> Why on earth would this have a global impact?
The United States has been (and will be for another two or three years) the cultural center of the world. We export to everyone. That includes our mode of thinking and the mode of thought we teach our children.
> Also, according to the abstract, the US actually sustained positive gains longer than other OECD nations, except South Korea.
The oldest data presented was from the mid 70s. We'd need data going back to the turn of the last century to get a good feel for how IQ has relative to education policy changes. The time-scale they claim is ~110 years since education policy in the US started changing.
