As a follow up to this, yes, 15 tends to be the standard deviation. However, most, if not all tests have a cap to the highest score they can return, which is about 160. I believe this is the case for both Stanford-Binet as well as Weschsler (WISC):

https://en.wikipedia.org/wiki/Stanford%E2%80%93Binet_Intelli...

https://en.wikipedia.org/wiki/Wechsler_Intelligence_Scale_fo...

I don't know for sure, but I suspect that one of the reasons that 160 is the max score is that the tests need to be normed and that's difficult to do once you pass so many standard deviations.

As another note, the overall composite score can qualify a student for services in a public school, but a good diagnostician will be using the test to assess areas of strength and weakness. Basically, a student who has high spatial reasoning, but poor verbal IQ requires different assistance than the reverse.

Anyway, yes, I'll agree that I hate IQ measuring contests because they're just like the other anatomical measuring contests. Further, if even someone wants to have one, they're almost never about the results from a properly normed test like those from above and, further, those tests contain a lot more information than a single number.

Thank you for clarification. I also like your comparison with NBA and A-actors. I am Mensa member which means my IQ is in top 2% of the general population of my country. Because of the membership and my active involvement, I know a lot of people with high IQ. And my conclusion is that IQ doesn't mean too much. Yes, I think that some of them are very smart, but not genius level smart. Not even close. In my opinion, the usefulness of the IQ metric is very questionable.

I'd say the comparison is not quite right, as everyone can be assigned an IQ (however useful that may be), but not everyone aspires to be an NBA player or A-List actress.