Contrary to popular belief there is no sound evidence for believing many of the claims made for IQ tests. IQ measures ones ability to do IQ tests and little else.
agreed. well put.
They were originally invented as a means of measuring the response of mentally defective patients so that their progress under different treatment regimes could be compared.
I will, however, have to point out, that the IG test was not originally developed to measure the response of mentally defective patients to anything. The first IQ test was developed to gauge the academic progress of school children. That is why the scores are calculated according to age. Yes, they were at a later date used for what you mentioned, and many other things at that. I agree with everything else you said.