Comment by tptacek
11 hours ago
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.