I’ve heard dismissals of the concept of measurable intelligence on the basis that “IQ tests only measure the ability to take IQ tests” or “intelligence is such a multi-faceted concept and everyone is intelligent in their own way, IQ is just one part of it”. I suspect these arguments (which are, btw, misunderstandings of what is meant by general intelligence in this context) conceal another objection which I happen to agree with.
The objection concerns organizations like Mensa having people take tests and telling them “this number is your intelligence”. That is stupid! If I took an IQ test and it told me something wildly different from what I expected, I’d only change my beliefs a little. In other words I wouldn’t believe the test.
(Sidenote: many of the same people who discount the concept of intelligence would consider this to be arrogant. One moment they’re saying how stupid it is to believe in intelligence, the next they’re laughing about how low George Bush’s IQ is. Or saying that race doesn’t exist and laughing about James Watson, who believes that black people have lower intelligence than the global average, being 1/6 black.)
What does an IQ test tell you? It’s an inaccurate measurement of a non-constant quantity that correlates with intelligence. Does that mean it’s meaningless? No, but it’s still a good way to quickly get some information about someone you don’t know much about. This is like armies choosing all the men and rejecting all the women: not perfect, but better than randomly choosing half of everyone.
But it’s not a very good way to find out your own intelligence, because you already have a ton of information about that. Almost everything that happens in your life has something to do with intelligence, so it’s hard to avoid forming some kind of an idea of your cognitive abilities. Similarily for people you spend a lot of time with. As the danimal said,
A smart person doesn’t need to hear how smart he is, any more than a pretty girl needs to hear how pretty she is. Anybody with an obviously outstanding attribute has been hearing about it their whole life.
People don’t want someone telling them how intelligent they are. It would feel like being told who to be (another false fear). The good news is that nobody can “tell them how intelligent they are”. The bad news is that everybody already knows.