people fall for unvalidated tests, often even totally fake ones that offer “training” to increase your “IQ”. Generally IQ tests are a very good measure of how well people take standardized tests. The problem is, scoring high on those tests might correlate with one’s capabilities, but it doesn’t mean real-world competence. In medicine for example, it’s not the people with the highest scores tend to be the best doctors, but the ones who follow up on issues, and that habit compounds. etc.