Thanks. I guess the thing that sparked my curiosity / skepticism was that if there is a correlation between IQ and income, but none between IQ and wealth, it would seem to suggest there is also no correlation between income and wealth (or economic status, as these articles call it). I've only read the free snippets from the articles you posted, where this point isn't addressed directly but I have to assume they addressed it in some fashion in the full texts.

I'm guessing getting wealthy only through income is not very common. People get wealthy by inheriting or by holding assets, not by earning a salary.