Is the relationship between IQ and brain processing speed/power linear, logarithmic or other?
For example lets say you two groups:
Random group of 25 people each with an IQ close to a 100 IQ (95 - 105 ... 5% difference).
Random group of 25 people each with an IQ close to a 150 IQ (142.5 - 157.5 ... 5% difference).
The individuals in each group have to solve one or more problems ... enough time required such that the testing time isn't so small as to introduce significant measurement error.
Lets say the problems are such that there is confidence all participants can solve them.
If we average the time to complete the task of the 100IQ group vs the 150IQ group, sans outliers, would that average time more likely be:
1) Linear, 50% faster (150 = 100 x 1.5) 2) logarithmic, 217% faster (log 150; base 10) = 2.71) 3) Other