Scores on any test can be improved with practice and training. The SATs are a notable example, but similar test preparation techniques will work for any other a

Scores on any test can be improved with practice and training. The SATs are a notable example, but similar test preparation techniques will work for any other aptitude test and IQ tests are aptitude tests. I'd go so far as to say that the rising prevalence of test preparation is critically reducing the signal these tests provide. When one cohort routinely prepares for the aptitude test and another one doesn't, the latter is going to appear disadvantaged, but what's being measured is no longer what the test was designed to measure. Top tier American universities have long been aware of this effect, which is why they negatively weight certain groups' test scores to balance out the bonus they are getting from test preparation. It's gotten so bad that the UC system is abandoning standardized testing altogether.