I don’t understand how an IQ test works, nor am I sure of their accuracy. A few months ago I took a few on the Internet and I got scores ranging from 130-176. The types of questions were different too, some involving multicolored figures where you had to figure out how it would look like when you folded it up, others were just verbal math questions.
In any case, what is it REALLY supposed to measure?
The test you took on the Internet was designed to measure how easily you can be persuaded to fork over thirty bucks for some worthless pieces of paper.
As for what IQ tests measure, it’s a bit hard to qualify it further than saying that they measure IQ. Since different sorts of IQ tests give similar scores for a given person, it’s safe to say that there is some sort of ability which people have to various degrees which can be reliably measured by such a test. But what, precisely, that corresponds to is somewhat debateable. There’s certainly some correlation with “smartness”, whatever the heck that is, but Marilyn vos Savant (who holds the world-record high IQ) is a long sight from being the smartest person on the planet (who is, of course, Cecil Adams). There’s also some correlation with how well a person will succeed in life, but there are 65 IQ janitors who are a lot more successful than 135 IQ slackers, too.
Thankfully the tests I took were free 
As for your explanation of what IQ tests measure, the results don’t sound very useful for anything other than bragging.
IQ is somewhat controversial. It doesn’t make sense to talk about the accuracy of IQ tests the same way it might to talk about the accuracy of your cholesterol, for example. There is no absolute quantity that is being measured. And specific skills vary widely in an individual. Savant Syndrome is the most extreme example, see Rain Man.
Online IQ tests are essentially worthless and bear little relation to the IQ tests used by professinal psychologists to determine cognitive ability. Even the latter are of questionable value and accuracy, but the former are good for nothing more than entertainment.
Another thing to consider: most online IQ tests consist of around two dozen questions. You need more information (which is what you get from questions) than that in order to form an accurate picture of someone’s intelligence. This applies to pretty much every testable or evaluable psychological aspect of a person. There’s no magical handful of questions that can accurately capture someone’s personality, intelligence, sanity, etc.
As for what’s being measured in an IQ test, I was told by my professor that IQ tests administered to young children may indicate how the child will perform in elementary school. The best indicator, however, of how a child will perform in later school years is how he/she did in previous years. So to see how a kid will do in high school, you should look at his intermediate school years. To see how he’ll do in college, look at his high school performance.
I always kinda regarded random mentions of IQ (such as in a news article) as a quick and dirty way of telling you what a person is like, rather than describing his intelligence. For example, if a captured criminal was described as having a high IQ, I would conclude he’s sneaky, cunning, clever, and ambitious. If he was described as having a low IQ, I’d conclude he was a rather inept specimin of the criminal breed.
Might I refer you here?
some of the posts in there do answer your question.