Sure - they're not the be-all answer to everything, but I've found them helpful in (re)assessing myself lately.
I found much more static-ness in my IQ over the last 30+ years. I was actually surprised at how consistent it was over decades and various tests (and, dare I say, slightly disappointed).
I agree about MBTI - until I understood that I was allowed to have a personality preference for perceiving over judging (preferring to live in the moment than plan ahead in detail) I was stressing myself worrying about why I was so rubbish at planning, rather than trying to find a career where it was less important! (the only careers I've come up with so far are stock exchange trading and politics - if anyone has any others I'd be interested to hear. I like coding, especially in sprints, but I am absolutely terrible at estimating how long it will take me to write things.)
I find that every time I take an IQ test I get a higher score - I presumed because I'm learning what sort of questions IQ tests ask and how to answer them faster - so when required I just quote the first ever test I took as my IQ (which was a very unscientific one, unfortunately, by answering questions along with a TV program. I also had a score bump for age, because I was only 16.) I was, at the time, delighted that I got higher than my maths teacher! remember too, though, that IQ is heavily biased towards people with a "western" education.
IQ isn't very important though, once you get above 130 - the differences don't correlate to greater performance in any real test cases. The difference in performance at those levels is to do with attitude, experience, vocabulary (outside of technical fields I've studied/worked in, mine is awful), and all sorts of soft factors.
(apologies if I'm wrong, but I assume that anyone with karma on hacker news is IQ >= 130 or so.)
IQ numbers vary based on tests, to some degree, so "130" doesn't necessarily mean a whole lot. What I'd found is that I was in the same percentile on all tests (took 3 a few years ago) compared to tests from 30 and 20 years ago.
The raw score numbers might have changed up or down slightly, but same percentile in my case.
... IQ is supposed to be a normal distribution, ">= 130" === "3 sigma above the mean," i.e. top 0.1%.
(bearing in mind that the test is inescapably biased towards people with our background - US/UK/etc, certainly English speaking, probably university educated.)
fair point indeed - the tests are highly weighted (and thus rather unsatisfactory - the skewing reduces the resolution of the test, if you like) for young people.
that has actually recently been updated with reliable sources. Some of the comments below this comment of yours make guesses about IQ tests that can be checked against the sources by referring to that article.
I found much more static-ness in my IQ over the last 30+ years. I was actually surprised at how consistent it was over decades and various tests (and, dare I say, slightly disappointed).