And of American culture and its people. You might re-evaluate some ideas you'd grown up with, becoming a more cosmopolitan/adaptable/understanding person, capable of having deeper relationships with a larger proportion of the Earth's population.
But it probably won't make you better at tests of cognitive capacity.
How do you test «cognitive capacity»? The other day on these pages a newcomer came and wrote he "distrusts them <category>". Some call ignorance relevant to "cognitive capacity".
(Some call it "much more than just relevant".)
Double Trouble
Spatial Planning
Odd One Out
Grammatical Reasoning
Feature Match
Polygons
Digit Span
Rotations
Token Search
Paired Associates
Spatial Span
Monkey Ladder
Most of us don't have access to the paper, although our tax dollars surely paid for it.
Although somewhat ironically, the person who proposed 'g factor' was specifically reporting correlations between student performance in latin, french, english, maths and music.