These stats are thrown off by a number of factors that it would be imprudent to get into here. Control for demographic samples similar to the other countries and you'll see a very different picture.
I don't think that's what I'm saying. Of course they _matter_, as much as any of us do anyhow.
What I'm saying is that if you actually compare people with similar demographically-expected IQ and socioeconomic situations, Americans stack up fine. It's the extenuating circumstances that drag the overall averages down.
All that really means is that overall averages across 300 million people aren't that useful.