Ones have considered that maybe lower-IQ people have been immigrating into these countries, and this has brought down the average. But even within families in Norway there have been measured decreases.
One possible explanation is a use it or lose it thing. Perhaps people are getting lower-challenge jobs, more these days, and this has resulted in poorer IQ test results. So, it could mean there is lower performance in taking tests, not necessarily lower potential.
One reference was made to American politics, being an indication that American IQ is going way down . . . and yet in the United States statistics show America's IQ is going up up up . . . while even England is going down down down.
But even if some number of politicians seem not to be very intelligent for making things work well, still ones consider Nancy and Donald both to be very clever and capable, though not using their abilities well, ones might find. So . . . ones can by being active keep up their ability to do well with IQ testing, maybe we could say.
But if ones are busy with less mentally challenging video games and non-socially stimulating things, they might shut down intellectually > not that they can't do well on a test, but they might be getting sludgy. This would be a risk in America, even if Americans are showing better IQ results than Western Europe is.
In America ones are maybe more free to think about different ideas and exercise themselves in debating, while in a socialist country like Norway . . . I think it is socialist . . . ones are not going to compete, mentally, as much so they are exercising their minds. They might have minds but not exercise so they do well on tests.
I think the real challenge and true genius has to do with being able to love and relate and communicate. This goes beyond just intellectual ability and has a better kind of creativity. And love can have our minds working better . . . the way God designed.