Estimation of Intelligence

[A_Nony_Mouse]

I always thought that people were all equally intelligent... more or less.... what changes is the amount of information they've acquired throughout their lives.

Were that the case IQ would increase with age. In fact it is remarkably stable from childhood to old age.

Of course, if you don't use that information... you forget it... and then it's not available for reasoning.
But, given the same information, all people should reason more or less the same way.

For the sake of argument assume all people know the addition tables. That is mutually shared information. There are always differences as to how quickly addition problems are solved. The longer the numbers the easier it is to discriminate.

As speed of reflexes and IQ generally have a positive correlation the same discriminate will appear even if everyone uses calculators.