Comment by tptacek
9 hours ago
It's probably more accurate to say that IQ is a useful indicator of many specific cognitive deficits, and basically unuseful within or above 2SD of the center.
9 hours ago
It's probably more accurate to say that IQ is a useful indicator of many specific cognitive deficits, and basically unuseful within or above 2SD of the center.
No. even within 1SD there are huge qualitative differences in what people are capable of.
There are huge qualitative differences between cognitive ability between pairs of people within that range, but IQ stops accurately selecting the more capable of the two. It gets worse as the scores get higher. IQ is not a ranking of cognitive ability.
My understanding is that people 75% of a standard deviation bellow average tend to struggle with basic thought experiments.
Yeah when you get into the upper tail it starts to get hard to find things to differentiate people.