I think “IQ tests accurately measure intelligence” is a simplistic statement, which may not be true. If a person only speaks French, but you give him an IQ test in English, he may score zero. You may say of course the test must be in the language native to the person being tested, but there are many subtle issues relating to a cultural group which the designer of a test may not allow for. A hunter gatherer may be able to climb a tall tree and gather honey from a wild bee hive, which likely involves quite a lot of intelligence, but he might not be able to answer questions about abstract things or things that are common knowledge to people who grow up in a different context. A hunter gatherer has the intelligence to survive in his own environment, where a city person with a PhD might be dead in a week. I suspect that different races have evolved over long periods to adapt to their environments. Intelligence is likely adapted also, as much as physical adaption. IQ tests may focus on different aspects of intelligence which a person from a particular race may not have his greatest strengths in. It is many years since I did an IQ test, and it is not a subject I know a great deal about. I just feel that designers of IQ tests may have egg shaped heads, and may often make assumptions about the test subjects experience and environment which may not be true. I don’t think a “one size fits all” test would work to compare persons from different cultures, races, and environments.
There are tests now like Raven’s Progressive Matrices that are so culture-fair that they utilize no language whatsoever. It’s all pattern recognition and whatnot. IQ tests line up very well with life success, grades in school, occupational status, degrees achieved, and tests of reaction time, head size, brain size on MRI, and a test for well the brain utilizes glucose metabolism. Reaction time and glucose utilization tests are tests of raw neurological speed and efficiency. Head size and brain size increases with rising IQ. The higher the IQ, the better the grades and the more and higher degrees one gets. Looks like it lines up pretty well with tests of brain size, speed and efficiency along with the things we associate with intelligence in a modern society. That hunter-gatherer has interesting skills, but now many of them are living in cities where their honey-gathering skills are useless? How useful is that “ability to survive in the wild intelligence” in a large modern First World City?