The best IQ tests (and to an extent SAT/ACT tests) can tell you is how similar you are to the person who made the test.
Echoed, I think you have the use of IQ test correct, even if you can't cite scholarly sources. For some history on IQ tests, see
http://www.audiblox2000.com/dyslexia...yslexia014.htm
http://www.aceviper.net/aceviper_net...e_iq_test.html
The most damning aspect of the IQ test is its association with the early 20th century eugenics movement (if you were stupid, crippled, deformed, or the wrong race/culture/religion, then you shouldn't have the right to exist).
One of my friends has a very poor vocabulary, so he sometimes comes across as a bit slow. I'm sure he wouldn't do all that well on standarized testing becuase of this. However, his opinions are almost always backed by well reasoned and logical arguments. Thats a lot more than I can say for most politician.