I've never taken an IQ test and never plan to. I took the SAT, but it has significantly changed over the years; my score today would not be translatable to my score then.
OT, but I really love GlaDOS and hope there's another Portal soon.
If you haven't seen it yet, check out "Portal Reloaded" on Steam. It's a fan-made game like "Portal Stories Mel" from a few years ago, but Reloaded goes as far as adding entirely new mechanics. It's about as close as we'll ever get to Portal 3.
More seriously, random pattern matching questions are the best you can do to control for the not-caring factor, because they eliminate the advantage of test prep. The SAT has a significant test prep factor, which I agree is highly confounded by "culture" (a byword for how much your parents make you study) and the circumstances and opportunities related to test prep, including the motivation of the student, and the availability of a place to study and study materials. IQ tests are significantly more meritocratic than algorithms interviews or the SAT.