> It is one the best predictors of job performance (up there with a work sample test), income, reaction time, how much schooling you'll get, how likely you are

> It is one the best predictors of job performance (up there with a work sample test), income, reaction time, how much schooling you'll get, how likely you are to commit crime, how long you'll live. People say stuff like this all the time as if it's an uncontroversial fact, and it's much less supported by the literature than you're implying. So much of this is a matter of interpretation and the people interpreting it are generally people personally vested in the concept of IQ https://pmc.ncbi.nlm.nih.gov/articles/PMC4557354/ https://pmc.ncbi.nlm.nih.gov/articles/PMC4557354/ I do agree that an IQ test can help measure severe intellectual impairment, or a change in an individual's ability because of illness or injury. I have a lot of doubts about it's meaningfulness beyond that.