IQ tests are just like anything else in life: If you practice enough, you will get good. If you are motivated enough to spend 10 hours a day practicing taking IQ tests, you will eventually get a high score. If you are motivated enough to practice the guitar 10 hours a day, you'll eventually become a guitar virtuoso. If you are motivated enough to spend 10 hours a day writing code, you'll eventually become a Rob Pike or Rich Hickey. If all you want in life is to be seen as smart by other people, then in my opinion, you need to re-examine some things in your life. I'd rather spend my time getting better at things that actually matter.
Ironically, this is similar to the original logic of the IQ test. If you are able to pick up and figure out the given questions quickly, you should be able to pick up and figure out many other things quickly, which is a pretty normal definition of intelligence.
There is no shortage of people who will do poorly at IQ tests because of cognitive difficulties and (sure) lack of motivation to practice. Does loading on factors like these make IQ tests less predictive of academic or career outcomes? No, both of those things also require a combination of cognitive ability and motivation.
Maybe, to some degree, that's true. But... I never spent any time learning how to take IQ tests, and have been tested at multiple stages - specifically IQ tests, and also the ACT/SAT.
First tests I remember, I was 9. Then ACT at... 15? Maybe it was 16. Then more IQ tests (3 different ones, IIRC) about 4 years ago. All showed me to be in the same X percentile, with a very small degree of variance between tests and over 30+ years of taking them.
And to repeat, I never spent any time learning how to 'take' a test. It was actually disappointing to get the test results and compare them to ~30 years earlier, and not see any change. I thought I'd have been 'smarter' as an adult, but I do realize it's not really testing that so much as... raw capacity perhaps? That hasn't demonstrably changed, despite all the life that's happened to me. No major health issues tho; I can certainly imagine that had I had a brain injury, my IQ test scores would be lower.
I have taken three and I have never applied for Mensa. Once in school when our biology class was curious about the topic; once online because somebody challenged me to it; once because it was in the TV magazine and I was bored, and I wanted to know if one really gets better at it. (I think I did)
I suspect you wouldn't have gotten demonstrably/statistically much better with repeated takings. Maybe if it was the same test multiple times, but even then I'm not sure.
A few years ago I had 3 IQ tests administered to me over several weeks. There wasn't any major difference between any of the scoring/ranking, despite the fact that I was taking multiple. I never got much 'better'.
I think it depends on many factors: Will I be told which answers were wrong and what would have been the right ones? I had similar problems with ambiguous questions as the OP and this might help me to understand what the test writers understand as "canonical" or "simplest" answer. Also, I am rather excited when I take a new type of test, so I guess my biggest jump would have been from the 1st to the 2nd test.
