By the way, before it drops off the thread, Steve is absolutely right about IQ tests. I have never held them in much esteem, but if you can get hold of one and look at at dispassionately it is startling how much of the tests are about, for example, culture not 'intelligence' . For example, I remember when I sat my 11+ there were questions like 'what is the twentieth letter of the Alphabet?"   At the time, I was too young to notice, but now a little knowledge says 'which alphabet? Welsh, or Spanish, for example?". And there, automatically, is a little bias in the test against the Welsh and Spanish, because it's they use their alphabet they will get the 'wrong' answer. Other tests I have see are things like 'insert the word that completes the first and starts the second Acro(...)ch", which is highly biased to households that read a lot and biased against those that spend the time doing other things. By analogy I am aware of English people who live in Germany, speak perfect fluent German, can read Leaflets and official notices and so on without difficultly but can't write it. Because nothing in the way they live requires them to write German as a matter of course.

So Steve's summary that IQ tests measure your ability to do IQ tests is spot on.