stream American Football and basketball online I am happy. Don't really want to visit and get shot, or worse, sent to Gitmo Bay as a terrorist, but maybe when there are enough Mexicans that I can blend in like one.