That's not really true. IQ doesn't predict well on the high end, but it's useful for predicting the outcomes of middle intellect people. And it works better for groups than for individuals.
For instance, IQ scores are bad at predicting wealth but are the best predictor of adult poverty we have.
And the US military uses them extensively. They generally don't allow anyone in with an IQ score below 90.
Yes, every time the subject comes up, this whole crowd of relatively intelligent people go into a moral dance about how stupid IQ tests are.
They were never meant to predict genius. The point is to organize people efficiently when you're slotting them for guard duty or heavy equipment operation or officer candidate school. Someone who points out BS about non-Kosher pigs and obscure integer sequences is being clever for the sake of it. IE, "Look how smart I am."
And, as you say, the military considers about 100 million Americans dangerously too stupid for the army. They didn't do this out of arrogance.
This is constantly overlooked in debates over IQ, SAT, etc.
In most cases where these tests are used, it is far more mportant to separate the above median from below median, or +2 STDDEV from median, etc, and not to pick winners in the Krelboyne Super Bowl.
Even assuming there is a total ordering of intelligence, how would a single 300-question test rank 300 million people?
Why fill half the test with questions that 99% of takers will get wrong, just to differentiate among the top 1% of scorers?
Funny, the police in Police State USA prefer low IQ's
' on the theory that those who scored too high could get bored with police work and leave soon after undergoing costly training'
Or perhaps that being smart doesn't make you an enthusiastic state thug?
For instance, IQ scores are bad at predicting wealth but are the best predictor of adult poverty we have.
And the US military uses them extensively. They generally don't allow anyone in with an IQ score below 90.