Using intelligence tests
There is one more problem with IQ tests, this time not about making them or giving them, but about using them:
There was an experiment by Rosenthal in which school teachers were casually told at the beginning of the school year that certain students (mentioned by name) were "spurters," that, according to some tests designed to measure "spurting," they would blossom in the coming year. Actually no such test had been given. In fact, no such test exists. The information was actually given about 20% of the students, chosen at random.
These kids not only did well academically (which we might expect, with teachers having some control over that), but actually increased their IQ test scores!
The same, incidentally, happens with rats: Graduate students told that certain rats had been bred for intelligence found that they did indeed do better at learning mazes -- even though the information was false!
This is a form of experimenter bias, of course, and part of the reason we have double blinds in experiments. but in the broader, social arena, we call this the self-fulfilling prophecy, or the labelling effect
. It is clear that we should take children as individuals and give them whatever education they can handle. Unfortunately, that is costly.