As for IQ, I dismiss the whole concept.? IQ is the score on an IQ test, and nothing more.
? --? Gene
--there is much to be said for that stance, but ultimately it is that of a proverbial ostrich burying head in sand. The nature of human intellect is important, and therefore should be studied, and therefore one has to try to do it right and infer whatever conclusions one can from the evidence. Unfortunately, I looked into that area quite a lot once (related to me discovering "mathematical definition of intelligence" which turned out to be essentially a rediscovery of same by Marcus Hutter a few years earlier) and it was rather blatantly obvious that this entire subfield of psychology had been done AWESOMELY badly by a bunch of incredibly poor researchers, who nevertheless are lauded as "greats." And there also are other things about human intellect worth researching too, such as memory; and again, the amount of ultra-poor-quality work about that has to be seen to be believed. Which all is a pity. I have also had some experience with other parts of psychology/psychiatry and maybe it is just bad luck, but every time I look into some subarea of their literature, the experience just blows my mind at how incredibly awful they have been and how many thousands of people have been hurt as a consequence.